From 0033fa35491680bce65ff78fb41445f472aa5baa Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 6 Jun 2023 18:02:03 -0700 Subject: [PATCH] KVM: x86/pmu: Use enums instead of hardcoded magic for arch event indices Add "enum intel_pmu_architectural_events" to replace the magic numbers for the (pseudo-)architectural events, and to give a meaningful name to each event so that new readers don't need psychic powers to understand what the code is doing. Cc: Aaron Lewis Cc: Like Xu Reviewed-by: Like Xu Link: https://lore.kernel.org/r/20230607010206.1425277-2-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/pmu_intel.c | 55 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 80c769c..1109cbd 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -22,23 +22,51 @@ #define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0) +enum intel_pmu_architectural_events { + /* + * The order of the architectural events matters as support for each + * event is enumerated via CPUID using the index of the event. + */ + INTEL_ARCH_CPU_CYCLES, + INTEL_ARCH_INSTRUCTIONS_RETIRED, + INTEL_ARCH_REFERENCE_CYCLES, + INTEL_ARCH_LLC_REFERENCES, + INTEL_ARCH_LLC_MISSES, + INTEL_ARCH_BRANCHES_RETIRED, + INTEL_ARCH_BRANCHES_MISPREDICTED, + + NR_REAL_INTEL_ARCH_EVENTS, + + /* + * Pseudo-architectural event used to implement IA32_FIXED_CTR2, a.k.a. + * TSC reference cycles. The architectural reference cycles event may + * or may not actually use the TSC as the reference, e.g. might use the + * core crystal clock or the bus clock (yeah, "architectural"). + */ + PSEUDO_ARCH_REFERENCE_CYCLES = NR_REAL_INTEL_ARCH_EVENTS, + NR_INTEL_ARCH_EVENTS, +}; + static struct { u8 eventsel; u8 unit_mask; } const intel_arch_events[] = { - [0] = { 0x3c, 0x00 }, - [1] = { 0xc0, 0x00 }, - [2] = { 0x3c, 0x01 }, - [3] = { 0x2e, 0x4f }, - [4] = { 0x2e, 0x41 }, - [5] = { 0xc4, 0x00 }, - [6] = { 0xc5, 0x00 }, - /* The above index must match CPUID 0x0A.EBX bit vector */ - [7] = { 0x00, 0x03 }, + [INTEL_ARCH_CPU_CYCLES] = { 0x3c, 0x00 }, + [INTEL_ARCH_INSTRUCTIONS_RETIRED] = { 0xc0, 0x00 }, + [INTEL_ARCH_REFERENCE_CYCLES] = { 0x3c, 0x01 }, + [INTEL_ARCH_LLC_REFERENCES] = { 0x2e, 0x4f }, + [INTEL_ARCH_LLC_MISSES] = { 0x2e, 0x41 }, + [INTEL_ARCH_BRANCHES_RETIRED] = { 0xc4, 0x00 }, + [INTEL_ARCH_BRANCHES_MISPREDICTED] = { 0xc5, 0x00 }, + [PSEUDO_ARCH_REFERENCE_CYCLES] = { 0x00, 0x03 }, }; /* mapping between fixed pmc index and intel_arch_events array */ -static int fixed_pmc_events[] = {1, 0, 7}; +static int fixed_pmc_events[] = { + [0] = INTEL_ARCH_INSTRUCTIONS_RETIRED, + [1] = INTEL_ARCH_CPU_CYCLES, + [2] = PSEUDO_ARCH_REFERENCE_CYCLES, +}; static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data) { @@ -80,13 +108,16 @@ static bool intel_hw_event_available(struct kvm_pmc *pmc) u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; int i; - for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++) { + BUILD_BUG_ON(ARRAY_SIZE(intel_arch_events) != NR_INTEL_ARCH_EVENTS); + + for (i = 0; i < NR_INTEL_ARCH_EVENTS; i++) { if (intel_arch_events[i].eventsel != event_select || intel_arch_events[i].unit_mask != unit_mask) continue; /* disable event that reported as not present by cpuid */ - if ((i < 7) && !(pmu->available_event_types & (1 << i))) + if ((i < PSEUDO_ARCH_REFERENCE_CYCLES) && + !(pmu->available_event_types & (1 << i))) return false; break; -- 2.7.4