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[PATCH 2/3] RISC-V: KVM: Update firmware counters for various events

Atish Patra posted 3 patches 1 year ago
There is a newer version of this series
[PATCH 2/3] RISC-V: KVM: Update firmware counters for various events
Posted by Atish Patra 1 year ago 
SBI PMU specification defines few firmware counters which can be
used by the guests to collect the statstics about various traps
occurred in the host.

Update these counters whenever a corresponding trap is taken

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/vcpu_exit.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index c9f8b2094554..acdcd619797e 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -165,6 +165,17 @@ void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
 	vcpu->arch.guest_context.sstatus |= SR_SPP;
 }
 
+static inline int vcpu_redirect(struct kvm_vcpu *vcpu, struct kvm_cpu_trap *trap)
+{
+	int ret = -EFAULT;
+
+	if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
+		kvm_riscv_vcpu_trap_redirect(vcpu, trap);
+		ret = 1;
+	}
+	return ret;
+}
+
 /*
  * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
  * proper exit to userspace.
@@ -183,15 +194,27 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	run->exit_reason = KVM_EXIT_UNKNOWN;
 	switch (trap->scause) {
 	case EXC_INST_ILLEGAL:
+		kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ILLEGAL_INSN);
+		ret = vcpu_redirect(vcpu, trap);
+		break;
 	case EXC_LOAD_MISALIGNED:
+		kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_LOAD);
+		ret = vcpu_redirect(vcpu, trap);
+		break;
 	case EXC_STORE_MISALIGNED:
+		kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_STORE);
+		ret = vcpu_redirect(vcpu, trap);
+		break;
 	case EXC_LOAD_ACCESS:
+		kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_LOAD);
+		ret = vcpu_redirect(vcpu, trap);
+		break;
 	case EXC_STORE_ACCESS:
+		kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_STORE);
+		ret = vcpu_redirect(vcpu, trap);
+		break;
 	case EXC_INST_ACCESS:
-		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
-			kvm_riscv_vcpu_trap_redirect(vcpu, trap);
-			ret = 1;
-		}
+		ret = vcpu_redirect(vcpu, trap);
 		break;
 	case EXC_VIRTUAL_INST_FAULT:
 		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)

-- 
2.34.1
Re: [PATCH 2/3] RISC-V: KVM: Update firmware counters for various events
Posted by Anup Patel 11 months, 3 weeks ago 
On Fri, Dec 13, 2024 at 2:27 AM Atish Patra <atishp@rivosinc.com> wrote:
>
> SBI PMU specification defines few firmware counters which can be
> used by the guests to collect the statstics about various traps
> occurred in the host.
>
> Update these counters whenever a corresponding trap is taken
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

LGTM.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup

> ---
>  arch/riscv/kvm/vcpu_exit.c | 31 +++++++++++++++++++++++++++----
>  1 file changed, 27 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
> index c9f8b2094554..acdcd619797e 100644
> --- a/arch/riscv/kvm/vcpu_exit.c
> +++ b/arch/riscv/kvm/vcpu_exit.c
> @@ -165,6 +165,17 @@ void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
>         vcpu->arch.guest_context.sstatus |= SR_SPP;
>  }
>
> +static inline int vcpu_redirect(struct kvm_vcpu *vcpu, struct kvm_cpu_trap *trap)
> +{
> +       int ret = -EFAULT;
> +
> +       if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
> +               kvm_riscv_vcpu_trap_redirect(vcpu, trap);
> +               ret = 1;
> +       }
> +       return ret;
> +}
> +
>  /*
>   * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
>   * proper exit to userspace.
> @@ -183,15 +194,27 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
>         run->exit_reason = KVM_EXIT_UNKNOWN;
>         switch (trap->scause) {
>         case EXC_INST_ILLEGAL:
> +               kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ILLEGAL_INSN);
> +               ret = vcpu_redirect(vcpu, trap);
> +               break;
>         case EXC_LOAD_MISALIGNED:
> +               kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_LOAD);
> +               ret = vcpu_redirect(vcpu, trap);
> +               break;
>         case EXC_STORE_MISALIGNED:
> +               kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_STORE);
> +               ret = vcpu_redirect(vcpu, trap);
> +               break;
>         case EXC_LOAD_ACCESS:
> +               kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_LOAD);
> +               ret = vcpu_redirect(vcpu, trap);
> +               break;
>         case EXC_STORE_ACCESS:
> +               kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_STORE);
> +               ret = vcpu_redirect(vcpu, trap);
> +               break;
>         case EXC_INST_ACCESS:
> -               if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
> -                       kvm_riscv_vcpu_trap_redirect(vcpu, trap);
> -                       ret = 1;
> -               }
> +               ret = vcpu_redirect(vcpu, trap);
>                 break;
>         case EXC_VIRTUAL_INST_FAULT:
>                 if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
>
> --
> 2.34.1
>

Patchew 2.1-devel-b67e4c2

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