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