OpenCloudOS-Kernel/arch/arm64/kvm/sys_regs.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Derived from arch/arm/kvm/coproc.c:
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Authors: Rusty Russell <rusty@rustcorp.com.au>
* Christoffer Dall <c.dall@virtualopensystems.com>
*/
#include <linux/bsearch.h>
#include <linux/kvm_host.h>
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_coproc.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/perf_event.h>
#include <asm/sysreg.h>
#include <trace/events/kvm.h>
#include "sys_regs.h"
#include "trace.h"
/*
* All of this file is extremely similar to the ARM coproc.c, but the
* types are different. My gut feeling is that it should be pretty
* easy to merge, but that would be an ABI breakage -- again. VFP
* would also need to be abstracted.
*
* For AArch32, we only take care of what is being trapped. Anything
* that has to do with init and userspace access has to go via the
* 64bit interface.
*/
static bool read_from_write_only(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *r)
{
WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n");
print_sys_reg_instr(params);
kvm_inject_undefined(vcpu);
return false;
}
static bool write_to_read_only(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *r)
{
WARN_ONCE(1, "Unexpected sys_reg write to read-only register\n");
print_sys_reg_instr(params);
kvm_inject_undefined(vcpu);
return false;
}
static bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
{
/*
* System registers listed in the switch are not saved on every
* exit from the guest but are only saved on vcpu_put.
*
* Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but
* should never be listed below, because the guest cannot modify its
* own MPIDR_EL1 and MPIDR_EL1 is accessed for VCPU A from VCPU B's
* thread when emulating cross-VCPU communication.
*/
switch (reg) {
case CSSELR_EL1: *val = read_sysreg_s(SYS_CSSELR_EL1); break;
case SCTLR_EL1: *val = read_sysreg_s(SYS_SCTLR_EL12); break;
case CPACR_EL1: *val = read_sysreg_s(SYS_CPACR_EL12); break;
case TTBR0_EL1: *val = read_sysreg_s(SYS_TTBR0_EL12); break;
case TTBR1_EL1: *val = read_sysreg_s(SYS_TTBR1_EL12); break;
case TCR_EL1: *val = read_sysreg_s(SYS_TCR_EL12); break;
case ESR_EL1: *val = read_sysreg_s(SYS_ESR_EL12); break;
case AFSR0_EL1: *val = read_sysreg_s(SYS_AFSR0_EL12); break;
case AFSR1_EL1: *val = read_sysreg_s(SYS_AFSR1_EL12); break;
case FAR_EL1: *val = read_sysreg_s(SYS_FAR_EL12); break;
case MAIR_EL1: *val = read_sysreg_s(SYS_MAIR_EL12); break;
case VBAR_EL1: *val = read_sysreg_s(SYS_VBAR_EL12); break;
case CONTEXTIDR_EL1: *val = read_sysreg_s(SYS_CONTEXTIDR_EL12);break;
case TPIDR_EL0: *val = read_sysreg_s(SYS_TPIDR_EL0); break;
case TPIDRRO_EL0: *val = read_sysreg_s(SYS_TPIDRRO_EL0); break;
case TPIDR_EL1: *val = read_sysreg_s(SYS_TPIDR_EL1); break;
case AMAIR_EL1: *val = read_sysreg_s(SYS_AMAIR_EL12); break;
case CNTKCTL_EL1: *val = read_sysreg_s(SYS_CNTKCTL_EL12); break;
case ELR_EL1: *val = read_sysreg_s(SYS_ELR_EL12); break;
case PAR_EL1: *val = read_sysreg_s(SYS_PAR_EL1); break;
case DACR32_EL2: *val = read_sysreg_s(SYS_DACR32_EL2); break;
case IFSR32_EL2: *val = read_sysreg_s(SYS_IFSR32_EL2); break;
case DBGVCR32_EL2: *val = read_sysreg_s(SYS_DBGVCR32_EL2); break;
default: return false;
}
return true;
}
static bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
{
/*
* System registers listed in the switch are not restored on every
* entry to the guest but are only restored on vcpu_load.
*
* Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but
* should never be listed below, because the MPIDR should only be set
* once, before running the VCPU, and never changed later.
*/
switch (reg) {
case CSSELR_EL1: write_sysreg_s(val, SYS_CSSELR_EL1); break;
case SCTLR_EL1: write_sysreg_s(val, SYS_SCTLR_EL12); break;
case CPACR_EL1: write_sysreg_s(val, SYS_CPACR_EL12); break;
case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); break;
case TTBR1_EL1: write_sysreg_s(val, SYS_TTBR1_EL12); break;
case TCR_EL1: write_sysreg_s(val, SYS_TCR_EL12); break;
case ESR_EL1: write_sysreg_s(val, SYS_ESR_EL12); break;
case AFSR0_EL1: write_sysreg_s(val, SYS_AFSR0_EL12); break;
case AFSR1_EL1: write_sysreg_s(val, SYS_AFSR1_EL12); break;
case FAR_EL1: write_sysreg_s(val, SYS_FAR_EL12); break;
case MAIR_EL1: write_sysreg_s(val, SYS_MAIR_EL12); break;
case VBAR_EL1: write_sysreg_s(val, SYS_VBAR_EL12); break;
case CONTEXTIDR_EL1: write_sysreg_s(val, SYS_CONTEXTIDR_EL12);break;
case TPIDR_EL0: write_sysreg_s(val, SYS_TPIDR_EL0); break;
case TPIDRRO_EL0: write_sysreg_s(val, SYS_TPIDRRO_EL0); break;
case TPIDR_EL1: write_sysreg_s(val, SYS_TPIDR_EL1); break;
case AMAIR_EL1: write_sysreg_s(val, SYS_AMAIR_EL12); break;
case CNTKCTL_EL1: write_sysreg_s(val, SYS_CNTKCTL_EL12); break;
case ELR_EL1: write_sysreg_s(val, SYS_ELR_EL12); break;
case PAR_EL1: write_sysreg_s(val, SYS_PAR_EL1); break;
case DACR32_EL2: write_sysreg_s(val, SYS_DACR32_EL2); break;
case IFSR32_EL2: write_sysreg_s(val, SYS_IFSR32_EL2); break;
case DBGVCR32_EL2: write_sysreg_s(val, SYS_DBGVCR32_EL2); break;
default: return false;
}
return true;
}
u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
{
u64 val = 0x8badf00d8badf00d;
if (vcpu->arch.sysregs_loaded_on_cpu &&
__vcpu_read_sys_reg_from_cpu(reg, &val))
return val;
return __vcpu_sys_reg(vcpu, reg);
}
void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
{
if (vcpu->arch.sysregs_loaded_on_cpu &&
__vcpu_write_sys_reg_to_cpu(val, reg))
return;
__vcpu_sys_reg(vcpu, reg) = val;
}
/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
static u32 cache_levels;
/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
#define CSSELR_MAX 12
/* Which cache CCSIDR represents depends on CSSELR value. */
static u32 get_ccsidr(u32 csselr)
{
u32 ccsidr;
/* Make sure noone else changes CSSELR during this! */
local_irq_disable();
write_sysreg(csselr, csselr_el1);
isb();
ccsidr = read_sysreg(ccsidr_el1);
local_irq_enable();
return ccsidr;
}
/*
* See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
*/
static bool access_dcsw(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (!p->is_write)
return read_from_write_only(vcpu, p, r);
/*
* Only track S/W ops if we don't have FWB. It still indicates
* that the guest is a bit broken (S/W operations should only
* be done by firmware, knowing that there is only a single
* CPU left in the system, and certainly not from non-secure
* software).
*/
if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB))
kvm_set_way_flush(vcpu);
return true;
}
/*
* Generic accessor for VM registers. Only called as long as HCR_TVM
* is set. If the guest enables the MMU, we stop trapping the VM
* sys_regs and leave it in complete control of the caches.
*/
static bool access_vm_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
bool was_enabled = vcpu_has_cache_enabled(vcpu);
u64 val;
int reg = r->reg;
BUG_ON(!p->is_write);
/* See the 32bit mapping in kvm_host.h */
if (p->is_aarch32)
reg = r->reg / 2;
if (!p->is_aarch32 || !p->is_32bit) {
val = p->regval;
} else {
val = vcpu_read_sys_reg(vcpu, reg);
if (r->reg % 2)
val = (p->regval << 32) | (u64)lower_32_bits(val);
else
val = ((u64)upper_32_bits(val) << 32) |
lower_32_bits(p->regval);
}
vcpu_write_sys_reg(vcpu, val, reg);
kvm_toggle_cache(vcpu, was_enabled);
return true;
}
static bool access_actlr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
p->regval = vcpu_read_sys_reg(vcpu, ACTLR_EL1);
if (p->is_aarch32) {
if (r->Op2 & 2)
p->regval = upper_32_bits(p->regval);
else
p->regval = lower_32_bits(p->regval);
}
return true;
}
/*
* Trap handler for the GICv3 SGI generation system register.
* Forward the request to the VGIC emulation.
* The cp15_64 code makes sure this automatically works
* for both AArch64 and AArch32 accesses.
*/
static bool access_gic_sgi(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
bool g1;
if (!p->is_write)
return read_from_write_only(vcpu, p, r);
/*
* In a system where GICD_CTLR.DS=1, a ICC_SGI0R_EL1 access generates
* Group0 SGIs only, while ICC_SGI1R_EL1 can generate either group,
* depending on the SGI configuration. ICC_ASGI1R_EL1 is effectively
* equivalent to ICC_SGI0R_EL1, as there is no "alternative" secure
* group.
*/
if (p->is_aarch32) {
switch (p->Op1) {
default: /* Keep GCC quiet */
case 0: /* ICC_SGI1R */
g1 = true;
break;
case 1: /* ICC_ASGI1R */
case 2: /* ICC_SGI0R */
g1 = false;
break;
}
} else {
switch (p->Op2) {
default: /* Keep GCC quiet */
case 5: /* ICC_SGI1R_EL1 */
g1 = true;
break;
case 6: /* ICC_ASGI1R_EL1 */
case 7: /* ICC_SGI0R_EL1 */
g1 = false;
break;
}
}
vgic_v3_dispatch_sgi(vcpu, p->regval, g1);
return true;
}
static bool access_gic_sre(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
p->regval = vcpu->arch.vgic_cpu.vgic_v3.vgic_sre;
return true;
}
static bool trap_raz_wi(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
else
return read_zero(vcpu, p);
}
/*
* ARMv8.1 mandates at least a trivial LORegion implementation, where all the
* RW registers are RES0 (which we can implement as RAZ/WI). On an ARMv8.0
* system, these registers should UNDEF. LORID_EL1 being a RO register, we
* treat it separately.
*/
static bool trap_loregion(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
u32 sr = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) {
kvm_inject_undefined(vcpu);
return false;
}
if (p->is_write && sr == SYS_LORID_EL1)
return write_to_read_only(vcpu, p, r);
return trap_raz_wi(vcpu, p, r);
}
static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
return ignore_write(vcpu, p);
} else {
p->regval = (1 << 3);
return true;
}
}
static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
return ignore_write(vcpu, p);
} else {
p->regval = read_sysreg(dbgauthstatus_el1);
return true;
}
}
/*
* We want to avoid world-switching all the DBG registers all the
* time:
*
* - If we've touched any debug register, it is likely that we're
* going to touch more of them. It then makes sense to disable the
* traps and start doing the save/restore dance
* - If debug is active (DBG_MDSCR_KDE or DBG_MDSCR_MDE set), it is
* then mandatory to save/restore the registers, as the guest
* depends on them.
*
* For this, we use a DIRTY bit, indicating the guest has modified the
* debug registers, used as follow:
*
* On guest entry:
* - If the dirty bit is set (because we're coming back from trapping),
* disable the traps, save host registers, restore guest registers.
* - If debug is actively in use (DBG_MDSCR_KDE or DBG_MDSCR_MDE set),
* set the dirty bit, disable the traps, save host registers,
* restore guest registers.
* - Otherwise, enable the traps
*
* On guest exit:
* - If the dirty bit is set, save guest registers, restore host
* registers and clear the dirty bit. This ensure that the host can
* now use the debug registers.
*/
static bool trap_debug_regs(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
vcpu_write_sys_reg(vcpu, p->regval, r->reg);
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
} else {
p->regval = vcpu_read_sys_reg(vcpu, r->reg);
}
trace_trap_reg(__func__, r->reg, p->is_write, p->regval);
return true;
}
/*
* reg_to_dbg/dbg_to_reg
*
* A 32 bit write to a debug register leave top bits alone
* A 32 bit read from a debug register only returns the bottom bits
*
* All writes will set the KVM_ARM64_DEBUG_DIRTY flag to ensure the
* hyp.S code switches between host and guest values in future.
*/
static void reg_to_dbg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
u64 *dbg_reg)
{
u64 val = p->regval;
if (p->is_32bit) {
val &= 0xffffffffUL;
val |= ((*dbg_reg >> 32) << 32);
}
*dbg_reg = val;
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
}
static void dbg_to_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
u64 *dbg_reg)
{
p->regval = *dbg_reg;
if (p->is_32bit)
p->regval &= 0xffffffffUL;
}
static bool trap_bvr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);
return true;
}
static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static void reset_bvr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg] = rd->val;
}
static bool trap_bcr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);
return true;
}
static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static void reset_bcr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg] = rd->val;
}
static bool trap_wvr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
trace_trap_reg(__func__, rd->reg, p->is_write,
vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg]);
return true;
}
static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static void reset_wvr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg] = rd->val;
}
static bool trap_wcr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);
return true;
}
static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static void reset_wcr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg] = rd->val;
}
static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 amair = read_sysreg(amair_el1);
vcpu_write_sys_reg(vcpu, amair, AMAIR_EL1);
}
static void reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 actlr = read_sysreg(actlr_el1);
vcpu_write_sys_reg(vcpu, actlr, ACTLR_EL1);
}
static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 mpidr;
/*
* Map the vcpu_id into the first three affinity level fields of
* the MPIDR. We limit the number of VCPUs in level 0 due to a
* limitation to 16 CPUs in that level in the ICC_SGIxR registers
* of the GICv3 to be able to address each CPU directly when
* sending IPIs.
*/
mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0);
mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1);
mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2);
vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1);
}
static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 pmcr, val;
pmcr = read_sysreg(pmcr_el0);
/*
* Writable bits of PMCR_EL0 (ARMV8_PMU_PMCR_MASK) are reset to UNKNOWN
* except PMCR.E resetting to zero.
*/
val = ((pmcr & ~ARMV8_PMU_PMCR_MASK)
| (ARMV8_PMU_PMCR_MASK & 0xdecafbad)) & (~ARMV8_PMU_PMCR_E);
if (!system_supports_32bit_el0())
val |= ARMV8_PMU_PMCR_LC;
__vcpu_sys_reg(vcpu, r->reg) = val;
}
static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags)
{
u64 reg = __vcpu_sys_reg(vcpu, PMUSERENR_EL0);
bool enabled = (reg & flags) || vcpu_mode_priv(vcpu);
if (!enabled)
kvm_inject_undefined(vcpu);
return !enabled;
}
static bool pmu_access_el0_disabled(struct kvm_vcpu *vcpu)
{
return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_EN);
}
static bool pmu_write_swinc_el0_disabled(struct kvm_vcpu *vcpu)
{
return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_SW | ARMV8_PMU_USERENR_EN);
}
static bool pmu_access_cycle_counter_el0_disabled(struct kvm_vcpu *vcpu)
{
return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_CR | ARMV8_PMU_USERENR_EN);
}
static bool pmu_access_event_counter_el0_disabled(struct kvm_vcpu *vcpu)
{
return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_EN);
}
static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 val;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (pmu_access_el0_disabled(vcpu))
return false;
if (p->is_write) {
/* Only update writeable bits of PMCR */
val = __vcpu_sys_reg(vcpu, PMCR_EL0);
val &= ~ARMV8_PMU_PMCR_MASK;
val |= p->regval & ARMV8_PMU_PMCR_MASK;
if (!system_supports_32bit_el0())
val |= ARMV8_PMU_PMCR_LC;
__vcpu_sys_reg(vcpu, PMCR_EL0) = val;
kvm_pmu_handle_pmcr(vcpu, val);
kvm_vcpu_pmu_restore_guest(vcpu);
} else {
/* PMCR.P & PMCR.C are RAZ */
val = __vcpu_sys_reg(vcpu, PMCR_EL0)
& ~(ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C);
p->regval = val;
}
return true;
}
static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (pmu_access_event_counter_el0_disabled(vcpu))
return false;
if (p->is_write)
__vcpu_sys_reg(vcpu, PMSELR_EL0) = p->regval;
else
/* return PMSELR.SEL field */
p->regval = __vcpu_sys_reg(vcpu, PMSELR_EL0)
& ARMV8_PMU_COUNTER_MASK;
return true;
}
static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 pmceid;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
BUG_ON(p->is_write);
if (pmu_access_el0_disabled(vcpu))
return false;
pmceid = kvm_pmu_get_pmceid(vcpu, (p->Op2 & 1));
p->regval = pmceid;
return true;
}
static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
{
u64 pmcr, val;
pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0);
val = (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX) {
kvm_inject_undefined(vcpu);
return false;
}
return true;
}
static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 idx;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (r->CRn == 9 && r->CRm == 13) {
if (r->Op2 == 2) {
/* PMXEVCNTR_EL0 */
if (pmu_access_event_counter_el0_disabled(vcpu))
return false;
idx = __vcpu_sys_reg(vcpu, PMSELR_EL0)
& ARMV8_PMU_COUNTER_MASK;
} else if (r->Op2 == 0) {
/* PMCCNTR_EL0 */
if (pmu_access_cycle_counter_el0_disabled(vcpu))
return false;
idx = ARMV8_PMU_CYCLE_IDX;
} else {
return false;
}
} else if (r->CRn == 0 && r->CRm == 9) {
/* PMCCNTR */
if (pmu_access_event_counter_el0_disabled(vcpu))
return false;
idx = ARMV8_PMU_CYCLE_IDX;
} else if (r->CRn == 14 && (r->CRm & 12) == 8) {
/* PMEVCNTRn_EL0 */
if (pmu_access_event_counter_el0_disabled(vcpu))
return false;
idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
} else {
return false;
}
if (!pmu_counter_idx_valid(vcpu, idx))
return false;
if (p->is_write) {
if (pmu_access_el0_disabled(vcpu))
return false;
kvm_pmu_set_counter_value(vcpu, idx, p->regval);
} else {
p->regval = kvm_pmu_get_counter_value(vcpu, idx);
}
return true;
}
static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 idx, reg;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (pmu_access_el0_disabled(vcpu))
return false;
if (r->CRn == 9 && r->CRm == 13 && r->Op2 == 1) {
/* PMXEVTYPER_EL0 */
idx = __vcpu_sys_reg(vcpu, PMSELR_EL0) & ARMV8_PMU_COUNTER_MASK;
reg = PMEVTYPER0_EL0 + idx;
} else if (r->CRn == 14 && (r->CRm & 12) == 12) {
idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
if (idx == ARMV8_PMU_CYCLE_IDX)
reg = PMCCFILTR_EL0;
else
/* PMEVTYPERn_EL0 */
reg = PMEVTYPER0_EL0 + idx;
} else {
BUG();
}
if (!pmu_counter_idx_valid(vcpu, idx))
return false;
if (p->is_write) {
kvm_pmu_set_counter_event_type(vcpu, p->regval, idx);
__vcpu_sys_reg(vcpu, reg) = p->regval & ARMV8_PMU_EVTYPE_MASK;
kvm_vcpu_pmu_restore_guest(vcpu);
} else {
p->regval = __vcpu_sys_reg(vcpu, reg) & ARMV8_PMU_EVTYPE_MASK;
}
return true;
}
static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 val, mask;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (pmu_access_el0_disabled(vcpu))
return false;
mask = kvm_pmu_valid_counter_mask(vcpu);
if (p->is_write) {
val = p->regval & mask;
if (r->Op2 & 0x1) {
/* accessing PMCNTENSET_EL0 */
__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) |= val;
kvm_pmu_enable_counter_mask(vcpu, val);
kvm_vcpu_pmu_restore_guest(vcpu);
} else {
/* accessing PMCNTENCLR_EL0 */
__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) &= ~val;
kvm_pmu_disable_counter_mask(vcpu, val);
}
} else {
p->regval = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask;
}
return true;
}
static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 mask = kvm_pmu_valid_counter_mask(vcpu);
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (!vcpu_mode_priv(vcpu)) {
kvm_inject_undefined(vcpu);
return false;
}
if (p->is_write) {
u64 val = p->regval & mask;
if (r->Op2 & 0x1)
/* accessing PMINTENSET_EL1 */
__vcpu_sys_reg(vcpu, PMINTENSET_EL1) |= val;
else
/* accessing PMINTENCLR_EL1 */
__vcpu_sys_reg(vcpu, PMINTENSET_EL1) &= ~val;
} else {
p->regval = __vcpu_sys_reg(vcpu, PMINTENSET_EL1) & mask;
}
return true;
}
static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 mask = kvm_pmu_valid_counter_mask(vcpu);
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (pmu_access_el0_disabled(vcpu))
return false;
if (p->is_write) {
if (r->CRm & 0x2)
/* accessing PMOVSSET_EL0 */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= (p->regval & mask);
else
/* accessing PMOVSCLR_EL0 */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) &= ~(p->regval & mask);
} else {
p->regval = __vcpu_sys_reg(vcpu, PMOVSSET_EL0) & mask;
}
return true;
}
static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 mask;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (!p->is_write)
return read_from_write_only(vcpu, p, r);
if (pmu_write_swinc_el0_disabled(vcpu))
return false;
mask = kvm_pmu_valid_counter_mask(vcpu);
kvm_pmu_software_increment(vcpu, p->regval & mask);
return true;
}
static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (p->is_write) {
if (!vcpu_mode_priv(vcpu)) {
kvm_inject_undefined(vcpu);
return false;
}
__vcpu_sys_reg(vcpu, PMUSERENR_EL0) =
p->regval & ARMV8_PMU_USERENR_MASK;
} else {
p->regval = __vcpu_sys_reg(vcpu, PMUSERENR_EL0)
& ARMV8_PMU_USERENR_MASK;
}
return true;
}
#define reg_to_encoding(x) \
sys_reg((u32)(x)->Op0, (u32)(x)->Op1, \
(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2);
/* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
#define DBG_BCR_BVR_WCR_WVR_EL1(n) \
{ SYS_DESC(SYS_DBGBVRn_EL1(n)), \
trap_bvr, reset_bvr, 0, 0, get_bvr, set_bvr }, \
{ SYS_DESC(SYS_DBGBCRn_EL1(n)), \
trap_bcr, reset_bcr, 0, 0, get_bcr, set_bcr }, \
{ SYS_DESC(SYS_DBGWVRn_EL1(n)), \
trap_wvr, reset_wvr, 0, 0, get_wvr, set_wvr }, \
{ SYS_DESC(SYS_DBGWCRn_EL1(n)), \
trap_wcr, reset_wcr, 0, 0, get_wcr, set_wcr }
/* Macro to expand the PMEVCNTRn_EL0 register */
#define PMU_PMEVCNTR_EL0(n) \
{ SYS_DESC(SYS_PMEVCNTRn_EL0(n)), \
access_pmu_evcntr, reset_unknown, (PMEVCNTR0_EL0 + n), }
/* Macro to expand the PMEVTYPERn_EL0 register */
#define PMU_PMEVTYPER_EL0(n) \
{ SYS_DESC(SYS_PMEVTYPERn_EL0(n)), \
access_pmu_evtyper, reset_unknown, (PMEVTYPER0_EL0 + n), }
static bool undef_access(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
kvm_inject_undefined(vcpu);
return false;
}
/* Macro to expand the AMU counter and type registers*/
#define AMU_AMEVCNTR0_EL0(n) { SYS_DESC(SYS_AMEVCNTR0_EL0(n)), undef_access }
#define AMU_AMEVTYPER0_EL0(n) { SYS_DESC(SYS_AMEVTYPER0_EL0(n)), undef_access }
#define AMU_AMEVCNTR1_EL0(n) { SYS_DESC(SYS_AMEVCNTR1_EL0(n)), undef_access }
#define AMU_AMEVTYPER1_EL0(n) { SYS_DESC(SYS_AMEVTYPER1_EL0(n)), undef_access }
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
static unsigned int ptrauth_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
return vcpu_has_ptrauth(vcpu) ? 0 : REG_HIDDEN;
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
}
/*
* If we land here on a PtrAuth access, that is because we didn't
* fixup the access on exit by allowing the PtrAuth sysregs. The only
* way this happens is when the guest does not have PtrAuth support
* enabled.
*/
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
#define __PTRAUTH_KEY(k) \
{ SYS_DESC(SYS_## k), undef_access, reset_unknown, k, \
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
.visibility = ptrauth_visibility}
#define PTRAUTH_KEY(k) \
__PTRAUTH_KEY(k ## KEYLO_EL1), \
__PTRAUTH_KEY(k ## KEYHI_EL1)
static bool access_arch_timer(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
enum kvm_arch_timers tmr;
enum kvm_arch_timer_regs treg;
u64 reg = reg_to_encoding(r);
switch (reg) {
case SYS_CNTP_TVAL_EL0:
case SYS_AARCH32_CNTP_TVAL:
tmr = TIMER_PTIMER;
treg = TIMER_REG_TVAL;
break;
case SYS_CNTP_CTL_EL0:
case SYS_AARCH32_CNTP_CTL:
tmr = TIMER_PTIMER;
treg = TIMER_REG_CTL;
break;
case SYS_CNTP_CVAL_EL0:
case SYS_AARCH32_CNTP_CVAL:
tmr = TIMER_PTIMER;
treg = TIMER_REG_CVAL;
break;
default:
BUG();
}
if (p->is_write)
kvm_arm_timer_write_sysreg(vcpu, tmr, treg, p->regval);
else
p->regval = kvm_arm_timer_read_sysreg(vcpu, tmr, treg);
return true;
}
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/* Read a sanitised cpufeature ID register by sys_reg_desc */
static u64 read_id_reg(const struct kvm_vcpu *vcpu,
struct sys_reg_desc const *r, bool raz)
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
{
u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
if (id == SYS_ID_AA64PFR0_EL1) {
if (!vcpu_has_sve(vcpu))
val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);
val &= ~(0xfUL << ID_AA64PFR0_CSV2_SHIFT);
val |= ((u64)vcpu->kvm->arch.pfr0_csv2 << ID_AA64PFR0_CSV2_SHIFT);
} else if (id == SYS_ID_AA64PFR1_EL1) {
val &= ~(0xfUL << ID_AA64PFR1_MTE_SHIFT);
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
(0xfUL << ID_AA64ISAR1_API_SHIFT) |
(0xfUL << ID_AA64ISAR1_GPA_SHIFT) |
(0xfUL << ID_AA64ISAR1_GPI_SHIFT));
} else if (id == SYS_ID_AA64DFR0_EL1) {
/* Limit guests to PMUv3 for ARMv8.1 */
val = cpuid_feature_cap_perfmon_field(val,
ID_AA64DFR0_PMUVER_SHIFT,
ID_AA64DFR0_PMUVER_8_1);
} else if (id == SYS_ID_DFR0_EL1) {
/* Limit guests to PMUv3 for ARMv8.1 */
val = cpuid_feature_cap_perfmon_field(val,
ID_DFR0_PERFMON_SHIFT,
ID_DFR0_PERFMON_8_1);
}
return val;
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *r)
{
u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
switch (id) {
case SYS_ID_AA64ZFR0_EL1:
if (!vcpu_has_sve(vcpu))
return REG_RAZ;
break;
}
return 0;
}
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/* cpufeature ID register access trap handlers */
static bool __access_id_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r,
bool raz)
{
if (p->is_write)
return write_to_read_only(vcpu, p, r);
p->regval = read_id_reg(vcpu, r, raz);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
return true;
}
static bool access_id_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
bool raz = sysreg_visible_as_raz(vcpu, r);
return __access_id_reg(vcpu, p, r, raz);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static bool access_raz_id_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
return __access_id_reg(vcpu, p, r, true);
}
static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
KVM: arm64/sve: System register context switch and access support This patch adds the necessary support for context switching ZCR_EL1 for each vcpu. ZCR_EL1 is trapped alongside the FPSIMD/SVE registers, so it makes sense for it to be handled as part of the guest FPSIMD/SVE context for context switch purposes instead of handling it as a general system register. This means that it can be switched in lazily at the appropriate time. No effort is made to track host context for this register, since SVE requires VHE: thus the hosts's value for this register lives permanently in ZCR_EL2 and does not alias the guest's value at any time. The Hyp switch and fpsimd context handling code is extended appropriately. Accessors are added in sys_regs.c to expose the SVE system registers and ID register fields. Because these need to be conditionally visible based on the guest configuration, they are implemented separately for now rather than by use of the generic system register helpers. This may be abstracted better later on when/if there are more features requiring this model. ID_AA64ZFR0_EL1 is RO-RAZ for MRS/MSR when SVE is disabled for the guest, but for compatibility with non-SVE aware KVM implementations the register should not be enumerated at all for KVM_GET_REG_LIST in this case. For consistency we also reject ioctl access to the register. This ensures that a non-SVE-enabled guest looks the same to userspace, irrespective of whether the kernel KVM implementation supports SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-28 21:39:16 +08:00
/* Visibility overrides for SVE-specific control registers */
static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
if (vcpu_has_sve(vcpu))
return 0;
return REG_HIDDEN;
KVM: arm64/sve: System register context switch and access support This patch adds the necessary support for context switching ZCR_EL1 for each vcpu. ZCR_EL1 is trapped alongside the FPSIMD/SVE registers, so it makes sense for it to be handled as part of the guest FPSIMD/SVE context for context switch purposes instead of handling it as a general system register. This means that it can be switched in lazily at the appropriate time. No effort is made to track host context for this register, since SVE requires VHE: thus the hosts's value for this register lives permanently in ZCR_EL2 and does not alias the guest's value at any time. The Hyp switch and fpsimd context handling code is extended appropriately. Accessors are added in sys_regs.c to expose the SVE system registers and ID register fields. Because these need to be conditionally visible based on the guest configuration, they are implemented separately for now rather than by use of the generic system register helpers. This may be abstracted better later on when/if there are more features requiring this model. ID_AA64ZFR0_EL1 is RO-RAZ for MRS/MSR when SVE is disabled for the guest, but for compatibility with non-SVE aware KVM implementations the register should not be enumerated at all for KVM_GET_REG_LIST in this case. For consistency we also reject ioctl access to the register. This ensures that a non-SVE-enabled guest looks the same to userspace, irrespective of whether the kernel KVM implementation supports SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-28 21:39:16 +08:00
}
static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
const u64 id = sys_reg_to_index(rd);
int err;
u64 val;
u8 csv2;
err = reg_from_user(&val, uaddr, id);
if (err)
return err;
/*
* Allow AA64PFR0_EL1.CSV2 to be set from userspace as long as
* it doesn't promise more than what is actually provided (the
* guest could otherwise be covered in ectoplasmic residue).
*/
csv2 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_CSV2_SHIFT);
if (csv2 > 1 ||
(csv2 && arm64_get_spectre_v2_state() != SPECTRE_UNAFFECTED))
return -EINVAL;
/* We can only differ with CSV2, and anything else is an error */
val ^= read_id_reg(vcpu, rd, false);
val &= ~(0xFUL << ID_AA64PFR0_CSV2_SHIFT);
if (val)
return -EINVAL;
vcpu->kvm->arch.pfr0_csv2 = csv2;
return 0;
}
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/*
* cpufeature ID register user accessors
*
* For now, these registers are immutable for userspace, so no values
* are stored, and for set_id_reg() we don't allow the effective value
* to be changed.
*/
static int __get_id_reg(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd, void __user *uaddr,
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
bool raz)
{
const u64 id = sys_reg_to_index(rd);
const u64 val = read_id_reg(vcpu, rd, raz);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
return reg_to_user(uaddr, &val, id);
}
static int __set_id_reg(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd, void __user *uaddr,
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
bool raz)
{
const u64 id = sys_reg_to_index(rd);
int err;
u64 val;
err = reg_from_user(&val, uaddr, id);
if (err)
return err;
/* This is what we mean by invariant: you can't change it. */
if (val != read_id_reg(vcpu, rd, raz))
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
return -EINVAL;
return 0;
}
static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
bool raz = sysreg_visible_as_raz(vcpu, rd);
return __get_id_reg(vcpu, rd, uaddr, raz);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
bool raz = sysreg_visible_as_raz(vcpu, rd);
return __set_id_reg(vcpu, rd, uaddr, raz);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static int get_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
return __get_id_reg(vcpu, rd, uaddr, true);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
return __set_id_reg(vcpu, rd, uaddr, true);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
static bool access_ctr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return write_to_read_only(vcpu, p, r);
p->regval = read_sanitised_ftr_reg(SYS_CTR_EL0);
return true;
}
static bool access_clidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write)
return write_to_read_only(vcpu, p, r);
p->regval = read_sysreg(clidr_el1);
return true;
}
static bool access_csselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
int reg = r->reg;
/* See the 32bit mapping in kvm_host.h */
if (p->is_aarch32)
reg = r->reg / 2;
if (p->is_write)
vcpu_write_sys_reg(vcpu, p->regval, reg);
else
p->regval = vcpu_read_sys_reg(vcpu, reg);
return true;
}
static bool access_ccsidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u32 csselr;
if (p->is_write)
return write_to_read_only(vcpu, p, r);
csselr = vcpu_read_sys_reg(vcpu, CSSELR_EL1);
p->regval = get_ccsidr(csselr);
/*
* Guests should not be doing cache operations by set/way at all, and
* for this reason, we trap them and attempt to infer the intent, so
* that we can flush the entire guest's address space at the appropriate
* time.
* To prevent this trapping from causing performance problems, let's
* expose the geometry of all data and unified caches (which are
* guaranteed to be PIPT and thus non-aliasing) as 1 set and 1 way.
* [If guests should attempt to infer aliasing properties from the
* geometry (which is not permitted by the architecture), they would
* only do so for virtually indexed caches.]
*/
if (!(csselr & 1)) // data or unified cache
p->regval &= ~GENMASK(27, 3);
return true;
}
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/* sys_reg_desc initialiser for known cpufeature ID registers */
#define ID_SANITISED(name) { \
SYS_DESC(SYS_##name), \
.access = access_id_reg, \
.get_user = get_id_reg, \
.set_user = set_id_reg, \
.visibility = id_visibility, \
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
}
/*
* sys_reg_desc initialiser for architecturally unallocated cpufeature ID
* register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
* (1 <= crm < 8, 0 <= Op2 < 8).
*/
#define ID_UNALLOCATED(crm, op2) { \
Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \
.access = access_raz_id_reg, \
.get_user = get_raz_id_reg, \
.set_user = set_raz_id_reg, \
}
/*
* sys_reg_desc initialiser for known ID registers that we hide from guests.
* For now, these are exposed just like unallocated ID regs: they appear
* RAZ for the guest.
*/
#define ID_HIDDEN(name) { \
SYS_DESC(SYS_##name), \
.access = access_raz_id_reg, \
.get_user = get_raz_id_reg, \
.set_user = set_raz_id_reg, \
}
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
*
* Debug handling: We do trap most, if not all debug related system
* registers. The implementation is good enough to ensure that a guest
* can use these with minimal performance degradation. The drawback is
* that we don't implement any of the external debug, none of the
* OSlock protocol. This should be revisited if we ever encounter a
* more demanding guest...
*/
static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_DC_ISW), access_dcsw },
{ SYS_DESC(SYS_DC_CSW), access_dcsw },
{ SYS_DESC(SYS_DC_CISW), access_dcsw },
DBG_BCR_BVR_WCR_WVR_EL1(0),
DBG_BCR_BVR_WCR_WVR_EL1(1),
{ SYS_DESC(SYS_MDCCINT_EL1), trap_debug_regs, reset_val, MDCCINT_EL1, 0 },
{ SYS_DESC(SYS_MDSCR_EL1), trap_debug_regs, reset_val, MDSCR_EL1, 0 },
DBG_BCR_BVR_WCR_WVR_EL1(2),
DBG_BCR_BVR_WCR_WVR_EL1(3),
DBG_BCR_BVR_WCR_WVR_EL1(4),
DBG_BCR_BVR_WCR_WVR_EL1(5),
DBG_BCR_BVR_WCR_WVR_EL1(6),
DBG_BCR_BVR_WCR_WVR_EL1(7),
DBG_BCR_BVR_WCR_WVR_EL1(8),
DBG_BCR_BVR_WCR_WVR_EL1(9),
DBG_BCR_BVR_WCR_WVR_EL1(10),
DBG_BCR_BVR_WCR_WVR_EL1(11),
DBG_BCR_BVR_WCR_WVR_EL1(12),
DBG_BCR_BVR_WCR_WVR_EL1(13),
DBG_BCR_BVR_WCR_WVR_EL1(14),
DBG_BCR_BVR_WCR_WVR_EL1(15),
{ SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 },
{ SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGCLAIMCLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGAUTHSTATUS_EL1), trap_dbgauthstatus_el1 },
{ SYS_DESC(SYS_MDCCSR_EL0), trap_raz_wi },
{ SYS_DESC(SYS_DBGDTR_EL0), trap_raz_wi },
// DBGDTR[TR]X_EL0 share the same encoding
{ SYS_DESC(SYS_DBGDTRTX_EL0), trap_raz_wi },
{ SYS_DESC(SYS_DBGVCR32_EL2), NULL, reset_val, DBGVCR32_EL2, 0 },
{ SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 },
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/*
* ID regs: all ID_SANITISED() entries here must have corresponding
* entries in arm64_ftr_regs[].
*/
/* AArch64 mappings of the AArch32 ID registers */
/* CRm=1 */
ID_SANITISED(ID_PFR0_EL1),
ID_SANITISED(ID_PFR1_EL1),
ID_SANITISED(ID_DFR0_EL1),
ID_HIDDEN(ID_AFR0_EL1),
ID_SANITISED(ID_MMFR0_EL1),
ID_SANITISED(ID_MMFR1_EL1),
ID_SANITISED(ID_MMFR2_EL1),
ID_SANITISED(ID_MMFR3_EL1),
/* CRm=2 */
ID_SANITISED(ID_ISAR0_EL1),
ID_SANITISED(ID_ISAR1_EL1),
ID_SANITISED(ID_ISAR2_EL1),
ID_SANITISED(ID_ISAR3_EL1),
ID_SANITISED(ID_ISAR4_EL1),
ID_SANITISED(ID_ISAR5_EL1),
ID_SANITISED(ID_MMFR4_EL1),
ID_SANITISED(ID_ISAR6_EL1),
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/* CRm=3 */
ID_SANITISED(MVFR0_EL1),
ID_SANITISED(MVFR1_EL1),
ID_SANITISED(MVFR2_EL1),
ID_UNALLOCATED(3,3),
ID_SANITISED(ID_PFR2_EL1),
ID_HIDDEN(ID_DFR1_EL1),
ID_SANITISED(ID_MMFR5_EL1),
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
ID_UNALLOCATED(3,7),
/* AArch64 ID registers */
/* CRm=4 */
{ SYS_DESC(SYS_ID_AA64PFR0_EL1), .access = access_id_reg,
.get_user = get_id_reg, .set_user = set_id_aa64pfr0_el1, },
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
ID_SANITISED(ID_AA64PFR1_EL1),
ID_UNALLOCATED(4,2),
ID_UNALLOCATED(4,3),
ID_SANITISED(ID_AA64ZFR0_EL1),
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
ID_UNALLOCATED(4,5),
ID_UNALLOCATED(4,6),
ID_UNALLOCATED(4,7),
/* CRm=5 */
ID_SANITISED(ID_AA64DFR0_EL1),
ID_SANITISED(ID_AA64DFR1_EL1),
ID_UNALLOCATED(5,2),
ID_UNALLOCATED(5,3),
ID_HIDDEN(ID_AA64AFR0_EL1),
ID_HIDDEN(ID_AA64AFR1_EL1),
ID_UNALLOCATED(5,6),
ID_UNALLOCATED(5,7),
/* CRm=6 */
ID_SANITISED(ID_AA64ISAR0_EL1),
ID_SANITISED(ID_AA64ISAR1_EL1),
ID_UNALLOCATED(6,2),
ID_UNALLOCATED(6,3),
ID_UNALLOCATED(6,4),
ID_UNALLOCATED(6,5),
ID_UNALLOCATED(6,6),
ID_UNALLOCATED(6,7),
/* CRm=7 */
ID_SANITISED(ID_AA64MMFR0_EL1),
ID_SANITISED(ID_AA64MMFR1_EL1),
ID_SANITISED(ID_AA64MMFR2_EL1),
ID_UNALLOCATED(7,3),
ID_UNALLOCATED(7,4),
ID_UNALLOCATED(7,5),
ID_UNALLOCATED(7,6),
ID_UNALLOCATED(7,7),
{ SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
{ SYS_DESC(SYS_ACTLR_EL1), access_actlr, reset_actlr, ACTLR_EL1 },
{ SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },
{ SYS_DESC(SYS_RGSR_EL1), undef_access },
{ SYS_DESC(SYS_GCR_EL1), undef_access },
KVM: arm64/sve: System register context switch and access support This patch adds the necessary support for context switching ZCR_EL1 for each vcpu. ZCR_EL1 is trapped alongside the FPSIMD/SVE registers, so it makes sense for it to be handled as part of the guest FPSIMD/SVE context for context switch purposes instead of handling it as a general system register. This means that it can be switched in lazily at the appropriate time. No effort is made to track host context for this register, since SVE requires VHE: thus the hosts's value for this register lives permanently in ZCR_EL2 and does not alias the guest's value at any time. The Hyp switch and fpsimd context handling code is extended appropriately. Accessors are added in sys_regs.c to expose the SVE system registers and ID register fields. Because these need to be conditionally visible based on the guest configuration, they are implemented separately for now rather than by use of the generic system register helpers. This may be abstracted better later on when/if there are more features requiring this model. ID_AA64ZFR0_EL1 is RO-RAZ for MRS/MSR when SVE is disabled for the guest, but for compatibility with non-SVE aware KVM implementations the register should not be enumerated at all for KVM_GET_REG_LIST in this case. For consistency we also reject ioctl access to the register. This ensures that a non-SVE-enabled guest looks the same to userspace, irrespective of whether the kernel KVM implementation supports SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-28 21:39:16 +08:00
{ SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
{ SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
{ SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
{ SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },
KVM: arm/arm64: Context-switch ptrauth registers When pointer authentication is supported, a guest may wish to use it. This patch adds the necessary KVM infrastructure for this to work, with a semi-lazy context switch of the pointer auth state. Pointer authentication feature is only enabled when VHE is built in the kernel and present in the CPU implementation so only VHE code paths are modified. When we schedule a vcpu, we disable guest usage of pointer authentication instructions and accesses to the keys. While these are disabled, we avoid context-switching the keys. When we trap the guest trying to use pointer authentication functionality, we change to eagerly context-switching the keys, and enable the feature. The next time the vcpu is scheduled out/in, we start again. However the host key save is optimized and implemented inside ptrauth instruction/register access trap. Pointer authentication consists of address authentication and generic authentication, and CPUs in a system might have varied support for either. Where support for either feature is not uniform, it is hidden from guests via ID register emulation, as a result of the cpufeature framework in the host. Unfortunately, address authentication and generic authentication cannot be trapped separately, as the architecture provides a single EL2 trap covering both. If we wish to expose one without the other, we cannot prevent a (badly-written) guest from intermittently using a feature which is not uniformly supported (when scheduled on a physical CPU which supports the relevant feature). Hence, this patch expects both type of authentication to be present in a cpu. This switch of key is done from guest enter/exit assembly as preparation for the upcoming in-kernel pointer authentication support. Hence, these key switching routines are not implemented in C code as they may cause pointer authentication key signing error in some situations. Signed-off-by: Mark Rutland <mark.rutland@arm.com> [Only VHE, key switch in full assembly, vcpu_has_ptrauth checks , save host key in ptrauth exception trap] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu [maz: various fixups] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-23 12:42:35 +08:00
PTRAUTH_KEY(APIA),
PTRAUTH_KEY(APIB),
PTRAUTH_KEY(APDA),
PTRAUTH_KEY(APDB),
PTRAUTH_KEY(APGA),
{ SYS_DESC(SYS_AFSR0_EL1), access_vm_reg, reset_unknown, AFSR0_EL1 },
{ SYS_DESC(SYS_AFSR1_EL1), access_vm_reg, reset_unknown, AFSR1_EL1 },
{ SYS_DESC(SYS_ESR_EL1), access_vm_reg, reset_unknown, ESR_EL1 },
{ SYS_DESC(SYS_ERRIDR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERRSELR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXFR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXCTLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXSTATUS_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXADDR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXMISC0_EL1), trap_raz_wi },
{ SYS_DESC(SYS_ERXMISC1_EL1), trap_raz_wi },
{ SYS_DESC(SYS_TFSR_EL1), undef_access },
{ SYS_DESC(SYS_TFSRE0_EL1), undef_access },
{ SYS_DESC(SYS_FAR_EL1), access_vm_reg, reset_unknown, FAR_EL1 },
{ SYS_DESC(SYS_PAR_EL1), NULL, reset_unknown, PAR_EL1 },
{ SYS_DESC(SYS_PMINTENSET_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
{ SYS_DESC(SYS_PMINTENCLR_EL1), access_pminten, reset_unknown, PMINTENSET_EL1 },
{ SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
{ SYS_DESC(SYS_LORSA_EL1), trap_loregion },
{ SYS_DESC(SYS_LOREA_EL1), trap_loregion },
{ SYS_DESC(SYS_LORN_EL1), trap_loregion },
{ SYS_DESC(SYS_LORC_EL1), trap_loregion },
{ SYS_DESC(SYS_LORID_EL1), trap_loregion },
{ SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
{ SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },
{ SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },
{ SYS_DESC(SYS_ICC_HPPIR0_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_DIR_EL1), read_from_write_only },
{ SYS_DESC(SYS_ICC_RPR_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
{ SYS_DESC(SYS_ICC_ASGI1R_EL1), access_gic_sgi },
{ SYS_DESC(SYS_ICC_SGI0R_EL1), access_gic_sgi },
{ SYS_DESC(SYS_ICC_IAR1_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_EOIR1_EL1), read_from_write_only },
{ SYS_DESC(SYS_ICC_HPPIR1_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_SRE_EL1), access_gic_sre },
{ SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
{ SYS_DESC(SYS_TPIDR_EL1), NULL, reset_unknown, TPIDR_EL1 },
{ SYS_DESC(SYS_CNTKCTL_EL1), NULL, reset_val, CNTKCTL_EL1, 0},
{ SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr },
{ SYS_DESC(SYS_CLIDR_EL1), access_clidr },
{ SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
{ SYS_DESC(SYS_CTR_EL0), access_ctr },
{ SYS_DESC(SYS_PMCR_EL0), access_pmcr, reset_pmcr, PMCR_EL0 },
{ SYS_DESC(SYS_PMCNTENSET_EL0), access_pmcnten, reset_unknown, PMCNTENSET_EL0 },
{ SYS_DESC(SYS_PMCNTENCLR_EL0), access_pmcnten, reset_unknown, PMCNTENSET_EL0 },
{ SYS_DESC(SYS_PMOVSCLR_EL0), access_pmovs, reset_unknown, PMOVSSET_EL0 },
{ SYS_DESC(SYS_PMSWINC_EL0), access_pmswinc, reset_unknown, PMSWINC_EL0 },
{ SYS_DESC(SYS_PMSELR_EL0), access_pmselr, reset_unknown, PMSELR_EL0 },
{ SYS_DESC(SYS_PMCEID0_EL0), access_pmceid },
{ SYS_DESC(SYS_PMCEID1_EL0), access_pmceid },
{ SYS_DESC(SYS_PMCCNTR_EL0), access_pmu_evcntr, reset_unknown, PMCCNTR_EL0 },
{ SYS_DESC(SYS_PMXEVTYPER_EL0), access_pmu_evtyper },
{ SYS_DESC(SYS_PMXEVCNTR_EL0), access_pmu_evcntr },
/*
* PMUSERENR_EL0 resets as unknown in 64bit mode while it resets as zero
* in 32bit mode. Here we choose to reset it as zero for consistency.
*/
{ SYS_DESC(SYS_PMUSERENR_EL0), access_pmuserenr, reset_val, PMUSERENR_EL0, 0 },
{ SYS_DESC(SYS_PMOVSSET_EL0), access_pmovs, reset_unknown, PMOVSSET_EL0 },
{ SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
{ SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
{ SYS_DESC(SYS_AMCR_EL0), undef_access },
{ SYS_DESC(SYS_AMCFGR_EL0), undef_access },
{ SYS_DESC(SYS_AMCGCR_EL0), undef_access },
{ SYS_DESC(SYS_AMUSERENR_EL0), undef_access },
{ SYS_DESC(SYS_AMCNTENCLR0_EL0), undef_access },
{ SYS_DESC(SYS_AMCNTENSET0_EL0), undef_access },
{ SYS_DESC(SYS_AMCNTENCLR1_EL0), undef_access },
{ SYS_DESC(SYS_AMCNTENSET1_EL0), undef_access },
AMU_AMEVCNTR0_EL0(0),
AMU_AMEVCNTR0_EL0(1),
AMU_AMEVCNTR0_EL0(2),
AMU_AMEVCNTR0_EL0(3),
AMU_AMEVCNTR0_EL0(4),
AMU_AMEVCNTR0_EL0(5),
AMU_AMEVCNTR0_EL0(6),
AMU_AMEVCNTR0_EL0(7),
AMU_AMEVCNTR0_EL0(8),
AMU_AMEVCNTR0_EL0(9),
AMU_AMEVCNTR0_EL0(10),
AMU_AMEVCNTR0_EL0(11),
AMU_AMEVCNTR0_EL0(12),
AMU_AMEVCNTR0_EL0(13),
AMU_AMEVCNTR0_EL0(14),
AMU_AMEVCNTR0_EL0(15),
AMU_AMEVTYPER0_EL0(0),
AMU_AMEVTYPER0_EL0(1),
AMU_AMEVTYPER0_EL0(2),
AMU_AMEVTYPER0_EL0(3),
AMU_AMEVTYPER0_EL0(4),
AMU_AMEVTYPER0_EL0(5),
AMU_AMEVTYPER0_EL0(6),
AMU_AMEVTYPER0_EL0(7),
AMU_AMEVTYPER0_EL0(8),
AMU_AMEVTYPER0_EL0(9),
AMU_AMEVTYPER0_EL0(10),
AMU_AMEVTYPER0_EL0(11),
AMU_AMEVTYPER0_EL0(12),
AMU_AMEVTYPER0_EL0(13),
AMU_AMEVTYPER0_EL0(14),
AMU_AMEVTYPER0_EL0(15),
AMU_AMEVCNTR1_EL0(0),
AMU_AMEVCNTR1_EL0(1),
AMU_AMEVCNTR1_EL0(2),
AMU_AMEVCNTR1_EL0(3),
AMU_AMEVCNTR1_EL0(4),
AMU_AMEVCNTR1_EL0(5),
AMU_AMEVCNTR1_EL0(6),
AMU_AMEVCNTR1_EL0(7),
AMU_AMEVCNTR1_EL0(8),
AMU_AMEVCNTR1_EL0(9),
AMU_AMEVCNTR1_EL0(10),
AMU_AMEVCNTR1_EL0(11),
AMU_AMEVCNTR1_EL0(12),
AMU_AMEVCNTR1_EL0(13),
AMU_AMEVCNTR1_EL0(14),
AMU_AMEVCNTR1_EL0(15),
AMU_AMEVTYPER1_EL0(0),
AMU_AMEVTYPER1_EL0(1),
AMU_AMEVTYPER1_EL0(2),
AMU_AMEVTYPER1_EL0(3),
AMU_AMEVTYPER1_EL0(4),
AMU_AMEVTYPER1_EL0(5),
AMU_AMEVTYPER1_EL0(6),
AMU_AMEVTYPER1_EL0(7),
AMU_AMEVTYPER1_EL0(8),
AMU_AMEVTYPER1_EL0(9),
AMU_AMEVTYPER1_EL0(10),
AMU_AMEVTYPER1_EL0(11),
AMU_AMEVTYPER1_EL0(12),
AMU_AMEVTYPER1_EL0(13),
AMU_AMEVTYPER1_EL0(14),
AMU_AMEVTYPER1_EL0(15),
{ SYS_DESC(SYS_CNTP_TVAL_EL0), access_arch_timer },
{ SYS_DESC(SYS_CNTP_CTL_EL0), access_arch_timer },
{ SYS_DESC(SYS_CNTP_CVAL_EL0), access_arch_timer },
/* PMEVCNTRn_EL0 */
PMU_PMEVCNTR_EL0(0),
PMU_PMEVCNTR_EL0(1),
PMU_PMEVCNTR_EL0(2),
PMU_PMEVCNTR_EL0(3),
PMU_PMEVCNTR_EL0(4),
PMU_PMEVCNTR_EL0(5),
PMU_PMEVCNTR_EL0(6),
PMU_PMEVCNTR_EL0(7),
PMU_PMEVCNTR_EL0(8),
PMU_PMEVCNTR_EL0(9),
PMU_PMEVCNTR_EL0(10),
PMU_PMEVCNTR_EL0(11),
PMU_PMEVCNTR_EL0(12),
PMU_PMEVCNTR_EL0(13),
PMU_PMEVCNTR_EL0(14),
PMU_PMEVCNTR_EL0(15),
PMU_PMEVCNTR_EL0(16),
PMU_PMEVCNTR_EL0(17),
PMU_PMEVCNTR_EL0(18),
PMU_PMEVCNTR_EL0(19),
PMU_PMEVCNTR_EL0(20),
PMU_PMEVCNTR_EL0(21),
PMU_PMEVCNTR_EL0(22),
PMU_PMEVCNTR_EL0(23),
PMU_PMEVCNTR_EL0(24),
PMU_PMEVCNTR_EL0(25),
PMU_PMEVCNTR_EL0(26),
PMU_PMEVCNTR_EL0(27),
PMU_PMEVCNTR_EL0(28),
PMU_PMEVCNTR_EL0(29),
PMU_PMEVCNTR_EL0(30),
/* PMEVTYPERn_EL0 */
PMU_PMEVTYPER_EL0(0),
PMU_PMEVTYPER_EL0(1),
PMU_PMEVTYPER_EL0(2),
PMU_PMEVTYPER_EL0(3),
PMU_PMEVTYPER_EL0(4),
PMU_PMEVTYPER_EL0(5),
PMU_PMEVTYPER_EL0(6),
PMU_PMEVTYPER_EL0(7),
PMU_PMEVTYPER_EL0(8),
PMU_PMEVTYPER_EL0(9),
PMU_PMEVTYPER_EL0(10),
PMU_PMEVTYPER_EL0(11),
PMU_PMEVTYPER_EL0(12),
PMU_PMEVTYPER_EL0(13),
PMU_PMEVTYPER_EL0(14),
PMU_PMEVTYPER_EL0(15),
PMU_PMEVTYPER_EL0(16),
PMU_PMEVTYPER_EL0(17),
PMU_PMEVTYPER_EL0(18),
PMU_PMEVTYPER_EL0(19),
PMU_PMEVTYPER_EL0(20),
PMU_PMEVTYPER_EL0(21),
PMU_PMEVTYPER_EL0(22),
PMU_PMEVTYPER_EL0(23),
PMU_PMEVTYPER_EL0(24),
PMU_PMEVTYPER_EL0(25),
PMU_PMEVTYPER_EL0(26),
PMU_PMEVTYPER_EL0(27),
PMU_PMEVTYPER_EL0(28),
PMU_PMEVTYPER_EL0(29),
PMU_PMEVTYPER_EL0(30),
/*
* PMCCFILTR_EL0 resets as unknown in 64bit mode while it resets as zero
* in 32bit mode. Here we choose to reset it as zero for consistency.
*/
{ SYS_DESC(SYS_PMCCFILTR_EL0), access_pmu_evtyper, reset_val, PMCCFILTR_EL0, 0 },
{ SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 },
{ SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 },
{ SYS_DESC(SYS_FPEXC32_EL2), NULL, reset_val, FPEXC32_EL2, 0x700 },
};
static bool trap_dbgidr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
return ignore_write(vcpu, p);
} else {
u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL3_SHIFT);
p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) |
(((dfr >> ID_AA64DFR0_BRPS_SHIFT) & 0xf) << 24) |
(((dfr >> ID_AA64DFR0_CTX_CMPS_SHIFT) & 0xf) << 20)
| (6 << 16) | (el3 << 14) | (el3 << 12));
return true;
}
}
static bool trap_debug32(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
if (p->is_write) {
vcpu_cp14(vcpu, r->reg) = p->regval;
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
} else {
p->regval = vcpu_cp14(vcpu, r->reg);
}
return true;
}
/* AArch32 debug register mappings
*
* AArch32 DBGBVRn is mapped to DBGBVRn_EL1[31:0]
* AArch32 DBGBXVRn is mapped to DBGBVRn_EL1[63:32]
*
* All control registers and watchpoint value registers are mapped to
* the lower 32 bits of their AArch64 equivalents. We share the trap
* handlers with the above AArch64 code which checks what mode the
* system is in.
*/
static bool trap_xvr(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (p->is_write) {
u64 val = *dbg_reg;
val &= 0xffffffffUL;
val |= p->regval << 32;
*dbg_reg = val;
vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
} else {
p->regval = *dbg_reg >> 32;
}
trace_trap_reg(__func__, rd->reg, p->is_write, *dbg_reg);
return true;
}
#define DBG_BCR_BVR_WCR_WVR(n) \
/* DBGBVRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_bvr, NULL, n }, \
/* DBGBCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_bcr, NULL, n }, \
/* DBGWVRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_wvr, NULL, n }, \
/* DBGWCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_wcr, NULL, n }
#define DBGBXVR(n) \
{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_xvr, NULL, n }
/*
* Trapped cp14 registers. We generally ignore most of the external
* debug, on the principle that they don't really make sense to a
* guest. Revisit this one day, would this principle change.
*/
static const struct sys_reg_desc cp14_regs[] = {
/* DBGIDR */
{ Op1( 0), CRn( 0), CRm( 0), Op2( 0), trap_dbgidr },
/* DBGDTRRXext */
{ Op1( 0), CRn( 0), CRm( 0), Op2( 2), trap_raz_wi },
DBG_BCR_BVR_WCR_WVR(0),
/* DBGDSCRint */
{ Op1( 0), CRn( 0), CRm( 1), Op2( 0), trap_raz_wi },
DBG_BCR_BVR_WCR_WVR(1),
/* DBGDCCINT */
{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), trap_debug32, NULL, cp14_DBGDCCINT },
/* DBGDSCRext */
{ Op1( 0), CRn( 0), CRm( 2), Op2( 2), trap_debug32, NULL, cp14_DBGDSCRext },
DBG_BCR_BVR_WCR_WVR(2),
/* DBGDTR[RT]Xint */
{ Op1( 0), CRn( 0), CRm( 3), Op2( 0), trap_raz_wi },
/* DBGDTR[RT]Xext */
{ Op1( 0), CRn( 0), CRm( 3), Op2( 2), trap_raz_wi },
DBG_BCR_BVR_WCR_WVR(3),
DBG_BCR_BVR_WCR_WVR(4),
DBG_BCR_BVR_WCR_WVR(5),
/* DBGWFAR */
{ Op1( 0), CRn( 0), CRm( 6), Op2( 0), trap_raz_wi },
/* DBGOSECCR */
{ Op1( 0), CRn( 0), CRm( 6), Op2( 2), trap_raz_wi },
DBG_BCR_BVR_WCR_WVR(6),
/* DBGVCR */
{ Op1( 0), CRn( 0), CRm( 7), Op2( 0), trap_debug32, NULL, cp14_DBGVCR },
DBG_BCR_BVR_WCR_WVR(7),
DBG_BCR_BVR_WCR_WVR(8),
DBG_BCR_BVR_WCR_WVR(9),
DBG_BCR_BVR_WCR_WVR(10),
DBG_BCR_BVR_WCR_WVR(11),
DBG_BCR_BVR_WCR_WVR(12),
DBG_BCR_BVR_WCR_WVR(13),
DBG_BCR_BVR_WCR_WVR(14),
DBG_BCR_BVR_WCR_WVR(15),
/* DBGDRAR (32bit) */
{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), trap_raz_wi },
DBGBXVR(0),
/* DBGOSLAR */
{ Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
DBGBXVR(1),
/* DBGOSLSR */
{ Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
DBGBXVR(2),
DBGBXVR(3),
/* DBGOSDLR */
{ Op1( 0), CRn( 1), CRm( 3), Op2( 4), trap_raz_wi },
DBGBXVR(4),
/* DBGPRCR */
{ Op1( 0), CRn( 1), CRm( 4), Op2( 4), trap_raz_wi },
DBGBXVR(5),
DBGBXVR(6),
DBGBXVR(7),
DBGBXVR(8),
DBGBXVR(9),
DBGBXVR(10),
DBGBXVR(11),
DBGBXVR(12),
DBGBXVR(13),
DBGBXVR(14),
DBGBXVR(15),
/* DBGDSAR (32bit) */
{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), trap_raz_wi },
/* DBGDEVID2 */
{ Op1( 0), CRn( 7), CRm( 0), Op2( 7), trap_raz_wi },
/* DBGDEVID1 */
{ Op1( 0), CRn( 7), CRm( 1), Op2( 7), trap_raz_wi },
/* DBGDEVID */
{ Op1( 0), CRn( 7), CRm( 2), Op2( 7), trap_raz_wi },
/* DBGCLAIMSET */
{ Op1( 0), CRn( 7), CRm( 8), Op2( 6), trap_raz_wi },
/* DBGCLAIMCLR */
{ Op1( 0), CRn( 7), CRm( 9), Op2( 6), trap_raz_wi },
/* DBGAUTHSTATUS */
{ Op1( 0), CRn( 7), CRm(14), Op2( 6), trap_dbgauthstatus_el1 },
};
/* Trapped cp14 64bit registers */
static const struct sys_reg_desc cp14_64_regs[] = {
/* DBGDRAR (64bit) */
{ Op1( 0), CRm( 1), .access = trap_raz_wi },
/* DBGDSAR (64bit) */
{ Op1( 0), CRm( 2), .access = trap_raz_wi },
};
/* Macro to expand the PMEVCNTRn register */
#define PMU_PMEVCNTR(n) \
/* PMEVCNTRn */ \
{ Op1(0), CRn(0b1110), \
CRm((0b1000 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
access_pmu_evcntr }
/* Macro to expand the PMEVTYPERn register */
#define PMU_PMEVTYPER(n) \
/* PMEVTYPERn */ \
{ Op1(0), CRn(0b1110), \
CRm((0b1100 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
access_pmu_evtyper }
/*
* Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
* depending on the way they are accessed (as a 32bit or a 64bit
* register).
*/
static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn( 0), CRm( 0), Op2( 1), access_ctr },
{ Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_vm_reg, NULL, c1_SCTLR },
{ Op1( 0), CRn( 1), CRm( 0), Op2( 1), access_actlr },
{ Op1( 0), CRn( 1), CRm( 0), Op2( 3), access_actlr },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR },
{ Op1( 0), CRn( 3), CRm( 0), Op2( 0), access_vm_reg, NULL, c3_DACR },
{ Op1( 0), CRn( 5), CRm( 0), Op2( 0), access_vm_reg, NULL, c5_DFSR },
{ Op1( 0), CRn( 5), CRm( 0), Op2( 1), access_vm_reg, NULL, c5_IFSR },
{ Op1( 0), CRn( 5), CRm( 1), Op2( 0), access_vm_reg, NULL, c5_ADFSR },
{ Op1( 0), CRn( 5), CRm( 1), Op2( 1), access_vm_reg, NULL, c5_AIFSR },
{ Op1( 0), CRn( 6), CRm( 0), Op2( 0), access_vm_reg, NULL, c6_DFAR },
{ Op1( 0), CRn( 6), CRm( 0), Op2( 2), access_vm_reg, NULL, c6_IFAR },
/*
* DC{C,I,CI}SW operations:
*/
{ Op1( 0), CRn( 7), CRm( 6), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },
/* PMU */
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr },
{ Op1( 0), CRn( 9), CRm(12), Op2( 1), access_pmcnten },
{ Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmcnten },
{ Op1( 0), CRn( 9), CRm(12), Op2( 3), access_pmovs },
{ Op1( 0), CRn( 9), CRm(12), Op2( 4), access_pmswinc },
{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
{ Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
{ Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid },
{ Op1( 0), CRn( 9), CRm(13), Op2( 0), access_pmu_evcntr },
{ Op1( 0), CRn( 9), CRm(13), Op2( 1), access_pmu_evtyper },
{ Op1( 0), CRn( 9), CRm(13), Op2( 2), access_pmu_evcntr },
{ Op1( 0), CRn( 9), CRm(14), Op2( 0), access_pmuserenr },
{ Op1( 0), CRn( 9), CRm(14), Op2( 1), access_pminten },
{ Op1( 0), CRn( 9), CRm(14), Op2( 2), access_pminten },
{ Op1( 0), CRn( 9), CRm(14), Op2( 3), access_pmovs },
{ Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, c10_PRRR },
{ Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, c10_NMRR },
{ Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, c10_AMAIR0 },
{ Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, c10_AMAIR1 },
/* ICC_SRE */
{ Op1( 0), CRn(12), CRm(12), Op2( 5), access_gic_sre },
{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
/* Arch Tmers */
{ SYS_DESC(SYS_AARCH32_CNTP_TVAL), access_arch_timer },
{ SYS_DESC(SYS_AARCH32_CNTP_CTL), access_arch_timer },
/* PMEVCNTRn */
PMU_PMEVCNTR(0),
PMU_PMEVCNTR(1),
PMU_PMEVCNTR(2),
PMU_PMEVCNTR(3),
PMU_PMEVCNTR(4),
PMU_PMEVCNTR(5),
PMU_PMEVCNTR(6),
PMU_PMEVCNTR(7),
PMU_PMEVCNTR(8),
PMU_PMEVCNTR(9),
PMU_PMEVCNTR(10),
PMU_PMEVCNTR(11),
PMU_PMEVCNTR(12),
PMU_PMEVCNTR(13),
PMU_PMEVCNTR(14),
PMU_PMEVCNTR(15),
PMU_PMEVCNTR(16),
PMU_PMEVCNTR(17),
PMU_PMEVCNTR(18),
PMU_PMEVCNTR(19),
PMU_PMEVCNTR(20),
PMU_PMEVCNTR(21),
PMU_PMEVCNTR(22),
PMU_PMEVCNTR(23),
PMU_PMEVCNTR(24),
PMU_PMEVCNTR(25),
PMU_PMEVCNTR(26),
PMU_PMEVCNTR(27),
PMU_PMEVCNTR(28),
PMU_PMEVCNTR(29),
PMU_PMEVCNTR(30),
/* PMEVTYPERn */
PMU_PMEVTYPER(0),
PMU_PMEVTYPER(1),
PMU_PMEVTYPER(2),
PMU_PMEVTYPER(3),
PMU_PMEVTYPER(4),
PMU_PMEVTYPER(5),
PMU_PMEVTYPER(6),
PMU_PMEVTYPER(7),
PMU_PMEVTYPER(8),
PMU_PMEVTYPER(9),
PMU_PMEVTYPER(10),
PMU_PMEVTYPER(11),
PMU_PMEVTYPER(12),
PMU_PMEVTYPER(13),
PMU_PMEVTYPER(14),
PMU_PMEVTYPER(15),
PMU_PMEVTYPER(16),
PMU_PMEVTYPER(17),
PMU_PMEVTYPER(18),
PMU_PMEVTYPER(19),
PMU_PMEVTYPER(20),
PMU_PMEVTYPER(21),
PMU_PMEVTYPER(22),
PMU_PMEVTYPER(23),
PMU_PMEVTYPER(24),
PMU_PMEVTYPER(25),
PMU_PMEVTYPER(26),
PMU_PMEVTYPER(27),
PMU_PMEVTYPER(28),
PMU_PMEVTYPER(29),
PMU_PMEVTYPER(30),
/* PMCCFILTR */
{ Op1(0), CRn(14), CRm(15), Op2(7), access_pmu_evtyper },
{ Op1(1), CRn( 0), CRm( 0), Op2(0), access_ccsidr },
{ Op1(1), CRn( 0), CRm( 0), Op2(1), access_clidr },
{ Op1(2), CRn( 0), CRm( 0), Op2(0), access_csselr, NULL, c0_CSSELR },
};
static const struct sys_reg_desc cp15_64_regs[] = {
{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
{ Op1( 0), CRn( 0), CRm( 9), Op2( 0), access_pmu_evcntr },
{ Op1( 0), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_SGI1R */
{ Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR1 },
{ Op1( 1), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_ASGI1R */
{ Op1( 2), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_SGI0R */
{ SYS_DESC(SYS_AARCH32_CNTP_CVAL), access_arch_timer },
};
static int check_sysreg_table(const struct sys_reg_desc *table, unsigned int n,
bool is_32)
{
unsigned int i;
for (i = 0; i < n; i++) {
if (!is_32 && table[i].reg && !table[i].reset) {
kvm_err("sys_reg table %p entry %d has lacks reset\n",
table, i);
return 1;
}
if (i && cmp_sys_reg(&table[i-1], &table[i]) >= 0) {
kvm_err("sys_reg table %p out of order (%d)\n", table, i - 1);
return 1;
}
}
return 0;
}
static int match_sys_reg(const void *key, const void *elt)
{
const unsigned long pval = (unsigned long)key;
const struct sys_reg_desc *r = elt;
return pval - reg_to_encoding(r);
}
static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
const struct sys_reg_desc table[],
unsigned int num)
{
unsigned long pval = reg_to_encoding(params);
return bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
}
int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu)
{
kvm_inject_undefined(vcpu);
return 1;
}
static void perform_access(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *r)
{
trace_kvm_sys_access(*vcpu_pc(vcpu), params, r);
/* Check for regs disabled by runtime config */
if (sysreg_hidden(vcpu, r)) {
kvm_inject_undefined(vcpu);
return;
}
/*
* Not having an accessor means that we have configured a trap
* that we don't know how to handle. This certainly qualifies
* as a gross bug that should be fixed right away.
*/
BUG_ON(!r->access);
/* Skip instruction if instructed so */
if (likely(r->access(vcpu, params, r)))
kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
}
/*
* emulate_cp -- tries to match a sys_reg access in a handling table, and
* call the corresponding trap handler.
*
* @params: pointer to the descriptor of the access
* @table: array of trap descriptors
* @num: size of the trap descriptor array
*
* Return 0 if the access has been handled, and -1 if not.
*/
static int emulate_cp(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *table,
size_t num)
{
const struct sys_reg_desc *r;
if (!table)
return -1; /* Not handled */
r = find_reg(params, table, num);
if (r) {
perform_access(vcpu, params, r);
return 0;
}
/* Not handled */
return -1;
}
static void unhandled_cp_access(struct kvm_vcpu *vcpu,
struct sys_reg_params *params)
{
u8 esr_ec = kvm_vcpu_trap_get_class(vcpu);
int cp = -1;
switch (esr_ec) {
case ESR_ELx_EC_CP15_32:
case ESR_ELx_EC_CP15_64:
cp = 15;
break;
case ESR_ELx_EC_CP14_MR:
case ESR_ELx_EC_CP14_64:
cp = 14;
break;
default:
WARN_ON(1);
}
print_sys_reg_msg(params,
"Unsupported guest CP%d access at: %08lx [%08lx]\n",
cp, *vcpu_pc(vcpu), *vcpu_cpsr(vcpu));
kvm_inject_undefined(vcpu);
}
/**
* kvm_handle_cp_64 -- handles a mrrc/mcrr trap on a guest CP14/CP15 access
* @vcpu: The VCPU pointer
* @run: The kvm_run struct
*/
static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *global,
size_t nr_global)
{
struct sys_reg_params params;
u32 esr = kvm_vcpu_get_esr(vcpu);
int Rt = kvm_vcpu_sys_get_rt(vcpu);
int Rt2 = (esr >> 10) & 0x1f;
params.is_aarch32 = true;
params.is_32bit = false;
params.CRm = (esr >> 1) & 0xf;
params.is_write = ((esr & 1) == 0);
params.Op0 = 0;
params.Op1 = (esr >> 16) & 0xf;
params.Op2 = 0;
params.CRn = 0;
/*
* Make a 64-bit value out of Rt and Rt2. As we use the same trap
* backends between AArch32 and AArch64, we get away with it.
*/
if (params.is_write) {
params.regval = vcpu_get_reg(vcpu, Rt) & 0xffffffff;
params.regval |= vcpu_get_reg(vcpu, Rt2) << 32;
}
/*
* If the table contains a handler, handle the
* potential register operation in the case of a read and return
* with success.
*/
if (!emulate_cp(vcpu, &params, global, nr_global)) {
/* Split up the value between registers for the read side */
if (!params.is_write) {
vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval));
vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval));
}
return 1;
}
unhandled_cp_access(vcpu, &params);
return 1;
}
/**
* kvm_handle_cp_32 -- handles a mrc/mcr trap on a guest CP14/CP15 access
* @vcpu: The VCPU pointer
* @run: The kvm_run struct
*/
static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *global,
size_t nr_global)
{
struct sys_reg_params params;
u32 esr = kvm_vcpu_get_esr(vcpu);
int Rt = kvm_vcpu_sys_get_rt(vcpu);
params.is_aarch32 = true;
params.is_32bit = true;
params.CRm = (esr >> 1) & 0xf;
params.regval = vcpu_get_reg(vcpu, Rt);
params.is_write = ((esr & 1) == 0);
params.CRn = (esr >> 10) & 0xf;
params.Op0 = 0;
params.Op1 = (esr >> 14) & 0x7;
params.Op2 = (esr >> 17) & 0x7;
if (!emulate_cp(vcpu, &params, global, nr_global)) {
if (!params.is_write)
vcpu_set_reg(vcpu, Rt, params.regval);
return 1;
}
unhandled_cp_access(vcpu, &params);
return 1;
}
int kvm_handle_cp15_64(struct kvm_vcpu *vcpu)
{
return kvm_handle_cp_64(vcpu, cp15_64_regs, ARRAY_SIZE(cp15_64_regs));
}
int kvm_handle_cp15_32(struct kvm_vcpu *vcpu)
{
return kvm_handle_cp_32(vcpu, cp15_regs, ARRAY_SIZE(cp15_regs));
}
int kvm_handle_cp14_64(struct kvm_vcpu *vcpu)
{
return kvm_handle_cp_64(vcpu, cp14_64_regs, ARRAY_SIZE(cp14_64_regs));
}
int kvm_handle_cp14_32(struct kvm_vcpu *vcpu)
{
return kvm_handle_cp_32(vcpu, cp14_regs, ARRAY_SIZE(cp14_regs));
}
static bool is_imp_def_sys_reg(struct sys_reg_params *params)
{
// See ARM DDI 0487E.a, section D12.3.2
return params->Op0 == 3 && (params->CRn & 0b1011) == 0b1011;
}
static int emulate_sys_reg(struct kvm_vcpu *vcpu,
struct sys_reg_params *params)
{
const struct sys_reg_desc *r;
r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
if (likely(r)) {
perform_access(vcpu, params, r);
} else if (is_imp_def_sys_reg(params)) {
kvm_inject_undefined(vcpu);
} else {
print_sys_reg_msg(params,
"Unsupported guest sys_reg access at: %lx [%08lx]\n",
*vcpu_pc(vcpu), *vcpu_cpsr(vcpu));
kvm_inject_undefined(vcpu);
}
return 1;
}
/**
* kvm_reset_sys_regs - sets system registers to reset value
* @vcpu: The VCPU pointer
*
* This function finds the right table above and sets the registers on the
* virtual CPU struct to their architecturally defined reset values.
*/
void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
{
unsigned long i;
for (i = 0; i < ARRAY_SIZE(sys_reg_descs); i++)
if (sys_reg_descs[i].reset)
sys_reg_descs[i].reset(vcpu, &sys_reg_descs[i]);
}
/**
* kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
* @vcpu: The VCPU pointer
*/
int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
{
struct sys_reg_params params;
unsigned long esr = kvm_vcpu_get_esr(vcpu);
int Rt = kvm_vcpu_sys_get_rt(vcpu);
int ret;
trace_kvm_handle_sys_reg(esr);
params.is_aarch32 = false;
params.is_32bit = false;
params.Op0 = (esr >> 20) & 3;
params.Op1 = (esr >> 14) & 0x7;
params.CRn = (esr >> 10) & 0xf;
params.CRm = (esr >> 1) & 0xf;
params.Op2 = (esr >> 17) & 0x7;
params.regval = vcpu_get_reg(vcpu, Rt);
params.is_write = !(esr & 1);
ret = emulate_sys_reg(vcpu, &params);
if (!params.is_write)
vcpu_set_reg(vcpu, Rt, params.regval);
return ret;
}
/******************************************************************************
* Userspace API
*****************************************************************************/
static bool index_to_params(u64 id, struct sys_reg_params *params)
{
switch (id & KVM_REG_SIZE_MASK) {
case KVM_REG_SIZE_U64:
/* Any unused index bits means it's not valid. */
if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
| KVM_REG_ARM_COPROC_MASK
| KVM_REG_ARM64_SYSREG_OP0_MASK
| KVM_REG_ARM64_SYSREG_OP1_MASK
| KVM_REG_ARM64_SYSREG_CRN_MASK
| KVM_REG_ARM64_SYSREG_CRM_MASK
| KVM_REG_ARM64_SYSREG_OP2_MASK))
return false;
params->Op0 = ((id & KVM_REG_ARM64_SYSREG_OP0_MASK)
>> KVM_REG_ARM64_SYSREG_OP0_SHIFT);
params->Op1 = ((id & KVM_REG_ARM64_SYSREG_OP1_MASK)
>> KVM_REG_ARM64_SYSREG_OP1_SHIFT);
params->CRn = ((id & KVM_REG_ARM64_SYSREG_CRN_MASK)
>> KVM_REG_ARM64_SYSREG_CRN_SHIFT);
params->CRm = ((id & KVM_REG_ARM64_SYSREG_CRM_MASK)
>> KVM_REG_ARM64_SYSREG_CRM_SHIFT);
params->Op2 = ((id & KVM_REG_ARM64_SYSREG_OP2_MASK)
>> KVM_REG_ARM64_SYSREG_OP2_SHIFT);
return true;
default:
return false;
}
}
const struct sys_reg_desc *find_reg_by_id(u64 id,
struct sys_reg_params *params,
const struct sys_reg_desc table[],
unsigned int num)
{
if (!index_to_params(id, params))
return NULL;
return find_reg(params, table, num);
}
/* Decode an index value, and find the sys_reg_desc entry. */
static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
u64 id)
{
const struct sys_reg_desc *r;
struct sys_reg_params params;
/* We only do sys_reg for now. */
if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
return NULL;
if (!index_to_params(id, &params))
return NULL;
r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
/* Not saved in the sys_reg array and not otherwise accessible? */
if (r && !(r->reg || r->get_user))
r = NULL;
return r;
}
/*
* These are the invariant sys_reg registers: we let the guest see the
* host versions of these, so they're part of the guest state.
*
* A future CPU may provide a mechanism to present different values to
* the guest, or a future kvm may trap them.
*/
#define FUNCTION_INVARIANT(reg) \
static void get_##reg(struct kvm_vcpu *v, \
const struct sys_reg_desc *r) \
{ \
((struct sys_reg_desc *)r)->val = read_sysreg(reg); \
}
FUNCTION_INVARIANT(midr_el1)
FUNCTION_INVARIANT(revidr_el1)
FUNCTION_INVARIANT(clidr_el1)
FUNCTION_INVARIANT(aidr_el1)
static void get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r)
{
((struct sys_reg_desc *)r)->val = read_sanitised_ftr_reg(SYS_CTR_EL0);
}
/* ->val is filled in by kvm_sys_reg_table_init() */
static struct sys_reg_desc invariant_sys_regs[] = {
{ SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 },
{ SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 },
{ SYS_DESC(SYS_CLIDR_EL1), NULL, get_clidr_el1 },
{ SYS_DESC(SYS_AIDR_EL1), NULL, get_aidr_el1 },
{ SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 },
};
static int reg_from_user(u64 *val, const void __user *uaddr, u64 id)
{
if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
return -EFAULT;
return 0;
}
static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
{
if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
return -EFAULT;
return 0;
}
static int get_invariant_sys_reg(u64 id, void __user *uaddr)
{
struct sys_reg_params params;
const struct sys_reg_desc *r;
r = find_reg_by_id(id, &params, invariant_sys_regs,
ARRAY_SIZE(invariant_sys_regs));
if (!r)
return -ENOENT;
return reg_to_user(uaddr, &r->val, id);
}
static int set_invariant_sys_reg(u64 id, void __user *uaddr)
{
struct sys_reg_params params;
const struct sys_reg_desc *r;
int err;
u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
r = find_reg_by_id(id, &params, invariant_sys_regs,
ARRAY_SIZE(invariant_sys_regs));
if (!r)
return -ENOENT;
err = reg_from_user(&val, uaddr, id);
if (err)
return err;
/* This is what we mean by invariant: you can't change it. */
if (r->val != val)
return -EINVAL;
return 0;
}
static bool is_valid_cache(u32 val)
{
u32 level, ctype;
if (val >= CSSELR_MAX)
return false;
/* Bottom bit is Instruction or Data bit. Next 3 bits are level. */
level = (val >> 1);
ctype = (cache_levels >> (level * 3)) & 7;
switch (ctype) {
case 0: /* No cache */
return false;
case 1: /* Instruction cache only */
return (val & 1);
case 2: /* Data cache only */
case 4: /* Unified cache */
return !(val & 1);
case 3: /* Separate instruction and data caches */
return true;
default: /* Reserved: we can't know instruction or data. */
return false;
}
}
static int demux_c15_get(u64 id, void __user *uaddr)
{
u32 val;
u32 __user *uval = uaddr;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
| ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
return -ENOENT;
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
if (!is_valid_cache(val))
return -ENOENT;
return put_user(get_ccsidr(val), uval);
default:
return -ENOENT;
}
}
static int demux_c15_set(u64 id, void __user *uaddr)
{
u32 val, newval;
u32 __user *uval = uaddr;
/* Fail if we have unknown bits set. */
if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
| ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
return -ENOENT;
switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
case KVM_REG_ARM_DEMUX_ID_CCSIDR:
if (KVM_REG_SIZE(id) != 4)
return -ENOENT;
val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
>> KVM_REG_ARM_DEMUX_VAL_SHIFT;
if (!is_valid_cache(val))
return -ENOENT;
if (get_user(newval, uval))
return -EFAULT;
/* This is also invariant: you can't change it. */
if (newval != get_ccsidr(val))
return -EINVAL;
return 0;
default:
return -ENOENT;
}
}
int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct sys_reg_desc *r;
void __user *uaddr = (void __user *)(unsigned long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_get(reg->id, uaddr);
if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
return -ENOENT;
r = index_to_sys_reg_desc(vcpu, reg->id);
if (!r)
return get_invariant_sys_reg(reg->id, uaddr);
/* Check for regs disabled by runtime config */
if (sysreg_hidden(vcpu, r))
return -ENOENT;
if (r->get_user)
return (r->get_user)(vcpu, r, reg, uaddr);
return reg_to_user(uaddr, &__vcpu_sys_reg(vcpu, r->reg), reg->id);
}
int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct sys_reg_desc *r;
void __user *uaddr = (void __user *)(unsigned long)reg->addr;
if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
return demux_c15_set(reg->id, uaddr);
if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
return -ENOENT;
r = index_to_sys_reg_desc(vcpu, reg->id);
if (!r)
return set_invariant_sys_reg(reg->id, uaddr);
/* Check for regs disabled by runtime config */
if (sysreg_hidden(vcpu, r))
return -ENOENT;
if (r->set_user)
return (r->set_user)(vcpu, r, reg, uaddr);
return reg_from_user(&__vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
}
static unsigned int num_demux_regs(void)
{
unsigned int i, count = 0;
for (i = 0; i < CSSELR_MAX; i++)
if (is_valid_cache(i))
count++;
return count;
}
static int write_demux_regids(u64 __user *uindices)
{
u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
unsigned int i;
val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
for (i = 0; i < CSSELR_MAX; i++) {
if (!is_valid_cache(i))
continue;
if (put_user(val | i, uindices))
return -EFAULT;
uindices++;
}
return 0;
}
static u64 sys_reg_to_index(const struct sys_reg_desc *reg)
{
return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 |
KVM_REG_ARM64_SYSREG |
(reg->Op0 << KVM_REG_ARM64_SYSREG_OP0_SHIFT) |
(reg->Op1 << KVM_REG_ARM64_SYSREG_OP1_SHIFT) |
(reg->CRn << KVM_REG_ARM64_SYSREG_CRN_SHIFT) |
(reg->CRm << KVM_REG_ARM64_SYSREG_CRM_SHIFT) |
(reg->Op2 << KVM_REG_ARM64_SYSREG_OP2_SHIFT));
}
static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
{
if (!*uind)
return true;
if (put_user(sys_reg_to_index(reg), *uind))
return false;
(*uind)++;
return true;
}
static int walk_one_sys_reg(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd,
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
u64 __user **uind,
unsigned int *total)
{
/*
* Ignore registers we trap but don't save,
* and for which no custom user accessor is provided.
*/
if (!(rd->reg || rd->get_user))
return 0;
if (sysreg_hidden(vcpu, rd))
return 0;
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
if (!copy_reg_to_user(rd, uind))
return -EFAULT;
(*total)++;
return 0;
}
/* Assumed ordered tables, see kvm_sys_reg_table_init. */
static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
{
const struct sys_reg_desc *i2, *end2;
unsigned int total = 0;
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
int err;
i2 = sys_reg_descs;
end2 = sys_reg_descs + ARRAY_SIZE(sys_reg_descs);
while (i2 != end2) {
err = walk_one_sys_reg(vcpu, i2++, &uind, &total);
arm64: KVM: Hide unsupported AArch64 CPU features from guests Currently, a guest kernel sees the true CPU feature registers (ID_*_EL1) when it reads them using MRS instructions. This means that the guest may observe features that are present in the hardware but the host doesn't understand or doesn't provide support for. A guest may legimitately try to use such a feature as per the architecture, but use of the feature may trap instead of working normally, triggering undef injection into the guest. This is not a problem for the host, but the guest may go wrong when running on newer hardware than the host knows about. This patch hides from guest VMs any AArch64-specific CPU features that the host doesn't support, by exposing to the guest the sanitised versions of the registers computed by the cpufeatures framework, instead of the true hardware registers. To achieve this, HCR_EL2.TID3 is now set for AArch64 guests, and emulation code is added to KVM to report the sanitised versions of the affected registers in response to MRS and register reads from userspace. The affected registers are removed from invariant_sys_regs[] (since the invariant_sys_regs handling is no longer quite correct for them) and added to sys_reg_desgs[], with appropriate access(), get_user() and set_user() methods. No runtime vcpu storage is allocated for the registers: instead, they are read on demand from the cpufeatures framework. This may need modification in the future if there is a need for userspace to customise the features visible to the guest. Attempts by userspace to write the registers are handled similarly to the current invariant_sys_regs handling: writes are permitted, but only if they don't attempt to change the value. This is sufficient to support VM snapshot/restore from userspace. Because of the additional registers, restoring a VM on an older kernel may not work unless userspace knows how to handle the extra VM registers exposed to the KVM user ABI by this patch. Under the principle of least damage, this patch makes no attempt to handle any of the other registers currently in invariant_sys_regs[], or to emulate registers for AArch32: however, these could be handled in a similar way in future, as necessary. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-31 23:50:56 +08:00
if (err)
return err;
}
return total;
}
unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu)
{
return ARRAY_SIZE(invariant_sys_regs)
+ num_demux_regs()
+ walk_sys_regs(vcpu, (u64 __user *)NULL);
}
int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
unsigned int i;
int err;
/* Then give them all the invariant registers' indices. */
for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) {
if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices))
return -EFAULT;
uindices++;
}
err = walk_sys_regs(vcpu, uindices);
if (err < 0)
return err;
uindices += err;
return write_demux_regids(uindices);
}
void kvm_sys_reg_table_init(void)
{
unsigned int i;
struct sys_reg_desc clidr;
/* Make sure tables are unique and in order. */
BUG_ON(check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false));
BUG_ON(check_sysreg_table(cp14_regs, ARRAY_SIZE(cp14_regs), true));
BUG_ON(check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true));
BUG_ON(check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true));
BUG_ON(check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true));
BUG_ON(check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false));
/* We abuse the reset function to overwrite the table itself. */
for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++)
invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]);
/*
* CLIDR format is awkward, so clean it up. See ARM B4.1.20:
*
* If software reads the Cache Type fields from Ctype1
* upwards, once it has seen a value of 0b000, no caches
* exist at further-out levels of the hierarchy. So, for
* example, if Ctype3 is the first Cache Type field with a
* value of 0b000, the values of Ctype4 to Ctype7 must be
* ignored.
*/
get_clidr_el1(NULL, &clidr); /* Ugly... */
cache_levels = clidr.val;
for (i = 0; i < 7; i++)
if (((cache_levels >> (i*3)) & 7) == 0)
break;
/* Clear all higher bits. */
cache_levels &= (1 << (i*3))-1;
}