| Message ID | 20220221115201.22208-2-likexu@tencent.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86/pmu: Get rid of PERF_TYPE_HARDWAR and other minor fixes | expand |
On Mon, Feb 21, 2022 at 3:52 AM Like Xu <like.xu.linux@gmail.com> wrote: > > From: Like Xu <likexu@tencent.com> > > 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@tencent.com> > --- > arch/x86/kvm/pmu.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c > index b1a02993782b..c4692f0ff87e 100644 > --- a/arch/x86/kvm/pmu.c > +++ b/arch/x86/kvm/pmu.c > @@ -34,7 +34,7 @@ > * 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_F15H_PERF_CTRn or MSR_K7_PERFCTRn. "Or" sounds exclusive. Maybe it would be better to say: 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.
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index b1a02993782b..c4692f0ff87e 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -34,7 +34,7 @@ * 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_F15H_PERF_CTRn or 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 +46,8 @@ * 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] or + * [0 .. AMD64_NUM_COUNTERS_CORE-1] <=> gp counters */ static void kvm_pmi_trigger_fn(struct irq_work *irq_work)