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OpenCloudOS-Kernel/arch/arm/kvm/coproc_a15.c

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KVM: ARM: Emulation framework and CP15 emulation Adds a new important function in the main KVM/ARM code called handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns from guest execution. This function examines the Hyp-Syndrome-Register (HSR), which contains information telling KVM what caused the exit from the guest. Some of the reasons for an exit are CP15 accesses, which are not allowed from the guest and this commit handles these exits by emulating the intended operation in software and skipping the guest instruction. Minor notes about the coproc register reset: 1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our table, at cost of 4 bytes per vcpu. 2) Added comments on the table indicating how we handle each register, for simplicity of understanding. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-21 07:28:09 +08:00
/*
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Authors: Rusty Russell <rusty@rustcorp.au>
* Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/kvm_host.h>
#include <asm/cputype.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
#include <linux/init.h>
static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
{
/*
KVM: ARM: Fix calculation of virtual CPU ID KVM does not have a notion of multiple clusters for CPUs, just a linear array of CPUs. When using a system with cores in more than one cluster, the current method for calculating the virtual MPIDR will leak the (physical) cluster information into the virtual MPIDR. One effect of this is that Linux under KVM fails to boot multiple CPUs that aren't in the 0th cluster. This patch does away with exposing the real MPIDR fields in favour of simply using the virtual CPU number (but preserving the U bit, as before). Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-09-26 23:49:27 +08:00
* Compute guest MPIDR. No need to mess around with different clusters
* but we read the 'U' bit from the underlying hardware directly.
KVM: ARM: Emulation framework and CP15 emulation Adds a new important function in the main KVM/ARM code called handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns from guest execution. This function examines the Hyp-Syndrome-Register (HSR), which contains information telling KVM what caused the exit from the guest. Some of the reasons for an exit are CP15 accesses, which are not allowed from the guest and this commit handles these exits by emulating the intended operation in software and skipping the guest instruction. Minor notes about the coproc register reset: 1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our table, at cost of 4 bytes per vcpu. 2) Added comments on the table indicating how we handle each register, for simplicity of understanding. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-21 07:28:09 +08:00
*/
KVM: ARM: Fix calculation of virtual CPU ID KVM does not have a notion of multiple clusters for CPUs, just a linear array of CPUs. When using a system with cores in more than one cluster, the current method for calculating the virtual MPIDR will leak the (physical) cluster information into the virtual MPIDR. One effect of this is that Linux under KVM fails to boot multiple CPUs that aren't in the 0th cluster. This patch does away with exposing the real MPIDR fields in favour of simply using the virtual CPU number (but preserving the U bit, as before). Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-09-26 23:49:27 +08:00
vcpu->arch.cp15[c0_MPIDR] = (read_cpuid_mpidr() & MPIDR_SMP_BITMASK)
| vcpu->vcpu_id;
KVM: ARM: Emulation framework and CP15 emulation Adds a new important function in the main KVM/ARM code called handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns from guest execution. This function examines the Hyp-Syndrome-Register (HSR), which contains information telling KVM what caused the exit from the guest. Some of the reasons for an exit are CP15 accesses, which are not allowed from the guest and this commit handles these exits by emulating the intended operation in software and skipping the guest instruction. Minor notes about the coproc register reset: 1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our table, at cost of 4 bytes per vcpu. 2) Added comments on the table indicating how we handle each register, for simplicity of understanding. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-21 07:28:09 +08:00
}
#include "coproc.h"
/* A15 TRM 4.3.28: RO WI */
static bool access_actlr(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c1_ACTLR];
return true;
}
/* A15 TRM 4.3.60: R/O. */
static bool access_cbar(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *r)
{
if (p->is_write)
return write_to_read_only(vcpu, p);
return read_zero(vcpu, p);
}
/* A15 TRM 4.3.48: R/O WI. */
static bool access_l2ctlr(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c9_L2CTLR];
return true;
}
static void reset_l2ctlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
{
u32 l2ctlr, ncores;
asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
l2ctlr &= ~(3 << 24);
ncores = atomic_read(&vcpu->kvm->online_vcpus) - 1;
l2ctlr |= (ncores & 3) << 24;
vcpu->arch.cp15[c9_L2CTLR] = l2ctlr;
}
static void reset_actlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
{
u32 actlr;
/* ACTLR contains SMP bit: make sure you create all cpus first! */
asm volatile("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
/* Make the SMP bit consistent with the guest configuration */
if (atomic_read(&vcpu->kvm->online_vcpus) > 1)
actlr |= 1U << 6;
else
actlr &= ~(1U << 6);
vcpu->arch.cp15[c1_ACTLR] = actlr;
}
/* A15 TRM 4.3.49: R/O WI (even if NSACR.NS_L2ERR, a write of 1 is ignored). */
static bool access_l2ectlr(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
*vcpu_reg(vcpu, p->Rt1) = 0;
return true;
}
/*
* A15-specific CP15 registers.
ARM: KVM: Fix 64-bit coprocessor handling The PAR was exported as CRn == 7 and CRm == 0, but in fact the primary coprocessor register number was determined by CRm for 64-bit coprocessor registers as the user space API was modeled after the coprocessor access instructions (see the ARM ARM rev. C - B3-1445). However, just changing the CRn to CRm breaks the sorting check when booting the kernel, because the internal kernel logic always treats CRn as the primary register number, and it makes the table sorting impossible to understand for humans. Alternatively we could change the logic to always have CRn == CRm, but that becomes unclear in the number of ways we do look up of a coprocessor register. We could also have a separate 64-bit table but that feels somewhat over-engineered. Instead, keep CRn the primary representation of the primary coproc. register number in-kernel and always export the primary number as CRm as per the existing user space ABI. Note: The TTBR registers just magically worked because they happened to follow the CRn(0) regs and were considered CRn(0) in the in-kernel representation. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2013-08-06 09:08:41 +08:00
* CRn denotes the primary register number, but is copied to the CRm in the
* user space API for 64-bit register access in line with the terminology used
* in the ARM ARM.
* Important: Must be sorted ascending by CRn, CRM, Op1, Op2 and with 64-bit
* registers preceding 32-bit ones.
KVM: ARM: Emulation framework and CP15 emulation Adds a new important function in the main KVM/ARM code called handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns from guest execution. This function examines the Hyp-Syndrome-Register (HSR), which contains information telling KVM what caused the exit from the guest. Some of the reasons for an exit are CP15 accesses, which are not allowed from the guest and this commit handles these exits by emulating the intended operation in software and skipping the guest instruction. Minor notes about the coproc register reset: 1) We reserve a value of 0 as an invalid cp15 offset, to catch bugs in our table, at cost of 4 bytes per vcpu. 2) Added comments on the table indicating how we handle each register, for simplicity of understanding. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
2013-01-21 07:28:09 +08:00
*/
static const struct coproc_reg a15_regs[] = {
/* MPIDR: we use VMPIDR for guest access. */
{ CRn( 0), CRm( 0), Op1( 0), Op2( 5), is32,
NULL, reset_mpidr, c0_MPIDR },
/* SCTLR: swapped by interrupt.S. */
{ CRn( 1), CRm( 0), Op1( 0), Op2( 0), is32,
NULL, reset_val, c1_SCTLR, 0x00C50078 },
/* ACTLR: trapped by HCR.TAC bit. */
{ CRn( 1), CRm( 0), Op1( 0), Op2( 1), is32,
access_actlr, reset_actlr, c1_ACTLR },
/* CPACR: swapped by interrupt.S. */
{ CRn( 1), CRm( 0), Op1( 0), Op2( 2), is32,
NULL, reset_val, c1_CPACR, 0x00000000 },
/*
* L2CTLR access (guest wants to know #CPUs).
*/
{ CRn( 9), CRm( 0), Op1( 1), Op2( 2), is32,
access_l2ctlr, reset_l2ctlr, c9_L2CTLR },
{ CRn( 9), CRm( 0), Op1( 1), Op2( 3), is32, access_l2ectlr},
/* The Configuration Base Address Register. */
{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
};
static struct kvm_coproc_target_table a15_target_table = {
.target = KVM_ARM_TARGET_CORTEX_A15,
.table = a15_regs,
.num = ARRAY_SIZE(a15_regs),
};
static int __init coproc_a15_init(void)
{
unsigned int i;
for (i = 1; i < ARRAY_SIZE(a15_regs); i++)
BUG_ON(cmp_reg(&a15_regs[i-1],
&a15_regs[i]) >= 0);
kvm_register_target_coproc_table(&a15_target_table);
return 0;
}
late_initcall(coproc_a15_init);