From: Like Xu <likexu@xxxxxxxxxxx> The obsolete comment could more accurately state that AMD platforms have two base MSR addresses and two different maximum numbers for gp counters, depending on the X86_FEATURE_PERFCTR_CORE feature. Signed-off-by: Like Xu <likexu@xxxxxxxxxxx> --- arch/x86/kvm/pmu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 618f529f1c4d..b52676f86562 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -34,7 +34,9 @@ * However AMD doesn't support fixed-counters; * - There are three types of index to access perf counters (PMC): * 1. MSR (named msr): For example Intel has MSR_IA32_PERFCTRn and AMD - * has MSR_K7_PERFCTRn. + * has MSR_K7_PERFCTRn and, for families 15H and later, + * MSR_F15H_PERF_CTRn, where MSR_F15H_PERF_CTR[0-3] are + * aliased to MSR_K7_PERFCTRn. * 2. MSR Index (named idx): This normally is used by RDPMC instruction. * For instance AMD RDPMC instruction uses 0000_0003h in ECX to access * C001_0007h (MSR_K7_PERCTR3). Intel has a similar mechanism, except @@ -46,7 +48,8 @@ * between pmc and perf counters is as the following: * * Intel: [0 .. INTEL_PMC_MAX_GENERIC-1] <=> gp counters * [INTEL_PMC_IDX_FIXED .. INTEL_PMC_IDX_FIXED + 2] <=> fixed - * * AMD: [0 .. AMD64_NUM_COUNTERS-1] <=> gp counters + * * AMD: [0 .. AMD64_NUM_COUNTERS-1] and, for families 15H + * and later, [0 .. AMD64_NUM_COUNTERS_CORE-1] <=> gp counters */ static struct kvm_pmu_ops kvm_pmu_ops __read_mostly; -- 2.35.1
