Re: [PATCH v5 15/22] RISC-V: KVM: Improve firmware counter read function

[Andrew Jones <ajones@ventanamicro.com>]

On Wed, Apr 03, 2024 at 01:04:44AM -0700, Atish Patra wrote:
> Rename the function to indicate that it is meant for firmware
> counter read. While at it, add a range sanity check for it as
> well.
> 
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  arch/riscv/include/asm/kvm_vcpu_pmu.h | 2 +-
>  arch/riscv/kvm/vcpu_pmu.c             | 7 ++++++-
>  arch/riscv/kvm/vcpu_sbi_pmu.c         | 2 +-
>  3 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> index 55861b5d3382..fa0f535bbbf0 100644
> --- a/arch/riscv/include/asm/kvm_vcpu_pmu.h
> +++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h
> @@ -89,7 +89,7 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba
>  				     unsigned long ctr_mask, unsigned long flags,
>  				     unsigned long eidx, u64 evtdata,
>  				     struct kvm_vcpu_sbi_return *retdata);
> -int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
> +int kvm_riscv_vcpu_pmu_fw_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
>  				struct kvm_vcpu_sbi_return *retdata);
>  int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx,
>  				      struct kvm_vcpu_sbi_return *retdata);
> diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
> index ff326152eeff..94efa88d054d 100644
> --- a/arch/riscv/kvm/vcpu_pmu.c
> +++ b/arch/riscv/kvm/vcpu_pmu.c
> @@ -235,6 +235,11 @@ static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
>  	u64 enabled, running;
>  	int fevent_code;
>  
> +	if (cidx >= kvm_pmu_num_counters(kvpmu) || cidx == 1) {
> +		pr_warn("Invalid counter id [%ld] during read\n", cidx);
> +		return -EINVAL;
> +	}
> +
>  	pmc = &kvpmu->pmc[cidx];
>  
>  	if (pmc->cinfo.type == SBI_PMU_CTR_TYPE_FW) {
> @@ -747,7 +752,7 @@ int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx,
>  	return 0;
>  }
>  
> -int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
> +int kvm_riscv_vcpu_pmu_fw_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
>  				struct kvm_vcpu_sbi_return *retdata)
>  {
>  	int ret;
> diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c
> index cf111de51bdb..e4be34e03e83 100644
> --- a/arch/riscv/kvm/vcpu_sbi_pmu.c
> +++ b/arch/riscv/kvm/vcpu_sbi_pmu.c
> @@ -62,7 +62,7 @@ static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
>  		ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2, retdata);
>  		break;
>  	case SBI_EXT_PMU_COUNTER_FW_READ:
> -		ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, retdata);
> +		ret = kvm_riscv_vcpu_pmu_fw_ctr_read(vcpu, cp->a0, retdata);
>  		break;
>  	case SBI_EXT_PMU_COUNTER_FW_READ_HI:
>  		if (IS_ENABLED(CONFIG_32BIT))
> -- 
> 2.34.1
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>