diff options
Diffstat (limited to 'arch/x86/kvm/pmu_amd.c')
| -rw-r--r-- | arch/x86/kvm/pmu_amd.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c new file mode 100644 index 000000000..886aa25a7 --- /dev/null +++ b/arch/x86/kvm/pmu_amd.c @@ -0,0 +1,207 @@ +/* + * KVM PMU support for AMD + * + * Copyright 2015, Red Hat, Inc. and/or its affiliates. + * + * Author: + * Wei Huang <wei@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * 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" + +/* 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] = { 0x80, 0x00, PERF_COUNT_HW_CACHE_REFERENCES }, + [3] = { 0x81, 0x00, 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 }, +}; + +static unsigned amd_find_arch_event(struct kvm_pmu *pmu, + u8 event_select, + u8 unit_mask) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++) + if (amd_event_mapping[i].eventsel == event_select + && amd_event_mapping[i].unit_mask == unit_mask) + break; + + if (i == ARRAY_SIZE(amd_event_mapping)) + return PERF_COUNT_HW_MAX; + + return amd_event_mapping[i].event_type; +} + +/* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */ +static unsigned amd_find_fixed_event(int idx) +{ + return PERF_COUNT_HW_MAX; +} + +/* 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) +{ + return get_gp_pmc(pmu, MSR_K7_EVNTSEL0 + pmc_idx, MSR_K7_EVNTSEL0); +} + +/* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */ +static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned 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_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx) +{ + 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) +{ + 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); + + return ret; +} + +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); + if (pmc) { + *data = pmc_read_counter(pmc); + return 0; + } + /* MSR_K7_EVNTSELn */ + pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0); + if (pmc) { + *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_K7_PERFCTRn */ + pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0); + if (pmc) { + if (!msr_info->host_initiated) + data = (s64)data; + pmc->counter += data - pmc_read_counter(pmc); + return 0; + } + /* MSR_K7_EVNTSELn */ + pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0); + if (pmc) { + if (data == pmc->eventsel) + return 0; + if (!(data & pmu->reserved_bits)) { + 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); + + 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 */ + pmu->counter_bitmask[KVM_PMC_FIXED] = 0; + pmu->nr_arch_fixed_counters = 0; + pmu->version = 0; + pmu->global_status = 0; +} + +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++) { + pmu->gp_counters[i].type = KVM_PMC_GP; + pmu->gp_counters[i].vcpu = vcpu; + pmu->gp_counters[i].idx = i; + } +} + +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++) { + struct kvm_pmc *pmc = &pmu->gp_counters[i]; + + pmc_stop_counter(pmc); + pmc->counter = pmc->eventsel = 0; + } +} + +struct kvm_pmu_ops amd_pmu_ops = { + .find_arch_event = amd_find_arch_event, + .find_fixed_event = amd_find_fixed_event, + .pmc_is_enabled = amd_pmc_is_enabled, + .pmc_idx_to_pmc = amd_pmc_idx_to_pmc, + .msr_idx_to_pmc = amd_msr_idx_to_pmc, + .is_valid_msr_idx = amd_is_valid_msr_idx, + .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, +}; |