arch/x86/kvm/hyperv.c

   1 /*
   2  * KVM Microsoft Hyper-V emulation
   3  *
   4  * derived from arch/x86/kvm/x86.c
   5  *
   6  * Copyright (C) 2006 Qumranet, Inc.
   7  * Copyright (C) 2008 Qumranet, Inc.
   8  * Copyright IBM Corporation, 2008
   9  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  10  * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
  11  *
  12  * Authors:
  13  *   Avi Kivity   <avi@qumranet.com>
  14  *   Yaniv Kamay  <yaniv@qumranet.com>
  15  *   Amit Shah    <amit.shah@qumranet.com>
  16  *   Ben-Ami Yassour <benami@il.ibm.com>
  17  *   Andrey Smetanin <asmetanin@virtuozzo.com>
  18  *
  19  * This work is licensed under the terms of the GNU GPL, version 2.  See
  20  * the COPYING file in the top-level directory.
  21  *
  22  */
  23
  24 #include "x86.h"
  25 #include "lapic.h"
  26 #include "ioapic.h"
  27 #include "hyperv.h"
  28
  29 #include <linux/kvm_host.h>
  30 #include <linux/highmem.h>
  31 #include <linux/nospec.h>
  32 #include <asm/apicdef.h>
  33 #include <trace/events/kvm.h>
  34
  35 #include "trace.h"
  36
  37 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
  38 {
  39         return atomic64_read(&synic->sint[sint]);
  40 }
  41
  42 static inline int synic_get_sint_vector(u64 sint_value)
  43 {
  44         if (sint_value & HV_SYNIC_SINT_MASKED)
  45                 return -1;
  46         return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
  47 }
  48
  49 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
  50                                       int vector)
  51 {
  52         int i;
  53
  54         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  55                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
  56                         return true;
  57         }
  58         return false;
  59 }
  60
  61 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
  62                                      int vector)
  63 {
  64         int i;
  65         u64 sint_value;
  66
  67         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  68                 sint_value = synic_read_sint(synic, i);
  69                 if (synic_get_sint_vector(sint_value) == vector &&
  70                     sint_value & HV_SYNIC_SINT_AUTO_EOI)
  71                         return true;
  72         }
  73         return false;
  74 }
  75
  76 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
  77                           u64 data, bool host)
  78 {
  79         int vector;
  80
  81         vector = data & HV_SYNIC_SINT_VECTOR_MASK;
  82         if (vector < 16 && !host)
  83                 return 1;
  84         /*
  85          * Guest may configure multiple SINTs to use the same vector, so
  86          * we maintain a bitmap of vectors handled by synic, and a
  87          * bitmap of vectors with auto-eoi behavior.  The bitmaps are
  88          * updated here, and atomically queried on fast paths.
  89          */
  90
  91         atomic64_set(&synic->sint[sint], data);
  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         /* Load SynIC vectors into EOI exit bitmap */
 104         kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
 105         return 0;
 106 }
 107
 108 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vcpu_id)
 109 {
 110         struct kvm_vcpu *vcpu;
 111         struct kvm_vcpu_hv_synic *synic;
 112
 113         if (vcpu_id >= atomic_read(&kvm->online_vcpus))
 114                 return NULL;
 115         vcpu = kvm_get_vcpu(kvm, vcpu_id);
 116         if (!vcpu)
 117                 return NULL;
 118         synic = vcpu_to_synic(vcpu);
 119         return (synic->active) ? synic : NULL;
 120 }
 121
 122 static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
 123                                         u32 sint)
 124 {
 125         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 126         struct page *page;
 127         gpa_t gpa;
 128         struct hv_message *msg;
 129         struct hv_message_page *msg_page;
 130
 131         gpa = synic->msg_page & PAGE_MASK;
 132         page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
 133         if (is_error_page(page)) {
 134                 vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
 135                          gpa);
 136                 return;
 137         }
 138         msg_page = kmap_atomic(page);
 139
 140         msg = &msg_page->sint_message[sint];
 141         msg->header.message_flags.msg_pending = 0;
 142
 143         kunmap_atomic(msg_page);
 144         kvm_release_page_dirty(page);
 145         kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
 146 }
 147
 148 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 149 {
 150         struct kvm *kvm = vcpu->kvm;
 151         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 152         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 153         struct kvm_vcpu_hv_stimer *stimer;
 154         int gsi, idx, stimers_pending;
 155
 156         trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
 157
 158         if (synic->msg_page & HV_SYNIC_SIMP_ENABLE)
 159                 synic_clear_sint_msg_pending(synic, sint);
 160
 161         /* Try to deliver pending Hyper-V SynIC timers messages */
 162         stimers_pending = 0;
 163         for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
 164                 stimer = &hv_vcpu->stimer[idx];
 165                 if (stimer->msg_pending &&
 166                     (stimer->config & HV_STIMER_ENABLE) &&
 167                     HV_STIMER_SINT(stimer->config) == sint) {
 168                         set_bit(stimer->index,
 169                                 hv_vcpu->stimer_pending_bitmap);
 170                         stimers_pending++;
 171                 }
 172         }
 173         if (stimers_pending)
 174                 kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 175
 176         idx = srcu_read_lock(&kvm->irq_srcu);
 177         gsi = atomic_read(&synic->sint_to_gsi[sint]);
 178         if (gsi != -1)
 179                 kvm_notify_acked_gsi(kvm, gsi);
 180         srcu_read_unlock(&kvm->irq_srcu, idx);
 181 }
 182
 183 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
 184 {
 185         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 186         struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
 187
 188         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
 189         hv_vcpu->exit.u.synic.msr = msr;
 190         hv_vcpu->exit.u.synic.control = synic->control;
 191         hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
 192         hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
 193
 194         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 195 }
 196
 197 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
 198                          u32 msr, u64 data, bool host)
 199 {
 200         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 201         int ret;
 202
 203         if (!synic->active)
 204                 return 1;
 205
 206         trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
 207
 208         ret = 0;
 209         switch (msr) {
 210         case HV_X64_MSR_SCONTROL:
 211                 synic->control = data;
 212                 if (!host)
 213                         synic_exit(synic, msr);
 214                 break;
 215         case HV_X64_MSR_SVERSION:
 216                 if (!host) {
 217                         ret = 1;
 218                         break;
 219                 }
 220                 synic->version = data;
 221                 break;
 222         case HV_X64_MSR_SIEFP:
 223                 if (data & HV_SYNIC_SIEFP_ENABLE)
 224                         if (kvm_clear_guest(vcpu->kvm,
 225                                             data & PAGE_MASK, PAGE_SIZE)) {
 226                                 ret = 1;
 227                                 break;
 228                         }
 229                 synic->evt_page = data;
 230                 if (!host)
 231                         synic_exit(synic, msr);
 232                 break;
 233         case HV_X64_MSR_SIMP:
 234                 if (data & HV_SYNIC_SIMP_ENABLE)
 235                         if (kvm_clear_guest(vcpu->kvm,
 236                                             data & PAGE_MASK, PAGE_SIZE)) {
 237                                 ret = 1;
 238                                 break;
 239                         }
 240                 synic->msg_page = data;
 241                 if (!host)
 242                         synic_exit(synic, msr);
 243                 break;
 244         case HV_X64_MSR_EOM: {
 245                 int i;
 246
 247                 if (!synic->active)
 248                         break;
 249
 250                 for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 251                         kvm_hv_notify_acked_sint(vcpu, i);
 252                 break;
 253         }
 254         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 255                 ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
 256                 break;
 257         default:
 258                 ret = 1;
 259                 break;
 260         }
 261         return ret;
 262 }
 263
 264 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata)
 265 {
 266         int ret;
 267
 268         if (!synic->active)
 269                 return 1;
 270
 271         ret = 0;
 272         switch (msr) {
 273         case HV_X64_MSR_SCONTROL:
 274                 *pdata = synic->control;
 275                 break;
 276         case HV_X64_MSR_SVERSION:
 277                 *pdata = synic->version;
 278                 break;
 279         case HV_X64_MSR_SIEFP:
 280                 *pdata = synic->evt_page;
 281                 break;
 282         case HV_X64_MSR_SIMP:
 283                 *pdata = synic->msg_page;
 284                 break;
 285         case HV_X64_MSR_EOM:
 286                 *pdata = 0;
 287                 break;
 288         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 289                 *pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
 290                 break;
 291         default:
 292                 ret = 1;
 293                 break;
 294         }
 295         return ret;
 296 }
 297
 298 int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
 299 {
 300         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 301         struct kvm_lapic_irq irq;
 302         int ret, vector;
 303
 304         if (sint >= ARRAY_SIZE(synic->sint))
 305                 return -EINVAL;
 306
 307         vector = synic_get_sint_vector(synic_read_sint(synic, sint));
 308         if (vector < 0)
 309                 return -ENOENT;
 310
 311         memset(&irq, 0, sizeof(irq));
 312         irq.dest_id = kvm_apic_id(vcpu->arch.apic);
 313         irq.dest_mode = APIC_DEST_PHYSICAL;
 314         irq.delivery_mode = APIC_DM_FIXED;
 315         irq.vector = vector;
 316         irq.level = 1;
 317
 318         ret = kvm_irq_delivery_to_apic(vcpu->kvm, NULL, &irq, NULL);
 319         trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
 320         return ret;
 321 }
 322
 323 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vcpu_id, u32 sint)
 324 {
 325         struct kvm_vcpu_hv_synic *synic;
 326
 327         synic = synic_get(kvm, vcpu_id);
 328         if (!synic)
 329                 return -EINVAL;
 330
 331         return synic_set_irq(synic, sint);
 332 }
 333
 334 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
 335 {
 336         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 337         int i;
 338
 339         trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
 340
 341         for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 342                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
 343                         kvm_hv_notify_acked_sint(vcpu, i);
 344 }
 345
 346 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vcpu_id, u32 sint, int gsi)
 347 {
 348         struct kvm_vcpu_hv_synic *synic;
 349
 350         synic = synic_get(kvm, vcpu_id);
 351         if (!synic)
 352                 return -EINVAL;
 353
 354         if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
 355                 return -EINVAL;
 356
 357         atomic_set(&synic->sint_to_gsi[sint], gsi);
 358         return 0;
 359 }
 360
 361 void kvm_hv_irq_routing_update(struct kvm *kvm)
 362 {
 363         struct kvm_irq_routing_table *irq_rt;
 364         struct kvm_kernel_irq_routing_entry *e;
 365         u32 gsi;
 366
 367         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
 368                                         lockdep_is_held(&kvm->irq_lock));
 369
 370         for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
 371                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
 372                         if (e->type == KVM_IRQ_ROUTING_HV_SINT)
 373                                 kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
 374                                                     e->hv_sint.sint, gsi);
 375                 }
 376         }
 377 }
 378
 379 static void synic_init(struct kvm_vcpu_hv_synic *synic)
 380 {
 381         int i;
 382
 383         memset(synic, 0, sizeof(*synic));
 384         synic->version = HV_SYNIC_VERSION_1;
 385         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
 386                 atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
 387                 atomic_set(&synic->sint_to_gsi[i], -1);
 388         }
 389 }
 390
 391 static u64 get_time_ref_counter(struct kvm *kvm)
 392 {
 393         struct kvm_hv *hv = &kvm->arch.hyperv;
 394         struct kvm_vcpu *vcpu;
 395         u64 tsc;
 396
 397         /*
 398          * The guest has not set up the TSC page or the clock isn't
 399          * stable, fall back to get_kvmclock_ns.
 400          */
 401         if (!hv->tsc_ref.tsc_sequence)
 402                 return div_u64(get_kvmclock_ns(kvm), 100);
 403
 404         vcpu = kvm_get_vcpu(kvm, 0);
 405         tsc = kvm_read_l1_tsc(vcpu, rdtsc());
 406         return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
 407                 + hv->tsc_ref.tsc_offset;
 408 }
 409
 410 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
 411                                 bool vcpu_kick)
 412 {
 413         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 414
 415         set_bit(stimer->index,
 416                 vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 417         kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 418         if (vcpu_kick)
 419                 kvm_vcpu_kick(vcpu);
 420 }
 421
 422 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
 423 {
 424         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 425
 426         trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
 427                                     stimer->index);
 428
 429         hrtimer_cancel(&stimer->timer);
 430         clear_bit(stimer->index,
 431                   vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 432         stimer->msg_pending = false;
 433         stimer->exp_time = 0;
 434 }
 435
 436 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
 437 {
 438         struct kvm_vcpu_hv_stimer *stimer;
 439
 440         stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
 441         trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
 442                                      stimer->index);
 443         stimer_mark_pending(stimer, true);
 444
 445         return HRTIMER_NORESTART;
 446 }
 447
 448 /*
 449  * stimer_start() assumptions:
 450  * a) stimer->count is not equal to 0
 451  * b) stimer->config has HV_STIMER_ENABLE flag
 452  */
 453 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
 454 {
 455         u64 time_now;
 456         ktime_t ktime_now;
 457
 458         time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
 459         ktime_now = ktime_get();
 460
 461         if (stimer->config & HV_STIMER_PERIODIC) {
 462                 if (stimer->exp_time) {
 463                         if (time_now >= stimer->exp_time) {
 464                                 u64 remainder;
 465
 466                                 div64_u64_rem(time_now - stimer->exp_time,
 467                                               stimer->count, &remainder);
 468                                 stimer->exp_time =
 469                                         time_now + (stimer->count - remainder);
 470                         }
 471                 } else
 472                         stimer->exp_time = time_now + stimer->count;
 473
 474                 trace_kvm_hv_stimer_start_periodic(
 475                                         stimer_to_vcpu(stimer)->vcpu_id,
 476                                         stimer->index,
 477                                         time_now, stimer->exp_time);
 478
 479                 hrtimer_start(&stimer->timer,
 480                               ktime_add_ns(ktime_now,
 481                                            100 * (stimer->exp_time - time_now)),
 482                               HRTIMER_MODE_ABS);
 483                 return 0;
 484         }
 485         stimer->exp_time = stimer->count;
 486         if (time_now >= stimer->count) {
 487                 /*
 488                  * Expire timer according to Hypervisor Top-Level Functional
 489                  * specification v4(15.3.1):
 490                  * "If a one shot is enabled and the specified count is in
 491                  * the past, it will expire immediately."
 492                  */
 493                 stimer_mark_pending(stimer, false);
 494                 return 0;
 495         }
 496
 497         trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
 498                                            stimer->index,
 499                                            time_now, stimer->count);
 500
 501         hrtimer_start(&stimer->timer,
 502                       ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
 503                       HRTIMER_MODE_ABS);
 504         return 0;
 505 }
 506
 507 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
 508                              bool host)
 509 {
 510         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 511         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 512
 513         if (!synic->active && (!host || config))
 514                 return 1;
 515
 516         trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
 517                                        stimer->index, config, host);
 518
 519         stimer_cleanup(stimer);
 520         if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0)
 521                 config &= ~HV_STIMER_ENABLE;
 522         stimer->config = config;
 523         stimer_mark_pending(stimer, false);
 524         return 0;
 525 }
 526
 527 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
 528                             bool host)
 529 {
 530         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 531         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 532
 533         if (!synic->active && (!host || count))
 534                 return 1;
 535
 536         trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
 537                                       stimer->index, count, host);
 538
 539         stimer_cleanup(stimer);
 540         stimer->count = count;
 541         if (stimer->count == 0)
 542                 stimer->config &= ~HV_STIMER_ENABLE;
 543         else if (stimer->config & HV_STIMER_AUTOENABLE)
 544                 stimer->config |= HV_STIMER_ENABLE;
 545         stimer_mark_pending(stimer, false);
 546         return 0;
 547 }
 548
 549 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
 550 {
 551         *pconfig = stimer->config;
 552         return 0;
 553 }
 554
 555 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
 556 {
 557         *pcount = stimer->count;
 558         return 0;
 559 }
 560
 561 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
 562                              struct hv_message *src_msg)
 563 {
 564         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 565         struct page *page;
 566         gpa_t gpa;
 567         struct hv_message *dst_msg;
 568         int r;
 569         struct hv_message_page *msg_page;
 570
 571         if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
 572                 return -ENOENT;
 573
 574         gpa = synic->msg_page & PAGE_MASK;
 575         page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
 576         if (is_error_page(page))
 577                 return -EFAULT;
 578
 579         msg_page = kmap_atomic(page);
 580         dst_msg = &msg_page->sint_message[sint];
 581         if (sync_cmpxchg(&dst_msg->header.message_type, HVMSG_NONE,
 582                          src_msg->header.message_type) != HVMSG_NONE) {
 583                 dst_msg->header.message_flags.msg_pending = 1;
 584                 r = -EAGAIN;
 585         } else {
 586                 memcpy(&dst_msg->u.payload, &src_msg->u.payload,
 587                        src_msg->header.payload_size);
 588                 dst_msg->header.message_type = src_msg->header.message_type;
 589                 dst_msg->header.payload_size = src_msg->header.payload_size;
 590                 r = synic_set_irq(synic, sint);
 591                 if (r >= 1)
 592                         r = 0;
 593                 else if (r == 0)
 594                         r = -EFAULT;
 595         }
 596         kunmap_atomic(msg_page);
 597         kvm_release_page_dirty(page);
 598         kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
 599         return r;
 600 }
 601
 602 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
 603 {
 604         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 605         struct hv_message *msg = &stimer->msg;
 606         struct hv_timer_message_payload *payload =
 607                         (struct hv_timer_message_payload *)&msg->u.payload;
 608
 609         payload->expiration_time = stimer->exp_time;
 610         payload->delivery_time = get_time_ref_counter(vcpu->kvm);
 611         return synic_deliver_msg(vcpu_to_synic(vcpu),
 612                                  HV_STIMER_SINT(stimer->config), msg);
 613 }
 614
 615 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
 616 {
 617         int r;
 618
 619         stimer->msg_pending = true;
 620         r = stimer_send_msg(stimer);
 621         trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
 622                                        stimer->index, r);
 623         if (!r) {
 624                 stimer->msg_pending = false;
 625                 if (!(stimer->config & HV_STIMER_PERIODIC))
 626                         stimer->config &= ~HV_STIMER_ENABLE;
 627         }
 628 }
 629
 630 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
 631 {
 632         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 633         struct kvm_vcpu_hv_stimer *stimer;
 634         u64 time_now, exp_time;
 635         int i;
 636
 637         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 638                 if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
 639                         stimer = &hv_vcpu->stimer[i];
 640                         if (stimer->config & HV_STIMER_ENABLE) {
 641                                 exp_time = stimer->exp_time;
 642
 643                                 if (exp_time) {
 644                                         time_now =
 645                                                 get_time_ref_counter(vcpu->kvm);
 646                                         if (time_now >= exp_time)
 647                                                 stimer_expiration(stimer);
 648                                 }
 649
 650                                 if ((stimer->config & HV_STIMER_ENABLE) &&
 651                                     stimer->count)
 652                                         stimer_start(stimer);
 653                                 else
 654                                         stimer_cleanup(stimer);
 655                         }
 656                 }
 657 }
 658
 659 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
 660 {
 661         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 662         int i;
 663
 664         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 665                 stimer_cleanup(&hv_vcpu->stimer[i]);
 666 }
 667
 668 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
 669 {
 670         struct hv_message *msg = &stimer->msg;
 671         struct hv_timer_message_payload *payload =
 672                         (struct hv_timer_message_payload *)&msg->u.payload;
 673
 674         memset(&msg->header, 0, sizeof(msg->header));
 675         msg->header.message_type = HVMSG_TIMER_EXPIRED;
 676         msg->header.payload_size = sizeof(*payload);
 677
 678         payload->timer_index = stimer->index;
 679         payload->expiration_time = 0;
 680         payload->delivery_time = 0;
 681 }
 682
 683 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
 684 {
 685         memset(stimer, 0, sizeof(*stimer));
 686         stimer->index = timer_index;
 687         hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 688         stimer->timer.function = stimer_timer_callback;
 689         stimer_prepare_msg(stimer);
 690 }
 691
 692 void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
 693 {
 694         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 695         int i;
 696
 697         synic_init(&hv_vcpu->synic);
 698
 699         bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
 700         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 701                 stimer_init(&hv_vcpu->stimer[i], i);
 702 }
 703
 704 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu)
 705 {
 706         /*
 707          * Hyper-V SynIC auto EOI SINT's are
 708          * not compatible with APICV, so deactivate APICV
 709          */
 710         kvm_vcpu_deactivate_apicv(vcpu);
 711         vcpu_to_synic(vcpu)->active = true;
 712         return 0;
 713 }
 714
 715 static bool kvm_hv_msr_partition_wide(u32 msr)
 716 {
 717         bool r = false;
 718
 719         switch (msr) {
 720         case HV_X64_MSR_GUEST_OS_ID:
 721         case HV_X64_MSR_HYPERCALL:
 722         case HV_X64_MSR_REFERENCE_TSC:
 723         case HV_X64_MSR_TIME_REF_COUNT:
 724         case HV_X64_MSR_CRASH_CTL:
 725         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
 726         case HV_X64_MSR_RESET:
 727                 r = true;
 728                 break;
 729         }
 730
 731         return r;
 732 }
 733
 734 static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
 735                                      u32 index, u64 *pdata)
 736 {
 737         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 738         size_t size = ARRAY_SIZE(hv->hv_crash_param);
 739
 740         if (WARN_ON_ONCE(index >= size))
 741                 return -EINVAL;
 742
 743         *pdata = hv->hv_crash_param[array_index_nospec(index, size)];
 744         return 0;
 745 }
 746
 747 static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
 748 {
 749         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 750
 751         *pdata = hv->hv_crash_ctl;
 752         return 0;
 753 }
 754
 755 static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
 756 {
 757         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 758
 759         if (host)
 760                 hv->hv_crash_ctl = data & HV_X64_MSR_CRASH_CTL_NOTIFY;
 761
 762         if (!host && (data & HV_X64_MSR_CRASH_CTL_NOTIFY)) {
 763
 764                 vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
 765                           hv->hv_crash_param[0],
 766                           hv->hv_crash_param[1],
 767                           hv->hv_crash_param[2],
 768                           hv->hv_crash_param[3],
 769                           hv->hv_crash_param[4]);
 770
 771                 /* Send notification about crash to user space */
 772                 kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
 773         }
 774
 775         return 0;
 776 }
 777
 778 static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
 779                                      u32 index, u64 data)
 780 {
 781         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 782         size_t size = ARRAY_SIZE(hv->hv_crash_param);
 783
 784         if (WARN_ON_ONCE(index >= size))
 785                 return -EINVAL;
 786
 787         hv->hv_crash_param[array_index_nospec(index, size)] = data;
 788         return 0;
 789 }
 790
 791 /*
 792  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
 793  * between them is possible:
 794  *
 795  * kvmclock formula:
 796  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
 797  *           + system_time
 798  *
 799  * Hyper-V formula:
 800  *    nsec/100 = ticks * scale / 2^64 + offset
 801  *
 802  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
 803  * By dividing the kvmclock formula by 100 and equating what's left we get:
 804  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 805  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
 806  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
 807  *
 808  * Now expand the kvmclock formula and divide by 100:
 809  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
 810  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
 811  *           + system_time
 812  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 813  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 814  *               + system_time / 100
 815  *
 816  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
 817  *    nsec/100 = ticks * scale / 2^64
 818  *               - tsc_timestamp * scale / 2^64
 819  *               + system_time / 100
 820  *
 821  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
 822  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
 823  *
 824  * These two equivalencies are implemented in this function.
 825  */
 826 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
 827                                         HV_REFERENCE_TSC_PAGE *tsc_ref)
 828 {
 829         u64 max_mul;
 830
 831         if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
 832                 return false;
 833
 834         /*
 835          * check if scale would overflow, if so we use the time ref counter
 836          *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
 837          *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
 838          *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
 839          */
 840         max_mul = 100ull << (32 - hv_clock->tsc_shift);
 841         if (hv_clock->tsc_to_system_mul >= max_mul)
 842                 return false;
 843
 844         /*
 845          * Otherwise compute the scale and offset according to the formulas
 846          * derived above.
 847          */
 848         tsc_ref->tsc_scale =
 849                 mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
 850                                 hv_clock->tsc_to_system_mul,
 851                                 100);
 852
 853         tsc_ref->tsc_offset = hv_clock->system_time;
 854         do_div(tsc_ref->tsc_offset, 100);
 855         tsc_ref->tsc_offset -=
 856                 mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
 857         return true;
 858 }
 859
 860 void kvm_hv_setup_tsc_page(struct kvm *kvm,
 861                            struct pvclock_vcpu_time_info *hv_clock)
 862 {
 863         struct kvm_hv *hv = &kvm->arch.hyperv;
 864         u32 tsc_seq;
 865         u64 gfn;
 866
 867         BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
 868         BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
 869
 870         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
 871                 return;
 872
 873         gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
 874         /*
 875          * Because the TSC parameters only vary when there is a
 876          * change in the master clock, do not bother with caching.
 877          */
 878         if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
 879                                     &tsc_seq, sizeof(tsc_seq))))
 880                 return;
 881
 882         /*
 883          * While we're computing and writing the parameters, force the
 884          * guest to use the time reference count MSR.
 885          */
 886         hv->tsc_ref.tsc_sequence = 0;
 887         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
 888                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
 889                 return;
 890
 891         if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
 892                 return;
 893
 894         /* Ensure sequence is zero before writing the rest of the struct.  */
 895         smp_wmb();
 896         if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
 897                 return;
 898
 899         /*
 900          * Now switch to the TSC page mechanism by writing the sequence.
 901          */
 902         tsc_seq++;
 903         if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
 904                 tsc_seq = 1;
 905
 906         /* Write the struct entirely before the non-zero sequence.  */
 907         smp_wmb();
 908
 909         hv->tsc_ref.tsc_sequence = tsc_seq;
 910         kvm_write_guest(kvm, gfn_to_gpa(gfn),
 911                         &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
 912 }
 913
 914 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
 915                              bool host)
 916 {
 917         struct kvm *kvm = vcpu->kvm;
 918         struct kvm_hv *hv = &kvm->arch.hyperv;
 919
 920         switch (msr) {
 921         case HV_X64_MSR_GUEST_OS_ID:
 922                 hv->hv_guest_os_id = data;
 923                 /* setting guest os id to zero disables hypercall page */
 924                 if (!hv->hv_guest_os_id)
 925                         hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
 926                 break;
 927         case HV_X64_MSR_HYPERCALL: {
 928                 u64 gfn;
 929                 unsigned long addr;
 930                 u8 instructions[4];
 931
 932                 /* if guest os id is not set hypercall should remain disabled */
 933                 if (!hv->hv_guest_os_id)
 934                         break;
 935                 if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
 936                         hv->hv_hypercall = data;
 937                         break;
 938                 }
 939                 gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
 940                 addr = gfn_to_hva(kvm, gfn);
 941                 if (kvm_is_error_hva(addr))
 942                         return 1;
 943                 kvm_x86_ops->patch_hypercall(vcpu, instructions);
 944                 ((unsigned char *)instructions)[3] = 0xc3; /* ret */
 945                 if (__copy_to_user((void __user *)addr, instructions, 4))
 946                         return 1;
 947                 hv->hv_hypercall = data;
 948                 mark_page_dirty(kvm, gfn);
 949                 break;
 950         }
 951         case HV_X64_MSR_REFERENCE_TSC:
 952                 hv->hv_tsc_page = data;
 953                 if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
 954                         kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
 955                 break;
 956         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
 957                 return kvm_hv_msr_set_crash_data(vcpu,
 958                                                  msr - HV_X64_MSR_CRASH_P0,
 959                                                  data);
 960         case HV_X64_MSR_CRASH_CTL:
 961                 return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
 962         case HV_X64_MSR_RESET:
 963                 if (data == 1) {
 964                         vcpu_debug(vcpu, "hyper-v reset requested\n");
 965                         kvm_make_request(KVM_REQ_HV_RESET, vcpu);
 966                 }
 967                 break;
 968         default:
 969                 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
 970                             msr, data);
 971                 return 1;
 972         }
 973         return 0;
 974 }
 975
 976 /* Calculate cpu time spent by current task in 100ns units */
 977 static u64 current_task_runtime_100ns(void)
 978 {
 979         cputime_t utime, stime;
 980
 981         task_cputime_adjusted(current, &utime, &stime);
 982         return div_u64(cputime_to_nsecs(utime + stime), 100);
 983 }
 984
 985 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
 986 {
 987         struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
 988
 989         switch (msr) {
 990         case HV_X64_MSR_APIC_ASSIST_PAGE: {
 991                 u64 gfn;
 992                 unsigned long addr;
 993
 994                 if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {
 995                         hv->hv_vapic = data;
 996                         if (kvm_lapic_enable_pv_eoi(vcpu, 0))
 997                                 return 1;
 998                         break;
 999                 }
1000                 gfn = data >> HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT;
1001                 addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1002                 if (kvm_is_error_hva(addr))
1003                         return 1;
1004                 if (__clear_user((void __user *)addr, PAGE_SIZE))
1005                         return 1;
1006                 hv->hv_vapic = data;
1007                 kvm_vcpu_mark_page_dirty(vcpu, gfn);
1008                 if (kvm_lapic_enable_pv_eoi(vcpu,
1009                                             gfn_to_gpa(gfn) | KVM_MSR_ENABLED))
1010                         return 1;
1011                 break;
1012         }
1013         case HV_X64_MSR_EOI:
1014                 return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1015         case HV_X64_MSR_ICR:
1016                 return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1017         case HV_X64_MSR_TPR:
1018                 return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1019         case HV_X64_MSR_VP_RUNTIME:
1020                 if (!host)
1021                         return 1;
1022                 hv->runtime_offset = data - current_task_runtime_100ns();
1023                 break;
1024         case HV_X64_MSR_SCONTROL:
1025         case HV_X64_MSR_SVERSION:
1026         case HV_X64_MSR_SIEFP:
1027         case HV_X64_MSR_SIMP:
1028         case HV_X64_MSR_EOM:
1029         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1030                 return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
1031         case HV_X64_MSR_STIMER0_CONFIG:
1032         case HV_X64_MSR_STIMER1_CONFIG:
1033         case HV_X64_MSR_STIMER2_CONFIG:
1034         case HV_X64_MSR_STIMER3_CONFIG: {
1035                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1036
1037                 return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
1038                                          data, host);
1039         }
1040         case HV_X64_MSR_STIMER0_COUNT:
1041         case HV_X64_MSR_STIMER1_COUNT:
1042         case HV_X64_MSR_STIMER2_COUNT:
1043         case HV_X64_MSR_STIMER3_COUNT: {
1044                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1045
1046                 return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
1047                                         data, host);
1048         }
1049         default:
1050                 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
1051                             msr, data);
1052                 return 1;
1053         }
1054
1055         return 0;
1056 }
1057
1058 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1059 {
1060         u64 data = 0;
1061         struct kvm *kvm = vcpu->kvm;
1062         struct kvm_hv *hv = &kvm->arch.hyperv;
1063
1064         switch (msr) {
1065         case HV_X64_MSR_GUEST_OS_ID:
1066                 data = hv->hv_guest_os_id;
1067                 break;
1068         case HV_X64_MSR_HYPERCALL:
1069                 data = hv->hv_hypercall;
1070                 break;
1071         case HV_X64_MSR_TIME_REF_COUNT:
1072                 data = get_time_ref_counter(kvm);
1073                 break;
1074         case HV_X64_MSR_REFERENCE_TSC:
1075                 data = hv->hv_tsc_page;
1076                 break;
1077         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1078                 return kvm_hv_msr_get_crash_data(vcpu,
1079                                                  msr - HV_X64_MSR_CRASH_P0,
1080                                                  pdata);
1081         case HV_X64_MSR_CRASH_CTL:
1082                 return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
1083         case HV_X64_MSR_RESET:
1084                 data = 0;
1085                 break;
1086         default:
1087                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1088                 return 1;
1089         }
1090
1091         *pdata = data;
1092         return 0;
1093 }
1094
1095 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1096 {
1097         u64 data = 0;
1098         struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
1099
1100         switch (msr) {
1101         case HV_X64_MSR_VP_INDEX: {
1102                 int r;
1103                 struct kvm_vcpu *v;
1104
1105                 kvm_for_each_vcpu(r, v, vcpu->kvm) {
1106                         if (v == vcpu) {
1107                                 data = r;
1108                                 break;
1109                         }
1110                 }
1111                 break;
1112         }
1113         case HV_X64_MSR_EOI:
1114                 return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1115         case HV_X64_MSR_ICR:
1116                 return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1117         case HV_X64_MSR_TPR:
1118                 return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1119         case HV_X64_MSR_APIC_ASSIST_PAGE:
1120                 data = hv->hv_vapic;
1121                 break;
1122         case HV_X64_MSR_VP_RUNTIME:
1123                 data = current_task_runtime_100ns() + hv->runtime_offset;
1124                 break;
1125         case HV_X64_MSR_SCONTROL:
1126         case HV_X64_MSR_SVERSION:
1127         case HV_X64_MSR_SIEFP:
1128         case HV_X64_MSR_SIMP:
1129         case HV_X64_MSR_EOM:
1130         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1131                 return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata);
1132         case HV_X64_MSR_STIMER0_CONFIG:
1133         case HV_X64_MSR_STIMER1_CONFIG:
1134         case HV_X64_MSR_STIMER2_CONFIG:
1135         case HV_X64_MSR_STIMER3_CONFIG: {
1136                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1137
1138                 return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
1139                                          pdata);
1140         }
1141         case HV_X64_MSR_STIMER0_COUNT:
1142         case HV_X64_MSR_STIMER1_COUNT:
1143         case HV_X64_MSR_STIMER2_COUNT:
1144         case HV_X64_MSR_STIMER3_COUNT: {
1145                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1146
1147                 return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
1148                                         pdata);
1149         }
1150         default:
1151                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1152                 return 1;
1153         }
1154         *pdata = data;
1155         return 0;
1156 }
1157
1158 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1159 {
1160         if (kvm_hv_msr_partition_wide(msr)) {
1161                 int r;
1162
1163                 mutex_lock(&vcpu->kvm->lock);
1164                 r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1165                 mutex_unlock(&vcpu->kvm->lock);
1166                 return r;
1167         } else
1168                 return kvm_hv_set_msr(vcpu, msr, data, host);
1169 }
1170
1171 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1172 {
1173         if (kvm_hv_msr_partition_wide(msr)) {
1174                 int r;
1175
1176                 mutex_lock(&vcpu->kvm->lock);
1177                 r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
1178                 mutex_unlock(&vcpu->kvm->lock);
1179                 return r;
1180         } else
1181                 return kvm_hv_get_msr(vcpu, msr, pdata);
1182 }
1183
1184 bool kvm_hv_hypercall_enabled(struct kvm *kvm)
1185 {
1186         return kvm->arch.hyperv.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE;
1187 }
1188
1189 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1190 {
1191         bool longmode;
1192
1193         longmode = is_64_bit_mode(vcpu);
1194         if (longmode)
1195                 kvm_register_write(vcpu, VCPU_REGS_RAX, result);
1196         else {
1197                 kvm_register_write(vcpu, VCPU_REGS_RDX, result >> 32);
1198                 kvm_register_write(vcpu, VCPU_REGS_RAX, result & 0xffffffff);
1199         }
1200 }
1201
1202 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1203 {
1204         struct kvm_run *run = vcpu->run;
1205
1206         kvm_hv_hypercall_set_result(vcpu, run->hyperv.u.hcall.result);
1207         return 1;
1208 }
1209
1210 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1211 {
1212         u64 param, ingpa, outgpa, ret;
1213         uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0;
1214         bool fast, longmode;
1215
1216         /*
1217          * hypercall generates UD from non zero cpl and real mode
1218          * per HYPER-V spec
1219          */
1220         if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
1221                 kvm_queue_exception(vcpu, UD_VECTOR);
1222                 return 1;
1223         }
1224
1225         longmode = is_64_bit_mode(vcpu);
1226
1227         if (!longmode) {
1228                 param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
1229                         (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
1230                 ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
1231                         (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
1232                 outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
1233                         (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
1234         }
1235 #ifdef CONFIG_X86_64
1236         else {
1237                 param = kvm_register_read(vcpu, VCPU_REGS_RCX);
1238                 ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
1239                 outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
1240         }
1241 #endif
1242
1243         code = param & 0xffff;
1244         fast = (param >> 16) & 0x1;
1245         rep_cnt = (param >> 32) & 0xfff;
1246         rep_idx = (param >> 48) & 0xfff;
1247
1248         trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
1249
1250         /* Hypercall continuation is not supported yet */
1251         if (rep_cnt || rep_idx) {
1252                 res = HV_STATUS_INVALID_HYPERCALL_CODE;
1253                 goto set_result;
1254         }
1255
1256         switch (code) {
1257         case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1258                 kvm_vcpu_on_spin(vcpu);
1259                 break;
1260         case HVCALL_POST_MESSAGE:
1261         case HVCALL_SIGNAL_EVENT:
1262                 /* don't bother userspace if it has no way to handle it */
1263                 if (!vcpu_to_synic(vcpu)->active) {
1264                         res = HV_STATUS_INVALID_HYPERCALL_CODE;
1265                         break;
1266                 }
1267                 vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1268                 vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1269                 vcpu->run->hyperv.u.hcall.input = param;
1270                 vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1271                 vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1272                 vcpu->arch.complete_userspace_io =
1273                                 kvm_hv_hypercall_complete_userspace;
1274                 return 0;
1275         default:
1276                 res = HV_STATUS_INVALID_HYPERCALL_CODE;
1277                 break;
1278         }
1279
1280 set_result:
1281         ret = res | (((u64)rep_done & 0xfff) << 32);
1282         kvm_hv_hypercall_set_result(vcpu, ret);
1283         return 1;
1284 }