On 3/3/2025 3:30 AM, Dongli Zhang wrote:
> When the PERFCORE is disabled with "-cpu host,-perfctr-core", it is
> reflected in in guest dmesg.
>
> [ 0.285136] Performance Events: AMD PMU driver.
>
> However, the guest CPUID indicates the PerfMonV2 is still available.
>
> CPU:
> Extended Performance Monitoring and Debugging (0x80000022):
> AMD performance monitoring V2 = true
> AMD LBR V2 = false
> AMD LBR stack & PMC freezing = false
> number of core perf ctrs = 0x6 (6)
> number of LBR stack entries = 0x0 (0)
> number of avail Northbridge perf ctrs = 0x0 (0)
> number of available UMC PMCs = 0x0 (0)
> active UMCs bitmask = 0x0
>
> Disable PerfMonV2 in CPUID when PERFCORE is disabled.
>
> Suggested-by: Zhao Liu <zhao1.liu@xxxxxxxxx>
> Fixes: 209b0ac12074 ("target/i386: Add PerfMonV2 feature bit")
> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx>
> ---
> Changed since v1:
> - Use feature_dependencies (suggested by Zhao Liu).
>
> target/i386/cpu.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 72ab147e85..b6d6167910 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1805,6 +1805,10 @@ static FeatureDep feature_dependencies[] = {
> .from = { FEAT_7_1_EDX, CPUID_7_1_EDX_AVX10 },
> .to = { FEAT_24_0_EBX, ~0ull },
> },
> + {
> + .from = { FEAT_8000_0001_ECX, CPUID_EXT3_PERFCORE },
> + .to = { FEAT_8000_0022_EAX, CPUID_8000_0022_EAX_PERFMON_V2 },
> + },
> };
>
> typedef struct X86RegisterInfo32 {
Reviewed-by: Sandipan Das <sandipan.das@xxxxxxx>
