KVM: x86: Add fixed counters to PMU filter
[linux-2.6-block.git] / arch / x86 / kvm / pmu.c
CommitLineData
20c8ccb1 1// SPDX-License-Identifier: GPL-2.0-only
f5132b01 2/*
c7a7062f 3 * Kernel-based Virtual Machine -- Performance Monitoring Unit support
f5132b01 4 *
25462f7f 5 * Copyright 2015 Red Hat, Inc. and/or its affiliates.
f5132b01
GN
6 *
7 * Authors:
8 * Avi Kivity <avi@redhat.com>
9 * Gleb Natapov <gleb@redhat.com>
25462f7f 10 * Wei Huang <wei@redhat.com>
f5132b01
GN
11 */
12
13#include <linux/types.h>
14#include <linux/kvm_host.h>
15#include <linux/perf_event.h>
d27aa7f1 16#include <asm/perf_event.h>
f5132b01
GN
17#include "x86.h"
18#include "cpuid.h"
19#include "lapic.h"
474a5bb9 20#include "pmu.h"
f5132b01 21
30cd8604
EH
22/* This is enough to filter the vast majority of currently defined events. */
23#define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300
66bb8a06 24
25462f7f
WH
25/* NOTE:
26 * - Each perf counter is defined as "struct kvm_pmc";
27 * - There are two types of perf counters: general purpose (gp) and fixed.
28 * gp counters are stored in gp_counters[] and fixed counters are stored
29 * in fixed_counters[] respectively. Both of them are part of "struct
30 * kvm_pmu";
31 * - pmu.c understands the difference between gp counters and fixed counters.
32 * However AMD doesn't support fixed-counters;
33 * - There are three types of index to access perf counters (PMC):
34 * 1. MSR (named msr): For example Intel has MSR_IA32_PERFCTRn and AMD
35 * has MSR_K7_PERFCTRn.
36 * 2. MSR Index (named idx): This normally is used by RDPMC instruction.
37 * For instance AMD RDPMC instruction uses 0000_0003h in ECX to access
38 * C001_0007h (MSR_K7_PERCTR3). Intel has a similar mechanism, except
39 * that it also supports fixed counters. idx can be used to as index to
40 * gp and fixed counters.
41 * 3. Global PMC Index (named pmc): pmc is an index specific to PMU
42 * code. Each pmc, stored in kvm_pmc.idx field, is unique across
43 * all perf counters (both gp and fixed). The mapping relationship
44 * between pmc and perf counters is as the following:
45 * * Intel: [0 .. INTEL_PMC_MAX_GENERIC-1] <=> gp counters
46 * [INTEL_PMC_IDX_FIXED .. INTEL_PMC_IDX_FIXED + 2] <=> fixed
47 * * AMD: [0 .. AMD64_NUM_COUNTERS-1] <=> gp counters
48 */
f5132b01 49
c6702c9d 50static void kvm_pmi_trigger_fn(struct irq_work *irq_work)
f5132b01 51{
212dba12
WH
52 struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu, irq_work);
53 struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
f5132b01 54
c6702c9d 55 kvm_pmu_deliver_pmi(vcpu);
f5132b01
GN
56}
57
58static void kvm_perf_overflow(struct perf_event *perf_event,
59 struct perf_sample_data *data,
60 struct pt_regs *regs)
61{
62 struct kvm_pmc *pmc = perf_event->overflow_handler_context;
212dba12 63 struct kvm_pmu *pmu = pmc_to_pmu(pmc);
e84cfe4c
WH
64
65 if (!test_and_set_bit(pmc->idx,
66 (unsigned long *)&pmu->reprogram_pmi)) {
671bd993
NA
67 __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
68 kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
69 }
f5132b01
GN
70}
71
72static void kvm_perf_overflow_intr(struct perf_event *perf_event,
e84cfe4c
WH
73 struct perf_sample_data *data,
74 struct pt_regs *regs)
f5132b01
GN
75{
76 struct kvm_pmc *pmc = perf_event->overflow_handler_context;
212dba12 77 struct kvm_pmu *pmu = pmc_to_pmu(pmc);
e84cfe4c
WH
78
79 if (!test_and_set_bit(pmc->idx,
80 (unsigned long *)&pmu->reprogram_pmi)) {
671bd993 81 __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
f5132b01 82 kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
e84cfe4c 83
f5132b01
GN
84 /*
85 * Inject PMI. If vcpu was in a guest mode during NMI PMI
86 * can be ejected on a guest mode re-entry. Otherwise we can't
87 * be sure that vcpu wasn't executing hlt instruction at the
e84cfe4c 88 * time of vmexit and is not going to re-enter guest mode until
f5132b01
GN
89 * woken up. So we should wake it, but this is impossible from
90 * NMI context. Do it from irq work instead.
91 */
92 if (!kvm_is_in_guest())
212dba12 93 irq_work_queue(&pmc_to_pmu(pmc)->irq_work);
f5132b01
GN
94 else
95 kvm_make_request(KVM_REQ_PMI, pmc->vcpu);
96 }
97}
98
c6702c9d 99static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
e84cfe4c
WH
100 unsigned config, bool exclude_user,
101 bool exclude_kernel, bool intr,
102 bool in_tx, bool in_tx_cp)
f5132b01
GN
103{
104 struct perf_event *event;
105 struct perf_event_attr attr = {
106 .type = type,
107 .size = sizeof(attr),
108 .pinned = true,
109 .exclude_idle = true,
110 .exclude_host = 1,
111 .exclude_user = exclude_user,
112 .exclude_kernel = exclude_kernel,
113 .config = config,
114 };
e84cfe4c 115
bba82fd7
RC
116 attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);
117
103af0a9
AK
118 if (in_tx)
119 attr.config |= HSW_IN_TX;
bba82fd7
RC
120 if (in_tx_cp) {
121 /*
122 * HSW_IN_TX_CHECKPOINTED is not supported with nonzero
123 * period. Just clear the sample period so at least
124 * allocating the counter doesn't fail.
125 */
126 attr.sample_period = 0;
103af0a9 127 attr.config |= HSW_IN_TX_CHECKPOINTED;
bba82fd7 128 }
f5132b01
GN
129
130 event = perf_event_create_kernel_counter(&attr, -1, current,
131 intr ? kvm_perf_overflow_intr :
132 kvm_perf_overflow, pmc);
133 if (IS_ERR(event)) {
6fc3977c
LX
134 pr_debug_ratelimited("kvm_pmu: event creation failed %ld for pmc->idx = %d\n",
135 PTR_ERR(event), pmc->idx);
f5132b01
GN
136 return;
137 }
138
139 pmc->perf_event = event;
212dba12 140 clear_bit(pmc->idx, (unsigned long*)&pmc_to_pmu(pmc)->reprogram_pmi);
f5132b01
GN
141}
142
25462f7f 143void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
f5132b01
GN
144{
145 unsigned config, type = PERF_TYPE_RAW;
146 u8 event_select, unit_mask;
66bb8a06
EH
147 struct kvm *kvm = pmc->vcpu->kvm;
148 struct kvm_pmu_event_filter *filter;
149 int i;
150 bool allow_event = true;
f5132b01 151
a7b9d2cc
GN
152 if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
153 printk_once("kvm pmu: pin control bit is ignored\n");
154
f5132b01
GN
155 pmc->eventsel = eventsel;
156
c6702c9d 157 pmc_stop_counter(pmc);
f5132b01 158
c6702c9d 159 if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_is_enabled(pmc))
f5132b01
GN
160 return;
161
66bb8a06
EH
162 filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
163 if (filter) {
164 for (i = 0; i < filter->nevents; i++)
165 if (filter->events[i] ==
166 (eventsel & AMD64_RAW_EVENT_MASK_NB))
167 break;
168 if (filter->action == KVM_PMU_EVENT_ALLOW &&
169 i == filter->nevents)
170 allow_event = false;
171 if (filter->action == KVM_PMU_EVENT_DENY &&
172 i < filter->nevents)
173 allow_event = false;
174 }
175 if (!allow_event)
176 return;
177
f5132b01
GN
178 event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
179 unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
180
fac33683 181 if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
e84cfe4c
WH
182 ARCH_PERFMON_EVENTSEL_INV |
183 ARCH_PERFMON_EVENTSEL_CMASK |
184 HSW_IN_TX |
185 HSW_IN_TX_CHECKPOINTED))) {
25462f7f
WH
186 config = kvm_x86_ops->pmu_ops->find_arch_event(pmc_to_pmu(pmc),
187 event_select,
188 unit_mask);
f5132b01
GN
189 if (config != PERF_COUNT_HW_MAX)
190 type = PERF_TYPE_HARDWARE;
191 }
192
193 if (type == PERF_TYPE_RAW)
194 config = eventsel & X86_RAW_EVENT_MASK;
195
c6702c9d 196 pmc_reprogram_counter(pmc, type, config,
e84cfe4c
WH
197 !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
198 !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
199 eventsel & ARCH_PERFMON_EVENTSEL_INT,
200 (eventsel & HSW_IN_TX),
201 (eventsel & HSW_IN_TX_CHECKPOINTED));
f5132b01 202}
25462f7f 203EXPORT_SYMBOL_GPL(reprogram_gp_counter);
f5132b01 204
25462f7f 205void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
f5132b01 206{
e84cfe4c
WH
207 unsigned en_field = ctrl & 0x3;
208 bool pmi = ctrl & 0x8;
30cd8604
EH
209 struct kvm_pmu_event_filter *filter;
210 struct kvm *kvm = pmc->vcpu->kvm;
f5132b01 211
c6702c9d 212 pmc_stop_counter(pmc);
f5132b01 213
e84cfe4c 214 if (!en_field || !pmc_is_enabled(pmc))
f5132b01
GN
215 return;
216
30cd8604
EH
217 filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
218 if (filter) {
219 if (filter->action == KVM_PMU_EVENT_DENY &&
220 test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
221 return;
222 if (filter->action == KVM_PMU_EVENT_ALLOW &&
223 !test_bit(idx, (ulong *)&filter->fixed_counter_bitmap))
224 return;
225 }
226
c6702c9d 227 pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,
25462f7f 228 kvm_x86_ops->pmu_ops->find_fixed_event(idx),
e84cfe4c
WH
229 !(en_field & 0x2), /* exclude user */
230 !(en_field & 0x1), /* exclude kernel */
231 pmi, false, false);
f5132b01 232}
25462f7f 233EXPORT_SYMBOL_GPL(reprogram_fixed_counter);
f5132b01 234
25462f7f 235void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx)
f5132b01 236{
25462f7f 237 struct kvm_pmc *pmc = kvm_x86_ops->pmu_ops->pmc_idx_to_pmc(pmu, pmc_idx);
f5132b01
GN
238
239 if (!pmc)
240 return;
241
242 if (pmc_is_gp(pmc))
243 reprogram_gp_counter(pmc, pmc->eventsel);
244 else {
e84cfe4c
WH
245 int idx = pmc_idx - INTEL_PMC_IDX_FIXED;
246 u8 ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, idx);
247
248 reprogram_fixed_counter(pmc, ctrl, idx);
f5132b01
GN
249 }
250}
25462f7f 251EXPORT_SYMBOL_GPL(reprogram_counter);
f5132b01 252
e5af058a
WH
253void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
254{
255 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
256 u64 bitmask;
257 int bit;
258
259 bitmask = pmu->reprogram_pmi;
260
261 for_each_set_bit(bit, (unsigned long *)&bitmask, X86_PMC_IDX_MAX) {
25462f7f 262 struct kvm_pmc *pmc = kvm_x86_ops->pmu_ops->pmc_idx_to_pmc(pmu, bit);
e5af058a
WH
263
264 if (unlikely(!pmc || !pmc->perf_event)) {
265 clear_bit(bit, (unsigned long *)&pmu->reprogram_pmi);
266 continue;
267 }
268
269 reprogram_counter(pmu, bit);
270 }
271}
272
273/* check if idx is a valid index to access PMU */
274int kvm_pmu_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
275{
25462f7f 276 return kvm_x86_ops->pmu_ops->is_valid_msr_idx(vcpu, idx);
41aac14a
WH
277}
278
2d7921c4
AM
279bool is_vmware_backdoor_pmc(u32 pmc_idx)
280{
281 switch (pmc_idx) {
282 case VMWARE_BACKDOOR_PMC_HOST_TSC:
283 case VMWARE_BACKDOOR_PMC_REAL_TIME:
284 case VMWARE_BACKDOOR_PMC_APPARENT_TIME:
285 return true;
286 }
287 return false;
288}
289
290static int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
291{
292 u64 ctr_val;
293
294 switch (idx) {
295 case VMWARE_BACKDOOR_PMC_HOST_TSC:
296 ctr_val = rdtsc();
297 break;
298 case VMWARE_BACKDOOR_PMC_REAL_TIME:
9285ec4c 299 ctr_val = ktime_get_boottime_ns();
2d7921c4
AM
300 break;
301 case VMWARE_BACKDOOR_PMC_APPARENT_TIME:
9285ec4c 302 ctr_val = ktime_get_boottime_ns() +
2d7921c4
AM
303 vcpu->kvm->arch.kvmclock_offset;
304 break;
305 default:
306 return 1;
307 }
308
309 *data = ctr_val;
310 return 0;
311}
312
41aac14a
WH
313int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
314{
315 bool fast_mode = idx & (1u << 31);
672ff6cf 316 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
41aac14a 317 struct kvm_pmc *pmc;
0e6f467e 318 u64 mask = fast_mode ? ~0u : ~0ull;
41aac14a 319
672ff6cf
LA
320 if (!pmu->version)
321 return 1;
322
2d7921c4
AM
323 if (is_vmware_backdoor_pmc(idx))
324 return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
325
0e6f467e 326 pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx, &mask);
41aac14a
WH
327 if (!pmc)
328 return 1;
329
0e6f467e 330 *data = pmc_read_counter(pmc) & mask;
e5af058a
WH
331 return 0;
332}
333
334void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
335{
bce87cce 336 if (lapic_in_kernel(vcpu))
e5af058a
WH
337 kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC);
338}
339
c6702c9d 340bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
f5132b01 341{
25462f7f 342 return kvm_x86_ops->pmu_ops->is_valid_msr(vcpu, msr);
f5132b01
GN
343}
344
25462f7f 345int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
f5132b01 346{
25462f7f 347 return kvm_x86_ops->pmu_ops->get_msr(vcpu, msr, data);
f5132b01
GN
348}
349
afd80d85 350int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
f5132b01 351{
25462f7f 352 return kvm_x86_ops->pmu_ops->set_msr(vcpu, msr_info);
f5132b01
GN
353}
354
e84cfe4c
WH
355/* refresh PMU settings. This function generally is called when underlying
356 * settings are changed (such as changes of PMU CPUID by guest VMs), which
357 * should rarely happen.
358 */
c6702c9d 359void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
f5132b01 360{
25462f7f 361 kvm_x86_ops->pmu_ops->refresh(vcpu);
f5132b01
GN
362}
363
f5132b01
GN
364void kvm_pmu_reset(struct kvm_vcpu *vcpu)
365{
212dba12 366 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
f5132b01
GN
367
368 irq_work_sync(&pmu->irq_work);
25462f7f 369 kvm_x86_ops->pmu_ops->reset(vcpu);
f5132b01
GN
370}
371
e5af058a 372void kvm_pmu_init(struct kvm_vcpu *vcpu)
f5132b01 373{
212dba12 374 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
f5132b01 375
e5af058a 376 memset(pmu, 0, sizeof(*pmu));
25462f7f 377 kvm_x86_ops->pmu_ops->init(vcpu);
e5af058a
WH
378 init_irq_work(&pmu->irq_work, kvm_pmi_trigger_fn);
379 kvm_pmu_refresh(vcpu);
380}
381
382void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
383{
384 kvm_pmu_reset(vcpu);
f5132b01 385}
66bb8a06
EH
386
387int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp)
388{
389 struct kvm_pmu_event_filter tmp, *filter;
390 size_t size;
391 int r;
392
393 if (copy_from_user(&tmp, argp, sizeof(tmp)))
394 return -EFAULT;
395
396 if (tmp.action != KVM_PMU_EVENT_ALLOW &&
397 tmp.action != KVM_PMU_EVENT_DENY)
398 return -EINVAL;
399
30cd8604
EH
400 if (tmp.flags != 0)
401 return -EINVAL;
402
66bb8a06
EH
403 if (tmp.nevents > KVM_PMU_EVENT_FILTER_MAX_EVENTS)
404 return -E2BIG;
405
406 size = struct_size(filter, events, tmp.nevents);
407 filter = kmalloc(size, GFP_KERNEL_ACCOUNT);
408 if (!filter)
409 return -ENOMEM;
410
411 r = -EFAULT;
412 if (copy_from_user(filter, argp, size))
413 goto cleanup;
414
415 /* Ensure nevents can't be changed between the user copies. */
416 *filter = tmp;
417
418 mutex_lock(&kvm->lock);
419 rcu_swap_protected(kvm->arch.pmu_event_filter, filter,
420 mutex_is_locked(&kvm->lock));
421 mutex_unlock(&kvm->lock);
422
423 synchronize_srcu_expedited(&kvm->srcu);
30cd8604 424 r = 0;
66bb8a06
EH
425cleanup:
426 kfree(filter);
30cd8604 427 return r;
66bb8a06 428}