KVM: x86/pmu: Add common define to capture fixed counters offset

Add a common define to "officially" solidify KVM's split of counters,
i.e. to commit to using bits 31:0 to track general purpose counters and
bits 63:32 to track fixed counters (which only Intel supports).  KVM
already bleeds this behavior all over common PMU code, and adding a KVM-
defined macro allows clarifying that the value is a _base_, as oppposed to
the _flag_ that is used to access fixed PMCs via RDPMC (which perf
confusingly calls INTEL_PMC_FIXED_RDPMC_BASE).

No functional change intended.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>

Author: sean-jc

arch/x86/kvm/pmu.c

@@ -67,7 +67,7 @@ static const struct x86_cpu_id vmx_pebs_pdist_cpu[] = {
  *        all perf counters (both gp and fixed). The mapping relationship
  *        between pmc and perf counters is as the following:
  *        * Intel: [0 .. KVM_INTEL_PMC_MAX_GENERIC-1] <=> gp counters
- *                 [INTEL_PMC_IDX_FIXED .. INTEL_PMC_IDX_FIXED + 2] <=> fixed
+ *                 [KVM_FIXED_PMC_BASE_IDX .. KVM_FIXED_PMC_BASE_IDX + 2] <=> fixed
  *        * AMD:   [0 .. AMD64_NUM_COUNTERS-1] and, for families 15H
  *          and later, [0 .. AMD64_NUM_COUNTERS_CORE-1] <=> gp counters
  */
@@ -411,7 +411,7 @@ static bool is_gp_event_allowed(struct kvm_x86_pmu_event_filter *f,
 static bool is_fixed_event_allowed(struct kvm_x86_pmu_event_filter *filter,
 				   int idx)
 {
-	int fixed_idx = idx - INTEL_PMC_IDX_FIXED;
+	int fixed_idx = idx - KVM_FIXED_PMC_BASE_IDX;
 
 	if (filter->action == KVM_PMU_EVENT_DENY &&
 	    test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap))
@@ -465,7 +465,7 @@ static void reprogram_counter(struct kvm_pmc *pmc)
 
 	if (pmc_is_fixed(pmc)) {
 		fixed_ctr_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl,
-						  pmc->idx - INTEL_PMC_IDX_FIXED);
+						  pmc->idx - KVM_FIXED_PMC_BASE_IDX);
 		if (fixed_ctr_ctrl & 0x1)
 			eventsel |= ARCH_PERFMON_EVENTSEL_OS;
 		if (fixed_ctr_ctrl & 0x2)
@@ -841,7 +841,7 @@ static inline bool cpl_is_matched(struct kvm_pmc *pmc)
 		select_user = config & ARCH_PERFMON_EVENTSEL_USR;
 	} else {
 		config = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl,
-					  pmc->idx - INTEL_PMC_IDX_FIXED);
+					  pmc->idx - KVM_FIXED_PMC_BASE_IDX);
 		select_os = config & 0x1;
 		select_user = config & 0x2;
 	}

arch/x86/kvm/pmu.h

@@ -18,6 +18,8 @@
 #define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
 
+#define KVM_FIXED_PMC_BASE_IDX INTEL_PMC_IDX_FIXED
+
 struct kvm_pmu_ops {
 	struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
 	struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
@@ -130,7 +132,7 @@ static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)
 
 	if (pmc_is_fixed(pmc))
 		return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
-					pmc->idx - INTEL_PMC_IDX_FIXED) & 0x3;
+					pmc->idx - KVM_FIXED_PMC_BASE_IDX) & 0x3;
 
 	return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
 }

arch/x86/kvm/vmx/pmu_intel.c

@@ -50,18 +50,18 @@ static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 
 		pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
 
-		__set_bit(INTEL_PMC_IDX_FIXED + i, pmu->pmc_in_use);
+		__set_bit(KVM_FIXED_PMC_BASE_IDX + i, pmu->pmc_in_use);
 		kvm_pmu_request_counter_reprogram(pmc);
 	}
 }
 
 static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 {
-	if (pmc_idx < INTEL_PMC_IDX_FIXED) {
+	if (pmc_idx < KVM_FIXED_PMC_BASE_IDX) {
 		return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
 				  MSR_P6_EVNTSEL0);
 	} else {
-		u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
+		u32 idx = pmc_idx - KVM_FIXED_PMC_BASE_IDX;
 
 		return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
 	}
@@ -516,7 +516,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	for (i = 0; i < pmu->nr_arch_fixed_counters; i++)
 		pmu->fixed_ctr_ctrl_mask &= ~(0xbull << (i * 4));
 	counter_mask = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
-		(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED));
+		(((1ull << pmu->nr_arch_fixed_counters) - 1) << KVM_FIXED_PMC_BASE_IDX));
 	pmu->global_ctrl_mask = counter_mask;
 
 	/*
@@ -560,7 +560,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 			pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE;
 			for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
 				pmu->fixed_ctr_ctrl_mask &=
-					~(1ULL << (INTEL_PMC_IDX_FIXED + i * 4));
+					~(1ULL << (KVM_FIXED_PMC_BASE_IDX + i * 4));
 			}
 			pmu->pebs_data_cfg_mask = ~0xff00000full;
 		} else {
@@ -586,7 +586,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu)
 	for (i = 0; i < KVM_PMC_MAX_FIXED; i++) {
 		pmu->fixed_counters[i].type = KVM_PMC_FIXED;
 		pmu->fixed_counters[i].vcpu = vcpu;
-		pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
+		pmu->fixed_counters[i].idx = i + KVM_FIXED_PMC_BASE_IDX;
 		pmu->fixed_counters[i].current_config = 0;
 		pmu->fixed_counters[i].eventsel = intel_get_fixed_pmc_eventsel(i);
 	}