Re: [PATCH v3 09/10] target/i386/kvm: support perfmon-v2 for reset

[Zhao Liu <zhao1.liu@intel.com>]

On Sun, Mar 30, 2025 at 06:32:28PM -0700, Dongli Zhang wrote:
> Date: Sun, 30 Mar 2025 18:32:28 -0700
> From: Dongli Zhang <dongli.zhang@oracle.com>
> Subject: [PATCH v3 09/10] target/i386/kvm: support perfmon-v2 for reset
> X-Mailer: git-send-email 2.43.5
> 
> Since perfmon-v2, the AMD PMU supports additional registers. This update
> includes get/put functionality for these extra registers.
> 
> Similar to the implementation in KVM:
> 
> - MSR_CORE_PERF_GLOBAL_STATUS and MSR_AMD64_PERF_CNTR_GLOBAL_STATUS both
> use env->msr_global_status.
> - MSR_CORE_PERF_GLOBAL_CTRL and MSR_AMD64_PERF_CNTR_GLOBAL_CTL both use
> env->msr_global_ctrl.
> - MSR_CORE_PERF_GLOBAL_OVF_CTRL and MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR
> both use env->msr_global_ovf_ctrl.
> 
> No changes are needed for vmstate_msr_architectural_pmu or
> pmu_enable_needed().
> 
> Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
> ---

...

> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index 3a35fd741d..f4532e6f2a 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -2149,6 +2149,16 @@ static void kvm_init_pmu_info_amd(struct kvm_cpuid2 *cpuid, X86CPU *cpu)
>      }
>  
>      num_pmu_gp_counters = AMD64_NUM_COUNTERS_CORE;
> +
> +    c = cpuid_find_entry(cpuid, 0x80000022, 0);
> +    if (c && (c->eax & CPUID_8000_0022_EAX_PERFMON_V2)) {
> +        pmu_version = 2;
> +        num_pmu_gp_counters = c->ebx & 0xf;
> +
> +        if (num_pmu_gp_counters > MAX_GP_COUNTERS) {
> +            num_pmu_gp_counters = MAX_GP_COUNTERS;

OK! KVM now supports 6 GP counters (KVM_MAX_NR_AMD_GP_COUNTERS).

> +        }
> +    }
>  }

Fine for me,

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>