KVM: x86: Add support for AMD Core Perf Extension in guest

Add support for AMD Core Performance counters in the guest. The base
event select and counter MSRs are changed. In addition, with the core
extension, there are 2 extra counters available for performance
measurements for a total of 6.

With the new MSRs, the logic to map them to the gp_counters[] is changed.
New functions are added to check the validity of the get/set MSRs.

If the guest has the X86_FEATURE_PERFCTR_CORE cpuid flag set, the number
of counters available to the vcpu is set to 6. It the flag is not set
then it is 4.
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
[Squashed "Expose AMD Core Perf Extension flag to guests" - Radim.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

arch/x86/kvm/cpuid.c

@@ -370,7 +370,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 		F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
 		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
-		F(TOPOEXT);
+		F(TOPOEXT) | F(PERFCTR_CORE);
 
 	/* cpuid 0x80000008.ebx */
 	const u32 kvm_cpuid_8000_0008_ebx_x86_features =

arch/x86/kvm/pmu_amd.c

@@ -19,6 +19,21 @@
 #include "lapic.h"
 #include "pmu.h"
 
+enum pmu_type {
+	PMU_TYPE_COUNTER = 0,
+	PMU_TYPE_EVNTSEL,
+};
+
+enum index {
+	INDEX_ZERO = 0,
+	INDEX_ONE,
+	INDEX_TWO,
+	INDEX_THREE,
+	INDEX_FOUR,
+	INDEX_FIVE,
+	INDEX_ERROR,
+};
+
 /* duplicated from amd_perfmon_event_map, K7 and above should work. */
 static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
 	[0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
@@ -31,6 +46,88 @@ static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
 	[7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
 };
 
+static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type)
+{
+	struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
+		if (type == PMU_TYPE_COUNTER)
+			return MSR_F15H_PERF_CTR;
+		else
+			return MSR_F15H_PERF_CTL;
+	} else {
+		if (type == PMU_TYPE_COUNTER)
+			return MSR_K7_PERFCTR0;
+		else
+			return MSR_K7_EVNTSEL0;
+	}
+}
+
+static enum index msr_to_index(u32 msr)
+{
+	switch (msr) {
+	case MSR_F15H_PERF_CTL0:
+	case MSR_F15H_PERF_CTR0:
+	case MSR_K7_EVNTSEL0:
+	case MSR_K7_PERFCTR0:
+		return INDEX_ZERO;
+	case MSR_F15H_PERF_CTL1:
+	case MSR_F15H_PERF_CTR1:
+	case MSR_K7_EVNTSEL1:
+	case MSR_K7_PERFCTR1:
+		return INDEX_ONE;
+	case MSR_F15H_PERF_CTL2:
+	case MSR_F15H_PERF_CTR2:
+	case MSR_K7_EVNTSEL2:
+	case MSR_K7_PERFCTR2:
+		return INDEX_TWO;
+	case MSR_F15H_PERF_CTL3:
+	case MSR_F15H_PERF_CTR3:
+	case MSR_K7_EVNTSEL3:
+	case MSR_K7_PERFCTR3:
+		return INDEX_THREE;
+	case MSR_F15H_PERF_CTL4:
+	case MSR_F15H_PERF_CTR4:
+		return INDEX_FOUR;
+	case MSR_F15H_PERF_CTL5:
+	case MSR_F15H_PERF_CTR5:
+		return INDEX_FIVE;
+	default:
+		return INDEX_ERROR;
+	}
+}
+
+static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
+					     enum pmu_type type)
+{
+	switch (msr) {
+	case MSR_F15H_PERF_CTL0:
+	case MSR_F15H_PERF_CTL1:
+	case MSR_F15H_PERF_CTL2:
+	case MSR_F15H_PERF_CTL3:
+	case MSR_F15H_PERF_CTL4:
+	case MSR_F15H_PERF_CTL5:
+	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
+		if (type != PMU_TYPE_EVNTSEL)
+			return NULL;
+		break;
+	case MSR_F15H_PERF_CTR0:
+	case MSR_F15H_PERF_CTR1:
+	case MSR_F15H_PERF_CTR2:
+	case MSR_F15H_PERF_CTR3:
+	case MSR_F15H_PERF_CTR4:
+	case MSR_F15H_PERF_CTR5:
+	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
+		if (type != PMU_TYPE_COUNTER)
+			return NULL;
+		break;
+	default:
+		return NULL;
+	}
+
+	return &pmu->gp_counters[msr_to_index(msr)];
+}
+
 static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
 				    u8 event_select,
 				    u8 unit_mask)
@@ -64,7 +161,18 @@ static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
 
 static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 {
-	return get_gp_pmc(pmu, MSR_K7_EVNTSEL0 + pmc_idx, MSR_K7_EVNTSEL0);
+	unsigned int base = get_msr_base(pmu, PMU_TYPE_COUNTER);
+	struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
+		/*
+		 * The idx is contiguous. The MSRs are not. The counter MSRs
+		 * are interleaved with the event select MSRs.
+		 */
+		pmc_idx *= 2;
+	}
+
+	return get_gp_pmc_amd(pmu, base + pmc_idx, PMU_TYPE_COUNTER);
 }
 
 /* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
@@ -96,8 +204,8 @@ static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	int ret = false;
 
-	ret = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0) ||
-		get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+	ret = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER) ||
+		get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 
 	return ret;
 }
@@ -107,14 +215,14 @@ static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	struct kvm_pmc *pmc;
 
-	/* MSR_K7_PERFCTRn */
-	pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
+	/* MSR_PERFCTRn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
 	if (pmc) {
 		*data = pmc_read_counter(pmc);
 		return 0;
 	}
-	/* MSR_K7_EVNTSELn */
-	pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+	/* MSR_EVNTSELn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 	if (pmc) {
 		*data = pmc->eventsel;
 		return 0;
@@ -130,14 +238,14 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	u32 msr = msr_info->index;
 	u64 data = msr_info->data;
 
-	/* MSR_K7_PERFCTRn */
-	pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
+	/* MSR_PERFCTRn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
 	if (pmc) {
 		pmc->counter += data - pmc_read_counter(pmc);
 		return 0;
 	}
-	/* MSR_K7_EVNTSELn */
-	pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+	/* MSR_EVNTSELn */
+	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 	if (pmc) {
 		if (data == pmc->eventsel)
 			return 0;
@@ -154,7 +262,11 @@ static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 
-	pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
+	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
+		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS_CORE;
+	else
+		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
+
 	pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
 	pmu->reserved_bits = 0xffffffff00200000ull;
 	/* not applicable to AMD; but clean them to prevent any fall out */
@@ -169,7 +281,9 @@ static void amd_pmu_init(struct kvm_vcpu *vcpu)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	int i;
 
-	for (i = 0; i < AMD64_NUM_COUNTERS ; i++) {
+	BUILD_BUG_ON(AMD64_NUM_COUNTERS_CORE > INTEL_PMC_MAX_GENERIC);
+
+	for (i = 0; i < AMD64_NUM_COUNTERS_CORE ; i++) {
 		pmu->gp_counters[i].type = KVM_PMC_GP;
 		pmu->gp_counters[i].vcpu = vcpu;
 		pmu->gp_counters[i].idx = i;
@@ -181,7 +295,7 @@ static void amd_pmu_reset(struct kvm_vcpu *vcpu)
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	int i;
 
-	for (i = 0; i < AMD64_NUM_COUNTERS; i++) {
+	for (i = 0; i < AMD64_NUM_COUNTERS_CORE; i++) {
 		struct kvm_pmc *pmc = &pmu->gp_counters[i];
 
 		pmc_stop_counter(pmc);

arch/x86/kvm/x86.c

@@ -2579,6 +2579,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	case MSR_AMD64_DC_CFG:
 		msr_info->data = 0;
 		break;
+	case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
 	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
 	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
 	case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1: