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 <asm/apicdef.h>
  32 #include <trace/events/kvm.h>
  33
  34 #include "trace.h"
  35
  36 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
  37 {
  38         return atomic64_read(&synic->sint[sint]);
  39 }
  40
  41 static inline int synic_get_sint_vector(u64 sint_value)
  42 {
  43         if (sint_value & HV_SYNIC_SINT_MASKED)
  44                 return -1;
  45         return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
  46 }
  47
  48 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
  49                                       int vector)
  50 {
  51         int i;
  52
  53         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  54                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
  55                         return true;
  56         }
  57         return false;
  58 }
  59
  60 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
  61                                      int vector)
  62 {
  63         int i;
  64         u64 sint_value;
  65
  66         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  67                 sint_value = synic_read_sint(synic, i);
  68                 if (synic_get_sint_vector(sint_value) == vector &&
  69                     sint_value & HV_SYNIC_SINT_AUTO_EOI)
  70                         return true;
  71         }
  72         return false;
  73 }
  74
  75 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
  76                           u64 data, bool host)
  77 {
  78         int vector;
  79
  80         vector = data & HV_SYNIC_SINT_VECTOR_MASK;
  81         if (vector < 16 && !host)
  82                 return 1;
  83         /*
  84          * Guest may configure multiple SINTs to use the same vector, so
  85          * we maintain a bitmap of vectors handled by synic, and a
  86          * bitmap of vectors with auto-eoi behavior.  The bitmaps are
  87          * updated here, and atomically queried on fast paths.
  88          */
  89
  90         atomic64_set(&synic->sint[sint], data);
  91
  92         if (synic_has_vector_connected(synic, vector))
  93                 __set_bit(vector, synic->vec_bitmap);
  94         else
  95                 __clear_bit(vector, synic->vec_bitmap);
  96
  97         if (synic_has_vector_auto_eoi(synic, vector))
  98                 __set_bit(vector, synic->auto_eoi_bitmap);
  99         else
 100                 __clear_bit(vector, synic->auto_eoi_bitmap);
 101
 102         /* Load SynIC vectors into EOI exit bitmap */
 103         kvm_make_request(KVM_REQ_SCAN_IOAPIC, synic_to_vcpu(synic));
 104         return 0;
 105 }
 106
 107 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vcpu_id)
 108 {
 109         struct kvm_vcpu *vcpu;
 110         struct kvm_vcpu_hv_synic *synic;
 111
 112         if (vcpu_id >= atomic_read(&kvm->online_vcpus))
 113                 return NULL;
 114         vcpu = kvm_get_vcpu(kvm, vcpu_id);
 115         if (!vcpu)
 116                 return NULL;
 117         synic = vcpu_to_synic(vcpu);
 118         return (synic->active) ? synic : NULL;
 119 }
 120
 121 static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
 122                                         u32 sint)
 123 {
 124         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 125         struct page *page;
 126         gpa_t gpa;
 127         struct hv_message *msg;
 128         struct hv_message_page *msg_page;
 129
 130         gpa = synic->msg_page & PAGE_MASK;
 131         page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
 132         if (is_error_page(page)) {
 133                 vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
 134                          gpa);
 135                 return;
 136         }
 137         msg_page = kmap_atomic(page);
 138
 139         msg = &msg_page->sint_message[sint];
 140         msg->header.message_flags.msg_pending = 0;
 141
 142         kunmap_atomic(msg_page);
 143         kvm_release_page_dirty(page);
 144         kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
 145 }
 146
 147 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 148 {
 149         struct kvm *kvm = vcpu->kvm;
 150         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 151         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 152         struct kvm_vcpu_hv_stimer *stimer;
 153         int gsi, idx, stimers_pending;
 154
 155         trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
 156
 157         if (synic->msg_page & HV_SYNIC_SIMP_ENABLE)
 158                 synic_clear_sint_msg_pending(synic, sint);
 159
 160         /* Try to deliver pending Hyper-V SynIC timers messages */
 161         stimers_pending = 0;
 162         for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
 163                 stimer = &hv_vcpu->stimer[idx];
 164                 if (stimer->msg_pending &&
 165                     (stimer->config & HV_STIMER_ENABLE) &&
 166                     HV_STIMER_SINT(stimer->config) == sint) {
 167                         set_bit(stimer->index,
 168                                 hv_vcpu->stimer_pending_bitmap);
 169                         stimers_pending++;
 170                 }
 171         }
 172         if (stimers_pending)
 173                 kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 174
 175         idx = srcu_read_lock(&kvm->irq_srcu);
 176         gsi = atomic_read(&synic->sint_to_gsi[sint]);
 177         if (gsi != -1)
 178                 kvm_notify_acked_gsi(kvm, gsi);
 179         srcu_read_unlock(&kvm->irq_srcu, idx);
 180 }
 181
 182 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
 183 {
 184         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 185         struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
 186
 187         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
 188         hv_vcpu->exit.u.synic.msr = msr;
 189         hv_vcpu->exit.u.synic.control = synic->control;
 190         hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
 191         hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
 192
 193         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 194 }
 195
 196 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
 197                          u32 msr, u64 data, bool host)
 198 {
 199         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 200         int ret;
 201
 202         if (!synic->active)
 203                 return 1;
 204
 205         trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
 206
 207         ret = 0;
 208         switch (msr) {
 209         case HV_X64_MSR_SCONTROL:
 210                 synic->control = data;
 211                 if (!host)
 212                         synic_exit(synic, msr);
 213                 break;
 214         case HV_X64_MSR_SVERSION:
 215                 if (!host) {
 216                         ret = 1;
 217                         break;
 218                 }
 219                 synic->version = data;
 220                 break;
 221         case HV_X64_MSR_SIEFP:
 222                 if (data & HV_SYNIC_SIEFP_ENABLE)
 223                         if (kvm_clear_guest(vcpu->kvm,
 224                                             data & PAGE_MASK, PAGE_SIZE)) {
 225                                 ret = 1;
 226                                 break;
 227                         }
 228                 synic->evt_page = data;
 229                 if (!host)
 230                         synic_exit(synic, msr);
 231                 break;
 232         case HV_X64_MSR_SIMP:
 233                 if (data & HV_SYNIC_SIMP_ENABLE)
 234                         if (kvm_clear_guest(vcpu->kvm,
 235                                             data & PAGE_MASK, PAGE_SIZE)) {
 236                                 ret = 1;
 237                                 break;
 238                         }
 239                 synic->msg_page = data;
 240                 if (!host)
 241                         synic_exit(synic, msr);
 242                 break;
 243         case HV_X64_MSR_EOM: {
 244                 int i;
 245
 246                 for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 247                         kvm_hv_notify_acked_sint(vcpu, i);
 248                 break;
 249         }
 250         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 251                 ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
 252                 break;
 253         default:
 254                 ret = 1;
 255                 break;
 256         }
 257         return ret;
 258 }
 259
 260 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata)
 261 {
 262         int ret;
 263
 264         if (!synic->active)
 265                 return 1;
 266
 267         ret = 0;
 268         switch (msr) {
 269         case HV_X64_MSR_SCONTROL:
 270                 *pdata = synic->control;
 271                 break;
 272         case HV_X64_MSR_SVERSION:
 273                 *pdata = synic->version;
 274                 break;
 275         case HV_X64_MSR_SIEFP:
 276                 *pdata = synic->evt_page;
 277                 break;
 278         case HV_X64_MSR_SIMP:
 279                 *pdata = synic->msg_page;
 280                 break;
 281         case HV_X64_MSR_EOM:
 282                 *pdata = 0;
 283                 break;
 284         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 285                 *pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
 286                 break;
 287         default:
 288                 ret = 1;
 289                 break;
 290         }
 291         return ret;
 292 }
 293
 294 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
 295 {
 296         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 297         struct kvm_lapic_irq irq;
 298         int ret, vector;
 299
 300         if (sint >= ARRAY_SIZE(synic->sint))
 301                 return -EINVAL;
 302
 303         vector = synic_get_sint_vector(synic_read_sint(synic, sint));
 304         if (vector < 0)
 305                 return -ENOENT;
 306
 307         memset(&irq, 0, sizeof(irq));
 308         irq.dest_id = kvm_apic_id(vcpu->arch.apic);
 309         irq.dest_mode = APIC_DEST_PHYSICAL;
 310         irq.delivery_mode = APIC_DM_FIXED;
 311         irq.vector = vector;
 312         irq.level = 1;
 313
 314         ret = kvm_irq_delivery_to_apic(vcpu->kvm, NULL, &irq, NULL);
 315         trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
 316         return ret;
 317 }
 318
 319 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vcpu_id, u32 sint)
 320 {
 321         struct kvm_vcpu_hv_synic *synic;
 322
 323         synic = synic_get(kvm, vcpu_id);
 324         if (!synic)
 325                 return -EINVAL;
 326
 327         return synic_set_irq(synic, sint);
 328 }
 329
 330 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
 331 {
 332         struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu);
 333         int i;
 334
 335         trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
 336
 337         for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 338                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
 339                         kvm_hv_notify_acked_sint(vcpu, i);
 340 }
 341
 342 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vcpu_id, u32 sint, int gsi)
 343 {
 344         struct kvm_vcpu_hv_synic *synic;
 345
 346         synic = synic_get(kvm, vcpu_id);
 347         if (!synic)
 348                 return -EINVAL;
 349
 350         if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
 351                 return -EINVAL;
 352
 353         atomic_set(&synic->sint_to_gsi[sint], gsi);
 354         return 0;
 355 }
 356
 357 void kvm_hv_irq_routing_update(struct kvm *kvm)
 358 {
 359         struct kvm_irq_routing_table *irq_rt;
 360         struct kvm_kernel_irq_routing_entry *e;
 361         u32 gsi;
 362
 363         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
 364                                         lockdep_is_held(&kvm->irq_lock));
 365
 366         for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
 367                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
 368                         if (e->type == KVM_IRQ_ROUTING_HV_SINT)
 369                                 kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
 370                                                     e->hv_sint.sint, gsi);
 371                 }
 372         }
 373 }
 374
 375 static void synic_init(struct kvm_vcpu_hv_synic *synic)
 376 {
 377         int i;
 378
 379         memset(synic, 0, sizeof(*synic));
 380         synic->version = HV_SYNIC_VERSION_1;
 381         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
 382                 atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
 383                 atomic_set(&synic->sint_to_gsi[i], -1);
 384         }
 385 }
 386
 387 static u64 get_time_ref_counter(struct kvm *kvm)
 388 {
 389         struct kvm_hv *hv = &kvm->arch.hyperv;
 390         struct kvm_vcpu *vcpu;
 391         u64 tsc;
 392
 393         /*
 394          * The guest has not set up the TSC page or the clock isn't
 395          * stable, fall back to get_kvmclock_ns.
 396          */
 397         if (!hv->tsc_ref.tsc_sequence)
 398                 return div_u64(get_kvmclock_ns(kvm), 100);
 399
 400         vcpu = kvm_get_vcpu(kvm, 0);
 401         tsc = kvm_read_l1_tsc(vcpu, rdtsc());
 402         return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
 403                 + hv->tsc_ref.tsc_offset;
 404 }
 405
 406 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
 407                                 bool vcpu_kick)
 408 {
 409         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 410
 411         set_bit(stimer->index,
 412                 vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 413         kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 414         if (vcpu_kick)
 415                 kvm_vcpu_kick(vcpu);
 416 }
 417
 418 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
 419 {
 420         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 421
 422         trace_kvm_hv_stimer_cleanup(stimer_to_vcpu(stimer)->vcpu_id,
 423                                     stimer->index);
 424
 425         hrtimer_cancel(&stimer->timer);
 426         clear_bit(stimer->index,
 427                   vcpu_to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 428         stimer->msg_pending = false;
 429         stimer->exp_time = 0;
 430 }
 431
 432 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
 433 {
 434         struct kvm_vcpu_hv_stimer *stimer;
 435
 436         stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
 437         trace_kvm_hv_stimer_callback(stimer_to_vcpu(stimer)->vcpu_id,
 438                                      stimer->index);
 439         stimer_mark_pending(stimer, true);
 440
 441         return HRTIMER_NORESTART;
 442 }
 443
 444 /*
 445  * stimer_start() assumptions:
 446  * a) stimer->count is not equal to 0
 447  * b) stimer->config has HV_STIMER_ENABLE flag
 448  */
 449 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
 450 {
 451         u64 time_now;
 452         ktime_t ktime_now;
 453
 454         time_now = get_time_ref_counter(stimer_to_vcpu(stimer)->kvm);
 455         ktime_now = ktime_get();
 456
 457         if (stimer->config & HV_STIMER_PERIODIC) {
 458                 if (stimer->exp_time) {
 459                         if (time_now >= stimer->exp_time) {
 460                                 u64 remainder;
 461
 462                                 div64_u64_rem(time_now - stimer->exp_time,
 463                                               stimer->count, &remainder);
 464                                 stimer->exp_time =
 465                                         time_now + (stimer->count - remainder);
 466                         }
 467                 } else
 468                         stimer->exp_time = time_now + stimer->count;
 469
 470                 trace_kvm_hv_stimer_start_periodic(
 471                                         stimer_to_vcpu(stimer)->vcpu_id,
 472                                         stimer->index,
 473                                         time_now, stimer->exp_time);
 474
 475                 hrtimer_start(&stimer->timer,
 476                               ktime_add_ns(ktime_now,
 477                                            100 * (stimer->exp_time - time_now)),
 478                               HRTIMER_MODE_ABS);
 479                 return 0;
 480         }
 481         stimer->exp_time = stimer->count;
 482         if (time_now >= stimer->count) {
 483                 /*
 484                  * Expire timer according to Hypervisor Top-Level Functional
 485                  * specification v4(15.3.1):
 486                  * "If a one shot is enabled and the specified count is in
 487                  * the past, it will expire immediately."
 488                  */
 489                 stimer_mark_pending(stimer, false);
 490                 return 0;
 491         }
 492
 493         trace_kvm_hv_stimer_start_one_shot(stimer_to_vcpu(stimer)->vcpu_id,
 494                                            stimer->index,
 495                                            time_now, stimer->count);
 496
 497         hrtimer_start(&stimer->timer,
 498                       ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
 499                       HRTIMER_MODE_ABS);
 500         return 0;
 501 }
 502
 503 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
 504                              bool host)
 505 {
 506         trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id,
 507                                        stimer->index, config, host);
 508
 509         stimer_cleanup(stimer);
 510         if ((stimer->config & HV_STIMER_ENABLE) && HV_STIMER_SINT(config) == 0)
 511                 config &= ~HV_STIMER_ENABLE;
 512         stimer->config = config;
 513         stimer_mark_pending(stimer, false);
 514         return 0;
 515 }
 516
 517 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
 518                             bool host)
 519 {
 520         trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id,
 521                                       stimer->index, count, host);
 522
 523         stimer_cleanup(stimer);
 524         stimer->count = count;
 525         if (stimer->count == 0)
 526                 stimer->config &= ~HV_STIMER_ENABLE;
 527         else if (stimer->config & HV_STIMER_AUTOENABLE)
 528                 stimer->config |= HV_STIMER_ENABLE;
 529         stimer_mark_pending(stimer, false);
 530         return 0;
 531 }
 532
 533 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
 534 {
 535         *pconfig = stimer->config;
 536         return 0;
 537 }
 538
 539 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
 540 {
 541         *pcount = stimer->count;
 542         return 0;
 543 }
 544
 545 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
 546                              struct hv_message *src_msg)
 547 {
 548         struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
 549         struct page *page;
 550         gpa_t gpa;
 551         struct hv_message *dst_msg;
 552         int r;
 553         struct hv_message_page *msg_page;
 554
 555         if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
 556                 return -ENOENT;
 557
 558         gpa = synic->msg_page & PAGE_MASK;
 559         page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
 560         if (is_error_page(page))
 561                 return -EFAULT;
 562
 563         msg_page = kmap_atomic(page);
 564         dst_msg = &msg_page->sint_message[sint];
 565         if (sync_cmpxchg(&dst_msg->header.message_type, HVMSG_NONE,
 566                          src_msg->header.message_type) != HVMSG_NONE) {
 567                 dst_msg->header.message_flags.msg_pending = 1;
 568                 r = -EAGAIN;
 569         } else {
 570                 memcpy(&dst_msg->u.payload, &src_msg->u.payload,
 571                        src_msg->header.payload_size);
 572                 dst_msg->header.message_type = src_msg->header.message_type;
 573                 dst_msg->header.payload_size = src_msg->header.payload_size;
 574                 r = synic_set_irq(synic, sint);
 575                 if (r >= 1)
 576                         r = 0;
 577                 else if (r == 0)
 578                         r = -EFAULT;
 579         }
 580         kunmap_atomic(msg_page);
 581         kvm_release_page_dirty(page);
 582         kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
 583         return r;
 584 }
 585
 586 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
 587 {
 588         struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer);
 589         struct hv_message *msg = &stimer->msg;
 590         struct hv_timer_message_payload *payload =
 591                         (struct hv_timer_message_payload *)&msg->u.payload;
 592
 593         payload->expiration_time = stimer->exp_time;
 594         payload->delivery_time = get_time_ref_counter(vcpu->kvm);
 595         return synic_deliver_msg(vcpu_to_synic(vcpu),
 596                                  HV_STIMER_SINT(stimer->config), msg);
 597 }
 598
 599 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
 600 {
 601         int r;
 602
 603         stimer->msg_pending = true;
 604         r = stimer_send_msg(stimer);
 605         trace_kvm_hv_stimer_expiration(stimer_to_vcpu(stimer)->vcpu_id,
 606                                        stimer->index, r);
 607         if (!r) {
 608                 stimer->msg_pending = false;
 609                 if (!(stimer->config & HV_STIMER_PERIODIC))
 610                         stimer->config &= ~HV_STIMER_ENABLE;
 611         }
 612 }
 613
 614 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
 615 {
 616         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 617         struct kvm_vcpu_hv_stimer *stimer;
 618         u64 time_now, exp_time;
 619         int i;
 620
 621         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 622                 if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
 623                         stimer = &hv_vcpu->stimer[i];
 624                         if (stimer->config & HV_STIMER_ENABLE) {
 625                                 exp_time = stimer->exp_time;
 626
 627                                 if (exp_time) {
 628                                         time_now =
 629                                                 get_time_ref_counter(vcpu->kvm);
 630                                         if (time_now >= exp_time)
 631                                                 stimer_expiration(stimer);
 632                                 }
 633
 634                                 if ((stimer->config & HV_STIMER_ENABLE) &&
 635                                     stimer->count)
 636                                         stimer_start(stimer);
 637                                 else
 638                                         stimer_cleanup(stimer);
 639                         }
 640                 }
 641 }
 642
 643 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
 644 {
 645         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 646         int i;
 647
 648         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 649                 stimer_cleanup(&hv_vcpu->stimer[i]);
 650 }
 651
 652 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
 653 {
 654         struct hv_message *msg = &stimer->msg;
 655         struct hv_timer_message_payload *payload =
 656                         (struct hv_timer_message_payload *)&msg->u.payload;
 657
 658         memset(&msg->header, 0, sizeof(msg->header));
 659         msg->header.message_type = HVMSG_TIMER_EXPIRED;
 660         msg->header.payload_size = sizeof(*payload);
 661
 662         payload->timer_index = stimer->index;
 663         payload->expiration_time = 0;
 664         payload->delivery_time = 0;
 665 }
 666
 667 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
 668 {
 669         memset(stimer, 0, sizeof(*stimer));
 670         stimer->index = timer_index;
 671         hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 672         stimer->timer.function = stimer_timer_callback;
 673         stimer_prepare_msg(stimer);
 674 }
 675
 676 void kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
 677 {
 678         struct kvm_vcpu_hv *hv_vcpu = vcpu_to_hv_vcpu(vcpu);
 679         int i;
 680
 681         synic_init(&hv_vcpu->synic);
 682
 683         bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
 684         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 685                 stimer_init(&hv_vcpu->stimer[i], i);
 686 }
 687
 688 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu)
 689 {
 690         /*
 691          * Hyper-V SynIC auto EOI SINT's are
 692          * not compatible with APICV, so deactivate APICV
 693          */
 694         kvm_vcpu_deactivate_apicv(vcpu);
 695         vcpu_to_synic(vcpu)->active = true;
 696         return 0;
 697 }
 698
 699 static bool kvm_hv_msr_partition_wide(u32 msr)
 700 {
 701         bool r = false;
 702
 703         switch (msr) {
 704         case HV_X64_MSR_GUEST_OS_ID:
 705         case HV_X64_MSR_HYPERCALL:
 706         case HV_X64_MSR_REFERENCE_TSC:
 707         case HV_X64_MSR_TIME_REF_COUNT:
 708         case HV_X64_MSR_CRASH_CTL:
 709         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
 710         case HV_X64_MSR_RESET:
 711                 r = true;
 712                 break;
 713         }
 714
 715         return r;
 716 }
 717
 718 static int kvm_hv_msr_get_crash_data(struct kvm_vcpu *vcpu,
 719                                      u32 index, u64 *pdata)
 720 {
 721         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 722
 723         if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
 724                 return -EINVAL;
 725
 726         *pdata = hv->hv_crash_param[index];
 727         return 0;
 728 }
 729
 730 static int kvm_hv_msr_get_crash_ctl(struct kvm_vcpu *vcpu, u64 *pdata)
 731 {
 732         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 733
 734         *pdata = hv->hv_crash_ctl;
 735         return 0;
 736 }
 737
 738 static int kvm_hv_msr_set_crash_ctl(struct kvm_vcpu *vcpu, u64 data, bool host)
 739 {
 740         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 741
 742         if (host)
 743                 hv->hv_crash_ctl = data & HV_X64_MSR_CRASH_CTL_NOTIFY;
 744
 745         if (!host && (data & HV_X64_MSR_CRASH_CTL_NOTIFY)) {
 746
 747                 vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
 748                           hv->hv_crash_param[0],
 749                           hv->hv_crash_param[1],
 750                           hv->hv_crash_param[2],
 751                           hv->hv_crash_param[3],
 752                           hv->hv_crash_param[4]);
 753
 754                 /* Send notification about crash to user space */
 755                 kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
 756         }
 757
 758         return 0;
 759 }
 760
 761 static int kvm_hv_msr_set_crash_data(struct kvm_vcpu *vcpu,
 762                                      u32 index, u64 data)
 763 {
 764         struct kvm_hv *hv = &vcpu->kvm->arch.hyperv;
 765
 766         if (WARN_ON_ONCE(index >= ARRAY_SIZE(hv->hv_crash_param)))
 767                 return -EINVAL;
 768
 769         hv->hv_crash_param[index] = data;
 770         return 0;
 771 }
 772
 773 /*
 774  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
 775  * between them is possible:
 776  *
 777  * kvmclock formula:
 778  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
 779  *           + system_time
 780  *
 781  * Hyper-V formula:
 782  *    nsec/100 = ticks * scale / 2^64 + offset
 783  *
 784  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
 785  * By dividing the kvmclock formula by 100 and equating what's left we get:
 786  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 787  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
 788  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
 789  *
 790  * Now expand the kvmclock formula and divide by 100:
 791  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
 792  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
 793  *           + system_time
 794  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 795  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
 796  *               + system_time / 100
 797  *
 798  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
 799  *    nsec/100 = ticks * scale / 2^64
 800  *               - tsc_timestamp * scale / 2^64
 801  *               + system_time / 100
 802  *
 803  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
 804  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
 805  *
 806  * These two equivalencies are implemented in this function.
 807  */
 808 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
 809                                         HV_REFERENCE_TSC_PAGE *tsc_ref)
 810 {
 811         u64 max_mul;
 812
 813         if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
 814                 return false;
 815
 816         /*
 817          * check if scale would overflow, if so we use the time ref counter
 818          *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
 819          *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
 820          *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
 821          */
 822         max_mul = 100ull << (32 - hv_clock->tsc_shift);
 823         if (hv_clock->tsc_to_system_mul >= max_mul)
 824                 return false;
 825
 826         /*
 827          * Otherwise compute the scale and offset according to the formulas
 828          * derived above.
 829          */
 830         tsc_ref->tsc_scale =
 831                 mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
 832                                 hv_clock->tsc_to_system_mul,
 833                                 100);
 834
 835         tsc_ref->tsc_offset = hv_clock->system_time;
 836         do_div(tsc_ref->tsc_offset, 100);
 837         tsc_ref->tsc_offset -=
 838                 mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
 839         return true;
 840 }
 841
 842 void kvm_hv_setup_tsc_page(struct kvm *kvm,
 843                            struct pvclock_vcpu_time_info *hv_clock)
 844 {
 845         struct kvm_hv *hv = &kvm->arch.hyperv;
 846         u32 tsc_seq;
 847         u64 gfn;
 848
 849         BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
 850         BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, tsc_sequence) != 0);
 851
 852         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
 853                 return;
 854
 855         mutex_lock(&kvm->arch.hyperv.hv_lock);
 856         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
 857                 goto out_unlock;
 858
 859         gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
 860         /*
 861          * Because the TSC parameters only vary when there is a
 862          * change in the master clock, do not bother with caching.
 863          */
 864         if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
 865                                     &tsc_seq, sizeof(tsc_seq))))
 866                 goto out_unlock;
 867
 868         /*
 869          * While we're computing and writing the parameters, force the
 870          * guest to use the time reference count MSR.
 871          */
 872         hv->tsc_ref.tsc_sequence = 0;
 873         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
 874                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
 875                 goto out_unlock;
 876
 877         if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
 878                 goto out_unlock;
 879
 880         /* Ensure sequence is zero before writing the rest of the struct.  */
 881         smp_wmb();
 882         if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
 883                 goto out_unlock;
 884
 885         /*
 886          * Now switch to the TSC page mechanism by writing the sequence.
 887          */
 888         tsc_seq++;
 889         if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
 890                 tsc_seq = 1;
 891
 892         /* Write the struct entirely before the non-zero sequence.  */
 893         smp_wmb();
 894
 895         hv->tsc_ref.tsc_sequence = tsc_seq;
 896         kvm_write_guest(kvm, gfn_to_gpa(gfn),
 897                         &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence));
 898 out_unlock:
 899         mutex_unlock(&kvm->arch.hyperv.hv_lock);
 900 }
 901
 902 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
 903                              bool host)
 904 {
 905         struct kvm *kvm = vcpu->kvm;
 906         struct kvm_hv *hv = &kvm->arch.hyperv;
 907
 908         switch (msr) {
 909         case HV_X64_MSR_GUEST_OS_ID:
 910                 hv->hv_guest_os_id = data;
 911                 /* setting guest os id to zero disables hypercall page */
 912                 if (!hv->hv_guest_os_id)
 913                         hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
 914                 break;
 915         case HV_X64_MSR_HYPERCALL: {
 916                 u64 gfn;
 917                 unsigned long addr;
 918                 u8 instructions[4];
 919
 920                 /* if guest os id is not set hypercall should remain disabled */
 921                 if (!hv->hv_guest_os_id)
 922                         break;
 923                 if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
 924                         hv->hv_hypercall = data;
 925                         break;
 926                 }
 927                 gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
 928                 addr = gfn_to_hva(kvm, gfn);
 929                 if (kvm_is_error_hva(addr))
 930                         return 1;
 931                 kvm_x86_ops->patch_hypercall(vcpu, instructions);
 932                 ((unsigned char *)instructions)[3] = 0xc3; /* ret */
 933                 if (__copy_to_user((void __user *)addr, instructions, 4))
 934                         return 1;
 935                 hv->hv_hypercall = data;
 936                 mark_page_dirty(kvm, gfn);
 937                 break;
 938         }
 939         case HV_X64_MSR_REFERENCE_TSC:
 940                 hv->hv_tsc_page = data;
 941                 if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)
 942                         kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
 943                 break;
 944         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
 945                 return kvm_hv_msr_set_crash_data(vcpu,
 946                                                  msr - HV_X64_MSR_CRASH_P0,
 947                                                  data);
 948         case HV_X64_MSR_CRASH_CTL:
 949                 return kvm_hv_msr_set_crash_ctl(vcpu, data, host);
 950         case HV_X64_MSR_RESET:
 951                 if (data == 1) {
 952                         vcpu_debug(vcpu, "hyper-v reset requested\n");
 953                         kvm_make_request(KVM_REQ_HV_RESET, vcpu);
 954                 }
 955                 break;
 956         default:
 957                 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
 958                             msr, data);
 959                 return 1;
 960         }
 961         return 0;
 962 }
 963
 964 /* Calculate cpu time spent by current task in 100ns units */
 965 static u64 current_task_runtime_100ns(void)
 966 {
 967         u64 utime, stime;
 968
 969         task_cputime_adjusted(current, &utime, &stime);
 970
 971         return div_u64(utime + stime, 100);
 972 }
 973
 974 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
 975 {
 976         struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
 977
 978         switch (msr) {
 979         case HV_X64_MSR_APIC_ASSIST_PAGE: {
 980                 u64 gfn;
 981                 unsigned long addr;
 982
 983                 if (!(data & HV_X64_MSR_APIC_ASSIST_PAGE_ENABLE)) {
 984                         hv->hv_vapic = data;
 985                         if (kvm_lapic_enable_pv_eoi(vcpu, 0))
 986                                 return 1;
 987                         break;
 988                 }
 989                 gfn = data >> HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT;
 990                 addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
 991                 if (kvm_is_error_hva(addr))
 992                         return 1;
 993                 if (__clear_user((void __user *)addr, PAGE_SIZE))
 994                         return 1;
 995                 hv->hv_vapic = data;
 996                 kvm_vcpu_mark_page_dirty(vcpu, gfn);
 997                 if (kvm_lapic_enable_pv_eoi(vcpu,
 998                                             gfn_to_gpa(gfn) | KVM_MSR_ENABLED))
 999                         return 1;
1000                 break;
1001         }
1002         case HV_X64_MSR_EOI:
1003                 return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1004         case HV_X64_MSR_ICR:
1005                 return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1006         case HV_X64_MSR_TPR:
1007                 return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1008         case HV_X64_MSR_VP_RUNTIME:
1009                 if (!host)
1010                         return 1;
1011                 hv->runtime_offset = data - current_task_runtime_100ns();
1012                 break;
1013         case HV_X64_MSR_SCONTROL:
1014         case HV_X64_MSR_SVERSION:
1015         case HV_X64_MSR_SIEFP:
1016         case HV_X64_MSR_SIMP:
1017         case HV_X64_MSR_EOM:
1018         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1019                 return synic_set_msr(vcpu_to_synic(vcpu), msr, data, host);
1020         case HV_X64_MSR_STIMER0_CONFIG:
1021         case HV_X64_MSR_STIMER1_CONFIG:
1022         case HV_X64_MSR_STIMER2_CONFIG:
1023         case HV_X64_MSR_STIMER3_CONFIG: {
1024                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1025
1026                 return stimer_set_config(vcpu_to_stimer(vcpu, timer_index),
1027                                          data, host);
1028         }
1029         case HV_X64_MSR_STIMER0_COUNT:
1030         case HV_X64_MSR_STIMER1_COUNT:
1031         case HV_X64_MSR_STIMER2_COUNT:
1032         case HV_X64_MSR_STIMER3_COUNT: {
1033                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1034
1035                 return stimer_set_count(vcpu_to_stimer(vcpu, timer_index),
1036                                         data, host);
1037         }
1038         default:
1039                 vcpu_unimpl(vcpu, "Hyper-V uhandled wrmsr: 0x%x data 0x%llx\n",
1040                             msr, data);
1041                 return 1;
1042         }
1043
1044         return 0;
1045 }
1046
1047 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1048 {
1049         u64 data = 0;
1050         struct kvm *kvm = vcpu->kvm;
1051         struct kvm_hv *hv = &kvm->arch.hyperv;
1052
1053         switch (msr) {
1054         case HV_X64_MSR_GUEST_OS_ID:
1055                 data = hv->hv_guest_os_id;
1056                 break;
1057         case HV_X64_MSR_HYPERCALL:
1058                 data = hv->hv_hypercall;
1059                 break;
1060         case HV_X64_MSR_TIME_REF_COUNT:
1061                 data = get_time_ref_counter(kvm);
1062                 break;
1063         case HV_X64_MSR_REFERENCE_TSC:
1064                 data = hv->hv_tsc_page;
1065                 break;
1066         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1067                 return kvm_hv_msr_get_crash_data(vcpu,
1068                                                  msr - HV_X64_MSR_CRASH_P0,
1069                                                  pdata);
1070         case HV_X64_MSR_CRASH_CTL:
1071                 return kvm_hv_msr_get_crash_ctl(vcpu, pdata);
1072         case HV_X64_MSR_RESET:
1073                 data = 0;
1074                 break;
1075         default:
1076                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1077                 return 1;
1078         }
1079
1080         *pdata = data;
1081         return 0;
1082 }
1083
1084 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1085 {
1086         u64 data = 0;
1087         struct kvm_vcpu_hv *hv = &vcpu->arch.hyperv;
1088
1089         switch (msr) {
1090         case HV_X64_MSR_VP_INDEX: {
1091                 int r;
1092                 struct kvm_vcpu *v;
1093
1094                 kvm_for_each_vcpu(r, v, vcpu->kvm) {
1095                         if (v == vcpu) {
1096                                 data = r;
1097                                 break;
1098                         }
1099                 }
1100                 break;
1101         }
1102         case HV_X64_MSR_EOI:
1103                 return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1104         case HV_X64_MSR_ICR:
1105                 return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1106         case HV_X64_MSR_TPR:
1107                 return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1108         case HV_X64_MSR_APIC_ASSIST_PAGE:
1109                 data = hv->hv_vapic;
1110                 break;
1111         case HV_X64_MSR_VP_RUNTIME:
1112                 data = current_task_runtime_100ns() + hv->runtime_offset;
1113                 break;
1114         case HV_X64_MSR_SCONTROL:
1115         case HV_X64_MSR_SVERSION:
1116         case HV_X64_MSR_SIEFP:
1117         case HV_X64_MSR_SIMP:
1118         case HV_X64_MSR_EOM:
1119         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1120                 return synic_get_msr(vcpu_to_synic(vcpu), msr, pdata);
1121         case HV_X64_MSR_STIMER0_CONFIG:
1122         case HV_X64_MSR_STIMER1_CONFIG:
1123         case HV_X64_MSR_STIMER2_CONFIG:
1124         case HV_X64_MSR_STIMER3_CONFIG: {
1125                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1126
1127                 return stimer_get_config(vcpu_to_stimer(vcpu, timer_index),
1128                                          pdata);
1129         }
1130         case HV_X64_MSR_STIMER0_COUNT:
1131         case HV_X64_MSR_STIMER1_COUNT:
1132         case HV_X64_MSR_STIMER2_COUNT:
1133         case HV_X64_MSR_STIMER3_COUNT: {
1134                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1135
1136                 return stimer_get_count(vcpu_to_stimer(vcpu, timer_index),
1137                                         pdata);
1138         }
1139         default:
1140                 vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
1141                 return 1;
1142         }
1143         *pdata = data;
1144         return 0;
1145 }
1146
1147 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1148 {
1149         if (kvm_hv_msr_partition_wide(msr)) {
1150                 int r;
1151
1152                 mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1153                 r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1154                 mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1155                 return r;
1156         } else
1157                 return kvm_hv_set_msr(vcpu, msr, data, host);
1158 }
1159
1160 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
1161 {
1162         if (kvm_hv_msr_partition_wide(msr)) {
1163                 int r;
1164
1165                 mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
1166                 r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
1167                 mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
1168                 return r;
1169         } else
1170                 return kvm_hv_get_msr(vcpu, msr, pdata);
1171 }
1172
1173 bool kvm_hv_hypercall_enabled(struct kvm *kvm)
1174 {
1175         return READ_ONCE(kvm->arch.hyperv.hv_hypercall) & HV_X64_MSR_HYPERCALL_ENABLE;
1176 }
1177
1178 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
1179 {
1180         bool longmode;
1181
1182         longmode = is_64_bit_mode(vcpu);
1183         if (longmode)
1184                 kvm_register_write(vcpu, VCPU_REGS_RAX, result);
1185         else {
1186                 kvm_register_write(vcpu, VCPU_REGS_RDX, result >> 32);
1187                 kvm_register_write(vcpu, VCPU_REGS_RAX, result & 0xffffffff);
1188         }
1189 }
1190
1191 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
1192 {
1193         struct kvm_run *run = vcpu->run;
1194
1195         kvm_hv_hypercall_set_result(vcpu, run->hyperv.u.hcall.result);
1196         return 1;
1197 }
1198
1199 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
1200 {
1201         u64 param, ingpa, outgpa, ret;
1202         uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0;
1203         bool fast, longmode;
1204
1205         /*
1206          * hypercall generates UD from non zero cpl and real mode
1207          * per HYPER-V spec
1208          */
1209         if (kvm_x86_ops->get_cpl(vcpu) != 0 || !is_protmode(vcpu)) {
1210                 kvm_queue_exception(vcpu, UD_VECTOR);
1211                 return 1;
1212         }
1213
1214         longmode = is_64_bit_mode(vcpu);
1215
1216         if (!longmode) {
1217                 param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
1218                         (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff);
1219                 ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) |
1220                         (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff);
1221                 outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) |
1222                         (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff);
1223         }
1224 #ifdef CONFIG_X86_64
1225         else {
1226                 param = kvm_register_read(vcpu, VCPU_REGS_RCX);
1227                 ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX);
1228                 outgpa = kvm_register_read(vcpu, VCPU_REGS_R8);
1229         }
1230 #endif
1231
1232         code = param & 0xffff;
1233         fast = (param >> 16) & 0x1;
1234         rep_cnt = (param >> 32) & 0xfff;
1235         rep_idx = (param >> 48) & 0xfff;
1236
1237         trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa);
1238
1239         /* Hypercall continuation is not supported yet */
1240         if (rep_cnt || rep_idx) {
1241                 res = HV_STATUS_INVALID_HYPERCALL_CODE;
1242                 goto set_result;
1243         }
1244
1245         switch (code) {
1246         case HVCALL_NOTIFY_LONG_SPIN_WAIT:
1247                 kvm_vcpu_on_spin(vcpu);
1248                 break;
1249         case HVCALL_POST_MESSAGE:
1250         case HVCALL_SIGNAL_EVENT:
1251                 /* don't bother userspace if it has no way to handle it */
1252                 if (!vcpu_to_synic(vcpu)->active) {
1253                         res = HV_STATUS_INVALID_HYPERCALL_CODE;
1254                         break;
1255                 }
1256                 vcpu->run->exit_reason = KVM_EXIT_HYPERV;
1257                 vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
1258                 vcpu->run->hyperv.u.hcall.input = param;
1259                 vcpu->run->hyperv.u.hcall.params[0] = ingpa;
1260                 vcpu->run->hyperv.u.hcall.params[1] = outgpa;
1261                 vcpu->arch.complete_userspace_io =
1262                                 kvm_hv_hypercall_complete_userspace;
1263                 return 0;
1264         default:
1265                 res = HV_STATUS_INVALID_HYPERCALL_CODE;
1266                 break;
1267         }
1268
1269 set_result:
1270         ret = res | (((u64)rep_done & 0xfff) << 32);
1271         kvm_hv_hypercall_set_result(vcpu, ret);
1272         return 1;
1273 }