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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/types.h>
3#include <linux/interrupt.h>
4
5#include <asm/xen/hypercall.h>
6#include <xen/xen.h>
7#include <xen/page.h>
8#include <xen/interface/xen.h>
9#include <xen/interface/vcpu.h>
10#include <xen/interface/xenpmu.h>
11
12#include "xen-ops.h"
13#include "pmu.h"
14
15/* x86_pmu.handle_irq definition */
16#include "../events/perf_event.h"
17
18#define XENPMU_IRQ_PROCESSING 1
19struct xenpmu {
20 /* Shared page between hypervisor and domain */
21 struct xen_pmu_data *xenpmu_data;
22
23 uint8_t flags;
24};
25static DEFINE_PER_CPU(struct xenpmu, xenpmu_shared);
26#define get_xenpmu_data() (this_cpu_ptr(&xenpmu_shared)->xenpmu_data)
27#define get_xenpmu_flags() (this_cpu_ptr(&xenpmu_shared)->flags)
28
29/* Macro for computing address of a PMU MSR bank */
30#define field_offset(ctxt, field) ((void *)((uintptr_t)ctxt + \
31 (uintptr_t)ctxt->field))
32
33/* AMD PMU */
34#define F15H_NUM_COUNTERS 6
35#define F10H_NUM_COUNTERS 4
36
37static __read_mostly uint32_t amd_counters_base;
38static __read_mostly uint32_t amd_ctrls_base;
39static __read_mostly int amd_msr_step;
40static __read_mostly int k7_counters_mirrored;
41static __read_mostly int amd_num_counters;
42
43/* Intel PMU */
44#define MSR_TYPE_COUNTER 0
45#define MSR_TYPE_CTRL 1
46#define MSR_TYPE_GLOBAL 2
47#define MSR_TYPE_ARCH_COUNTER 3
48#define MSR_TYPE_ARCH_CTRL 4
49
50/* Number of general pmu registers (CPUID.EAX[0xa].EAX[8..15]) */
51#define PMU_GENERAL_NR_SHIFT 8
52#define PMU_GENERAL_NR_BITS 8
53#define PMU_GENERAL_NR_MASK (((1 << PMU_GENERAL_NR_BITS) - 1) \
54 << PMU_GENERAL_NR_SHIFT)
55
56/* Number of fixed pmu registers (CPUID.EDX[0xa].EDX[0..4]) */
57#define PMU_FIXED_NR_SHIFT 0
58#define PMU_FIXED_NR_BITS 5
59#define PMU_FIXED_NR_MASK (((1 << PMU_FIXED_NR_BITS) - 1) \
60 << PMU_FIXED_NR_SHIFT)
61
62/* Alias registers (0x4c1) for full-width writes to PMCs */
63#define MSR_PMC_ALIAS_MASK (~(MSR_IA32_PERFCTR0 ^ MSR_IA32_PMC0))
64
65#define INTEL_PMC_TYPE_SHIFT 30
66
67static __read_mostly int intel_num_arch_counters, intel_num_fixed_counters;
68
69
70static void xen_pmu_arch_init(void)
71{
72 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
73
74 switch (boot_cpu_data.x86) {
75 case 0x15:
76 amd_num_counters = F15H_NUM_COUNTERS;
77 amd_counters_base = MSR_F15H_PERF_CTR;
78 amd_ctrls_base = MSR_F15H_PERF_CTL;
79 amd_msr_step = 2;
80 k7_counters_mirrored = 1;
81 break;
82 case 0x10:
83 case 0x12:
84 case 0x14:
85 case 0x16:
86 default:
87 amd_num_counters = F10H_NUM_COUNTERS;
88 amd_counters_base = MSR_K7_PERFCTR0;
89 amd_ctrls_base = MSR_K7_EVNTSEL0;
90 amd_msr_step = 1;
91 k7_counters_mirrored = 0;
92 break;
93 }
94 } else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
95 amd_num_counters = F10H_NUM_COUNTERS;
96 amd_counters_base = MSR_K7_PERFCTR0;
97 amd_ctrls_base = MSR_K7_EVNTSEL0;
98 amd_msr_step = 1;
99 k7_counters_mirrored = 0;
100 } else {
101 uint32_t eax, ebx, ecx, edx;
102
103 cpuid(0xa, &eax, &ebx, &ecx, &edx);
104
105 intel_num_arch_counters = (eax & PMU_GENERAL_NR_MASK) >>
106 PMU_GENERAL_NR_SHIFT;
107 intel_num_fixed_counters = (edx & PMU_FIXED_NR_MASK) >>
108 PMU_FIXED_NR_SHIFT;
109 }
110}
111
112static inline uint32_t get_fam15h_addr(u32 addr)
113{
114 switch (addr) {
115 case MSR_K7_PERFCTR0:
116 case MSR_K7_PERFCTR1:
117 case MSR_K7_PERFCTR2:
118 case MSR_K7_PERFCTR3:
119 return MSR_F15H_PERF_CTR + (addr - MSR_K7_PERFCTR0);
120 case MSR_K7_EVNTSEL0:
121 case MSR_K7_EVNTSEL1:
122 case MSR_K7_EVNTSEL2:
123 case MSR_K7_EVNTSEL3:
124 return MSR_F15H_PERF_CTL + (addr - MSR_K7_EVNTSEL0);
125 default:
126 break;
127 }
128
129 return addr;
130}
131
132static inline bool is_amd_pmu_msr(unsigned int msr)
133{
134 if ((msr >= MSR_F15H_PERF_CTL &&
135 msr < MSR_F15H_PERF_CTR + (amd_num_counters * 2)) ||
136 (msr >= MSR_K7_EVNTSEL0 &&
137 msr < MSR_K7_PERFCTR0 + amd_num_counters))
138 return true;
139
140 return false;
141}
142
143static int is_intel_pmu_msr(u32 msr_index, int *type, int *index)
144{
145 u32 msr_index_pmc;
146
147 switch (msr_index) {
148 case MSR_CORE_PERF_FIXED_CTR_CTRL:
149 case MSR_IA32_DS_AREA:
150 case MSR_IA32_PEBS_ENABLE:
151 *type = MSR_TYPE_CTRL;
152 return true;
153
154 case MSR_CORE_PERF_GLOBAL_CTRL:
155 case MSR_CORE_PERF_GLOBAL_STATUS:
156 case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
157 *type = MSR_TYPE_GLOBAL;
158 return true;
159
160 default:
161
162 if ((msr_index >= MSR_CORE_PERF_FIXED_CTR0) &&
163 (msr_index < MSR_CORE_PERF_FIXED_CTR0 +
164 intel_num_fixed_counters)) {
165 *index = msr_index - MSR_CORE_PERF_FIXED_CTR0;
166 *type = MSR_TYPE_COUNTER;
167 return true;
168 }
169
170 if ((msr_index >= MSR_P6_EVNTSEL0) &&
171 (msr_index < MSR_P6_EVNTSEL0 + intel_num_arch_counters)) {
172 *index = msr_index - MSR_P6_EVNTSEL0;
173 *type = MSR_TYPE_ARCH_CTRL;
174 return true;
175 }
176
177 msr_index_pmc = msr_index & MSR_PMC_ALIAS_MASK;
178 if ((msr_index_pmc >= MSR_IA32_PERFCTR0) &&
179 (msr_index_pmc < MSR_IA32_PERFCTR0 +
180 intel_num_arch_counters)) {
181 *type = MSR_TYPE_ARCH_COUNTER;
182 *index = msr_index_pmc - MSR_IA32_PERFCTR0;
183 return true;
184 }
185 return false;
186 }
187}
188
189static bool xen_intel_pmu_emulate(unsigned int msr, u64 *val, int type,
190 int index, bool is_read)
191{
192 uint64_t *reg = NULL;
193 struct xen_pmu_intel_ctxt *ctxt;
194 uint64_t *fix_counters;
195 struct xen_pmu_cntr_pair *arch_cntr_pair;
196 struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
197 uint8_t xenpmu_flags = get_xenpmu_flags();
198
199
200 if (!xenpmu_data || !(xenpmu_flags & XENPMU_IRQ_PROCESSING))
201 return false;
202
203 ctxt = &xenpmu_data->pmu.c.intel;
204
205 switch (msr) {
206 case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
207 reg = &ctxt->global_ovf_ctrl;
208 break;
209 case MSR_CORE_PERF_GLOBAL_STATUS:
210 reg = &ctxt->global_status;
211 break;
212 case MSR_CORE_PERF_GLOBAL_CTRL:
213 reg = &ctxt->global_ctrl;
214 break;
215 case MSR_CORE_PERF_FIXED_CTR_CTRL:
216 reg = &ctxt->fixed_ctrl;
217 break;
218 default:
219 switch (type) {
220 case MSR_TYPE_COUNTER:
221 fix_counters = field_offset(ctxt, fixed_counters);
222 reg = &fix_counters[index];
223 break;
224 case MSR_TYPE_ARCH_COUNTER:
225 arch_cntr_pair = field_offset(ctxt, arch_counters);
226 reg = &arch_cntr_pair[index].counter;
227 break;
228 case MSR_TYPE_ARCH_CTRL:
229 arch_cntr_pair = field_offset(ctxt, arch_counters);
230 reg = &arch_cntr_pair[index].control;
231 break;
232 default:
233 return false;
234 }
235 }
236
237 if (reg) {
238 if (is_read)
239 *val = *reg;
240 else {
241 *reg = *val;
242
243 if (msr == MSR_CORE_PERF_GLOBAL_OVF_CTRL)
244 ctxt->global_status &= (~(*val));
245 }
246 return true;
247 }
248
249 return false;
250}
251
252static bool xen_amd_pmu_emulate(unsigned int msr, u64 *val, bool is_read)
253{
254 uint64_t *reg = NULL;
255 int i, off = 0;
256 struct xen_pmu_amd_ctxt *ctxt;
257 uint64_t *counter_regs, *ctrl_regs;
258 struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
259 uint8_t xenpmu_flags = get_xenpmu_flags();
260
261 if (!xenpmu_data || !(xenpmu_flags & XENPMU_IRQ_PROCESSING))
262 return false;
263
264 if (k7_counters_mirrored &&
265 ((msr >= MSR_K7_EVNTSEL0) && (msr <= MSR_K7_PERFCTR3)))
266 msr = get_fam15h_addr(msr);
267
268 ctxt = &xenpmu_data->pmu.c.amd;
269 for (i = 0; i < amd_num_counters; i++) {
270 if (msr == amd_ctrls_base + off) {
271 ctrl_regs = field_offset(ctxt, ctrls);
272 reg = &ctrl_regs[i];
273 break;
274 } else if (msr == amd_counters_base + off) {
275 counter_regs = field_offset(ctxt, counters);
276 reg = &counter_regs[i];
277 break;
278 }
279 off += amd_msr_step;
280 }
281
282 if (reg) {
283 if (is_read)
284 *val = *reg;
285 else
286 *reg = *val;
287
288 return true;
289 }
290 return false;
291}
292
293bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err)
294{
295 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
296 if (is_amd_pmu_msr(msr)) {
297 if (!xen_amd_pmu_emulate(msr, val, 1))
298 *val = native_read_msr_safe(msr, err);
299 return true;
300 }
301 } else {
302 int type, index;
303
304 if (is_intel_pmu_msr(msr, &type, &index)) {
305 if (!xen_intel_pmu_emulate(msr, val, type, index, 1))
306 *val = native_read_msr_safe(msr, err);
307 return true;
308 }
309 }
310
311 return false;
312}
313
314bool pmu_msr_write(unsigned int msr, uint32_t low, uint32_t high, int *err)
315{
316 uint64_t val = ((uint64_t)high << 32) | low;
317
318 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
319 if (is_amd_pmu_msr(msr)) {
320 if (!xen_amd_pmu_emulate(msr, &val, 0))
321 *err = native_write_msr_safe(msr, low, high);
322 return true;
323 }
324 } else {
325 int type, index;
326
327 if (is_intel_pmu_msr(msr, &type, &index)) {
328 if (!xen_intel_pmu_emulate(msr, &val, type, index, 0))
329 *err = native_write_msr_safe(msr, low, high);
330 return true;
331 }
332 }
333
334 return false;
335}
336
337static unsigned long long xen_amd_read_pmc(int counter)
338{
339 struct xen_pmu_amd_ctxt *ctxt;
340 uint64_t *counter_regs;
341 struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
342 uint8_t xenpmu_flags = get_xenpmu_flags();
343
344 if (!xenpmu_data || !(xenpmu_flags & XENPMU_IRQ_PROCESSING)) {
345 uint32_t msr;
346 int err;
347
348 msr = amd_counters_base + (counter * amd_msr_step);
349 return native_read_msr_safe(msr, &err);
350 }
351
352 ctxt = &xenpmu_data->pmu.c.amd;
353 counter_regs = field_offset(ctxt, counters);
354 return counter_regs[counter];
355}
356
357static unsigned long long xen_intel_read_pmc(int counter)
358{
359 struct xen_pmu_intel_ctxt *ctxt;
360 uint64_t *fixed_counters;
361 struct xen_pmu_cntr_pair *arch_cntr_pair;
362 struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
363 uint8_t xenpmu_flags = get_xenpmu_flags();
364
365 if (!xenpmu_data || !(xenpmu_flags & XENPMU_IRQ_PROCESSING)) {
366 uint32_t msr;
367 int err;
368
369 if (counter & (1 << INTEL_PMC_TYPE_SHIFT))
370 msr = MSR_CORE_PERF_FIXED_CTR0 + (counter & 0xffff);
371 else
372 msr = MSR_IA32_PERFCTR0 + counter;
373
374 return native_read_msr_safe(msr, &err);
375 }
376
377 ctxt = &xenpmu_data->pmu.c.intel;
378 if (counter & (1 << INTEL_PMC_TYPE_SHIFT)) {
379 fixed_counters = field_offset(ctxt, fixed_counters);
380 return fixed_counters[counter & 0xffff];
381 }
382
383 arch_cntr_pair = field_offset(ctxt, arch_counters);
384 return arch_cntr_pair[counter].counter;
385}
386
387unsigned long long xen_read_pmc(int counter)
388{
389 if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
390 return xen_amd_read_pmc(counter);
391 else
392 return xen_intel_read_pmc(counter);
393}
394
395int pmu_apic_update(uint32_t val)
396{
397 int ret;
398 struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
399
400 if (!xenpmu_data) {
401 pr_warn_once("%s: pmudata not initialized\n", __func__);
402 return -EINVAL;
403 }
404
405 xenpmu_data->pmu.l.lapic_lvtpc = val;
406
407 if (get_xenpmu_flags() & XENPMU_IRQ_PROCESSING)
408 return 0;
409
410 ret = HYPERVISOR_xenpmu_op(XENPMU_lvtpc_set, NULL);
411
412 return ret;
413}
414
415/* perf callbacks */
416static int xen_is_in_guest(void)
417{
418 const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
419
420 if (!xenpmu_data) {
421 pr_warn_once("%s: pmudata not initialized\n", __func__);
422 return 0;
423 }
424
425 if (!xen_initial_domain() || (xenpmu_data->domain_id >= DOMID_SELF))
426 return 0;
427
428 return 1;
429}
430
431static int xen_is_user_mode(void)
432{
433 const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
434
435 if (!xenpmu_data) {
436 pr_warn_once("%s: pmudata not initialized\n", __func__);
437 return 0;
438 }
439
440 if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV)
441 return (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER);
442 else
443 return !!(xenpmu_data->pmu.r.regs.cpl & 3);
444}
445
446static unsigned long xen_get_guest_ip(void)
447{
448 const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
449
450 if (!xenpmu_data) {
451 pr_warn_once("%s: pmudata not initialized\n", __func__);
452 return 0;
453 }
454
455 return xenpmu_data->pmu.r.regs.ip;
456}
457
458static struct perf_guest_info_callbacks xen_guest_cbs = {
459 .is_in_guest = xen_is_in_guest,
460 .is_user_mode = xen_is_user_mode,
461 .get_guest_ip = xen_get_guest_ip,
462};
463
464/* Convert registers from Xen's format to Linux' */
465static void xen_convert_regs(const struct xen_pmu_regs *xen_regs,
466 struct pt_regs *regs, uint64_t pmu_flags)
467{
468 regs->ip = xen_regs->ip;
469 regs->cs = xen_regs->cs;
470 regs->sp = xen_regs->sp;
471
472 if (pmu_flags & PMU_SAMPLE_PV) {
473 if (pmu_flags & PMU_SAMPLE_USER)
474 regs->cs |= 3;
475 else
476 regs->cs &= ~3;
477 } else {
478 if (xen_regs->cpl)
479 regs->cs |= 3;
480 else
481 regs->cs &= ~3;
482 }
483}
484
485irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id)
486{
487 int err, ret = IRQ_NONE;
488 struct pt_regs regs = {0};
489 const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
490 uint8_t xenpmu_flags = get_xenpmu_flags();
491
492 if (!xenpmu_data) {
493 pr_warn_once("%s: pmudata not initialized\n", __func__);
494 return ret;
495 }
496
497 this_cpu_ptr(&xenpmu_shared)->flags =
498 xenpmu_flags | XENPMU_IRQ_PROCESSING;
499 xen_convert_regs(&xenpmu_data->pmu.r.regs, ®s,
500 xenpmu_data->pmu.pmu_flags);
501 if (x86_pmu.handle_irq(®s))
502 ret = IRQ_HANDLED;
503
504 /* Write out cached context to HW */
505 err = HYPERVISOR_xenpmu_op(XENPMU_flush, NULL);
506 this_cpu_ptr(&xenpmu_shared)->flags = xenpmu_flags;
507 if (err) {
508 pr_warn_once("%s: failed hypercall, err: %d\n", __func__, err);
509 return IRQ_NONE;
510 }
511
512 return ret;
513}
514
515bool is_xen_pmu(int cpu)
516{
517 return (get_xenpmu_data() != NULL);
518}
519
520void xen_pmu_init(int cpu)
521{
522 int err;
523 struct xen_pmu_params xp;
524 unsigned long pfn;
525 struct xen_pmu_data *xenpmu_data;
526
527 BUILD_BUG_ON(sizeof(struct xen_pmu_data) > PAGE_SIZE);
528
529 if (xen_hvm_domain())
530 return;
531
532 xenpmu_data = (struct xen_pmu_data *)get_zeroed_page(GFP_KERNEL);
533 if (!xenpmu_data) {
534 pr_err("VPMU init: No memory\n");
535 return;
536 }
537 pfn = virt_to_pfn(xenpmu_data);
538
539 xp.val = pfn_to_mfn(pfn);
540 xp.vcpu = cpu;
541 xp.version.maj = XENPMU_VER_MAJ;
542 xp.version.min = XENPMU_VER_MIN;
543 err = HYPERVISOR_xenpmu_op(XENPMU_init, &xp);
544 if (err)
545 goto fail;
546
547 per_cpu(xenpmu_shared, cpu).xenpmu_data = xenpmu_data;
548 per_cpu(xenpmu_shared, cpu).flags = 0;
549
550 if (cpu == 0) {
551 perf_register_guest_info_callbacks(&xen_guest_cbs);
552 xen_pmu_arch_init();
553 }
554
555 return;
556
557fail:
558 if (err == -EOPNOTSUPP || err == -ENOSYS)
559 pr_info_once("VPMU disabled by hypervisor.\n");
560 else
561 pr_info_once("Could not initialize VPMU for cpu %d, error %d\n",
562 cpu, err);
563 free_pages((unsigned long)xenpmu_data, 0);
564}
565
566void xen_pmu_finish(int cpu)
567{
568 struct xen_pmu_params xp;
569
570 if (xen_hvm_domain())
571 return;
572
573 xp.vcpu = cpu;
574 xp.version.maj = XENPMU_VER_MAJ;
575 xp.version.min = XENPMU_VER_MIN;
576
577 (void)HYPERVISOR_xenpmu_op(XENPMU_finish, &xp);
578
579 free_pages((unsigned long)per_cpu(xenpmu_shared, cpu).xenpmu_data, 0);
580 per_cpu(xenpmu_shared, cpu).xenpmu_data = NULL;
581}