arch/x86/xen/pmu.c

   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
  19 struct xenpmu {
  20         /* Shared page between hypervisor and domain */
  21         struct xen_pmu_data *xenpmu_data;
  22
  23         uint8_t flags;
  24 };
  25 static 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
  37 static __read_mostly uint32_t amd_counters_base;
  38 static __read_mostly uint32_t amd_ctrls_base;
  39 static __read_mostly int amd_msr_step;
  40 static __read_mostly int k7_counters_mirrored;
  41 static __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
  67 static __read_mostly int intel_num_arch_counters, intel_num_fixed_counters;
  68
  69
  70 static 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
 112 static 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
 132 static 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
 143 static 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
 189 static 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
 252 static 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
 293 bool 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
 314 bool 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
 337 static 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
 357 static 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
 387 unsigned 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
 395 int 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 */
 416 static 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
 431 static 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
 446 static 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
 458 static 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' */
 465 static 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
 485 irqreturn_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, &regs,
 500                          xenpmu_data->pmu.pmu_flags);
 501         if (x86_pmu.handle_irq(&regs))
 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
 515 bool is_xen_pmu(int cpu)
 516 {
 517         return (get_xenpmu_data() != NULL);
 518 }
 519
 520 void 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
 557 fail:
 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
 566 void 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 }