kevin/linux
1
Fork 0
Code

KVM: riscv: Support guest wrs.nto

Browse Source 
When a guest traps on wrs.nto, call kvm_vcpu_on_spin() to attempt
to yield to the lock holding VCPU. Also extend the KVM ISA extension
ONE_REG interface to allow KVM userspace to detect and enable the
Zawrs extension for the Guest/VM.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240426100820.14762-13-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Andrew Jones 2024-04-26 12:08:25 +02:00 committed by Palmer Dabbelt
parent 244c18fbf6
commit 86d6a86e59
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
5 changed files with 20 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/riscv/include/asm/kvm_host.h
View File

@ -69,6 +69,7 @@ struct kvm_vcpu_stat {
struct kvm_vcpu_stat_generic generic;
u64 ecall_exit_stat;
u64 wfi_exit_stat;
u64 wrs_exit_stat;
u64 mmio_exit_user;
u64 mmio_exit_kernel;
u64 csr_exit_user;

1
arch/riscv/include/uapi/asm/kvm.h
View File

@ -167,6 +167,7 @@ enum KVM_RISCV_ISA_EXT_ID {
KVM_RISCV_ISA_EXT_ZFA,
KVM_RISCV_ISA_EXT_ZTSO,
KVM_RISCV_ISA_EXT_ZACAS,
KVM_RISCV_ISA_EXT_ZAWRS,
KVM_RISCV_ISA_EXT_MAX,
};

1
arch/riscv/kvm/vcpu.c
View File

@ -25,6 +25,7 @@ const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
KVM_GENERIC_VCPU_STATS(),
STATS_DESC_COUNTER(VCPU, ecall_exit_stat),
STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
STATS_DESC_COUNTER(VCPU, wrs_exit_stat),
STATS_DESC_COUNTER(VCPU, mmio_exit_user),
STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
STATS_DESC_COUNTER(VCPU, csr_exit_user),

15
arch/riscv/kvm/vcpu_insn.c
View File

@ -16,6 +16,9 @@
#define INSN_MASK_WFI 0xffffffff
#define INSN_MATCH_WFI 0x10500073
#define INSN_MASK_WRS 0xffffffff
#define INSN_MATCH_WRS 0x00d00073
#define INSN_MATCH_CSRRW 0x1073
#define INSN_MASK_CSRRW 0x707f
#define INSN_MATCH_CSRRS 0x2073
@ -203,6 +206,13 @@ static int wfi_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, ulong insn)
return KVM_INSN_CONTINUE_NEXT_SEPC;
}
static int wrs_insn(struct kvm_vcpu *vcpu, struct kvm_run *run, ulong insn)
{
vcpu->stat.wrs_exit_stat++;
kvm_vcpu_on_spin(vcpu, vcpu->arch.guest_context.sstatus & SR_SPP);
return KVM_INSN_CONTINUE_NEXT_SEPC;
}
struct csr_func {
unsigned int base;
unsigned int count;
@ -378,6 +388,11 @@ static const struct insn_func system_opcode_funcs[] = {
.match = INSN_MATCH_WFI,
.func = wfi_insn,
},
{
.mask = INSN_MASK_WRS,
.match = INSN_MATCH_WRS,
.func = wrs_insn,
},
};
static int system_opcode_insn(struct kvm_vcpu *vcpu, struct kvm_run *run,

2
arch/riscv/kvm/vcpu_onereg.c
View File

@ -41,6 +41,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
KVM_ISA_EXT_ARR(SVNAPOT),
KVM_ISA_EXT_ARR(SVPBMT),
KVM_ISA_EXT_ARR(ZACAS),
KVM_ISA_EXT_ARR(ZAWRS),
KVM_ISA_EXT_ARR(ZBA),
KVM_ISA_EXT_ARR(ZBB),
KVM_ISA_EXT_ARR(ZBC),
@ -120,6 +121,7 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
case KVM_RISCV_ISA_EXT_SVINVAL:
case KVM_RISCV_ISA_EXT_SVNAPOT:
case KVM_RISCV_ISA_EXT_ZACAS:
case KVM_RISCV_ISA_EXT_ZAWRS:
case KVM_RISCV_ISA_EXT_ZBA:
case KVM_RISCV_ISA_EXT_ZBB:
case KVM_RISCV_ISA_EXT_ZBC: