RISC-V: KVM: Virtualize per-HART AIA CSRs

The AIA specification introduce per-HART AIA CSRs which primarily
support:
* 64 local interrupts on both RV64 and RV32
* priority for each of the 64 local interrupts
* interrupt filtering for local interrupts

This patch virtualize above mentioned AIA CSRs and also extend
ONE_REG interface to allow user-space save/restore Guest/VM
view of these CSRs.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Anup Patel 2023-01-11 11:26:10 +05:30 committed by Anup Patel
parent 6b1e8ba4ba
commit 2f4d58f763
3 changed files with 381 additions and 34 deletions

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@ -12,6 +12,7 @@
#include <linux/jump_label.h>
#include <linux/kvm_types.h>
#include <asm/csr.h>
struct kvm_aia {
/* In-kernel irqchip created */
@ -21,7 +22,22 @@ struct kvm_aia {
bool initialized;
};
struct kvm_vcpu_aia_csr {
unsigned long vsiselect;
unsigned long hviprio1;
unsigned long hviprio2;
unsigned long vsieh;
unsigned long hviph;
unsigned long hviprio1h;
unsigned long hviprio2h;
};
struct kvm_vcpu_aia {
/* CPU AIA CSR context of Guest VCPU */
struct kvm_vcpu_aia_csr guest_csr;
/* CPU AIA CSR context upon Guest VCPU reset */
struct kvm_vcpu_aia_csr guest_reset_csr;
};
#define kvm_riscv_aia_initialized(k) ((k)->arch.aia.initialized)
@ -32,48 +48,50 @@ DECLARE_STATIC_KEY_FALSE(kvm_riscv_aia_available);
#define kvm_riscv_aia_available() \
static_branch_unlikely(&kvm_riscv_aia_available)
#define KVM_RISCV_AIA_IMSIC_TOPEI (ISELECT_MASK + 1)
static inline int kvm_riscv_vcpu_aia_imsic_rmw(struct kvm_vcpu *vcpu,
unsigned long isel,
unsigned long *val,
unsigned long new_val,
unsigned long wr_mask)
{
return 0;
}
#ifdef CONFIG_32BIT
void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu);
#else
static inline void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu)
{
}
static inline void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)
{
}
#endif
bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
static inline bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu,
u64 mask)
{
return false;
}
static inline void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)
{
}
static inline void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)
{
}
static inline void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)
{
}
static inline int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu);
void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu);
int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
unsigned long reg_num,
unsigned long *out_val)
{
*out_val = 0;
return 0;
}
static inline int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
unsigned long *out_val);
int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
unsigned long reg_num,
unsigned long val)
{
return 0;
}
unsigned long val);
#define KVM_RISCV_VCPU_AIA_CSR_FUNCS
int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
unsigned int csr_num,
unsigned long *val,
unsigned long new_val,
unsigned long wr_mask);
int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
unsigned long *val, unsigned long new_val,
unsigned long wr_mask);
#define KVM_RISCV_VCPU_AIA_CSR_FUNCS \
{ .base = CSR_SIREG, .count = 1, .func = kvm_riscv_vcpu_aia_rmw_ireg }, \
{ .base = CSR_STOPEI, .count = 1, .func = kvm_riscv_vcpu_aia_rmw_topei },
static inline int kvm_riscv_vcpu_aia_update(struct kvm_vcpu *vcpu)
{

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@ -81,6 +81,13 @@ struct kvm_riscv_csr {
/* AIA CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
struct kvm_riscv_aia_csr {
unsigned long siselect;
unsigned long iprio1;
unsigned long iprio2;
unsigned long sieh;
unsigned long siph;
unsigned long iprio1h;
unsigned long iprio2h;
};
/* TIMER registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */

View File

@ -7,6 +7,7 @@
* Anup Patel <apatel@ventanamicro.com>
*/
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <asm/hwcap.h>
@ -26,6 +27,327 @@ static void aia_set_hvictl(bool ext_irq_pending)
csr_write(CSR_HVICTL, hvictl);
}
#ifdef CONFIG_32BIT
void kvm_riscv_vcpu_aia_flush_interrupts(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
unsigned long mask, val;
if (!kvm_riscv_aia_available())
return;
if (READ_ONCE(vcpu->arch.irqs_pending_mask[1])) {
mask = xchg_acquire(&vcpu->arch.irqs_pending_mask[1], 0);
val = READ_ONCE(vcpu->arch.irqs_pending[1]) & mask;
csr->hviph &= ~mask;
csr->hviph |= val;
}
}
void kvm_riscv_vcpu_aia_sync_interrupts(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
if (kvm_riscv_aia_available())
csr->vsieh = csr_read(CSR_VSIEH);
}
#endif
bool kvm_riscv_vcpu_aia_has_interrupts(struct kvm_vcpu *vcpu, u64 mask)
{
unsigned long seip;
if (!kvm_riscv_aia_available())
return false;
#ifdef CONFIG_32BIT
if (READ_ONCE(vcpu->arch.irqs_pending[1]) &
(vcpu->arch.aia_context.guest_csr.vsieh & upper_32_bits(mask)))
return true;
#endif
seip = vcpu->arch.guest_csr.vsie;
seip &= (unsigned long)mask;
seip &= BIT(IRQ_S_EXT);
if (!kvm_riscv_aia_initialized(vcpu->kvm) || !seip)
return false;
return false;
}
void kvm_riscv_vcpu_aia_update_hvip(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
if (!kvm_riscv_aia_available())
return;
#ifdef CONFIG_32BIT
csr_write(CSR_HVIPH, vcpu->arch.aia_context.guest_csr.hviph);
#endif
aia_set_hvictl(!!(csr->hvip & BIT(IRQ_VS_EXT)));
}
void kvm_riscv_vcpu_aia_load(struct kvm_vcpu *vcpu, int cpu)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
if (!kvm_riscv_aia_available())
return;
csr_write(CSR_VSISELECT, csr->vsiselect);
csr_write(CSR_HVIPRIO1, csr->hviprio1);
csr_write(CSR_HVIPRIO2, csr->hviprio2);
#ifdef CONFIG_32BIT
csr_write(CSR_VSIEH, csr->vsieh);
csr_write(CSR_HVIPH, csr->hviph);
csr_write(CSR_HVIPRIO1H, csr->hviprio1h);
csr_write(CSR_HVIPRIO2H, csr->hviprio2h);
#endif
}
void kvm_riscv_vcpu_aia_put(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
if (!kvm_riscv_aia_available())
return;
csr->vsiselect = csr_read(CSR_VSISELECT);
csr->hviprio1 = csr_read(CSR_HVIPRIO1);
csr->hviprio2 = csr_read(CSR_HVIPRIO2);
#ifdef CONFIG_32BIT
csr->vsieh = csr_read(CSR_VSIEH);
csr->hviph = csr_read(CSR_HVIPH);
csr->hviprio1h = csr_read(CSR_HVIPRIO1H);
csr->hviprio2h = csr_read(CSR_HVIPRIO2H);
#endif
}
int kvm_riscv_vcpu_aia_get_csr(struct kvm_vcpu *vcpu,
unsigned long reg_num,
unsigned long *out_val)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long))
return -EINVAL;
*out_val = 0;
if (kvm_riscv_aia_available())
*out_val = ((unsigned long *)csr)[reg_num];
return 0;
}
int kvm_riscv_vcpu_aia_set_csr(struct kvm_vcpu *vcpu,
unsigned long reg_num,
unsigned long val)
{
struct kvm_vcpu_aia_csr *csr = &vcpu->arch.aia_context.guest_csr;
if (reg_num >= sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long))
return -EINVAL;
if (kvm_riscv_aia_available()) {
((unsigned long *)csr)[reg_num] = val;
#ifdef CONFIG_32BIT
if (reg_num == KVM_REG_RISCV_CSR_AIA_REG(siph))
WRITE_ONCE(vcpu->arch.irqs_pending_mask[1], 0);
#endif
}
return 0;
}
int kvm_riscv_vcpu_aia_rmw_topei(struct kvm_vcpu *vcpu,
unsigned int csr_num,
unsigned long *val,
unsigned long new_val,
unsigned long wr_mask)
{
/* If AIA not available then redirect trap */
if (!kvm_riscv_aia_available())
return KVM_INSN_ILLEGAL_TRAP;
/* If AIA not initialized then forward to user space */
if (!kvm_riscv_aia_initialized(vcpu->kvm))
return KVM_INSN_EXIT_TO_USER_SPACE;
return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, KVM_RISCV_AIA_IMSIC_TOPEI,
val, new_val, wr_mask);
}
/*
* External IRQ priority always read-only zero. This means default
* priority order is always preferred for external IRQs unless
* HVICTL.IID == 9 and HVICTL.IPRIO != 0
*/
static int aia_irq2bitpos[] = {
0, 8, -1, -1, 16, 24, -1, -1, /* 0 - 7 */
32, -1, -1, -1, -1, 40, 48, 56, /* 8 - 15 */
64, 72, 80, 88, 96, 104, 112, 120, /* 16 - 23 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 24 - 31 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 32 - 39 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 40 - 47 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 48 - 55 */
-1, -1, -1, -1, -1, -1, -1, -1, /* 56 - 63 */
};
static u8 aia_get_iprio8(struct kvm_vcpu *vcpu, unsigned int irq)
{
unsigned long hviprio;
int bitpos = aia_irq2bitpos[irq];
if (bitpos < 0)
return 0;
switch (bitpos / BITS_PER_LONG) {
case 0:
hviprio = csr_read(CSR_HVIPRIO1);
break;
case 1:
#ifndef CONFIG_32BIT
hviprio = csr_read(CSR_HVIPRIO2);
break;
#else
hviprio = csr_read(CSR_HVIPRIO1H);
break;
case 2:
hviprio = csr_read(CSR_HVIPRIO2);
break;
case 3:
hviprio = csr_read(CSR_HVIPRIO2H);
break;
#endif
default:
return 0;
}
return (hviprio >> (bitpos % BITS_PER_LONG)) & TOPI_IPRIO_MASK;
}
static void aia_set_iprio8(struct kvm_vcpu *vcpu, unsigned int irq, u8 prio)
{
unsigned long hviprio;
int bitpos = aia_irq2bitpos[irq];
if (bitpos < 0)
return;
switch (bitpos / BITS_PER_LONG) {
case 0:
hviprio = csr_read(CSR_HVIPRIO1);
break;
case 1:
#ifndef CONFIG_32BIT
hviprio = csr_read(CSR_HVIPRIO2);
break;
#else
hviprio = csr_read(CSR_HVIPRIO1H);
break;
case 2:
hviprio = csr_read(CSR_HVIPRIO2);
break;
case 3:
hviprio = csr_read(CSR_HVIPRIO2H);
break;
#endif
default:
return;
}
hviprio &= ~(TOPI_IPRIO_MASK << (bitpos % BITS_PER_LONG));
hviprio |= (unsigned long)prio << (bitpos % BITS_PER_LONG);
switch (bitpos / BITS_PER_LONG) {
case 0:
csr_write(CSR_HVIPRIO1, hviprio);
break;
case 1:
#ifndef CONFIG_32BIT
csr_write(CSR_HVIPRIO2, hviprio);
break;
#else
csr_write(CSR_HVIPRIO1H, hviprio);
break;
case 2:
csr_write(CSR_HVIPRIO2, hviprio);
break;
case 3:
csr_write(CSR_HVIPRIO2H, hviprio);
break;
#endif
default:
return;
}
}
static int aia_rmw_iprio(struct kvm_vcpu *vcpu, unsigned int isel,
unsigned long *val, unsigned long new_val,
unsigned long wr_mask)
{
int i, first_irq, nirqs;
unsigned long old_val;
u8 prio;
#ifndef CONFIG_32BIT
if (isel & 0x1)
return KVM_INSN_ILLEGAL_TRAP;
#endif
nirqs = 4 * (BITS_PER_LONG / 32);
first_irq = (isel - ISELECT_IPRIO0) * 4;
old_val = 0;
for (i = 0; i < nirqs; i++) {
prio = aia_get_iprio8(vcpu, first_irq + i);
old_val |= (unsigned long)prio << (TOPI_IPRIO_BITS * i);
}
if (val)
*val = old_val;
if (wr_mask) {
new_val = (old_val & ~wr_mask) | (new_val & wr_mask);
for (i = 0; i < nirqs; i++) {
prio = (new_val >> (TOPI_IPRIO_BITS * i)) &
TOPI_IPRIO_MASK;
aia_set_iprio8(vcpu, first_irq + i, prio);
}
}
return KVM_INSN_CONTINUE_NEXT_SEPC;
}
#define IMSIC_FIRST 0x70
#define IMSIC_LAST 0xff
int kvm_riscv_vcpu_aia_rmw_ireg(struct kvm_vcpu *vcpu, unsigned int csr_num,
unsigned long *val, unsigned long new_val,
unsigned long wr_mask)
{
unsigned int isel;
/* If AIA not available then redirect trap */
if (!kvm_riscv_aia_available())
return KVM_INSN_ILLEGAL_TRAP;
/* First try to emulate in kernel space */
isel = csr_read(CSR_VSISELECT) & ISELECT_MASK;
if (isel >= ISELECT_IPRIO0 && isel <= ISELECT_IPRIO15)
return aia_rmw_iprio(vcpu, isel, val, new_val, wr_mask);
else if (isel >= IMSIC_FIRST && isel <= IMSIC_LAST &&
kvm_riscv_aia_initialized(vcpu->kvm))
return kvm_riscv_vcpu_aia_imsic_rmw(vcpu, isel, val, new_val,
wr_mask);
/* We can't handle it here so redirect to user space */
return KVM_INSN_EXIT_TO_USER_SPACE;
}
void kvm_riscv_aia_enable(void)
{
if (!kvm_riscv_aia_available())