Re: [PATCH v5 11/14] RISC-V: KVM: Implement trap & emulate for hpmcounters

[Andrew Jones]

On Sat, Feb 04, 2023 at 05:15:12PM -0800, Atish Patra wrote:
> As the KVM guests only see the virtual PMU counters, all hpmcounter
> access should trap and KVM emulates the read access on behalf of guests.
> 
> Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
> Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/kvm_vcpu_pmu.h | 16 ++++++++
>  arch/riscv/kvm/vcpu_insn.c            |  4 +-
>  arch/riscv/kvm/vcpu_pmu.c             | 59 ++++++++++++++++++++++++++-
>  3 files changed, 77 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> index 40905db..344a3ad 100644
> --- a/arch/riscv/include/asm/kvm_vcpu_pmu.h
> +++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> @@ -48,6 +48,19 @@ struct kvm_pmu {
>  #define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu_context)
>  #define pmu_to_vcpu(pmu)  (container_of((pmu), struct kvm_vcpu, arch.pmu_context))
>  
> +#if defined(CONFIG_32BIT)
> +#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
> +{.base = CSR_CYCLEH,     .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm }, \
> +{.base = CSR_CYCLE,      .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm },
                      ^ should be tabs?

> +#else
> +#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
> +{.base = CSR_CYCLE,      .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm },
                      ^ here too
> +#endif
> +
> +int kvm_riscv_vcpu_pmu_read_hpm(struct kvm_vcpu *vcpu, unsigned int csr_num,
> +				unsigned long *val, unsigned long new_val,
> +				unsigned long wr_mask);
> +
>  int kvm_riscv_vcpu_pmu_num_ctrs(struct kvm_vcpu *vcpu, struct kvm_vcpu_sbi_return *retdata);
>  int kvm_riscv_vcpu_pmu_ctr_info(struct kvm_vcpu *vcpu, unsigned long cidx,
>  				struct kvm_vcpu_sbi_return *retdata);
> @@ -71,6 +84,9 @@ void kvm_riscv_vcpu_pmu_reset(struct kvm_vcpu *vcpu);
>  struct kvm_pmu {
>  };
>  
> +#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
> +{ .base = 0,      .count = 0, .func = NULL },
               ^ and here and aligned with the ones above?

Thanks,
drew