2 * KVM PMU support for AMD
4 * Copyright 2015, Red Hat, Inc. and/or its affiliates.
7 * Wei Huang <wei@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
12 * Implementation is based on pmu_intel.c file
14 #include <linux/types.h>
15 #include <linux/kvm_host.h>
16 #include <linux/perf_event.h>
22 /* duplicated from amd_perfmon_event_map, K7 and above should work. */
23 static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
24 [0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
25 [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
26 [2] = { 0x7d, 0x07, PERF_COUNT_HW_CACHE_REFERENCES },
27 [3] = { 0x7e, 0x07, PERF_COUNT_HW_CACHE_MISSES },
28 [4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
29 [5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
30 [6] = { 0xd0, 0x00, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
31 [7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
34 static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
40 for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)
41 if (amd_event_mapping[i].eventsel == event_select
42 && amd_event_mapping[i].unit_mask == unit_mask)
45 if (i == ARRAY_SIZE(amd_event_mapping))
46 return PERF_COUNT_HW_MAX;
48 return amd_event_mapping[i].event_type;
51 /* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */
52 static unsigned amd_find_fixed_event(int idx)
54 return PERF_COUNT_HW_MAX;
57 /* check if a PMC is enabled by comparing it against global_ctrl bits. Because
58 * AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE).
60 static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
65 static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
67 return get_gp_pmc(pmu, MSR_K7_EVNTSEL0 + pmc_idx, MSR_K7_EVNTSEL0);
70 /* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
71 static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
73 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
77 return (idx >= pmu->nr_arch_gp_counters);
80 /* idx is the ECX register of RDPMC instruction */
81 static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx)
83 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
84 struct kvm_pmc *counters;
87 if (idx >= pmu->nr_arch_gp_counters)
89 counters = pmu->gp_counters;
91 return &counters[idx];
94 static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
96 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
99 ret = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0) ||
100 get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
105 static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
107 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
110 /* MSR_K7_PERFCTRn */
111 pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
113 *data = pmc_read_counter(pmc);
116 /* MSR_K7_EVNTSELn */
117 pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
119 *data = pmc->eventsel;
126 static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
128 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
130 u32 msr = msr_info->index;
131 u64 data = msr_info->data;
133 /* MSR_K7_PERFCTRn */
134 pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
136 pmc->counter += data - pmc_read_counter(pmc);
139 /* MSR_K7_EVNTSELn */
140 pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
142 data &= ~pmu->reserved_bits;
143 if (data != pmc->eventsel)
144 reprogram_gp_counter(pmc, data);
151 static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
153 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
155 pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
156 pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
157 pmu->reserved_bits = 0xffffffff00200000ull;
158 /* not applicable to AMD; but clean them to prevent any fall out */
159 pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
160 pmu->nr_arch_fixed_counters = 0;
162 pmu->global_status = 0;
165 static void amd_pmu_init(struct kvm_vcpu *vcpu)
167 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
170 for (i = 0; i < AMD64_NUM_COUNTERS ; i++) {
171 pmu->gp_counters[i].type = KVM_PMC_GP;
172 pmu->gp_counters[i].vcpu = vcpu;
173 pmu->gp_counters[i].idx = i;
177 static void amd_pmu_reset(struct kvm_vcpu *vcpu)
179 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
182 for (i = 0; i < AMD64_NUM_COUNTERS; i++) {
183 struct kvm_pmc *pmc = &pmu->gp_counters[i];
185 pmc_stop_counter(pmc);
186 pmc->counter = pmc->eventsel = 0;
190 struct kvm_pmu_ops amd_pmu_ops = {
191 .find_arch_event = amd_find_arch_event,
192 .find_fixed_event = amd_find_fixed_event,
193 .pmc_is_enabled = amd_pmc_is_enabled,
194 .pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
195 .msr_idx_to_pmc = amd_msr_idx_to_pmc,
196 .is_valid_msr_idx = amd_is_valid_msr_idx,
197 .is_valid_msr = amd_is_valid_msr,
198 .get_msr = amd_pmu_get_msr,
199 .set_msr = amd_pmu_set_msr,
200 .refresh = amd_pmu_refresh,
201 .init = amd_pmu_init,
202 .reset = amd_pmu_reset,