diff options
| author | Like Xu <likexu@tencent.com> | 2023-06-03 04:10:54 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-06-07 03:31:44 +0300 |
| commit | d338d8789e64b2d8ed2f82f9364c415d6efa118d (patch) | |
| tree | 000419ab62a2020cea3a1290dda2c7fa810afd15 /arch/x86/kvm/svm | |
| parent | 6a08083f294cb623fbc882417b28c5646b01f4bf (diff) | |
| download | linux-d338d8789e64b2d8ed2f82f9364c415d6efa118d.tar.xz | |
KVM: x86/pmu: Advertise PERFCTR_CORE iff the min nr of counters is met
Enable and advertise PERFCTR_CORE if and only if the minimum number of
required counters are available, i.e. if perf says there are less than six
general purpose counters.
Opportunistically, use kvm_cpu_cap_check_and_set() instead of open coding
the check for host support.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
[sean: massage shortlog and changelog]
Link: https://lore.kernel.org/r/20230603011058.1038821-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index ca32389f3c36..d9669e3cc00a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -5025,9 +5025,18 @@ static __init void svm_set_cpu_caps(void) boot_cpu_has(X86_FEATURE_AMD_SSBD)) kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); - /* AMD PMU PERFCTR_CORE CPUID */ - if (enable_pmu && boot_cpu_has(X86_FEATURE_PERFCTR_CORE)) - kvm_cpu_cap_set(X86_FEATURE_PERFCTR_CORE); + if (enable_pmu) { + /* + * Enumerate support for PERFCTR_CORE if and only if KVM has + * access to enough counters to virtualize "core" support, + * otherwise limit vPMU support to the legacy number of counters. + */ + if (kvm_pmu_cap.num_counters_gp < AMD64_NUM_COUNTERS_CORE) + kvm_pmu_cap.num_counters_gp = min(AMD64_NUM_COUNTERS, + kvm_pmu_cap.num_counters_gp); + else + kvm_cpu_cap_check_and_set(X86_FEATURE_PERFCTR_CORE); + } /* CPUID 0x8000001F (SME/SEV features) */ sev_set_cpu_caps(); |