https://github.com/torvalds/linux
Tip revision: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f authored by Linus Torvalds on 22 May 2022, 19:52:31 UTC
Linux 5.18
Linux 5.18
Tip revision: 4b0986a
pmu.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* KVM PMU support for AMD
*
* Copyright 2015, Red Hat, Inc. and/or its affiliates.
*
* Author:
* Wei Huang <wei@redhat.com>
*
* Implementation is based on pmu_intel.c file
*/
#include <linux/types.h>
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
#include "x86.h"
#include "cpuid.h"
#include "lapic.h"
#include "pmu.h"
#include "svm.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 },
[1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
[2] = { 0x7d, 0x07, PERF_COUNT_HW_CACHE_REFERENCES },
[3] = { 0x7e, 0x07, PERF_COUNT_HW_CACHE_MISSES },
[4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
[5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
[6] = { 0xd0, 0x00, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
[7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
};
/* duplicated from amd_f17h_perfmon_event_map. */
static struct kvm_event_hw_type_mapping amd_f17h_event_mapping[] = {
[0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
[1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
[2] = { 0x60, 0xff, PERF_COUNT_HW_CACHE_REFERENCES },
[3] = { 0x64, 0x09, PERF_COUNT_HW_CACHE_MISSES },
[4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
[5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
[6] = { 0x87, 0x02, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
[7] = { 0x87, 0x01, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
};
/* amd_pmc_perf_hw_id depends on these being the same size */
static_assert(ARRAY_SIZE(amd_event_mapping) ==
ARRAY_SIZE(amd_f17h_event_mapping));
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)
{
struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
if (!vcpu->kvm->arch.enable_pmu)
return NULL;
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:
if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
return NULL;
fallthrough;
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:
if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
return NULL;
fallthrough;
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 int amd_pmc_perf_hw_id(struct kvm_pmc *pmc)
{
struct kvm_event_hw_type_mapping *event_mapping;
u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
int i;
/* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */
if (WARN_ON(pmc_is_fixed(pmc)))
return PERF_COUNT_HW_MAX;
if (guest_cpuid_family(pmc->vcpu) >= 0x17)
event_mapping = amd_f17h_event_mapping;
else
event_mapping = amd_event_mapping;
for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)
if (event_mapping[i].eventsel == event_select
&& event_mapping[i].unit_mask == unit_mask)
break;
if (i == ARRAY_SIZE(amd_event_mapping))
return PERF_COUNT_HW_MAX;
return event_mapping[i].event_type;
}
/* check if a PMC is enabled by comparing it against global_ctrl bits. Because
* AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE).
*/
static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
{
return true;
}
static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
{
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);
}
static bool amd_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
idx &= ~(3u << 30);
return idx < pmu->nr_arch_gp_counters;
}
/* idx is the ECX register of RDPMC instruction */
static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
unsigned int idx, u64 *mask)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *counters;
idx &= ~(3u << 30);
if (idx >= pmu->nr_arch_gp_counters)
return NULL;
counters = pmu->gp_counters;
return &counters[idx];
}
static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
{
/* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough. */
return false;
}
static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
pmc = pmc ? pmc : get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
return pmc;
}
static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
u32 msr = msr_info->index;
/* MSR_PERFCTRn */
pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
if (pmc) {
msr_info->data = pmc_read_counter(pmc);
return 0;
}
/* MSR_EVNTSELn */
pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
if (pmc) {
msr_info->data = pmc->eventsel;
return 0;
}
return 1;
}
static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
u32 msr = msr_info->index;
u64 data = msr_info->data;
/* MSR_PERFCTRn */
pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
if (pmc) {
pmc->counter += data - pmc_read_counter(pmc);
pmc_update_sample_period(pmc);
return 0;
}
/* MSR_EVNTSELn */
pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
if (pmc) {
data &= ~pmu->reserved_bits;
if (data != pmc->eventsel)
reprogram_gp_counter(pmc, data);
return 0;
}
return 1;
}
static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
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 = 0xfffffff000280000ull;
pmu->raw_event_mask = AMD64_RAW_EVENT_MASK;
pmu->version = 1;
/* not applicable to AMD; but clean them to prevent any fall out */
pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
pmu->nr_arch_fixed_counters = 0;
pmu->global_status = 0;
bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters);
}
static void amd_pmu_init(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
int 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;
pmu->gp_counters[i].current_config = 0;
}
}
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_CORE; i++) {
struct kvm_pmc *pmc = &pmu->gp_counters[i];
pmc_stop_counter(pmc);
pmc->counter = pmc->eventsel = 0;
}
}
struct kvm_pmu_ops amd_pmu_ops = {
.pmc_perf_hw_id = amd_pmc_perf_hw_id,
.pmc_is_enabled = amd_pmc_is_enabled,
.pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
.rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc,
.msr_idx_to_pmc = amd_msr_idx_to_pmc,
.is_valid_rdpmc_ecx = amd_is_valid_rdpmc_ecx,
.is_valid_msr = amd_is_valid_msr,
.get_msr = amd_pmu_get_msr,
.set_msr = amd_pmu_set_msr,
.refresh = amd_pmu_refresh,
.init = amd_pmu_init,
.reset = amd_pmu_reset,
};