arch/x86/kvm/hyperv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * KVM Microsoft Hyper-V emulation
   4  *
   5  * derived from arch/x86/kvm/x86.c
   6  *
   7  * Copyright (C) 2006 Qumranet, Inc.
   8  * Copyright (C) 2008 Qumranet, Inc.
   9  * Copyright IBM Corporation, 2008
  10  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  11  * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
  12  *
  13  * Authors:
  14  *   Avi Kivity   <avi@qumranet.com>
  15  *   Yaniv Kamay  <yaniv@qumranet.com>
  16  *   Amit Shah    <amit.shah@qumranet.com>
  17  *   Ben-Ami Yassour <benami@il.ibm.com>
  18  *   Andrey Smetanin <asmetanin@virtuozzo.com>
  19  */
  20
  21 #include "x86.h"
  22 #include "lapic.h"
  23 #include "ioapic.h"
  24 #include "cpuid.h"
  25 #include "hyperv.h"
  26 #include "xen.h"
  27
  28 #include <linux/cpu.h>
  29 #include <linux/kvm_host.h>
  30 #include <linux/highmem.h>
  31 #include <linux/sched/cputime.h>
  32 #include <linux/eventfd.h>
  33
  34 #include <asm/apicdef.h>
  35 #include <trace/events/kvm.h>
  36
  37 #include "trace.h"
  38 #include "irq.h"
  39
  40 /* "Hv#1" signature */
  41 #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648
  42
  43 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, 64)
  44
  45 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
  46                                 bool vcpu_kick);
  47
  48 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
  49 {
  50         return atomic64_read(&synic->sint[sint]);
  51 }
  52
  53 static inline int synic_get_sint_vector(u64 sint_value)
  54 {
  55         if (sint_value & HV_SYNIC_SINT_MASKED)
  56                 return -1;
  57         return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
  58 }
  59
  60 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
  61                                       int vector)
  62 {
  63         int i;
  64
  65         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  66                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
  67                         return true;
  68         }
  69         return false;
  70 }
  71
  72 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
  73                                      int vector)
  74 {
  75         int i;
  76         u64 sint_value;
  77
  78         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  79                 sint_value = synic_read_sint(synic, i);
  80                 if (synic_get_sint_vector(sint_value) == vector &&
  81                     sint_value & HV_SYNIC_SINT_AUTO_EOI)
  82                         return true;
  83         }
  84         return false;
  85 }
  86
  87 static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
  88                                 int vector)
  89 {
  90         if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
  91                 return;
  92
  93         if (synic_has_vector_connected(synic, vector))
  94                 __set_bit(vector, synic->vec_bitmap);
  95         else
  96                 __clear_bit(vector, synic->vec_bitmap);
  97
  98         if (synic_has_vector_auto_eoi(synic, vector))
  99                 __set_bit(vector, synic->auto_eoi_bitmap);
 100         else
 101                 __clear_bit(vector, synic->auto_eoi_bitmap);
 102 }
 103
 104 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
 105                           u64 data, bool host)
 106 {
 107         int vector, old_vector;
 108         bool masked;
 109
 110         vector = data & HV_SYNIC_SINT_VECTOR_MASK;
 111         masked = data & HV_SYNIC_SINT_MASKED;
 112
 113         /*
 114          * Valid vectors are 16-255, however, nested Hyper-V attempts to write
 115          * default '0x10000' value on boot and this should not #GP. We need to
 116          * allow zero-initing the register from host as well.
 117          */
 118         if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
 119                 return 1;
 120         /*
 121          * Guest may configure multiple SINTs to use the same vector, so
 122          * we maintain a bitmap of vectors handled by synic, and a
 123          * bitmap of vectors with auto-eoi behavior.  The bitmaps are
 124          * updated here, and atomically queried on fast paths.
 125          */
 126         old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
 127
 128         atomic64_set(&synic->sint[sint], data);
 129
 130         synic_update_vector(synic, old_vector);
 131
 132         synic_update_vector(synic, vector);
 133
 134         /* Load SynIC vectors into EOI exit bitmap */
 135         kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
 136         return 0;
 137 }
 138
 139 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
 140 {
 141         struct kvm_vcpu *vcpu = NULL;
 142         int i;
 143
 144         if (vpidx >= KVM_MAX_VCPUS)
 145                 return NULL;
 146
 147         vcpu = kvm_get_vcpu(kvm, vpidx);
 148         if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
 149                 return vcpu;
 150         kvm_for_each_vcpu(i, vcpu, kvm)
 151                 if (kvm_hv_get_vpindex(vcpu) == vpidx)
 152                         return vcpu;
 153         return NULL;
 154 }
 155
 156 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
 157 {
 158         struct kvm_vcpu *vcpu;
 159         struct kvm_vcpu_hv_synic *synic;
 160
 161         vcpu = get_vcpu_by_vpidx(kvm, vpidx);
 162         if (!vcpu || !to_hv_vcpu(vcpu))
 163                 return NULL;
 164         synic = to_hv_synic(vcpu);
 165         return (synic->active) ? synic : NULL;
 166 }
 167
 168 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 169 {
 170         struct kvm *kvm = vcpu->kvm;
 171         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 172         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 173         struct kvm_vcpu_hv_stimer *stimer;
 174         int gsi, idx;
 175
 176         trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
 177
 178         /* Try to deliver pending Hyper-V SynIC timers messages */
 179         for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
 180                 stimer = &hv_vcpu->stimer[idx];
 181                 if (stimer->msg_pending && stimer->config.enable &&
 182                     !stimer->config.direct_mode &&
 183                     stimer->config.sintx == sint)
 184                         stimer_mark_pending(stimer, false);
 185         }
 186
 187         idx = srcu_read_lock(&kvm->irq_srcu);
 188         gsi = atomic_read(&synic->sint_to_gsi[sint]);
 189         if (gsi != -1)
 190                 kvm_notify_acked_gsi(kvm, gsi);
 191         srcu_read_unlock(&kvm->irq_srcu, idx);
 192 }
 193
 194 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
 195 {
 196         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 197         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 198
 199         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
 200         hv_vcpu->exit.u.synic.msr = msr;
 201         hv_vcpu->exit.u.synic.control = synic->control;
 202         hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
 203         hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
 204
 205         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 206 }
 207
 208 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
 209                          u32 msr, u64 data, bool host)
 210 {
 211         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 212         int ret;
 213
 214         if (!synic->active && !host)
 215                 return 1;
 216
 217         trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
 218
 219         ret = 0;
 220         switch (msr) {
 221         case HV_X64_MSR_SCONTROL:
 222                 synic->control = data;
 223                 if (!host)
 224                         synic_exit(synic, msr);
 225                 break;
 226         case HV_X64_MSR_SVERSION:
 227                 if (!host) {
 228                         ret = 1;
 229                         break;
 230                 }
 231                 synic->version = data;
 232                 break;
 233         case HV_X64_MSR_SIEFP:
 234                 if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
 235                     !synic->dont_zero_synic_pages)
 236                         if (kvm_clear_guest(vcpu->kvm,
 237                                             data & PAGE_MASK, PAGE_SIZE)) {
 238                                 ret = 1;
 239                                 break;
 240                         }
 241                 synic->evt_page = data;
 242                 if (!host)
 243                         synic_exit(synic, msr);
 244                 break;
 245         case HV_X64_MSR_SIMP:
 246                 if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
 247                     !synic->dont_zero_synic_pages)
 248                         if (kvm_clear_guest(vcpu->kvm,
 249                                             data & PAGE_MASK, PAGE_SIZE)) {
 250                                 ret = 1;
 251                                 break;
 252                         }
 253                 synic->msg_page = data;
 254                 if (!host)
 255                         synic_exit(synic, msr);
 256                 break;
 257         case HV_X64_MSR_EOM: {
 258                 int i;
 259
 260                 for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 261                         kvm_hv_notify_acked_sint(vcpu, i);
 262                 break;
 263         }
 264         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 265                 ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
 266                 break;
 267         default:
 268                 ret = 1;
 269                 break;
 270         }
 271         return ret;
 272 }
 273
 274 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
 275 {
 276         struct kvm_cpuid_entry2 *entry;
 277
 278         entry = kvm_find_cpuid_entry(vcpu,
 279                                      HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES,
 280                                      0);
 281         if (!entry)
 282                 return false;
 283
 284         return entry->eax & HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
 285 }
 286
 287 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
 288 {
 289         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
 290
 291         if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
 292                 hv->hv_syndbg.control.status =
 293                         vcpu->run->hyperv.u.syndbg.status;
 294         return 1;
 295 }
 296
 297 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
 298 {
 299         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 300         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 301
 302         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
 303         hv_vcpu->exit.u.syndbg.msr = msr;
 304         hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
 305         hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
 306         hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
 307         hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
 308         vcpu->arch.complete_userspace_io =
 309                         kvm_hv_syndbg_complete_userspace;
 310
 311         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 312 }
 313
 314 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
 315 {
 316         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 317
 318         if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
 319                 return 1;
 320
 321         trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
 322                                     to_hv_vcpu(vcpu)->vp_index, msr, data);
 323         switch (msr) {
 324         case HV_X64_MSR_SYNDBG_CONTROL:
 325                 syndbg->control.control = data;
 326                 if (!host)
 327                         syndbg_exit(vcpu, msr);
 328                 break;
 329         case HV_X64_MSR_SYNDBG_STATUS:
 330                 syndbg->control.status = data;
 331                 break;
 332         case HV_X64_MSR_SYNDBG_SEND_BUFFER:
 333                 syndbg->control.send_page = data;
 334                 break;
 335         case HV_X64_MSR_SYNDBG_RECV_BUFFER:
 336                 syndbg->control.recv_page = data;
 337                 break;
 338         case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
 339                 syndbg->control.pending_page = data;
 340                 if (!host)
 341                         syndbg_exit(vcpu, msr);
 342                 break;
 343         case HV_X64_MSR_SYNDBG_OPTIONS:
 344                 syndbg->options = data;
 345                 break;
 346         default:
 347                 break;
 348         }
 349
 350         return 0;
 351 }
 352
 353 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
 354 {
 355         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 356
 357         if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
 358                 return 1;
 359
 360         switch (msr) {
 361         case HV_X64_MSR_SYNDBG_CONTROL:
 362                 *pdata = syndbg->control.control;
 363                 break;
 364         case HV_X64_MSR_SYNDBG_STATUS:
 365                 *pdata = syndbg->control.status;
 366                 break;
 367         case HV_X64_MSR_SYNDBG_SEND_BUFFER:
 368                 *pdata = syndbg->control.send_page;
 369                 break;
 370         case HV_X64_MSR_SYNDBG_RECV_BUFFER:
 371                 *pdata = syndbg->control.recv_page;
 372                 break;
 373         case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
 374                 *pdata = syndbg->control.pending_page;
 375                 break;
 376         case HV_X64_MSR_SYNDBG_OPTIONS:
 377                 *pdata = syndbg->options;
 378                 break;
 379         default:
 380                 break;
 381         }
 382
 383         trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
 384
 385         return 0;
 386 }
 387
 388 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
 389                          bool host)
 390 {
 391         int ret;
 392
 393         if (!synic->active && !host)
 394                 return 1;
 395
 396         ret = 0;
 397         switch (msr) {
 398         case HV_X64_MSR_SCONTROL:
 399                 *pdata = synic->control;
 400                 break;
 401         case HV_X64_MSR_SVERSION:
 402                 *pdata = synic->version;
 403                 break;
 404         case HV_X64_MSR_SIEFP:
 405                 *pdata = synic->evt_page;
 406                 break;
 407         case HV_X64_MSR_SIMP:
 408                 *pdata = synic->msg_page;
 409                 break;
 410         case HV_X64_MSR_EOM:
 411                 *pdata = 0;
 412                 break;
 413         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 414                 *pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
 415                 break;
 416         default:
 417                 ret = 1;
 418                 break;
 419         }
 420         return ret;
 421 }
 422
 423 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
 424 {
 425         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 426         struct kvm_lapic_irq irq;
 427         int ret, vector;
 428
 429         if (sint >= ARRAY_SIZE(synic->sint))
 430                 return -EINVAL;
 431
 432         vector = synic_get_sint_vector(synic_read_sint(synic, sint));
 433         if (vector < 0)
 434                 return -ENOENT;
 435
 436         memset(&irq, 0, sizeof(irq));
 437         irq.shorthand = APIC_DEST_SELF;
 438         irq.dest_mode = APIC_DEST_PHYSICAL;
 439         irq.delivery_mode = APIC_DM_FIXED;
 440         irq.vector = vector;
 441         irq.level = 1;
 442
 443         ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
 444         trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
 445         return ret;
 446 }
 447
 448 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
 449 {
 450         struct kvm_vcpu_hv_synic *synic;
 451
 452         synic = synic_get(kvm, vpidx);
 453         if (!synic)
 454                 return -EINVAL;
 455
 456         return synic_set_irq(synic, sint);
 457 }
 458
 459 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
 460 {
 461         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 462         int i;
 463
 464         trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
 465
 466         for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 467                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
 468                         kvm_hv_notify_acked_sint(vcpu, i);
 469 }
 470
 471 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
 472 {
 473         struct kvm_vcpu_hv_synic *synic;
 474
 475         synic = synic_get(kvm, vpidx);
 476         if (!synic)
 477                 return -EINVAL;
 478
 479         if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
 480                 return -EINVAL;
 481
 482         atomic_set(&synic->sint_to_gsi[sint], gsi);
 483         return 0;
 484 }
 485
 486 void kvm_hv_irq_routing_update(struct kvm *kvm)
 487 {
 488         struct kvm_irq_routing_table *irq_rt;
 489         struct kvm_kernel_irq_routing_entry *e;
 490         u32 gsi;
 491
 492         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
 493                                         lockdep_is_held(&kvm->irq_lock));
 494
 495         for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
 496                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
 497                         if (e->type == KVM_IRQ_ROUTING_HV_SINT)
 498                                 kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
 499                                                     e->hv_sint.sint, gsi);
 500                 }
 501         }
 502 }
 503
 504 static void synic_init(struct kvm_vcpu_hv_synic *synic)
 505 {
 506         int i;
 507
 508         memset(synic, 0, sizeof(*synic));
 509         synic->version = HV_SYNIC_VERSION_1;
 510         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
 511                 atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
 512                 atomic_set(&synic->sint_to_gsi[i], -1);
 513         }
 514 }
 515
 516 static u64 get_time_ref_counter(struct kvm *kvm)
 517 {
 518         struct kvm_hv *hv = to_kvm_hv(kvm);
 519         struct kvm_vcpu *vcpu;
 520         u64 tsc;
 521
 522         /*
 523          * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
 524          * is broken, disabled or being updated.
 525          */
 526         if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
 527                 return div_u64(get_kvmclock_ns(kvm), 100);
 528
 529         vcpu = kvm_get_vcpu(kvm, 0);
 530         tsc = kvm_read_l1_tsc(vcpu, rdtsc());
 531         return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
 532                 + hv->tsc_ref.tsc_offset;
 533 }
 534
 535 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
 536                                 bool vcpu_kick)
 537 {
 538         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 539
 540         set_bit(stimer->index,
 541                 to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 542         kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 543         if (vcpu_kick)
 544                 kvm_vcpu_kick(vcpu);
 545 }
 546
 547 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
 548 {
 549         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 550
 551         trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
 552                                     stimer->index);
 553
 554         hrtimer_cancel(&stimer->timer);
 555         clear_bit(stimer->index,
 556                   to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 557         stimer->msg_pending = false;
 558         stimer->exp_time = 0;
 559 }
 560
 561 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
 562 {
 563         struct kvm_vcpu_hv_stimer *stimer;
 564
 565         stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
 566         trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
 567                                      stimer->index);
 568         stimer_mark_pending(stimer, true);
 569
 570         return HRTIMER_NORESTART;
 571 }
 572
 573 /*
 574  * stimer_start() assumptions:
 575  * a) stimer->count is not equal to 0
 576  * b) stimer->config has HV_STIMER_ENABLE flag
 577  */
 578 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
 579 {
 580         u64 time_now;
 581         ktime_t ktime_now;
 582
 583         time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
 584         ktime_now = ktime_get();
 585
 586         if (stimer->config.periodic) {
 587                 if (stimer->exp_time) {
 588                         if (time_now >= stimer->exp_time) {
 589                                 u64 remainder;
 590
 591                                 div64_u64_rem(time_now - stimer->exp_time,
 592                                               stimer->count, &remainder);
 593                                 stimer->exp_time =
 594                                         time_now + (stimer->count - remainder);
 595                         }
 596                 } else
 597                         stimer->exp_time = time_now + stimer->count;
 598
 599                 trace_kvm_hv_stimer_start_periodic(
 600                                         hv_stimer_to_vcpu(stimer)->vcpu_id,
 601                                         stimer->index,
 602                                         time_now, stimer->exp_time);
 603
 604                 hrtimer_start(&stimer->timer,
 605                               ktime_add_ns(ktime_now,
 606                                            100 * (stimer->exp_time - time_now)),
 607                               HRTIMER_MODE_ABS);
 608                 return 0;
 609         }
 610         stimer->exp_time = stimer->count;
 611         if (time_now >= stimer->count) {
 612                 /*
 613                  * Expire timer according to Hypervisor Top-Level Functional
 614                  * specification v4(15.3.1):
 615                  * "If a one shot is enabled and the specified count is in
 616                  * the past, it will expire immediately."
 617                  */
 618                 stimer_mark_pending(stimer, false);
 619                 return 0;
 620         }
 621
 622         trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
 623                                            stimer->index,
 624                                            time_now, stimer->count);
 625
 626         hrtimer_start(&stimer->timer,
 627                       ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
 628                       HRTIMER_MODE_ABS);
 629         return 0;
 630 }
 631
 632 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
 633                              bool host)
 634 {
 635         union hv_stimer_config new_config = {.as_uint64 = config},
 636                 old_config = {.as_uint64 = stimer->config.as_uint64};
 637         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 638         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 639
 640         if (!synic->active && !host)
 641                 return 1;
 642
 643         trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
 644                                        stimer->index, config, host);
 645
 646         stimer_cleanup(stimer);
 647         if (old_config.enable &&
 648             !new_config.direct_mode && new_config.sintx == 0)
 649                 new_config.enable = 0;
 650         stimer->config.as_uint64 = new_config.as_uint64;
 651
 652         if (stimer->config.enable)
 653                 stimer_mark_pending(stimer, false);
 654
 655         return 0;
 656 }
 657
 658 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
 659                             bool host)
 660 {
 661         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 662         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 663
 664         if (!synic->active && !host)
 665                 return 1;
 666
 667         trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
 668                                       stimer->index, count, host);
 669
 670         stimer_cleanup(stimer);
 671         stimer->count = count;
 672         if (stimer->count == 0)
 673                 stimer->config.enable = 0;
 674         else if (stimer->config.auto_enable)
 675                 stimer->config.enable = 1;
 676
 677         if (stimer->config.enable)
 678                 stimer_mark_pending(stimer, false);
 679
 680         return 0;
 681 }
 682
 683 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
 684 {
 685         *pconfig = stimer->config.as_uint64;
 686         return 0;
 687 }
 688
 689 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
 690 {
 691         *pcount = stimer->count;
 692         return 0;
 693 }
 694
 695 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
 696                              struct hv_message *src_msg, bool no_retry)
 697 {
 698         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 699         int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
 700         gfn_t msg_page_gfn;
 701         struct hv_message_header hv_hdr;
 702         int r;
 703
 704         if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
 705                 return -ENOENT;
 706
 707         msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
 708
 709         /*
 710          * Strictly following the spec-mandated ordering would assume setting
 711          * .msg_pending before checking .message_type.  However, this function
 712          * is only called in vcpu context so the entire update is atomic from
 713          * guest POV and thus the exact order here doesn't matter.
 714          */
 715         r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
 716                                      msg_off + offsetof(struct hv_message,
 717                                                         header.message_type),
 718                                      sizeof(hv_hdr.message_type));
 719         if (r < 0)
 720                 return r;
 721
 722         if (hv_hdr.message_type != HVMSG_NONE) {
 723                 if (no_retry)
 724                         return 0;
 725
 726                 hv_hdr.message_flags.msg_pending = 1;
 727                 r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
 728                                               &hv_hdr.message_flags,
 729                                               msg_off +
 730                                               offsetof(struct hv_message,
 731                                                        header.message_flags),
 732                                               sizeof(hv_hdr.message_flags));
 733                 if (r < 0)
 734                         return r;
 735                 return -EAGAIN;
 736         }
 737
 738         r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
 739                                       sizeof(src_msg->header) +
 740                                       src_msg->header.payload_size);
 741         if (r < 0)
 742                 return r;
 743
 744         r = synic_set_irq(synic, sint);
 745         if (r < 0)
 746                 return r;
 747         if (r == 0)
 748                 return -EFAULT;
 749         return 0;
 750 }
 751
 752 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
 753 {
 754         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 755         struct hv_message *msg = &stimer->msg;
 756         struct hv_timer_message_payload *payload =
 757                         (struct hv_timer_message_payload *)&msg->u.payload;
 758
 759         /*
 760          * To avoid piling up periodic ticks, don't retry message
 761          * delivery for them (within "lazy" lost ticks policy).
 762          */
 763         bool no_retry = stimer->config.periodic;
 764
 765         payload->expiration_time = stimer->exp_time;
 766         payload->delivery_time = get_time_ref_counter(vcpu->kvm);
 767         return synic_deliver_msg(to_hv_synic(vcpu),
 768                                  stimer->config.sintx, msg,
 769                                  no_retry);
 770 }
 771
 772 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
 773 {
 774         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 775         struct kvm_lapic_irq irq = {
 776                 .delivery_mode = APIC_DM_FIXED,
 777                 .vector = stimer->config.apic_vector
 778         };
 779
 780         if (lapic_in_kernel(vcpu))
 781                 return !kvm_apic_set_irq(vcpu, &irq, NULL);
 782         return 0;
 783 }
 784
 785 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
 786 {
 787         int r, direct = stimer->config.direct_mode;
 788
 789         stimer->msg_pending = true;
 790         if (!direct)
 791                 r = stimer_send_msg(stimer);
 792         else
 793                 r = stimer_notify_direct(stimer);
 794         trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
 795                                        stimer->index, direct, r);
 796         if (!r) {
 797                 stimer->msg_pending = false;
 798                 if (!(stimer->config.periodic))
 799                         stimer->config.enable = 0;
 800         }
 801 }
 802
 803 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
 804 {
 805         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 806         struct kvm_vcpu_hv_stimer *stimer;
 807         u64 time_now, exp_time;
 808         int i;
 809
 810         if (!hv_vcpu)
 811                 return;
 812
 813         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 814                 if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
 815                         stimer = &hv_vcpu->stimer[i];
 816                         if (stimer->config.enable) {
 817                                 exp_time = stimer->exp_time;
 818
 819                                 if (exp_time) {
 820                                         time_now =
 821                                                 get_time_ref_counter(vcpu->kvm);
 822                                         if (time_now >= exp_time)
 823                                                 stimer_expiration(stimer);
 824                                 }
 825
 826                                 if ((stimer->config.enable) &&
 827                                     stimer->count) {
 828                                         if (!stimer->msg_pending)
 829                                                 stimer_start(stimer);
 830                                 } else
 831                                         stimer_cleanup(stimer);
 832                         }
 833                 }
 834 }
 835
 836 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
 837 {
 838         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 839         int i;
 840
 841         if (!hv_vcpu)
 842                 return;
 843
 844         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 845                 stimer_cleanup(&hv_vcpu->stimer[i]);
 846
 847         kfree(hv_vcpu);
 848         vcpu->arch.hyperv = NULL;
 849 }
 850
 851 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
 852 {
 853         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 854
 855         if (!hv_vcpu)
 856                 return false;
 857
 858         if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
 859                 return false;
 860         return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
 861 }
 862 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
 863
 864 bool kvm_hv_get_assist_page(struct kvm_vcpu *vcpu,
 865                             struct hv_vp_assist_page *assist_page)
 866 {
 867         if (!kvm_hv_assist_page_enabled(vcpu))
 868                 return false;
 869         return !kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
 870                                       assist_page, sizeof(*assist_page));
 871 }
 872 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
 873
 874 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
 875 {
 876         struct hv_message *msg = &stimer->msg;
 877         struct hv_timer_message_payload *payload =
 878                         (struct hv_timer_message_payload *)&msg->u.payload;
 879
 880         memset(&msg->header, 0, sizeof(msg->header));
 881         msg->header.message_type = HVMSG_TIMER_EXPIRED;
 882         msg->header.payload_size = sizeof(*payload);
 883
 884         payload->timer_index = stimer->index;
 885         payload->expiration_time = 0;
 886         payload->delivery_time = 0;
 887 }
 888
 889 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
 890 {
 891         memset(stimer, 0, sizeof(*stimer));
 892         stimer->index = timer_index;
 893         hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 894         stimer->timer.function = stimer_timer_callback;
 895         stimer_prepare_msg(stimer);
 896 }
 897
 898 static int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
 899 {
 900         struct kvm_vcpu_hv *hv_vcpu;
 901         int i;
 902
 903         hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
 904         if (!hv_vcpu)
 905                 return -ENOMEM;
 906
 907         vcpu->arch.hyperv = hv_vcpu;
 908         hv_vcpu->vcpu = vcpu;
 909
 910         synic_init(&hv_vcpu->synic);
 911
 912         bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
 913         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 914                 stimer_init(&hv_vcpu->stimer[i], i);
 915
 916         hv_vcpu->vp_index = kvm_vcpu_get_idx(vcpu);
 917
 918         return 0;
 919 }
 920
 921 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
 922 {
 923         struct kvm_vcpu_hv_synic *synic;
 924         int r;
 925
 926         if (!to_hv_vcpu(vcpu)) {
 927                 r = kvm_hv_vcpu_init(vcpu);
 928                 if (r)
 929                         return r;
 930         }
 931
 932         synic = to_hv_synic(vcpu);
 933
 934         /*
 935          * Hyper-V SynIC auto EOI SINT's are
 936          * not compatible with APICV, so request
 937          * to deactivate APICV permanently.
 938          */
 939         kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_HYPERV);
 940         synic->active = true;
 941         synic->dont_zero_synic_pages = dont_zero_synic_pages;
 942         synic->control = HV_SYNIC_CONTROL_ENABLE;
 943         return 0;
 944 }
 945
 946 static bool kvm_hv_msr_partition_wide(u32 msr)
 947 {
 948         bool r = false;
 949
 950         switch (msr) {
 951         case HV_X64_MSR_GUEST_OS_ID:
 952         case HV_X64_MSR_HYPERCALL:
 953         case HV_X64_MSR_REFERENCE_TSC:
 954         case HV_X64_MSR_TIME_REF_COUNT:
 955         case HV_X64_MSR_CRASH_CTL:
 956         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
 957         case HV_X64_MSR_RESET:
 958         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
 959         case HV_X64_MSR_TSC_EMULATION_CONTROL:
 960         case HV_X64_MSR_TSC_EMULATION_STATUS:
 961         case HV_X64_MSR_SYNDBG_OPTIONS:
 962         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
 963                 r = true;
 964                 break;
 965         }
 966
 967         return r;
 968 }
 969
 970 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
 971 {
 972         struct kvm_hv *hv = to_kvm_hv(kvm);
 973         size_t size = ARRAY_SIZE(hv->hv_crash_param);
 974
 975         if (WARN_ON_ONCE(index >= size))
 976                 return -EINVAL;
 977
 978         *pdata = hv->hv_crash_param[array_index_nospec(index, size)];
 979         return 0;
 980 }
 981
 982 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
 983 {
 984         struct kvm_hv *hv = to_kvm_hv(kvm);
 985
 986         *pdata = hv->hv_crash_ctl;
 987         return 0;
 988 }
 989
 990 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
 991 {
 992         struct kvm_hv *hv = to_kvm_hv(kvm);
 993
 994         hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
 995
 996         return 0;
 997 }
 998
 999 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1000 {
1001         struct kvm_hv *hv = to_kvm_hv(kvm);
1002         size_t size = ARRAY_SIZE(hv->hv_crash_param);
1003
1004         if (WARN_ON_ONCE(index >= size))
1005                 return -EINVAL;
1006
1007         hv->hv_crash_param[array_index_nospec(index, size)] = data;
1008         return 0;
1009 }
1010
1011 /*
1012  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1013  * between them is possible:
1014  *
1015  * kvmclock formula:
1016  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1017  *           + system_time
1018  *
1019  * Hyper-V formula:
1020  *    nsec/100 = ticks * scale / 2^64 + offset
1021  *
1022  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1023  * By dividing the kvmclock formula by 100 and equating what's left we get:
1024  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1025  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1026  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1027  *
1028  * Now expand the kvmclock formula and divide by 100:
1029  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1030  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1031  *           + system_time
1032  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1033  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1034  *               + system_time / 100
1035  *
1036  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1037  *    nsec/100 = ticks * scale / 2^64
1038  *               - tsc_timestamp * scale / 2^64
1039  *               + system_time / 100
1040  *
1041  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1042  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1043  *
1044  * These two equivalencies are implemented in this function.
1045  */
1046 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1047                                         struct ms_hyperv_tsc_page *tsc_ref)
1048 {
1049         u64 max_mul;
1050
1051         if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1052                 return false;
1053
1054         /*
1055          * check if scale would overflow, if so we use the time ref counter
1056          *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1057          *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1058          *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1059          */
1060         max_mul = 100ull << (32 - hv_clock->tsc_shift);
1061         if (hv_clock->tsc_to_system_mul >= max_mul)
1062                 return false;
1063
1064         /*
1065          * Otherwise compute the scale and offset according to the formulas
1066          * derived above.
1067          */
1068         tsc_ref->tsc_scale =
1069                 mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1070                                 hv_clock->tsc_to_system_mul,
1071                                 100);
1072
1073         tsc_ref->tsc_offset = hv_clock->system_time;
1074         do_div(tsc_ref->tsc_offset, 100);
1075         tsc_ref->tsc_offset -=
1076                 mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1077         return true;
1078 }
1079
1080 /*
1081  * Don't touch TSC page values if the guest has opted for TSC emulation after
1082  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1083  * access emulation and Hyper-V is known to expect the values in TSC page to
1084  * stay constant before TSC access emulation is disabled from guest side
1085  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1086  * frequency and guest visible TSC value across migration (and prevent it when
1087  * TSC scaling is unsupported).
1088  */
1089 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1090 {
1091         return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1092                 hv->hv_tsc_emulation_control;
1093 }
1094
1095 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1096                            struct pvclock_vcpu_time_info *hv_clock)
1097 {
1098         struct kvm_hv *hv = to_kvm_hv(kvm);
1099         u32 tsc_seq;
1100         u64 gfn;
1101
1102         BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1103         BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1104
1105         if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1106             hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1107                 return;
1108
1109         mutex_lock(&hv->hv_lock);
1110         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1111                 goto out_unlock;
1112
1113         gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1114         /*
1115          * Because the TSC parameters only vary when there is a
1116          * change in the master clock, do not bother with caching.
1117          */
1118         if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1119                                     &tsc_seq, sizeof(tsc_seq))))
1120                 goto out_err;
1121
1122         if (tsc_seq && tsc_page_update_unsafe(hv)) {
1123                 if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1124                         goto out_err;
1125
1126                 hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1127                 goto out_unlock;
1128         }
1129
1130         /*
1131          * While we're computing and writing the parameters, force the
1132          * guest to use the time reference count MSR.
1133          */
1134         hv->tsc_ref.tsc_sequence = 0;
1135         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1136                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1137                 goto out_err;
1138
1139         if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1140                 goto out_err;
1141
1142         /* Ensure sequence is zero before writing the rest of the struct.  */
1143         smp_wmb();
1144         if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1145                 goto out_err;
1146
1147         /*
1148          * Now switch to the TSC page mechanism by writing the sequence.
1149          */
1150         tsc_seq++;
1151         if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1152                 tsc_seq = 1;
1153
1154         /* Write the struct entirely before the non-zero sequence.  */
1155         smp_wmb();
1156
1157         hv->tsc_ref.tsc_sequence = tsc_seq;
1158         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1159                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1160                 goto out_err;
1161
1162         hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1163         goto out_unlock;
1164
1165 out_err:
1166         hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1167 out_unlock:
1168         mutex_unlock(&hv->hv_lock);
1169 }
1170
1171 void kvm_hv_invalidate_tsc_page(struct kvm *kvm)
1172 {
1173         struct kvm_hv *hv = to_kvm_hv(kvm);
1174         u64 gfn;
1175
1176         if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1177             hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET ||
1178             tsc_page_update_unsafe(hv))
1179                 return;
1180
1181         mutex_lock(&hv->hv_lock);
1182
1183         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1184                 goto out_unlock;
1185
1186         /* Preserve HV_TSC_PAGE_GUEST_CHANGED/HV_TSC_PAGE_HOST_CHANGED states */
1187         if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET)
1188                 hv->hv_tsc_page_status = HV_TSC_PAGE_UPDATING;
1189
1190         gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1191
1192         hv->tsc_ref.tsc_sequence = 0;
1193         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1194                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1195                 hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1196
1197 out_unlock:
1198         mutex_unlock(&hv->hv_lock);
1199 }
1200
1201 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1202                              bool host)
1203 {
1204         struct kvm *kvm = vcpu->kvm;
1205         struct kvm_hv *hv = to_kvm_hv(kvm);
1206
1207         switch (msr) {
1208         case HV_X64_MSR_GUEST_OS_ID:
1209                 hv->hv_guest_os_id = data;
1210                 /* setting guest os id to zero disables hypercall page */
1211                 if (!hv->hv_guest_os_id)
1212                         hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1213                 break;
1214         case HV_X64_MSR_HYPERCALL: {
1215                 u8 instructions[9];
1216                 int i = 0;
1217                 u64 addr;
1218
1219                 /* if guest os id is not set hypercall should remain disabled */
1220                 if (!hv->hv_guest_os_id)
1221                         break;
1222                 if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1223                         hv->hv_hypercall = data;
1224                         break;
1225                 }
1226
1227                 /*
1228                  * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1229                  * the same way Xen itself does, by setting the bit 31 of EAX
1230                  * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1231                  * going to be clobbered on 64-bit.
1232                  */
1233                 if (kvm_xen_hypercall_enabled(kvm)) {
1234                         /* orl $0x80000000, %eax */
1235                         instructions[i++] = 0x0d;
1236                         instructions[i++] = 0x00;
1237                         instructions[i++] = 0x00;
1238                         instructions[i++] = 0x00;
1239                         instructions[i++] = 0x80;
1240                 }
1241
1242                 /* vmcall/vmmcall */
1243                 static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1244                 i += 3;
1245
1246                 /* ret */
1247                 ((unsigned char *)instructions)[i++] = 0xc3;
1248
1249                 addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1250                 if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1251                         return 1;
1252                 hv->hv_hypercall = data;
1253                 break;
1254         }
1255         case HV_X64_MSR_REFERENCE_TSC:
1256                 hv->hv_tsc_page = data;
1257                 if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1258                         if (!host)
1259                                 hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1260                         else
1261                                 hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1262                         kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1263                 } else {
1264                         hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1265                 }
1266                 break;
1267         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1268                 return kvm_hv_msr_set_crash_data(kvm,
1269                                                  msr - HV_X64_MSR_CRASH_P0,
1270                                                  data);
1271         case HV_X64_MSR_CRASH_CTL:
1272                 if (host)
1273                         return kvm_hv_msr_set_crash_ctl(kvm, data);
1274
1275                 if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1276                         vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1277                                    hv->hv_crash_param[0],
1278                                    hv->hv_crash_param[1],
1279                                    hv->hv_crash_param[2],
1280                                    hv->hv_crash_param[3],
1281                                    hv->hv_crash_param[4]);
1282
1283                         /* Send notification about crash to user space */
1284                         kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1285                 }
1286                 break;
1287         case HV_X64_MSR_RESET:
1288                 if (data == 1) {
1289                         vcpu_debug(vcpu, "hyper-v reset requested\n");
1290                         kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1291                 }
1292                 break;
1293         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1294                 hv->hv_reenlightenment_control = data;
1295                 break;
1296         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1297                 hv->hv_tsc_emulation_control = data;
1298                 break;
1299         case HV_X64_MSR_TSC_EMULATION_STATUS:
1300                 if (data && !host)
1301                         return 1;
1302
1303                 hv->hv_tsc_emulation_status = data;
1304                 break;
1305         case HV_X64_MSR_TIME_REF_COUNT:
1306                 /* read-only, but still ignore it if host-initiated */
1307                 if (!host)
1308                         return 1;
1309                 break;
1310         case HV_X64_MSR_SYNDBG_OPTIONS:
1311         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1312                 return syndbg_set_msr(vcpu, msr, data, host);
1313         default:
1314                 vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1315                             msr, data);
1316                 return 1;
1317         }
1318         return 0;
1319 }
1320
1321 /* Calculate cpu time spent by current task in 100ns units */
1322 static u64 current_task_runtime_100ns(void)
1323 {
1324         u64 utime, stime;
1325
1326         task_cputime_adjusted(current, &utime, &stime);
1327
1328         return div_u64(utime + stime, 100);
1329 }
1330
1331 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1332 {
1333         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1334
1335         switch (msr) {
1336         case HV_X64_MSR_VP_INDEX: {
1337                 struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1338                 int vcpu_idx = kvm_vcpu_get_idx(vcpu);
1339                 u32 new_vp_index = (u32)data;
1340
1341                 if (!host || new_vp_index >= KVM_MAX_VCPUS)
1342                         return 1;
1343
1344                 if (new_vp_index == hv_vcpu->vp_index)
1345                         return 0;
1346
1347                 /*
1348                  * The VP index is initialized to vcpu_index by
1349                  * kvm_hv_vcpu_postcreate so they initially match.  Now the
1350                  * VP index is changing, adjust num_mismatched_vp_indexes if
1351                  * it now matches or no longer matches vcpu_idx.
1352                  */
1353                 if (hv_vcpu->vp_index == vcpu_idx)
1354                         atomic_inc(&hv->num_mismatched_vp_indexes);
1355                 else if (new_vp_index == vcpu_idx)
1356                         atomic_dec(&hv->num_mismatched_vp_indexes);
1357
1358                 hv_vcpu->vp_index = new_vp_index;
1359                 break;
1360         }
1361         case HV_X64_MSR_VP_ASSIST_PAGE: {
1362                 u64 gfn;
1363                 unsigned long addr;
1364
1365                 if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1366                         hv_vcpu->hv_vapic = data;
1367                         if (kvm_lapic_enable_pv_eoi(vcpu, 0, 0))
1368                                 return 1;
1369                         break;
1370                 }
1371                 gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1372                 addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1373                 if (kvm_is_error_hva(addr))
1374                         return 1;
1375
1376                 /*
1377                  * Clear apic_assist portion of struct hv_vp_assist_page
1378                  * only, there can be valuable data in the rest which needs
1379                  * to be preserved e.g. on migration.
1380                  */
1381                 if (__put_user(0, (u32 __user *)addr))
1382                         return 1;
1383                 hv_vcpu->hv_vapic = data;
1384                 kvm_vcpu_mark_page_dirty(vcpu, gfn);
1385                 if (kvm_lapic_enable_pv_eoi(vcpu,
1386                                             gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1387                                             sizeof(struct hv_vp_assist_page)))
1388                         return 1;
1389                 break;
1390         }
1391         case HV_X64_MSR_EOI:
1392                 return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1393         case HV_X64_MSR_ICR:
1394                 return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1395         case HV_X64_MSR_TPR:
1396                 return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1397         case HV_X64_MSR_VP_RUNTIME:
1398                 if (!host)
1399                         return 1;
1400                 hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1401                 break;
1402         case HV_X64_MSR_SCONTROL:
1403         case HV_X64_MSR_SVERSION:
1404         case HV_X64_MSR_SIEFP:
1405         case HV_X64_MSR_SIMP:
1406         case HV_X64_MSR_EOM:
1407         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1408                 return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1409         case HV_X64_MSR_STIMER0_CONFIG:
1410         case HV_X64_MSR_STIMER1_CONFIG:
1411         case HV_X64_MSR_STIMER2_CONFIG:
1412         case HV_X64_MSR_STIMER3_CONFIG: {
1413                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1414
1415                 return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1416                                          data, host);
1417         }
1418         case HV_X64_MSR_STIMER0_COUNT:
1419         case HV_X64_MSR_STIMER1_COUNT:
1420         case HV_X64_MSR_STIMER2_COUNT:
1421         case HV_X64_MSR_STIMER3_COUNT: {
1422                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1423
1424                 return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1425                                         data, host);
1426         }
1427         case HV_X64_MSR_TSC_FREQUENCY:
1428         case HV_X64_MSR_APIC_FREQUENCY:
1429                 /* read-only, but still ignore it if host-initiated */
1430                 if (!host)
1431                         return 1;
1432                 break;
1433         default:
1434                 vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
1435                             msr, data);
1436                 return 1;
1437         }
1438
1439         return 0;
1440 }
1441
1442 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1443                              bool host)
1444 {
1445         u64 data = 0;
1446         struct kvm *kvm = vcpu->kvm;
1447         struct kvm_hv *hv = to_kvm_hv(kvm);
1448
1449         switch (msr) {
1450         case HV_X64_MSR_GUEST_OS_ID:
1451                 data = hv->hv_guest_os_id;
1452                 break;
1453         case HV_X64_MSR_HYPERCALL:
1454                 data = hv->hv_hypercall;
1455                 break;
1456         case HV_X64_MSR_TIME_REF_COUNT:
1457                 data = get_time_ref_counter(kvm);
1458                 break;
1459         case HV_X64_MSR_REFERENCE_TSC:
1460                 data = hv->hv_tsc_page;
1461                 break;
1462         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1463                 return kvm_hv_msr_get_crash_data(kvm,
1464                                                  msr - HV_X64_MSR_CRASH_P0,
1465                                                  pdata);
1466         case HV_X64_MSR_CRASH_CTL:
1467                 return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1468         case HV_X64_MSR_RESET:
1469                 data = 0;
1470                 break;
1471         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1472                 data = hv->hv_reenlightenment_control;
1473                 break;
1474         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1475                 data = hv->hv_tsc_emulation_control;
1476                 break;
1477         case HV_X64_MSR_TSC_EMULATION_STATUS:
1478                 data = hv->hv_tsc_emulation_status;
1479                 break;
1480         case HV_X64_MSR_SYNDBG_OPTIONS:
1481         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1482                 return syndbg_get_msr(vcpu, msr, pdata, host);
1483         default:
1484                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1485                 return 1;
1486         }
1487
1488         *pdata = data;
1489         return 0;
1490 }
1491
1492 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1493                           bool host)
1494 {
1495         u64 data = 0;
1496         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1497
1498         switch (msr) {
1499         case HV_X64_MSR_VP_INDEX:
1500                 data = hv_vcpu->vp_index;
1501                 break;
1502         case HV_X64_MSR_EOI:
1503                 return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1504         case HV_X64_MSR_ICR:
1505                 return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1506         case HV_X64_MSR_TPR:
1507                 return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1508         case HV_X64_MSR_VP_ASSIST_PAGE:
1509                 data = hv_vcpu->hv_vapic;
1510                 break;
1511         case HV_X64_MSR_VP_RUNTIME:
1512                 data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1513                 break;
1514         case HV_X64_MSR_SCONTROL:
1515         case HV_X64_MSR_SVERSION:
1516         case HV_X64_MSR_SIEFP:
1517         case HV_X64_MSR_SIMP:
1518         case HV_X64_MSR_EOM:
1519         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1520                 return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1521         case HV_X64_MSR_STIMER0_CONFIG:
1522         case HV_X64_MSR_STIMER1_CONFIG:
1523         case HV_X64_MSR_STIMER2_CONFIG:
1524         case HV_X64_MSR_STIMER3_CONFIG: {
1525                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1526
1527                 return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1528                                          pdata);
1529         }
1530         case HV_X64_MSR_STIMER0_COUNT:
1531         case HV_X64_MSR_STIMER1_COUNT:
1532         case HV_X64_MSR_STIMER2_COUNT:
1533         case HV_X64_MSR_STIMER3_COUNT: {
1534                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1535
1536                 return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1537                                         pdata);
1538         }
1539         case HV_X64_MSR_TSC_FREQUENCY:
1540                 data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1541                 break;
1542         case HV_X64_MSR_APIC_FREQUENCY:
1543                 data = APIC_BUS_FREQUENCY;
1544                 break;
1545         default:
1546                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1547                 return 1;
1548         }
1549         *pdata = data;
1550         return 0;
1551 }
1552
1553 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1554 {
1555         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1556
1557         if (!host && !vcpu->arch.hyperv_enabled)
1558                 return 1;
1559
1560         if (!to_hv_vcpu(vcpu)) {
1561                 if (kvm_hv_vcpu_init(vcpu))
1562                         return 1;
1563         }
1564
1565         if (kvm_hv_msr_partition_wide(msr)) {
1566                 int r;
1567
1568                 mutex_lock(&hv->hv_lock);
1569                 r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1570                 mutex_unlock(&hv->hv_lock);
1571                 return r;
1572         } else
1573                 return kvm_hv_set_msr(vcpu, msr, data, host);
1574 }
1575
1576 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1577 {
1578         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1579
1580         if (!host && !vcpu->arch.hyperv_enabled)
1581                 return 1;
1582
1583         if (!to_hv_vcpu(vcpu)) {
1584                 if (kvm_hv_vcpu_init(vcpu))
1585                         return 1;
1586         }
1587
1588         if (kvm_hv_msr_partition_wide(msr)) {
1589                 int r;
1590
1591                 mutex_lock(&hv->hv_lock);
1592                 r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1593                 mutex_unlock(&hv->hv_lock);
1594                 return r;
1595         } else
1596                 return kvm_hv_get_msr(vcpu, msr, pdata, host);
1597 }
1598
1599 static __always_inline unsigned long *sparse_set_to_vcpu_mask(
1600         struct kvm *kvm, u64 *sparse_banks, u64 valid_bank_mask,
1601         u64 *vp_bitmap, unsigned long *vcpu_bitmap)
1602 {
1603         struct kvm_hv *hv = to_kvm_hv(kvm);
1604         struct kvm_vcpu *vcpu;
1605         int i, bank, sbank = 0;
1606
1607         memset(vp_bitmap, 0,
1608                KVM_HV_MAX_SPARSE_VCPU_SET_BITS * sizeof(*vp_bitmap));
1609         for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1610                          KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1611                 vp_bitmap[bank] = sparse_banks[sbank++];
1612
1613         if (likely(!atomic_read(&hv->num_mismatched_vp_indexes))) {
1614                 /* for all vcpus vp_index == vcpu_idx */
1615                 return (unsigned long *)vp_bitmap;
1616         }
1617
1618         bitmap_zero(vcpu_bitmap, KVM_MAX_VCPUS);
1619         kvm_for_each_vcpu(i, vcpu, kvm) {
1620                 if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1621                         __set_bit(i, vcpu_bitmap);
1622         }
1623         return vcpu_bitmap;
1624 }
1625
1626 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, u64 ingpa, u16 rep_cnt, bool ex)
1627 {
1628         struct kvm *kvm = vcpu->kvm;
1629         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1630         struct hv_tlb_flush_ex flush_ex;
1631         struct hv_tlb_flush flush;
1632         u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1633         DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1634         unsigned long *vcpu_mask;
1635         u64 valid_bank_mask;
1636         u64 sparse_banks[64];
1637         int sparse_banks_len;
1638         bool all_cpus;
1639
1640         if (!ex) {
1641                 if (unlikely(kvm_read_guest(kvm, ingpa, &flush, sizeof(flush))))
1642                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1643
1644                 trace_kvm_hv_flush_tlb(flush.processor_mask,
1645                                        flush.address_space, flush.flags);
1646
1647                 valid_bank_mask = BIT_ULL(0);
1648                 sparse_banks[0] = flush.processor_mask;
1649
1650                 /*
1651                  * Work around possible WS2012 bug: it sends hypercalls
1652                  * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
1653                  * while also expecting us to flush something and crashing if
1654                  * we don't. Let's treat processor_mask == 0 same as
1655                  * HV_FLUSH_ALL_PROCESSORS.
1656                  */
1657                 all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
1658                         flush.processor_mask == 0;
1659         } else {
1660                 if (unlikely(kvm_read_guest(kvm, ingpa, &flush_ex,
1661                                             sizeof(flush_ex))))
1662                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1663
1664                 trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
1665                                           flush_ex.hv_vp_set.format,
1666                                           flush_ex.address_space,
1667                                           flush_ex.flags);
1668
1669                 valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
1670                 all_cpus = flush_ex.hv_vp_set.format !=
1671                         HV_GENERIC_SET_SPARSE_4K;
1672
1673                 sparse_banks_len =
1674                         bitmap_weight((unsigned long *)&valid_bank_mask, 64) *
1675                         sizeof(sparse_banks[0]);
1676
1677                 if (!sparse_banks_len && !all_cpus)
1678                         goto ret_success;
1679
1680                 if (!all_cpus &&
1681                     kvm_read_guest(kvm,
1682                                    ingpa + offsetof(struct hv_tlb_flush_ex,
1683                                                     hv_vp_set.bank_contents),
1684                                    sparse_banks,
1685                                    sparse_banks_len))
1686                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1687         }
1688
1689         cpumask_clear(&hv_vcpu->tlb_flush);
1690
1691         vcpu_mask = all_cpus ? NULL :
1692                 sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1693                                         vp_bitmap, vcpu_bitmap);
1694
1695         /*
1696          * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
1697          * analyze it here, flush TLB regardless of the specified address space.
1698          */
1699         kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH,
1700                                     NULL, vcpu_mask, &hv_vcpu->tlb_flush);
1701
1702 ret_success:
1703         /* We always do full TLB flush, set rep_done = rep_cnt. */
1704         return (u64)HV_STATUS_SUCCESS |
1705                 ((u64)rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
1706 }
1707
1708 static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
1709                                  unsigned long *vcpu_bitmap)
1710 {
1711         struct kvm_lapic_irq irq = {
1712                 .delivery_mode = APIC_DM_FIXED,
1713                 .vector = vector
1714         };
1715         struct kvm_vcpu *vcpu;
1716         int i;
1717
1718         kvm_for_each_vcpu(i, vcpu, kvm) {
1719                 if (vcpu_bitmap && !test_bit(i, vcpu_bitmap))
1720                         continue;
1721
1722                 /* We fail only when APIC is disabled */
1723                 kvm_apic_set_irq(vcpu, &irq, NULL);
1724         }
1725 }
1726
1727 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, u64 ingpa, u64 outgpa,
1728                            bool ex, bool fast)
1729 {
1730         struct kvm *kvm = vcpu->kvm;
1731         struct hv_send_ipi_ex send_ipi_ex;
1732         struct hv_send_ipi send_ipi;
1733         u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1734         DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
1735         unsigned long *vcpu_mask;
1736         unsigned long valid_bank_mask;
1737         u64 sparse_banks[64];
1738         int sparse_banks_len;
1739         u32 vector;
1740         bool all_cpus;
1741
1742         if (!ex) {
1743                 if (!fast) {
1744                         if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi,
1745                                                     sizeof(send_ipi))))
1746                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
1747                         sparse_banks[0] = send_ipi.cpu_mask;
1748                         vector = send_ipi.vector;
1749                 } else {
1750                         /* 'reserved' part of hv_send_ipi should be 0 */
1751                         if (unlikely(ingpa >> 32 != 0))
1752                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
1753                         sparse_banks[0] = outgpa;
1754                         vector = (u32)ingpa;
1755                 }
1756                 all_cpus = false;
1757                 valid_bank_mask = BIT_ULL(0);
1758
1759                 trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
1760         } else {
1761                 if (unlikely(kvm_read_guest(kvm, ingpa, &send_ipi_ex,
1762                                             sizeof(send_ipi_ex))))
1763                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1764
1765                 trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
1766                                          send_ipi_ex.vp_set.format,
1767                                          send_ipi_ex.vp_set.valid_bank_mask);
1768
1769                 vector = send_ipi_ex.vector;
1770                 valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
1771                 sparse_banks_len = bitmap_weight(&valid_bank_mask, 64) *
1772                         sizeof(sparse_banks[0]);
1773
1774                 all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
1775
1776                 if (!sparse_banks_len)
1777                         goto ret_success;
1778
1779                 if (!all_cpus &&
1780                     kvm_read_guest(kvm,
1781                                    ingpa + offsetof(struct hv_send_ipi_ex,
1782                                                     vp_set.bank_contents),
1783                                    sparse_banks,
1784                                    sparse_banks_len))
1785                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1786         }
1787
1788         if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
1789                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
1790
1791         vcpu_mask = all_cpus ? NULL :
1792                 sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask,
1793                                         vp_bitmap, vcpu_bitmap);
1794
1795         kvm_send_ipi_to_many(kvm, vector, vcpu_mask);
1796
1797 ret_success:
1798         return HV_STATUS_SUCCESS;
1799 }
1800
1801 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu)
1802 {
1803         struct kvm_cpuid_entry2 *entry;
1804
1805         entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_INTERFACE, 0);
1806         if (entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX)
1807                 vcpu->arch.hyperv_enabled = true;
1808         else
1809                 vcpu->arch.hyperv_enabled = false;
1810 }
1811
1812 bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
1813 {
1814         return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
1815 }
1816
1817 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1818 {
1819         bool longmode;
1820
1821         longmode = is_64_bit_mode(vcpu);
1822         if (longmode)
1823                 kvm_rax_write(vcpu, result);
1824         else {
1825                 kvm_rdx_write(vcpu, result >> 32);
1826                 kvm_rax_write(vcpu, result & 0xffffffff);
1827         }
1828 }
1829
1830 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
1831 {
1832         kvm_hv_hypercall_set_result(vcpu, result);
1833         ++vcpu->stat.hypercalls;
1834         return kvm_skip_emulated_instruction(vcpu);
1835 }
1836
1837 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1838 {
1839         return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
1840 }
1841
1842 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
1843 {
1844         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1845         struct eventfd_ctx *eventfd;
1846
1847         if (unlikely(!fast)) {
1848                 int ret;
1849                 gpa_t gpa = param;
1850
1851                 if ((gpa & (__alignof__(param) - 1)) ||
1852                     offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
1853                         return HV_STATUS_INVALID_ALIGNMENT;
1854
1855                 ret = kvm_vcpu_read_guest(vcpu, gpa, &param, sizeof(param));
1856                 if (ret < 0)
1857                         return HV_STATUS_INVALID_ALIGNMENT;
1858         }
1859
1860         /*
1861          * Per spec, bits 32-47 contain the extra "flag number".  However, we
1862          * have no use for it, and in all known usecases it is zero, so just
1863          * report lookup failure if it isn't.
1864          */
1865         if (param & 0xffff00000000ULL)
1866                 return HV_STATUS_INVALID_PORT_ID;
1867         /* remaining bits are reserved-zero */
1868         if (param & ~KVM_HYPERV_CONN_ID_MASK)
1869                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
1870
1871         /* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
1872         rcu_read_lock();
1873         eventfd = idr_find(&hv->conn_to_evt, param);
1874         rcu_read_unlock();
1875         if (!eventfd)
1876                 return HV_STATUS_INVALID_PORT_ID;
1877
1878         eventfd_signal(eventfd, 1);
1879         return HV_STATUS_SUCCESS;
1880 }
1881
1882 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1883 {
1884         u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
1885         uint16_t code, rep_idx, rep_cnt;
1886         bool fast, rep;
1887
1888         /*
1889          * hypercall generates UD from non zero cpl and real mode
1890          * per HYPER-V spec
1891          */
1892         if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
1893                 kvm_queue_exception(vcpu, UD_VECTOR);
1894                 return 1;
1895         }
1896
1897 #ifdef CONFIG_X86_64
1898         if (is_64_bit_mode(vcpu)) {
1899                 param = kvm_rcx_read(vcpu);
1900                 ingpa = kvm_rdx_read(vcpu);
1901                 outgpa = kvm_r8_read(vcpu);
1902         } else
1903 #endif
1904         {
1905                 param = ((u64)kvm_rdx_read(vcpu) << 32) |
1906                         (kvm_rax_read(vcpu) & 0xffffffff);
1907                 ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
1908                         (kvm_rcx_read(vcpu) & 0xffffffff);
1909                 outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
1910                         (kvm_rsi_read(vcpu) & 0xffffffff);
1911         }
1912
1913         code = param & 0xffff;
1914         fast = !!(param & HV_HYPERCALL_FAST_BIT);
1915         rep_cnt = (param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
1916         rep_idx = (param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
1917         rep = !!(rep_cnt || rep_idx);
1918
1919         trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
1920
1921         switch (code) {
1922         case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1923                 if (unlikely(rep)) {
1924                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1925                         break;
1926                 }
1927                 kvm_vcpu_on_spin(vcpu, true);
1928                 break;
1929         case HVCALL_SIGNAL_EVENT:
1930                 if (unlikely(rep)) {
1931                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1932                         break;
1933                 }
1934                 ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
1935                 if (ret != HV_STATUS_INVALID_PORT_ID)
1936                         break;
1937                 fallthrough;    /* maybe userspace knows this conn_id */
1938         case HVCALL_POST_MESSAGE:
1939                 /* don't bother userspace if it has no way to handle it */
1940                 if (unlikely(rep || !to_hv_synic(vcpu)->active)) {
1941                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1942                         break;
1943                 }
1944                 vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1945                 vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1946                 vcpu->run->hyperv.u.hcall.input = param;
1947                 vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1948                 vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1949                 vcpu->arch.complete_userspace_io =
1950                                 kvm_hv_hypercall_complete_userspace;
1951                 return 0;
1952         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
1953                 if (unlikely(fast || !rep_cnt || rep_idx)) {
1954                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1955                         break;
1956                 }
1957                 ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1958                 break;
1959         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
1960                 if (unlikely(fast || rep)) {
1961                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1962                         break;
1963                 }
1964                 ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, false);
1965                 break;
1966         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
1967                 if (unlikely(fast || !rep_cnt || rep_idx)) {
1968                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1969                         break;
1970                 }
1971                 ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1972                 break;
1973         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
1974                 if (unlikely(fast || rep)) {
1975                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1976                         break;
1977                 }
1978                 ret = kvm_hv_flush_tlb(vcpu, ingpa, rep_cnt, true);
1979                 break;
1980         case HVCALL_SEND_IPI:
1981                 if (unlikely(rep)) {
1982                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1983                         break;
1984                 }
1985                 ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, false, fast);
1986                 break;
1987         case HVCALL_SEND_IPI_EX:
1988                 if (unlikely(fast || rep)) {
1989                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
1990                         break;
1991                 }
1992                 ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, true, false);
1993                 break;
1994         case HVCALL_POST_DEBUG_DATA:
1995         case HVCALL_RETRIEVE_DEBUG_DATA:
1996                 if (unlikely(fast)) {
1997                         ret = HV_STATUS_INVALID_PARAMETER;
1998                         break;
1999                 }
2000                 fallthrough;
2001         case HVCALL_RESET_DEBUG_SESSION: {
2002                 struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2003
2004                 if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2005                         ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2006                         break;
2007                 }
2008
2009                 if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2010                         ret = HV_STATUS_OPERATION_DENIED;
2011                         break;
2012                 }
2013                 vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2014                 vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2015                 vcpu->run->hyperv.u.hcall.input = param;
2016                 vcpu->run->hyperv.u.hcall.params[0] = ingpa;
2017                 vcpu->run->hyperv.u.hcall.params[1] = outgpa;
2018                 vcpu->arch.complete_userspace_io =
2019                                 kvm_hv_hypercall_complete_userspace;
2020                 return 0;
2021         }
2022         default:
2023                 ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2024                 break;
2025         }
2026
2027         return kvm_hv_hypercall_complete(vcpu, ret);
2028 }
2029
2030 void kvm_hv_init_vm(struct kvm *kvm)
2031 {
2032         struct kvm_hv *hv = to_kvm_hv(kvm);
2033
2034         mutex_init(&hv->hv_lock);
2035         idr_init(&hv->conn_to_evt);
2036 }
2037
2038 void kvm_hv_destroy_vm(struct kvm *kvm)
2039 {
2040         struct kvm_hv *hv = to_kvm_hv(kvm);
2041         struct eventfd_ctx *eventfd;
2042         int i;
2043
2044         idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2045                 eventfd_ctx_put(eventfd);
2046         idr_destroy(&hv->conn_to_evt);
2047 }
2048
2049 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2050 {
2051         struct kvm_hv *hv = to_kvm_hv(kvm);
2052         struct eventfd_ctx *eventfd;
2053         int ret;
2054
2055         eventfd = eventfd_ctx_fdget(fd);
2056         if (IS_ERR(eventfd))
2057                 return PTR_ERR(eventfd);
2058
2059         mutex_lock(&hv->hv_lock);
2060         ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2061                         GFP_KERNEL_ACCOUNT);
2062         mutex_unlock(&hv->hv_lock);
2063
2064         if (ret >= 0)
2065                 return 0;
2066
2067         if (ret == -ENOSPC)
2068                 ret = -EEXIST;
2069         eventfd_ctx_put(eventfd);
2070         return ret;
2071 }
2072
2073 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2074 {
2075         struct kvm_hv *hv = to_kvm_hv(kvm);
2076         struct eventfd_ctx *eventfd;
2077
2078         mutex_lock(&hv->hv_lock);
2079         eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2080         mutex_unlock(&hv->hv_lock);
2081
2082         if (!eventfd)
2083                 return -ENOENT;
2084
2085         synchronize_srcu(&kvm->srcu);
2086         eventfd_ctx_put(eventfd);
2087         return 0;
2088 }
2089
2090 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2091 {
2092         if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2093             (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2094                 return -EINVAL;
2095
2096         if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2097                 return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2098         return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2099 }
2100
2101 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2102                      struct kvm_cpuid_entry2 __user *entries)
2103 {
2104         uint16_t evmcs_ver = 0;
2105         struct kvm_cpuid_entry2 cpuid_entries[] = {
2106                 { .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2107                 { .function = HYPERV_CPUID_INTERFACE },
2108                 { .function = HYPERV_CPUID_VERSION },
2109                 { .function = HYPERV_CPUID_FEATURES },
2110                 { .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2111                 { .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2112                 { .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2113                 { .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2114                 { .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES },
2115                 { .function = HYPERV_CPUID_NESTED_FEATURES },
2116         };
2117         int i, nent = ARRAY_SIZE(cpuid_entries);
2118
2119         if (kvm_x86_ops.nested_ops->get_evmcs_version)
2120                 evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2121
2122         /* Skip NESTED_FEATURES if eVMCS is not supported */
2123         if (!evmcs_ver)
2124                 --nent;
2125
2126         if (cpuid->nent < nent)
2127                 return -E2BIG;
2128
2129         if (cpuid->nent > nent)
2130                 cpuid->nent = nent;
2131
2132         for (i = 0; i < nent; i++) {
2133                 struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2134                 u32 signature[3];
2135
2136                 switch (ent->function) {
2137                 case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2138                         memcpy(signature, "Linux KVM Hv", 12);
2139
2140                         ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2141                         ent->ebx = signature[0];
2142                         ent->ecx = signature[1];
2143                         ent->edx = signature[2];
2144                         break;
2145
2146                 case HYPERV_CPUID_INTERFACE:
2147                         ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2148                         break;
2149
2150                 case HYPERV_CPUID_VERSION:
2151                         /*
2152                          * We implement some Hyper-V 2016 functions so let's use
2153                          * this version.
2154                          */
2155                         ent->eax = 0x00003839;
2156                         ent->ebx = 0x000A0000;
2157                         break;
2158
2159                 case HYPERV_CPUID_FEATURES:
2160                         ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2161                         ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2162                         ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2163                         ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2164                         ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2165                         ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2166                         ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2167                         ent->eax |= HV_MSR_RESET_AVAILABLE;
2168                         ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2169                         ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2170                         ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2171
2172                         ent->ebx |= HV_POST_MESSAGES;
2173                         ent->ebx |= HV_SIGNAL_EVENTS;
2174
2175                         ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2176                         ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2177
2178                         ent->ebx |= HV_DEBUGGING;
2179                         ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2180                         ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2181
2182                         /*
2183                          * Direct Synthetic timers only make sense with in-kernel
2184                          * LAPIC
2185                          */
2186                         if (!vcpu || lapic_in_kernel(vcpu))
2187                                 ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2188
2189                         break;
2190
2191                 case HYPERV_CPUID_ENLIGHTMENT_INFO:
2192                         ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2193                         ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2194                         ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2195                         ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2196                         ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2197                         if (evmcs_ver)
2198                                 ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2199                         if (!cpu_smt_possible())
2200                                 ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2201                         /*
2202                          * Default number of spinlock retry attempts, matches
2203                          * HyperV 2016.
2204                          */
2205                         ent->ebx = 0x00000FFF;
2206
2207                         break;
2208
2209                 case HYPERV_CPUID_IMPLEMENT_LIMITS:
2210                         /* Maximum number of virtual processors */
2211                         ent->eax = KVM_MAX_VCPUS;
2212                         /*
2213                          * Maximum number of logical processors, matches
2214                          * HyperV 2016.
2215                          */
2216                         ent->ebx = 64;
2217
2218                         break;
2219
2220                 case HYPERV_CPUID_NESTED_FEATURES:
2221                         ent->eax = evmcs_ver;
2222
2223                         break;
2224
2225                 case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2226                         memcpy(signature, "Linux KVM Hv", 12);
2227
2228                         ent->eax = 0;
2229                         ent->ebx = signature[0];
2230                         ent->ecx = signature[1];
2231                         ent->edx = signature[2];
2232                         break;
2233
2234                 case HYPERV_CPUID_SYNDBG_INTERFACE:
2235                         memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2236                         ent->eax = signature[0];
2237                         break;
2238
2239                 case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2240                         ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2241                         break;
2242
2243                 default:
2244                         break;
2245                 }
2246         }
2247
2248         if (copy_to_user(entries, cpuid_entries,
2249                          nent * sizeof(struct kvm_cpuid_entry2)))
2250                 return -EFAULT;
2251
2252         return 0;
2253 }