GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / kvm / pmu_amd.c
1 /*
2  * KVM PMU support for AMD
3  *
4  * Copyright 2015, Red Hat, Inc. and/or its affiliates.
5  *
6  * Author:
7  *   Wei Huang <wei@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  * Implementation is based on pmu_intel.c file
13  */
14 #include <linux/types.h>
15 #include <linux/kvm_host.h>
16 #include <linux/perf_event.h>
17 #include "x86.h"
18 #include "cpuid.h"
19 #include "lapic.h"
20 #include "pmu.h"
21
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 },
32 };
33
34 static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
35                                     u8 event_select,
36                                     u8 unit_mask)
37 {
38         int i;
39
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)
43                         break;
44
45         if (i == ARRAY_SIZE(amd_event_mapping))
46                 return PERF_COUNT_HW_MAX;
47
48         return amd_event_mapping[i].event_type;
49 }
50
51 /* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */
52 static unsigned amd_find_fixed_event(int idx)
53 {
54         return PERF_COUNT_HW_MAX;
55 }
56
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).
59  */
60 static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
61 {
62         return true;
63 }
64
65 static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
66 {
67         return get_gp_pmc(pmu, MSR_K7_EVNTSEL0 + pmc_idx, MSR_K7_EVNTSEL0);
68 }
69
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)
72 {
73         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
74
75         idx &= ~(3u << 30);
76
77         return (idx >= pmu->nr_arch_gp_counters);
78 }
79
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)
82 {
83         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
84         struct kvm_pmc *counters;
85
86         idx &= ~(3u << 30);
87         if (idx >= pmu->nr_arch_gp_counters)
88                 return NULL;
89         counters = pmu->gp_counters;
90
91         return &counters[idx];
92 }
93
94 static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
95 {
96         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
97         int ret = false;
98
99         ret = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0) ||
100                 get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
101
102         return ret;
103 }
104
105 static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
106 {
107         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
108         struct kvm_pmc *pmc;
109
110         /* MSR_K7_PERFCTRn */
111         pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
112         if (pmc) {
113                 *data = pmc_read_counter(pmc);
114                 return 0;
115         }
116         /* MSR_K7_EVNTSELn */
117         pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
118         if (pmc) {
119                 *data = pmc->eventsel;
120                 return 0;
121         }
122
123         return 1;
124 }
125
126 static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
127 {
128         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
129         struct kvm_pmc *pmc;
130         u32 msr = msr_info->index;
131         u64 data = msr_info->data;
132
133         /* MSR_K7_PERFCTRn */
134         pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
135         if (pmc) {
136                 pmc->counter += data - pmc_read_counter(pmc);
137                 return 0;
138         }
139         /* MSR_K7_EVNTSELn */
140         pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
141         if (pmc) {
142                 if (data == pmc->eventsel)
143                         return 0;
144                 if (!(data & pmu->reserved_bits)) {
145                         reprogram_gp_counter(pmc, data);
146                         return 0;
147                 }
148         }
149
150         return 1;
151 }
152
153 static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
154 {
155         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
156
157         pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
158         pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
159         pmu->reserved_bits = 0xffffffff00200000ull;
160         /* not applicable to AMD; but clean them to prevent any fall out */
161         pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
162         pmu->nr_arch_fixed_counters = 0;
163         pmu->version = 0;
164         pmu->global_status = 0;
165 }
166
167 static void amd_pmu_init(struct kvm_vcpu *vcpu)
168 {
169         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
170         int i;
171
172         for (i = 0; i < AMD64_NUM_COUNTERS ; i++) {
173                 pmu->gp_counters[i].type = KVM_PMC_GP;
174                 pmu->gp_counters[i].vcpu = vcpu;
175                 pmu->gp_counters[i].idx = i;
176         }
177 }
178
179 static void amd_pmu_reset(struct kvm_vcpu *vcpu)
180 {
181         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
182         int i;
183
184         for (i = 0; i < AMD64_NUM_COUNTERS; i++) {
185                 struct kvm_pmc *pmc = &pmu->gp_counters[i];
186
187                 pmc_stop_counter(pmc);
188                 pmc->counter = pmc->eventsel = 0;
189         }
190 }
191
192 struct kvm_pmu_ops amd_pmu_ops = {
193         .find_arch_event = amd_find_arch_event,
194         .find_fixed_event = amd_find_fixed_event,
195         .pmc_is_enabled = amd_pmc_is_enabled,
196         .pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
197         .msr_idx_to_pmc = amd_msr_idx_to_pmc,
198         .is_valid_msr_idx = amd_is_valid_msr_idx,
199         .is_valid_msr = amd_is_valid_msr,
200         .get_msr = amd_pmu_get_msr,
201         .set_msr = amd_pmu_set_msr,
202         .refresh = amd_pmu_refresh,
203         .init = amd_pmu_init,
204         .reset = amd_pmu_reset,
205 };