arch/x86/kvm/hyperv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * KVM Microsoft Hyper-V emulation
   4  *
   5  * derived from arch/x86/kvm/x86.c
   6  *
   7  * Copyright (C) 2006 Qumranet, Inc.
   8  * Copyright (C) 2008 Qumranet, Inc.
   9  * Copyright IBM Corporation, 2008
  10  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  11  * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
  12  *
  13  * Authors:
  14  *   Avi Kivity   <avi@qumranet.com>
  15  *   Yaniv Kamay  <yaniv@qumranet.com>
  16  *   Amit Shah    <amit.shah@qumranet.com>
  17  *   Ben-Ami Yassour <benami@il.ibm.com>
  18  *   Andrey Smetanin <asmetanin@virtuozzo.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include "x86.h"
  23 #include "lapic.h"
  24 #include "ioapic.h"
  25 #include "cpuid.h"
  26 #include "hyperv.h"
  27 #include "mmu.h"
  28 #include "xen.h"
  29
  30 #include <linux/cpu.h>
  31 #include <linux/kvm_host.h>
  32 #include <linux/highmem.h>
  33 #include <linux/sched/cputime.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/eventfd.h>
  36
  37 #include <asm/apicdef.h>
  38 #include <asm/mshyperv.h>
  39 #include <trace/events/kvm.h>
  40
  41 #include "trace.h"
  42 #include "irq.h"
  43 #include "fpu.h"
  44
  45 #define KVM_HV_MAX_SPARSE_VCPU_SET_BITS DIV_ROUND_UP(KVM_MAX_VCPUS, HV_VCPUS_PER_SPARSE_BANK)
  46
  47 /*
  48  * As per Hyper-V TLFS, extended hypercalls start from 0x8001
  49  * (HvExtCallQueryCapabilities). Response of this hypercalls is a 64 bit value
  50  * where each bit tells which extended hypercall is available besides
  51  * HvExtCallQueryCapabilities.
  52  *
  53  * 0x8001 - First extended hypercall, HvExtCallQueryCapabilities, no bit
  54  * assigned.
  55  *
  56  * 0x8002 - Bit 0
  57  * 0x8003 - Bit 1
  58  * ..
  59  * 0x8041 - Bit 63
  60  *
  61  * Therefore, HV_EXT_CALL_MAX = 0x8001 + 64
  62  */
  63 #define HV_EXT_CALL_MAX (HV_EXT_CALL_QUERY_CAPABILITIES + 64)
  64
  65 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
  66                                 bool vcpu_kick);
  67
  68 static inline u64 synic_read_sint(struct kvm_vcpu_hv_synic *synic, int sint)
  69 {
  70         return atomic64_read(&synic->sint[sint]);
  71 }
  72
  73 static inline int synic_get_sint_vector(u64 sint_value)
  74 {
  75         if (sint_value & HV_SYNIC_SINT_MASKED)
  76                 return -1;
  77         return sint_value & HV_SYNIC_SINT_VECTOR_MASK;
  78 }
  79
  80 static bool synic_has_vector_connected(struct kvm_vcpu_hv_synic *synic,
  81                                       int vector)
  82 {
  83         int i;
  84
  85         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  86                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
  87                         return true;
  88         }
  89         return false;
  90 }
  91
  92 static bool synic_has_vector_auto_eoi(struct kvm_vcpu_hv_synic *synic,
  93                                      int vector)
  94 {
  95         int i;
  96         u64 sint_value;
  97
  98         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
  99                 sint_value = synic_read_sint(synic, i);
 100                 if (synic_get_sint_vector(sint_value) == vector &&
 101                     sint_value & HV_SYNIC_SINT_AUTO_EOI)
 102                         return true;
 103         }
 104         return false;
 105 }
 106
 107 static void synic_update_vector(struct kvm_vcpu_hv_synic *synic,
 108                                 int vector)
 109 {
 110         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 111         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
 112         bool auto_eoi_old, auto_eoi_new;
 113
 114         if (vector < HV_SYNIC_FIRST_VALID_VECTOR)
 115                 return;
 116
 117         if (synic_has_vector_connected(synic, vector))
 118                 __set_bit(vector, synic->vec_bitmap);
 119         else
 120                 __clear_bit(vector, synic->vec_bitmap);
 121
 122         auto_eoi_old = !bitmap_empty(synic->auto_eoi_bitmap, 256);
 123
 124         if (synic_has_vector_auto_eoi(synic, vector))
 125                 __set_bit(vector, synic->auto_eoi_bitmap);
 126         else
 127                 __clear_bit(vector, synic->auto_eoi_bitmap);
 128
 129         auto_eoi_new = !bitmap_empty(synic->auto_eoi_bitmap, 256);
 130
 131         if (auto_eoi_old == auto_eoi_new)
 132                 return;
 133
 134         if (!enable_apicv)
 135                 return;
 136
 137         down_write(&vcpu->kvm->arch.apicv_update_lock);
 138
 139         if (auto_eoi_new)
 140                 hv->synic_auto_eoi_used++;
 141         else
 142                 hv->synic_auto_eoi_used--;
 143
 144         /*
 145          * Inhibit APICv if any vCPU is using SynIC's AutoEOI, which relies on
 146          * the hypervisor to manually inject IRQs.
 147          */
 148         __kvm_set_or_clear_apicv_inhibit(vcpu->kvm,
 149                                          APICV_INHIBIT_REASON_HYPERV,
 150                                          !!hv->synic_auto_eoi_used);
 151
 152         up_write(&vcpu->kvm->arch.apicv_update_lock);
 153 }
 154
 155 static int synic_set_sint(struct kvm_vcpu_hv_synic *synic, int sint,
 156                           u64 data, bool host)
 157 {
 158         int vector, old_vector;
 159         bool masked;
 160
 161         vector = data & HV_SYNIC_SINT_VECTOR_MASK;
 162         masked = data & HV_SYNIC_SINT_MASKED;
 163
 164         /*
 165          * Valid vectors are 16-255, however, nested Hyper-V attempts to write
 166          * default '0x10000' value on boot and this should not #GP. We need to
 167          * allow zero-initing the register from host as well.
 168          */
 169         if (vector < HV_SYNIC_FIRST_VALID_VECTOR && !host && !masked)
 170                 return 1;
 171         /*
 172          * Guest may configure multiple SINTs to use the same vector, so
 173          * we maintain a bitmap of vectors handled by synic, and a
 174          * bitmap of vectors with auto-eoi behavior.  The bitmaps are
 175          * updated here, and atomically queried on fast paths.
 176          */
 177         old_vector = synic_read_sint(synic, sint) & HV_SYNIC_SINT_VECTOR_MASK;
 178
 179         atomic64_set(&synic->sint[sint], data);
 180
 181         synic_update_vector(synic, old_vector);
 182
 183         synic_update_vector(synic, vector);
 184
 185         /* Load SynIC vectors into EOI exit bitmap */
 186         kvm_make_request(KVM_REQ_SCAN_IOAPIC, hv_synic_to_vcpu(synic));
 187         return 0;
 188 }
 189
 190 static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx)
 191 {
 192         struct kvm_vcpu *vcpu = NULL;
 193         unsigned long i;
 194
 195         if (vpidx >= KVM_MAX_VCPUS)
 196                 return NULL;
 197
 198         vcpu = kvm_get_vcpu(kvm, vpidx);
 199         if (vcpu && kvm_hv_get_vpindex(vcpu) == vpidx)
 200                 return vcpu;
 201         kvm_for_each_vcpu(i, vcpu, kvm)
 202                 if (kvm_hv_get_vpindex(vcpu) == vpidx)
 203                         return vcpu;
 204         return NULL;
 205 }
 206
 207 static struct kvm_vcpu_hv_synic *synic_get(struct kvm *kvm, u32 vpidx)
 208 {
 209         struct kvm_vcpu *vcpu;
 210         struct kvm_vcpu_hv_synic *synic;
 211
 212         vcpu = get_vcpu_by_vpidx(kvm, vpidx);
 213         if (!vcpu || !to_hv_vcpu(vcpu))
 214                 return NULL;
 215         synic = to_hv_synic(vcpu);
 216         return (synic->active) ? synic : NULL;
 217 }
 218
 219 static void kvm_hv_notify_acked_sint(struct kvm_vcpu *vcpu, u32 sint)
 220 {
 221         struct kvm *kvm = vcpu->kvm;
 222         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 223         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 224         struct kvm_vcpu_hv_stimer *stimer;
 225         int gsi, idx;
 226
 227         trace_kvm_hv_notify_acked_sint(vcpu->vcpu_id, sint);
 228
 229         /* Try to deliver pending Hyper-V SynIC timers messages */
 230         for (idx = 0; idx < ARRAY_SIZE(hv_vcpu->stimer); idx++) {
 231                 stimer = &hv_vcpu->stimer[idx];
 232                 if (stimer->msg_pending && stimer->config.enable &&
 233                     !stimer->config.direct_mode &&
 234                     stimer->config.sintx == sint)
 235                         stimer_mark_pending(stimer, false);
 236         }
 237
 238         idx = srcu_read_lock(&kvm->irq_srcu);
 239         gsi = atomic_read(&synic->sint_to_gsi[sint]);
 240         if (gsi != -1)
 241                 kvm_notify_acked_gsi(kvm, gsi);
 242         srcu_read_unlock(&kvm->irq_srcu, idx);
 243 }
 244
 245 static void synic_exit(struct kvm_vcpu_hv_synic *synic, u32 msr)
 246 {
 247         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 248         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 249
 250         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNIC;
 251         hv_vcpu->exit.u.synic.msr = msr;
 252         hv_vcpu->exit.u.synic.control = synic->control;
 253         hv_vcpu->exit.u.synic.evt_page = synic->evt_page;
 254         hv_vcpu->exit.u.synic.msg_page = synic->msg_page;
 255
 256         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 257 }
 258
 259 static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
 260                          u32 msr, u64 data, bool host)
 261 {
 262         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 263         int ret;
 264
 265         if (!synic->active && (!host || data))
 266                 return 1;
 267
 268         trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host);
 269
 270         ret = 0;
 271         switch (msr) {
 272         case HV_X64_MSR_SCONTROL:
 273                 synic->control = data;
 274                 if (!host)
 275                         synic_exit(synic, msr);
 276                 break;
 277         case HV_X64_MSR_SVERSION:
 278                 if (!host) {
 279                         ret = 1;
 280                         break;
 281                 }
 282                 synic->version = data;
 283                 break;
 284         case HV_X64_MSR_SIEFP:
 285                 if ((data & HV_SYNIC_SIEFP_ENABLE) && !host &&
 286                     !synic->dont_zero_synic_pages)
 287                         if (kvm_clear_guest(vcpu->kvm,
 288                                             data & PAGE_MASK, PAGE_SIZE)) {
 289                                 ret = 1;
 290                                 break;
 291                         }
 292                 synic->evt_page = data;
 293                 if (!host)
 294                         synic_exit(synic, msr);
 295                 break;
 296         case HV_X64_MSR_SIMP:
 297                 if ((data & HV_SYNIC_SIMP_ENABLE) && !host &&
 298                     !synic->dont_zero_synic_pages)
 299                         if (kvm_clear_guest(vcpu->kvm,
 300                                             data & PAGE_MASK, PAGE_SIZE)) {
 301                                 ret = 1;
 302                                 break;
 303                         }
 304                 synic->msg_page = data;
 305                 if (!host)
 306                         synic_exit(synic, msr);
 307                 break;
 308         case HV_X64_MSR_EOM: {
 309                 int i;
 310
 311                 if (!synic->active)
 312                         break;
 313
 314                 for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 315                         kvm_hv_notify_acked_sint(vcpu, i);
 316                 break;
 317         }
 318         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 319                 ret = synic_set_sint(synic, msr - HV_X64_MSR_SINT0, data, host);
 320                 break;
 321         default:
 322                 ret = 1;
 323                 break;
 324         }
 325         return ret;
 326 }
 327
 328 static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
 329 {
 330         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 331
 332         return hv_vcpu->cpuid_cache.syndbg_cap_eax &
 333                 HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
 334 }
 335
 336 static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
 337 {
 338         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
 339
 340         if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
 341                 hv->hv_syndbg.control.status =
 342                         vcpu->run->hyperv.u.syndbg.status;
 343         return 1;
 344 }
 345
 346 static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
 347 {
 348         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 349         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 350
 351         hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
 352         hv_vcpu->exit.u.syndbg.msr = msr;
 353         hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
 354         hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
 355         hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
 356         hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
 357         vcpu->arch.complete_userspace_io =
 358                         kvm_hv_syndbg_complete_userspace;
 359
 360         kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
 361 }
 362
 363 static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
 364 {
 365         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 366
 367         if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
 368                 return 1;
 369
 370         trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
 371                                     to_hv_vcpu(vcpu)->vp_index, msr, data);
 372         switch (msr) {
 373         case HV_X64_MSR_SYNDBG_CONTROL:
 374                 syndbg->control.control = data;
 375                 if (!host)
 376                         syndbg_exit(vcpu, msr);
 377                 break;
 378         case HV_X64_MSR_SYNDBG_STATUS:
 379                 syndbg->control.status = data;
 380                 break;
 381         case HV_X64_MSR_SYNDBG_SEND_BUFFER:
 382                 syndbg->control.send_page = data;
 383                 break;
 384         case HV_X64_MSR_SYNDBG_RECV_BUFFER:
 385                 syndbg->control.recv_page = data;
 386                 break;
 387         case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
 388                 syndbg->control.pending_page = data;
 389                 if (!host)
 390                         syndbg_exit(vcpu, msr);
 391                 break;
 392         case HV_X64_MSR_SYNDBG_OPTIONS:
 393                 syndbg->options = data;
 394                 break;
 395         default:
 396                 break;
 397         }
 398
 399         return 0;
 400 }
 401
 402 static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
 403 {
 404         struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 405
 406         if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
 407                 return 1;
 408
 409         switch (msr) {
 410         case HV_X64_MSR_SYNDBG_CONTROL:
 411                 *pdata = syndbg->control.control;
 412                 break;
 413         case HV_X64_MSR_SYNDBG_STATUS:
 414                 *pdata = syndbg->control.status;
 415                 break;
 416         case HV_X64_MSR_SYNDBG_SEND_BUFFER:
 417                 *pdata = syndbg->control.send_page;
 418                 break;
 419         case HV_X64_MSR_SYNDBG_RECV_BUFFER:
 420                 *pdata = syndbg->control.recv_page;
 421                 break;
 422         case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
 423                 *pdata = syndbg->control.pending_page;
 424                 break;
 425         case HV_X64_MSR_SYNDBG_OPTIONS:
 426                 *pdata = syndbg->options;
 427                 break;
 428         default:
 429                 break;
 430         }
 431
 432         trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id, kvm_hv_get_vpindex(vcpu), msr, *pdata);
 433
 434         return 0;
 435 }
 436
 437 static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
 438                          bool host)
 439 {
 440         int ret;
 441
 442         if (!synic->active && !host)
 443                 return 1;
 444
 445         ret = 0;
 446         switch (msr) {
 447         case HV_X64_MSR_SCONTROL:
 448                 *pdata = synic->control;
 449                 break;
 450         case HV_X64_MSR_SVERSION:
 451                 *pdata = synic->version;
 452                 break;
 453         case HV_X64_MSR_SIEFP:
 454                 *pdata = synic->evt_page;
 455                 break;
 456         case HV_X64_MSR_SIMP:
 457                 *pdata = synic->msg_page;
 458                 break;
 459         case HV_X64_MSR_EOM:
 460                 *pdata = 0;
 461                 break;
 462         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
 463                 *pdata = atomic64_read(&synic->sint[msr - HV_X64_MSR_SINT0]);
 464                 break;
 465         default:
 466                 ret = 1;
 467                 break;
 468         }
 469         return ret;
 470 }
 471
 472 static int synic_set_irq(struct kvm_vcpu_hv_synic *synic, u32 sint)
 473 {
 474         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 475         struct kvm_lapic_irq irq;
 476         int ret, vector;
 477
 478         if (KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm))
 479                 return -EINVAL;
 480
 481         if (sint >= ARRAY_SIZE(synic->sint))
 482                 return -EINVAL;
 483
 484         vector = synic_get_sint_vector(synic_read_sint(synic, sint));
 485         if (vector < 0)
 486                 return -ENOENT;
 487
 488         memset(&irq, 0, sizeof(irq));
 489         irq.shorthand = APIC_DEST_SELF;
 490         irq.dest_mode = APIC_DEST_PHYSICAL;
 491         irq.delivery_mode = APIC_DM_FIXED;
 492         irq.vector = vector;
 493         irq.level = 1;
 494
 495         ret = kvm_irq_delivery_to_apic(vcpu->kvm, vcpu->arch.apic, &irq, NULL);
 496         trace_kvm_hv_synic_set_irq(vcpu->vcpu_id, sint, irq.vector, ret);
 497         return ret;
 498 }
 499
 500 int kvm_hv_synic_set_irq(struct kvm *kvm, u32 vpidx, u32 sint)
 501 {
 502         struct kvm_vcpu_hv_synic *synic;
 503
 504         synic = synic_get(kvm, vpidx);
 505         if (!synic)
 506                 return -EINVAL;
 507
 508         return synic_set_irq(synic, sint);
 509 }
 510
 511 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
 512 {
 513         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 514         int i;
 515
 516         trace_kvm_hv_synic_send_eoi(vcpu->vcpu_id, vector);
 517
 518         for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
 519                 if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
 520                         kvm_hv_notify_acked_sint(vcpu, i);
 521 }
 522
 523 static int kvm_hv_set_sint_gsi(struct kvm *kvm, u32 vpidx, u32 sint, int gsi)
 524 {
 525         struct kvm_vcpu_hv_synic *synic;
 526
 527         synic = synic_get(kvm, vpidx);
 528         if (!synic)
 529                 return -EINVAL;
 530
 531         if (sint >= ARRAY_SIZE(synic->sint_to_gsi))
 532                 return -EINVAL;
 533
 534         atomic_set(&synic->sint_to_gsi[sint], gsi);
 535         return 0;
 536 }
 537
 538 void kvm_hv_irq_routing_update(struct kvm *kvm)
 539 {
 540         struct kvm_irq_routing_table *irq_rt;
 541         struct kvm_kernel_irq_routing_entry *e;
 542         u32 gsi;
 543
 544         irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,
 545                                         lockdep_is_held(&kvm->irq_lock));
 546
 547         for (gsi = 0; gsi < irq_rt->nr_rt_entries; gsi++) {
 548                 hlist_for_each_entry(e, &irq_rt->map[gsi], link) {
 549                         if (e->type == KVM_IRQ_ROUTING_HV_SINT)
 550                                 kvm_hv_set_sint_gsi(kvm, e->hv_sint.vcpu,
 551                                                     e->hv_sint.sint, gsi);
 552                 }
 553         }
 554 }
 555
 556 static void synic_init(struct kvm_vcpu_hv_synic *synic)
 557 {
 558         int i;
 559
 560         memset(synic, 0, sizeof(*synic));
 561         synic->version = HV_SYNIC_VERSION_1;
 562         for (i = 0; i < ARRAY_SIZE(synic->sint); i++) {
 563                 atomic64_set(&synic->sint[i], HV_SYNIC_SINT_MASKED);
 564                 atomic_set(&synic->sint_to_gsi[i], -1);
 565         }
 566 }
 567
 568 static u64 get_time_ref_counter(struct kvm *kvm)
 569 {
 570         struct kvm_hv *hv = to_kvm_hv(kvm);
 571         struct kvm_vcpu *vcpu;
 572         u64 tsc;
 573
 574         /*
 575          * Fall back to get_kvmclock_ns() when TSC page hasn't been set up,
 576          * is broken, disabled or being updated.
 577          */
 578         if (hv->hv_tsc_page_status != HV_TSC_PAGE_SET)
 579                 return div_u64(get_kvmclock_ns(kvm), 100);
 580
 581         vcpu = kvm_get_vcpu(kvm, 0);
 582         tsc = kvm_read_l1_tsc(vcpu, rdtsc());
 583         return mul_u64_u64_shr(tsc, hv->tsc_ref.tsc_scale, 64)
 584                 + hv->tsc_ref.tsc_offset;
 585 }
 586
 587 static void stimer_mark_pending(struct kvm_vcpu_hv_stimer *stimer,
 588                                 bool vcpu_kick)
 589 {
 590         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 591
 592         set_bit(stimer->index,
 593                 to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 594         kvm_make_request(KVM_REQ_HV_STIMER, vcpu);
 595         if (vcpu_kick)
 596                 kvm_vcpu_kick(vcpu);
 597 }
 598
 599 static void stimer_cleanup(struct kvm_vcpu_hv_stimer *stimer)
 600 {
 601         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 602
 603         trace_kvm_hv_stimer_cleanup(hv_stimer_to_vcpu(stimer)->vcpu_id,
 604                                     stimer->index);
 605
 606         hrtimer_cancel(&stimer->timer);
 607         clear_bit(stimer->index,
 608                   to_hv_vcpu(vcpu)->stimer_pending_bitmap);
 609         stimer->msg_pending = false;
 610         stimer->exp_time = 0;
 611 }
 612
 613 static enum hrtimer_restart stimer_timer_callback(struct hrtimer *timer)
 614 {
 615         struct kvm_vcpu_hv_stimer *stimer;
 616
 617         stimer = container_of(timer, struct kvm_vcpu_hv_stimer, timer);
 618         trace_kvm_hv_stimer_callback(hv_stimer_to_vcpu(stimer)->vcpu_id,
 619                                      stimer->index);
 620         stimer_mark_pending(stimer, true);
 621
 622         return HRTIMER_NORESTART;
 623 }
 624
 625 /*
 626  * stimer_start() assumptions:
 627  * a) stimer->count is not equal to 0
 628  * b) stimer->config has HV_STIMER_ENABLE flag
 629  */
 630 static int stimer_start(struct kvm_vcpu_hv_stimer *stimer)
 631 {
 632         u64 time_now;
 633         ktime_t ktime_now;
 634
 635         time_now = get_time_ref_counter(hv_stimer_to_vcpu(stimer)->kvm);
 636         ktime_now = ktime_get();
 637
 638         if (stimer->config.periodic) {
 639                 if (stimer->exp_time) {
 640                         if (time_now >= stimer->exp_time) {
 641                                 u64 remainder;
 642
 643                                 div64_u64_rem(time_now - stimer->exp_time,
 644                                               stimer->count, &remainder);
 645                                 stimer->exp_time =
 646                                         time_now + (stimer->count - remainder);
 647                         }
 648                 } else
 649                         stimer->exp_time = time_now + stimer->count;
 650
 651                 trace_kvm_hv_stimer_start_periodic(
 652                                         hv_stimer_to_vcpu(stimer)->vcpu_id,
 653                                         stimer->index,
 654                                         time_now, stimer->exp_time);
 655
 656                 hrtimer_start(&stimer->timer,
 657                               ktime_add_ns(ktime_now,
 658                                            100 * (stimer->exp_time - time_now)),
 659                               HRTIMER_MODE_ABS);
 660                 return 0;
 661         }
 662         stimer->exp_time = stimer->count;
 663         if (time_now >= stimer->count) {
 664                 /*
 665                  * Expire timer according to Hypervisor Top-Level Functional
 666                  * specification v4(15.3.1):
 667                  * "If a one shot is enabled and the specified count is in
 668                  * the past, it will expire immediately."
 669                  */
 670                 stimer_mark_pending(stimer, false);
 671                 return 0;
 672         }
 673
 674         trace_kvm_hv_stimer_start_one_shot(hv_stimer_to_vcpu(stimer)->vcpu_id,
 675                                            stimer->index,
 676                                            time_now, stimer->count);
 677
 678         hrtimer_start(&stimer->timer,
 679                       ktime_add_ns(ktime_now, 100 * (stimer->count - time_now)),
 680                       HRTIMER_MODE_ABS);
 681         return 0;
 682 }
 683
 684 static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config,
 685                              bool host)
 686 {
 687         union hv_stimer_config new_config = {.as_uint64 = config},
 688                 old_config = {.as_uint64 = stimer->config.as_uint64};
 689         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 690         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 691         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 692
 693         if (!synic->active && (!host || config))
 694                 return 1;
 695
 696         if (unlikely(!host && hv_vcpu->enforce_cpuid && new_config.direct_mode &&
 697                      !(hv_vcpu->cpuid_cache.features_edx &
 698                        HV_STIMER_DIRECT_MODE_AVAILABLE)))
 699                 return 1;
 700
 701         trace_kvm_hv_stimer_set_config(hv_stimer_to_vcpu(stimer)->vcpu_id,
 702                                        stimer->index, config, host);
 703
 704         stimer_cleanup(stimer);
 705         if (old_config.enable &&
 706             !new_config.direct_mode && new_config.sintx == 0)
 707                 new_config.enable = 0;
 708         stimer->config.as_uint64 = new_config.as_uint64;
 709
 710         if (stimer->config.enable)
 711                 stimer_mark_pending(stimer, false);
 712
 713         return 0;
 714 }
 715
 716 static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count,
 717                             bool host)
 718 {
 719         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 720         struct kvm_vcpu_hv_synic *synic = to_hv_synic(vcpu);
 721
 722         if (!synic->active && (!host || count))
 723                 return 1;
 724
 725         trace_kvm_hv_stimer_set_count(hv_stimer_to_vcpu(stimer)->vcpu_id,
 726                                       stimer->index, count, host);
 727
 728         stimer_cleanup(stimer);
 729         stimer->count = count;
 730         if (!host) {
 731                 if (stimer->count == 0)
 732                         stimer->config.enable = 0;
 733                 else if (stimer->config.auto_enable)
 734                         stimer->config.enable = 1;
 735         }
 736
 737         if (stimer->config.enable)
 738                 stimer_mark_pending(stimer, false);
 739
 740         return 0;
 741 }
 742
 743 static int stimer_get_config(struct kvm_vcpu_hv_stimer *stimer, u64 *pconfig)
 744 {
 745         *pconfig = stimer->config.as_uint64;
 746         return 0;
 747 }
 748
 749 static int stimer_get_count(struct kvm_vcpu_hv_stimer *stimer, u64 *pcount)
 750 {
 751         *pcount = stimer->count;
 752         return 0;
 753 }
 754
 755 static int synic_deliver_msg(struct kvm_vcpu_hv_synic *synic, u32 sint,
 756                              struct hv_message *src_msg, bool no_retry)
 757 {
 758         struct kvm_vcpu *vcpu = hv_synic_to_vcpu(synic);
 759         int msg_off = offsetof(struct hv_message_page, sint_message[sint]);
 760         gfn_t msg_page_gfn;
 761         struct hv_message_header hv_hdr;
 762         int r;
 763
 764         if (!(synic->msg_page & HV_SYNIC_SIMP_ENABLE))
 765                 return -ENOENT;
 766
 767         msg_page_gfn = synic->msg_page >> PAGE_SHIFT;
 768
 769         /*
 770          * Strictly following the spec-mandated ordering would assume setting
 771          * .msg_pending before checking .message_type.  However, this function
 772          * is only called in vcpu context so the entire update is atomic from
 773          * guest POV and thus the exact order here doesn't matter.
 774          */
 775         r = kvm_vcpu_read_guest_page(vcpu, msg_page_gfn, &hv_hdr.message_type,
 776                                      msg_off + offsetof(struct hv_message,
 777                                                         header.message_type),
 778                                      sizeof(hv_hdr.message_type));
 779         if (r < 0)
 780                 return r;
 781
 782         if (hv_hdr.message_type != HVMSG_NONE) {
 783                 if (no_retry)
 784                         return 0;
 785
 786                 hv_hdr.message_flags.msg_pending = 1;
 787                 r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn,
 788                                               &hv_hdr.message_flags,
 789                                               msg_off +
 790                                               offsetof(struct hv_message,
 791                                                        header.message_flags),
 792                                               sizeof(hv_hdr.message_flags));
 793                 if (r < 0)
 794                         return r;
 795                 return -EAGAIN;
 796         }
 797
 798         r = kvm_vcpu_write_guest_page(vcpu, msg_page_gfn, src_msg, msg_off,
 799                                       sizeof(src_msg->header) +
 800                                       src_msg->header.payload_size);
 801         if (r < 0)
 802                 return r;
 803
 804         r = synic_set_irq(synic, sint);
 805         if (r < 0)
 806                 return r;
 807         if (r == 0)
 808                 return -EFAULT;
 809         return 0;
 810 }
 811
 812 static int stimer_send_msg(struct kvm_vcpu_hv_stimer *stimer)
 813 {
 814         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 815         struct hv_message *msg = &stimer->msg;
 816         struct hv_timer_message_payload *payload =
 817                         (struct hv_timer_message_payload *)&msg->u.payload;
 818
 819         /*
 820          * To avoid piling up periodic ticks, don't retry message
 821          * delivery for them (within "lazy" lost ticks policy).
 822          */
 823         bool no_retry = stimer->config.periodic;
 824
 825         payload->expiration_time = stimer->exp_time;
 826         payload->delivery_time = get_time_ref_counter(vcpu->kvm);
 827         return synic_deliver_msg(to_hv_synic(vcpu),
 828                                  stimer->config.sintx, msg,
 829                                  no_retry);
 830 }
 831
 832 static int stimer_notify_direct(struct kvm_vcpu_hv_stimer *stimer)
 833 {
 834         struct kvm_vcpu *vcpu = hv_stimer_to_vcpu(stimer);
 835         struct kvm_lapic_irq irq = {
 836                 .delivery_mode = APIC_DM_FIXED,
 837                 .vector = stimer->config.apic_vector
 838         };
 839
 840         if (lapic_in_kernel(vcpu))
 841                 return !kvm_apic_set_irq(vcpu, &irq, NULL);
 842         return 0;
 843 }
 844
 845 static void stimer_expiration(struct kvm_vcpu_hv_stimer *stimer)
 846 {
 847         int r, direct = stimer->config.direct_mode;
 848
 849         stimer->msg_pending = true;
 850         if (!direct)
 851                 r = stimer_send_msg(stimer);
 852         else
 853                 r = stimer_notify_direct(stimer);
 854         trace_kvm_hv_stimer_expiration(hv_stimer_to_vcpu(stimer)->vcpu_id,
 855                                        stimer->index, direct, r);
 856         if (!r) {
 857                 stimer->msg_pending = false;
 858                 if (!(stimer->config.periodic))
 859                         stimer->config.enable = 0;
 860         }
 861 }
 862
 863 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu)
 864 {
 865         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 866         struct kvm_vcpu_hv_stimer *stimer;
 867         u64 time_now, exp_time;
 868         int i;
 869
 870         if (!hv_vcpu)
 871                 return;
 872
 873         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 874                 if (test_and_clear_bit(i, hv_vcpu->stimer_pending_bitmap)) {
 875                         stimer = &hv_vcpu->stimer[i];
 876                         if (stimer->config.enable) {
 877                                 exp_time = stimer->exp_time;
 878
 879                                 if (exp_time) {
 880                                         time_now =
 881                                                 get_time_ref_counter(vcpu->kvm);
 882                                         if (time_now >= exp_time)
 883                                                 stimer_expiration(stimer);
 884                                 }
 885
 886                                 if ((stimer->config.enable) &&
 887                                     stimer->count) {
 888                                         if (!stimer->msg_pending)
 889                                                 stimer_start(stimer);
 890                                 } else
 891                                         stimer_cleanup(stimer);
 892                         }
 893                 }
 894 }
 895
 896 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu)
 897 {
 898         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 899         int i;
 900
 901         if (!hv_vcpu)
 902                 return;
 903
 904         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 905                 stimer_cleanup(&hv_vcpu->stimer[i]);
 906
 907         kfree(hv_vcpu);
 908         vcpu->arch.hyperv = NULL;
 909 }
 910
 911 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu)
 912 {
 913         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 914
 915         if (!hv_vcpu)
 916                 return false;
 917
 918         if (!(hv_vcpu->hv_vapic & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE))
 919                 return false;
 920         return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED;
 921 }
 922 EXPORT_SYMBOL_GPL(kvm_hv_assist_page_enabled);
 923
 924 int kvm_hv_get_assist_page(struct kvm_vcpu *vcpu)
 925 {
 926         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 927
 928         if (!hv_vcpu || !kvm_hv_assist_page_enabled(vcpu))
 929                 return -EFAULT;
 930
 931         return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data,
 932                                      &hv_vcpu->vp_assist_page, sizeof(struct hv_vp_assist_page));
 933 }
 934 EXPORT_SYMBOL_GPL(kvm_hv_get_assist_page);
 935
 936 static void stimer_prepare_msg(struct kvm_vcpu_hv_stimer *stimer)
 937 {
 938         struct hv_message *msg = &stimer->msg;
 939         struct hv_timer_message_payload *payload =
 940                         (struct hv_timer_message_payload *)&msg->u.payload;
 941
 942         memset(&msg->header, 0, sizeof(msg->header));
 943         msg->header.message_type = HVMSG_TIMER_EXPIRED;
 944         msg->header.payload_size = sizeof(*payload);
 945
 946         payload->timer_index = stimer->index;
 947         payload->expiration_time = 0;
 948         payload->delivery_time = 0;
 949 }
 950
 951 static void stimer_init(struct kvm_vcpu_hv_stimer *stimer, int timer_index)
 952 {
 953         memset(stimer, 0, sizeof(*stimer));
 954         stimer->index = timer_index;
 955         hrtimer_init(&stimer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 956         stimer->timer.function = stimer_timer_callback;
 957         stimer_prepare_msg(stimer);
 958 }
 959
 960 int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
 961 {
 962         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 963         int i;
 964
 965         if (hv_vcpu)
 966                 return 0;
 967
 968         hv_vcpu = kzalloc(sizeof(struct kvm_vcpu_hv), GFP_KERNEL_ACCOUNT);
 969         if (!hv_vcpu)
 970                 return -ENOMEM;
 971
 972         vcpu->arch.hyperv = hv_vcpu;
 973         hv_vcpu->vcpu = vcpu;
 974
 975         synic_init(&hv_vcpu->synic);
 976
 977         bitmap_zero(hv_vcpu->stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
 978         for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++)
 979                 stimer_init(&hv_vcpu->stimer[i], i);
 980
 981         hv_vcpu->vp_index = vcpu->vcpu_idx;
 982
 983         for (i = 0; i < HV_NR_TLB_FLUSH_FIFOS; i++) {
 984                 INIT_KFIFO(hv_vcpu->tlb_flush_fifo[i].entries);
 985                 spin_lock_init(&hv_vcpu->tlb_flush_fifo[i].write_lock);
 986         }
 987
 988         return 0;
 989 }
 990
 991 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages)
 992 {
 993         struct kvm_vcpu_hv_synic *synic;
 994         int r;
 995
 996         r = kvm_hv_vcpu_init(vcpu);
 997         if (r)
 998                 return r;
 999
1000         synic = to_hv_synic(vcpu);
1001
1002         synic->active = true;
1003         synic->dont_zero_synic_pages = dont_zero_synic_pages;
1004         synic->control = HV_SYNIC_CONTROL_ENABLE;
1005         return 0;
1006 }
1007
1008 static bool kvm_hv_msr_partition_wide(u32 msr)
1009 {
1010         bool r = false;
1011
1012         switch (msr) {
1013         case HV_X64_MSR_GUEST_OS_ID:
1014         case HV_X64_MSR_HYPERCALL:
1015         case HV_X64_MSR_REFERENCE_TSC:
1016         case HV_X64_MSR_TIME_REF_COUNT:
1017         case HV_X64_MSR_CRASH_CTL:
1018         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1019         case HV_X64_MSR_RESET:
1020         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1021         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1022         case HV_X64_MSR_TSC_EMULATION_STATUS:
1023         case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1024         case HV_X64_MSR_SYNDBG_OPTIONS:
1025         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1026                 r = true;
1027                 break;
1028         }
1029
1030         return r;
1031 }
1032
1033 static int kvm_hv_msr_get_crash_data(struct kvm *kvm, u32 index, u64 *pdata)
1034 {
1035         struct kvm_hv *hv = to_kvm_hv(kvm);
1036         size_t size = ARRAY_SIZE(hv->hv_crash_param);
1037
1038         if (WARN_ON_ONCE(index >= size))
1039                 return -EINVAL;
1040
1041         *pdata = hv->hv_crash_param[array_index_nospec(index, size)];
1042         return 0;
1043 }
1044
1045 static int kvm_hv_msr_get_crash_ctl(struct kvm *kvm, u64 *pdata)
1046 {
1047         struct kvm_hv *hv = to_kvm_hv(kvm);
1048
1049         *pdata = hv->hv_crash_ctl;
1050         return 0;
1051 }
1052
1053 static int kvm_hv_msr_set_crash_ctl(struct kvm *kvm, u64 data)
1054 {
1055         struct kvm_hv *hv = to_kvm_hv(kvm);
1056
1057         hv->hv_crash_ctl = data & HV_CRASH_CTL_CRASH_NOTIFY;
1058
1059         return 0;
1060 }
1061
1062 static int kvm_hv_msr_set_crash_data(struct kvm *kvm, u32 index, u64 data)
1063 {
1064         struct kvm_hv *hv = to_kvm_hv(kvm);
1065         size_t size = ARRAY_SIZE(hv->hv_crash_param);
1066
1067         if (WARN_ON_ONCE(index >= size))
1068                 return -EINVAL;
1069
1070         hv->hv_crash_param[array_index_nospec(index, size)] = data;
1071         return 0;
1072 }
1073
1074 /*
1075  * The kvmclock and Hyper-V TSC page use similar formulas, and converting
1076  * between them is possible:
1077  *
1078  * kvmclock formula:
1079  *    nsec = (ticks - tsc_timestamp) * tsc_to_system_mul * 2^(tsc_shift-32)
1080  *           + system_time
1081  *
1082  * Hyper-V formula:
1083  *    nsec/100 = ticks * scale / 2^64 + offset
1084  *
1085  * When tsc_timestamp = system_time = 0, offset is zero in the Hyper-V formula.
1086  * By dividing the kvmclock formula by 100 and equating what's left we get:
1087  *    ticks * scale / 2^64 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1088  *            scale / 2^64 =         tsc_to_system_mul * 2^(tsc_shift-32) / 100
1089  *            scale        =         tsc_to_system_mul * 2^(32+tsc_shift) / 100
1090  *
1091  * Now expand the kvmclock formula and divide by 100:
1092  *    nsec = ticks * tsc_to_system_mul * 2^(tsc_shift-32)
1093  *           - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32)
1094  *           + system_time
1095  *    nsec/100 = ticks * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1096  *               - tsc_timestamp * tsc_to_system_mul * 2^(tsc_shift-32) / 100
1097  *               + system_time / 100
1098  *
1099  * Replace tsc_to_system_mul * 2^(tsc_shift-32) / 100 by scale / 2^64:
1100  *    nsec/100 = ticks * scale / 2^64
1101  *               - tsc_timestamp * scale / 2^64
1102  *               + system_time / 100
1103  *
1104  * Equate with the Hyper-V formula so that ticks * scale / 2^64 cancels out:
1105  *    offset = system_time / 100 - tsc_timestamp * scale / 2^64
1106  *
1107  * These two equivalencies are implemented in this function.
1108  */
1109 static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info *hv_clock,
1110                                         struct ms_hyperv_tsc_page *tsc_ref)
1111 {
1112         u64 max_mul;
1113
1114         if (!(hv_clock->flags & PVCLOCK_TSC_STABLE_BIT))
1115                 return false;
1116
1117         /*
1118          * check if scale would overflow, if so we use the time ref counter
1119          *    tsc_to_system_mul * 2^(tsc_shift+32) / 100 >= 2^64
1120          *    tsc_to_system_mul / 100 >= 2^(32-tsc_shift)
1121          *    tsc_to_system_mul >= 100 * 2^(32-tsc_shift)
1122          */
1123         max_mul = 100ull << (32 - hv_clock->tsc_shift);
1124         if (hv_clock->tsc_to_system_mul >= max_mul)
1125                 return false;
1126
1127         /*
1128          * Otherwise compute the scale and offset according to the formulas
1129          * derived above.
1130          */
1131         tsc_ref->tsc_scale =
1132                 mul_u64_u32_div(1ULL << (32 + hv_clock->tsc_shift),
1133                                 hv_clock->tsc_to_system_mul,
1134                                 100);
1135
1136         tsc_ref->tsc_offset = hv_clock->system_time;
1137         do_div(tsc_ref->tsc_offset, 100);
1138         tsc_ref->tsc_offset -=
1139                 mul_u64_u64_shr(hv_clock->tsc_timestamp, tsc_ref->tsc_scale, 64);
1140         return true;
1141 }
1142
1143 /*
1144  * Don't touch TSC page values if the guest has opted for TSC emulation after
1145  * migration. KVM doesn't fully support reenlightenment notifications and TSC
1146  * access emulation and Hyper-V is known to expect the values in TSC page to
1147  * stay constant before TSC access emulation is disabled from guest side
1148  * (HV_X64_MSR_TSC_EMULATION_STATUS). KVM userspace is expected to preserve TSC
1149  * frequency and guest visible TSC value across migration (and prevent it when
1150  * TSC scaling is unsupported).
1151  */
1152 static inline bool tsc_page_update_unsafe(struct kvm_hv *hv)
1153 {
1154         return (hv->hv_tsc_page_status != HV_TSC_PAGE_GUEST_CHANGED) &&
1155                 hv->hv_tsc_emulation_control;
1156 }
1157
1158 void kvm_hv_setup_tsc_page(struct kvm *kvm,
1159                            struct pvclock_vcpu_time_info *hv_clock)
1160 {
1161         struct kvm_hv *hv = to_kvm_hv(kvm);
1162         u32 tsc_seq;
1163         u64 gfn;
1164
1165         BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
1166         BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
1167
1168         mutex_lock(&hv->hv_lock);
1169
1170         if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
1171             hv->hv_tsc_page_status == HV_TSC_PAGE_SET ||
1172             hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
1173                 goto out_unlock;
1174
1175         if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
1176                 goto out_unlock;
1177
1178         gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
1179         /*
1180          * Because the TSC parameters only vary when there is a
1181          * change in the master clock, do not bother with caching.
1182          */
1183         if (unlikely(kvm_read_guest(kvm, gfn_to_gpa(gfn),
1184                                     &tsc_seq, sizeof(tsc_seq))))
1185                 goto out_err;
1186
1187         if (tsc_seq && tsc_page_update_unsafe(hv)) {
1188                 if (kvm_read_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1189                         goto out_err;
1190
1191                 hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1192                 goto out_unlock;
1193         }
1194
1195         /*
1196          * While we're computing and writing the parameters, force the
1197          * guest to use the time reference count MSR.
1198          */
1199         hv->tsc_ref.tsc_sequence = 0;
1200         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1201                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1202                 goto out_err;
1203
1204         if (!compute_tsc_page_parameters(hv_clock, &hv->tsc_ref))
1205                 goto out_err;
1206
1207         /* Ensure sequence is zero before writing the rest of the struct.  */
1208         smp_wmb();
1209         if (kvm_write_guest(kvm, gfn_to_gpa(gfn), &hv->tsc_ref, sizeof(hv->tsc_ref)))
1210                 goto out_err;
1211
1212         /*
1213          * Now switch to the TSC page mechanism by writing the sequence.
1214          */
1215         tsc_seq++;
1216         if (tsc_seq == 0xFFFFFFFF || tsc_seq == 0)
1217                 tsc_seq = 1;
1218
1219         /* Write the struct entirely before the non-zero sequence.  */
1220         smp_wmb();
1221
1222         hv->tsc_ref.tsc_sequence = tsc_seq;
1223         if (kvm_write_guest(kvm, gfn_to_gpa(gfn),
1224                             &hv->tsc_ref, sizeof(hv->tsc_ref.tsc_sequence)))
1225                 goto out_err;
1226
1227         hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
1228         goto out_unlock;
1229
1230 out_err:
1231         hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
1232 out_unlock:
1233         mutex_unlock(&hv->hv_lock);
1234 }
1235
1236 void kvm_hv_request_tsc_page_update(struct kvm *kvm)
1237 {
1238         struct kvm_hv *hv = to_kvm_hv(kvm);
1239
1240         mutex_lock(&hv->hv_lock);
1241
1242         if (hv->hv_tsc_page_status == HV_TSC_PAGE_SET &&
1243             !tsc_page_update_unsafe(hv))
1244                 hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1245
1246         mutex_unlock(&hv->hv_lock);
1247 }
1248
1249 static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr)
1250 {
1251         if (!hv_vcpu->enforce_cpuid)
1252                 return true;
1253
1254         switch (msr) {
1255         case HV_X64_MSR_GUEST_OS_ID:
1256         case HV_X64_MSR_HYPERCALL:
1257                 return hv_vcpu->cpuid_cache.features_eax &
1258                         HV_MSR_HYPERCALL_AVAILABLE;
1259         case HV_X64_MSR_VP_RUNTIME:
1260                 return hv_vcpu->cpuid_cache.features_eax &
1261                         HV_MSR_VP_RUNTIME_AVAILABLE;
1262         case HV_X64_MSR_TIME_REF_COUNT:
1263                 return hv_vcpu->cpuid_cache.features_eax &
1264                         HV_MSR_TIME_REF_COUNT_AVAILABLE;
1265         case HV_X64_MSR_VP_INDEX:
1266                 return hv_vcpu->cpuid_cache.features_eax &
1267                         HV_MSR_VP_INDEX_AVAILABLE;
1268         case HV_X64_MSR_RESET:
1269                 return hv_vcpu->cpuid_cache.features_eax &
1270                         HV_MSR_RESET_AVAILABLE;
1271         case HV_X64_MSR_REFERENCE_TSC:
1272                 return hv_vcpu->cpuid_cache.features_eax &
1273                         HV_MSR_REFERENCE_TSC_AVAILABLE;
1274         case HV_X64_MSR_SCONTROL:
1275         case HV_X64_MSR_SVERSION:
1276         case HV_X64_MSR_SIEFP:
1277         case HV_X64_MSR_SIMP:
1278         case HV_X64_MSR_EOM:
1279         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1280                 return hv_vcpu->cpuid_cache.features_eax &
1281                         HV_MSR_SYNIC_AVAILABLE;
1282         case HV_X64_MSR_STIMER0_CONFIG:
1283         case HV_X64_MSR_STIMER1_CONFIG:
1284         case HV_X64_MSR_STIMER2_CONFIG:
1285         case HV_X64_MSR_STIMER3_CONFIG:
1286         case HV_X64_MSR_STIMER0_COUNT:
1287         case HV_X64_MSR_STIMER1_COUNT:
1288         case HV_X64_MSR_STIMER2_COUNT:
1289         case HV_X64_MSR_STIMER3_COUNT:
1290                 return hv_vcpu->cpuid_cache.features_eax &
1291                         HV_MSR_SYNTIMER_AVAILABLE;
1292         case HV_X64_MSR_EOI:
1293         case HV_X64_MSR_ICR:
1294         case HV_X64_MSR_TPR:
1295         case HV_X64_MSR_VP_ASSIST_PAGE:
1296                 return hv_vcpu->cpuid_cache.features_eax &
1297                         HV_MSR_APIC_ACCESS_AVAILABLE;
1298         case HV_X64_MSR_TSC_FREQUENCY:
1299         case HV_X64_MSR_APIC_FREQUENCY:
1300                 return hv_vcpu->cpuid_cache.features_eax &
1301                         HV_ACCESS_FREQUENCY_MSRS;
1302         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1303         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1304         case HV_X64_MSR_TSC_EMULATION_STATUS:
1305                 return hv_vcpu->cpuid_cache.features_eax &
1306                         HV_ACCESS_REENLIGHTENMENT;
1307         case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1308                 return hv_vcpu->cpuid_cache.features_eax &
1309                         HV_ACCESS_TSC_INVARIANT;
1310         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1311         case HV_X64_MSR_CRASH_CTL:
1312                 return hv_vcpu->cpuid_cache.features_edx &
1313                         HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
1314         case HV_X64_MSR_SYNDBG_OPTIONS:
1315         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1316                 return hv_vcpu->cpuid_cache.features_edx &
1317                         HV_FEATURE_DEBUG_MSRS_AVAILABLE;
1318         default:
1319                 break;
1320         }
1321
1322         return false;
1323 }
1324
1325 #define KVM_HV_WIN2016_GUEST_ID 0x1040a00003839
1326 #define KVM_HV_WIN2016_GUEST_ID_MASK (~GENMASK_ULL(23, 16)) /* mask out the service version */
1327
1328 /*
1329  * Hyper-V enabled Windows Server 2016 SMP VMs fail to boot in !XSAVES && XSAVEC
1330  * configuration.
1331  * Such configuration can result from, for example, AMD Erratum 1386 workaround.
1332  *
1333  * Print a notice so users aren't left wondering what's suddenly gone wrong.
1334  */
1335 static void __kvm_hv_xsaves_xsavec_maybe_warn(struct kvm_vcpu *vcpu)
1336 {
1337         struct kvm *kvm = vcpu->kvm;
1338         struct kvm_hv *hv = to_kvm_hv(kvm);
1339
1340         /* Check again under the hv_lock.  */
1341         if (hv->xsaves_xsavec_checked)
1342                 return;
1343
1344         if ((hv->hv_guest_os_id & KVM_HV_WIN2016_GUEST_ID_MASK) !=
1345             KVM_HV_WIN2016_GUEST_ID)
1346                 return;
1347
1348         hv->xsaves_xsavec_checked = true;
1349
1350         /* UP configurations aren't affected */
1351         if (atomic_read(&kvm->online_vcpus) < 2)
1352                 return;
1353
1354         if (guest_cpuid_has(vcpu, X86_FEATURE_XSAVES) ||
1355             !guest_cpuid_has(vcpu, X86_FEATURE_XSAVEC))
1356                 return;
1357
1358         pr_notice_ratelimited("Booting SMP Windows KVM VM with !XSAVES && XSAVEC. "
1359                               "If it fails to boot try disabling XSAVEC in the VM config.\n");
1360 }
1361
1362 void kvm_hv_xsaves_xsavec_maybe_warn(struct kvm_vcpu *vcpu)
1363 {
1364         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1365
1366         if (!vcpu->arch.hyperv_enabled ||
1367             hv->xsaves_xsavec_checked)
1368                 return;
1369
1370         mutex_lock(&hv->hv_lock);
1371         __kvm_hv_xsaves_xsavec_maybe_warn(vcpu);
1372         mutex_unlock(&hv->hv_lock);
1373 }
1374
1375 static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
1376                              bool host)
1377 {
1378         struct kvm *kvm = vcpu->kvm;
1379         struct kvm_hv *hv = to_kvm_hv(kvm);
1380
1381         if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1382                 return 1;
1383
1384         switch (msr) {
1385         case HV_X64_MSR_GUEST_OS_ID:
1386                 hv->hv_guest_os_id = data;
1387                 /* setting guest os id to zero disables hypercall page */
1388                 if (!hv->hv_guest_os_id)
1389                         hv->hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE;
1390                 break;
1391         case HV_X64_MSR_HYPERCALL: {
1392                 u8 instructions[9];
1393                 int i = 0;
1394                 u64 addr;
1395
1396                 /* if guest os id is not set hypercall should remain disabled */
1397                 if (!hv->hv_guest_os_id)
1398                         break;
1399                 if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) {
1400                         hv->hv_hypercall = data;
1401                         break;
1402                 }
1403
1404                 /*
1405                  * If Xen and Hyper-V hypercalls are both enabled, disambiguate
1406                  * the same way Xen itself does, by setting the bit 31 of EAX
1407                  * which is RsvdZ in the 32-bit Hyper-V hypercall ABI and just
1408                  * going to be clobbered on 64-bit.
1409                  */
1410                 if (kvm_xen_hypercall_enabled(kvm)) {
1411                         /* orl $0x80000000, %eax */
1412                         instructions[i++] = 0x0d;
1413                         instructions[i++] = 0x00;
1414                         instructions[i++] = 0x00;
1415                         instructions[i++] = 0x00;
1416                         instructions[i++] = 0x80;
1417                 }
1418
1419                 /* vmcall/vmmcall */
1420                 static_call(kvm_x86_patch_hypercall)(vcpu, instructions + i);
1421                 i += 3;
1422
1423                 /* ret */
1424                 ((unsigned char *)instructions)[i++] = 0xc3;
1425
1426                 addr = data & HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK;
1427                 if (kvm_vcpu_write_guest(vcpu, addr, instructions, i))
1428                         return 1;
1429                 hv->hv_hypercall = data;
1430                 break;
1431         }
1432         case HV_X64_MSR_REFERENCE_TSC:
1433                 hv->hv_tsc_page = data;
1434                 if (hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE) {
1435                         if (!host)
1436                                 hv->hv_tsc_page_status = HV_TSC_PAGE_GUEST_CHANGED;
1437                         else
1438                                 hv->hv_tsc_page_status = HV_TSC_PAGE_HOST_CHANGED;
1439                         kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
1440                 } else {
1441                         hv->hv_tsc_page_status = HV_TSC_PAGE_UNSET;
1442                 }
1443                 break;
1444         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1445                 return kvm_hv_msr_set_crash_data(kvm,
1446                                                  msr - HV_X64_MSR_CRASH_P0,
1447                                                  data);
1448         case HV_X64_MSR_CRASH_CTL:
1449                 if (host)
1450                         return kvm_hv_msr_set_crash_ctl(kvm, data);
1451
1452                 if (data & HV_CRASH_CTL_CRASH_NOTIFY) {
1453                         vcpu_debug(vcpu, "hv crash (0x%llx 0x%llx 0x%llx 0x%llx 0x%llx)\n",
1454                                    hv->hv_crash_param[0],
1455                                    hv->hv_crash_param[1],
1456                                    hv->hv_crash_param[2],
1457                                    hv->hv_crash_param[3],
1458                                    hv->hv_crash_param[4]);
1459
1460                         /* Send notification about crash to user space */
1461                         kvm_make_request(KVM_REQ_HV_CRASH, vcpu);
1462                 }
1463                 break;
1464         case HV_X64_MSR_RESET:
1465                 if (data == 1) {
1466                         vcpu_debug(vcpu, "hyper-v reset requested\n");
1467                         kvm_make_request(KVM_REQ_HV_RESET, vcpu);
1468                 }
1469                 break;
1470         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1471                 hv->hv_reenlightenment_control = data;
1472                 break;
1473         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1474                 hv->hv_tsc_emulation_control = data;
1475                 break;
1476         case HV_X64_MSR_TSC_EMULATION_STATUS:
1477                 if (data && !host)
1478                         return 1;
1479
1480                 hv->hv_tsc_emulation_status = data;
1481                 break;
1482         case HV_X64_MSR_TIME_REF_COUNT:
1483                 /* read-only, but still ignore it if host-initiated */
1484                 if (!host)
1485                         return 1;
1486                 break;
1487         case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1488                 /* Only bit 0 is supported */
1489                 if (data & ~HV_EXPOSE_INVARIANT_TSC)
1490                         return 1;
1491
1492                 /* The feature can't be disabled from the guest */
1493                 if (!host && hv->hv_invtsc_control && !data)
1494                         return 1;
1495
1496                 hv->hv_invtsc_control = data;
1497                 break;
1498         case HV_X64_MSR_SYNDBG_OPTIONS:
1499         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1500                 return syndbg_set_msr(vcpu, msr, data, host);
1501         default:
1502                 kvm_pr_unimpl_wrmsr(vcpu, msr, data);
1503                 return 1;
1504         }
1505         return 0;
1506 }
1507
1508 /* Calculate cpu time spent by current task in 100ns units */
1509 static u64 current_task_runtime_100ns(void)
1510 {
1511         u64 utime, stime;
1512
1513         task_cputime_adjusted(current, &utime, &stime);
1514
1515         return div_u64(utime + stime, 100);
1516 }
1517
1518 static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1519 {
1520         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1521
1522         if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1523                 return 1;
1524
1525         switch (msr) {
1526         case HV_X64_MSR_VP_INDEX: {
1527                 struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1528                 u32 new_vp_index = (u32)data;
1529
1530                 if (!host || new_vp_index >= KVM_MAX_VCPUS)
1531                         return 1;
1532
1533                 if (new_vp_index == hv_vcpu->vp_index)
1534                         return 0;
1535
1536                 /*
1537                  * The VP index is initialized to vcpu_index by
1538                  * kvm_hv_vcpu_postcreate so they initially match.  Now the
1539                  * VP index is changing, adjust num_mismatched_vp_indexes if
1540                  * it now matches or no longer matches vcpu_idx.
1541                  */
1542                 if (hv_vcpu->vp_index == vcpu->vcpu_idx)
1543                         atomic_inc(&hv->num_mismatched_vp_indexes);
1544                 else if (new_vp_index == vcpu->vcpu_idx)
1545                         atomic_dec(&hv->num_mismatched_vp_indexes);
1546
1547                 hv_vcpu->vp_index = new_vp_index;
1548                 break;
1549         }
1550         case HV_X64_MSR_VP_ASSIST_PAGE: {
1551                 u64 gfn;
1552                 unsigned long addr;
1553
1554                 if (!(data & HV_X64_MSR_VP_ASSIST_PAGE_ENABLE)) {
1555                         hv_vcpu->hv_vapic = data;
1556                         if (kvm_lapic_set_pv_eoi(vcpu, 0, 0))
1557                                 return 1;
1558                         break;
1559                 }
1560                 gfn = data >> HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT;
1561                 addr = kvm_vcpu_gfn_to_hva(vcpu, gfn);
1562                 if (kvm_is_error_hva(addr))
1563                         return 1;
1564
1565                 /*
1566                  * Clear apic_assist portion of struct hv_vp_assist_page
1567                  * only, there can be valuable data in the rest which needs
1568                  * to be preserved e.g. on migration.
1569                  */
1570                 if (__put_user(0, (u32 __user *)addr))
1571                         return 1;
1572                 hv_vcpu->hv_vapic = data;
1573                 kvm_vcpu_mark_page_dirty(vcpu, gfn);
1574                 if (kvm_lapic_set_pv_eoi(vcpu,
1575                                             gfn_to_gpa(gfn) | KVM_MSR_ENABLED,
1576                                             sizeof(struct hv_vp_assist_page)))
1577                         return 1;
1578                 break;
1579         }
1580         case HV_X64_MSR_EOI:
1581                 return kvm_hv_vapic_msr_write(vcpu, APIC_EOI, data);
1582         case HV_X64_MSR_ICR:
1583                 return kvm_hv_vapic_msr_write(vcpu, APIC_ICR, data);
1584         case HV_X64_MSR_TPR:
1585                 return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
1586         case HV_X64_MSR_VP_RUNTIME:
1587                 if (!host)
1588                         return 1;
1589                 hv_vcpu->runtime_offset = data - current_task_runtime_100ns();
1590                 break;
1591         case HV_X64_MSR_SCONTROL:
1592         case HV_X64_MSR_SVERSION:
1593         case HV_X64_MSR_SIEFP:
1594         case HV_X64_MSR_SIMP:
1595         case HV_X64_MSR_EOM:
1596         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1597                 return synic_set_msr(to_hv_synic(vcpu), msr, data, host);
1598         case HV_X64_MSR_STIMER0_CONFIG:
1599         case HV_X64_MSR_STIMER1_CONFIG:
1600         case HV_X64_MSR_STIMER2_CONFIG:
1601         case HV_X64_MSR_STIMER3_CONFIG: {
1602                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1603
1604                 return stimer_set_config(to_hv_stimer(vcpu, timer_index),
1605                                          data, host);
1606         }
1607         case HV_X64_MSR_STIMER0_COUNT:
1608         case HV_X64_MSR_STIMER1_COUNT:
1609         case HV_X64_MSR_STIMER2_COUNT:
1610         case HV_X64_MSR_STIMER3_COUNT: {
1611                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1612
1613                 return stimer_set_count(to_hv_stimer(vcpu, timer_index),
1614                                         data, host);
1615         }
1616         case HV_X64_MSR_TSC_FREQUENCY:
1617         case HV_X64_MSR_APIC_FREQUENCY:
1618                 /* read-only, but still ignore it if host-initiated */
1619                 if (!host)
1620                         return 1;
1621                 break;
1622         default:
1623                 kvm_pr_unimpl_wrmsr(vcpu, msr, data);
1624                 return 1;
1625         }
1626
1627         return 0;
1628 }
1629
1630 static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1631                              bool host)
1632 {
1633         u64 data = 0;
1634         struct kvm *kvm = vcpu->kvm;
1635         struct kvm_hv *hv = to_kvm_hv(kvm);
1636
1637         if (unlikely(!host && !hv_check_msr_access(to_hv_vcpu(vcpu), msr)))
1638                 return 1;
1639
1640         switch (msr) {
1641         case HV_X64_MSR_GUEST_OS_ID:
1642                 data = hv->hv_guest_os_id;
1643                 break;
1644         case HV_X64_MSR_HYPERCALL:
1645                 data = hv->hv_hypercall;
1646                 break;
1647         case HV_X64_MSR_TIME_REF_COUNT:
1648                 data = get_time_ref_counter(kvm);
1649                 break;
1650         case HV_X64_MSR_REFERENCE_TSC:
1651                 data = hv->hv_tsc_page;
1652                 break;
1653         case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
1654                 return kvm_hv_msr_get_crash_data(kvm,
1655                                                  msr - HV_X64_MSR_CRASH_P0,
1656                                                  pdata);
1657         case HV_X64_MSR_CRASH_CTL:
1658                 return kvm_hv_msr_get_crash_ctl(kvm, pdata);
1659         case HV_X64_MSR_RESET:
1660                 data = 0;
1661                 break;
1662         case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
1663                 data = hv->hv_reenlightenment_control;
1664                 break;
1665         case HV_X64_MSR_TSC_EMULATION_CONTROL:
1666                 data = hv->hv_tsc_emulation_control;
1667                 break;
1668         case HV_X64_MSR_TSC_EMULATION_STATUS:
1669                 data = hv->hv_tsc_emulation_status;
1670                 break;
1671         case HV_X64_MSR_TSC_INVARIANT_CONTROL:
1672                 data = hv->hv_invtsc_control;
1673                 break;
1674         case HV_X64_MSR_SYNDBG_OPTIONS:
1675         case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
1676                 return syndbg_get_msr(vcpu, msr, pdata, host);
1677         default:
1678                 kvm_pr_unimpl_rdmsr(vcpu, msr);
1679                 return 1;
1680         }
1681
1682         *pdata = data;
1683         return 0;
1684 }
1685
1686 static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
1687                           bool host)
1688 {
1689         u64 data = 0;
1690         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1691
1692         if (unlikely(!host && !hv_check_msr_access(hv_vcpu, msr)))
1693                 return 1;
1694
1695         switch (msr) {
1696         case HV_X64_MSR_VP_INDEX:
1697                 data = hv_vcpu->vp_index;
1698                 break;
1699         case HV_X64_MSR_EOI:
1700                 return kvm_hv_vapic_msr_read(vcpu, APIC_EOI, pdata);
1701         case HV_X64_MSR_ICR:
1702                 return kvm_hv_vapic_msr_read(vcpu, APIC_ICR, pdata);
1703         case HV_X64_MSR_TPR:
1704                 return kvm_hv_vapic_msr_read(vcpu, APIC_TASKPRI, pdata);
1705         case HV_X64_MSR_VP_ASSIST_PAGE:
1706                 data = hv_vcpu->hv_vapic;
1707                 break;
1708         case HV_X64_MSR_VP_RUNTIME:
1709                 data = current_task_runtime_100ns() + hv_vcpu->runtime_offset;
1710                 break;
1711         case HV_X64_MSR_SCONTROL:
1712         case HV_X64_MSR_SVERSION:
1713         case HV_X64_MSR_SIEFP:
1714         case HV_X64_MSR_SIMP:
1715         case HV_X64_MSR_EOM:
1716         case HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15:
1717                 return synic_get_msr(to_hv_synic(vcpu), msr, pdata, host);
1718         case HV_X64_MSR_STIMER0_CONFIG:
1719         case HV_X64_MSR_STIMER1_CONFIG:
1720         case HV_X64_MSR_STIMER2_CONFIG:
1721         case HV_X64_MSR_STIMER3_CONFIG: {
1722                 int timer_index = (msr - HV_X64_MSR_STIMER0_CONFIG)/2;
1723
1724                 return stimer_get_config(to_hv_stimer(vcpu, timer_index),
1725                                          pdata);
1726         }
1727         case HV_X64_MSR_STIMER0_COUNT:
1728         case HV_X64_MSR_STIMER1_COUNT:
1729         case HV_X64_MSR_STIMER2_COUNT:
1730         case HV_X64_MSR_STIMER3_COUNT: {
1731                 int timer_index = (msr - HV_X64_MSR_STIMER0_COUNT)/2;
1732
1733                 return stimer_get_count(to_hv_stimer(vcpu, timer_index),
1734                                         pdata);
1735         }
1736         case HV_X64_MSR_TSC_FREQUENCY:
1737                 data = (u64)vcpu->arch.virtual_tsc_khz * 1000;
1738                 break;
1739         case HV_X64_MSR_APIC_FREQUENCY:
1740                 data = APIC_BUS_FREQUENCY;
1741                 break;
1742         default:
1743                 kvm_pr_unimpl_rdmsr(vcpu, msr);
1744                 return 1;
1745         }
1746         *pdata = data;
1747         return 0;
1748 }
1749
1750 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
1751 {
1752         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1753
1754         if (!host && !vcpu->arch.hyperv_enabled)
1755                 return 1;
1756
1757         if (kvm_hv_vcpu_init(vcpu))
1758                 return 1;
1759
1760         if (kvm_hv_msr_partition_wide(msr)) {
1761                 int r;
1762
1763                 mutex_lock(&hv->hv_lock);
1764                 r = kvm_hv_set_msr_pw(vcpu, msr, data, host);
1765                 mutex_unlock(&hv->hv_lock);
1766                 return r;
1767         } else
1768                 return kvm_hv_set_msr(vcpu, msr, data, host);
1769 }
1770
1771 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
1772 {
1773         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
1774
1775         if (!host && !vcpu->arch.hyperv_enabled)
1776                 return 1;
1777
1778         if (kvm_hv_vcpu_init(vcpu))
1779                 return 1;
1780
1781         if (kvm_hv_msr_partition_wide(msr)) {
1782                 int r;
1783
1784                 mutex_lock(&hv->hv_lock);
1785                 r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
1786                 mutex_unlock(&hv->hv_lock);
1787                 return r;
1788         } else
1789                 return kvm_hv_get_msr(vcpu, msr, pdata, host);
1790 }
1791
1792 static void sparse_set_to_vcpu_mask(struct kvm *kvm, u64 *sparse_banks,
1793                                     u64 valid_bank_mask, unsigned long *vcpu_mask)
1794 {
1795         struct kvm_hv *hv = to_kvm_hv(kvm);
1796         bool has_mismatch = atomic_read(&hv->num_mismatched_vp_indexes);
1797         u64 vp_bitmap[KVM_HV_MAX_SPARSE_VCPU_SET_BITS];
1798         struct kvm_vcpu *vcpu;
1799         int bank, sbank = 0;
1800         unsigned long i;
1801         u64 *bitmap;
1802
1803         BUILD_BUG_ON(sizeof(vp_bitmap) >
1804                      sizeof(*vcpu_mask) * BITS_TO_LONGS(KVM_MAX_VCPUS));
1805
1806         /*
1807          * If vp_index == vcpu_idx for all vCPUs, fill vcpu_mask directly, else
1808          * fill a temporary buffer and manually test each vCPU's VP index.
1809          */
1810         if (likely(!has_mismatch))
1811                 bitmap = (u64 *)vcpu_mask;
1812         else
1813                 bitmap = vp_bitmap;
1814
1815         /*
1816          * Each set of 64 VPs is packed into sparse_banks, with valid_bank_mask
1817          * having a '1' for each bank that exists in sparse_banks.  Sets must
1818          * be in ascending order, i.e. bank0..bankN.
1819          */
1820         memset(bitmap, 0, sizeof(vp_bitmap));
1821         for_each_set_bit(bank, (unsigned long *)&valid_bank_mask,
1822                          KVM_HV_MAX_SPARSE_VCPU_SET_BITS)
1823                 bitmap[bank] = sparse_banks[sbank++];
1824
1825         if (likely(!has_mismatch))
1826                 return;
1827
1828         bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
1829         kvm_for_each_vcpu(i, vcpu, kvm) {
1830                 if (test_bit(kvm_hv_get_vpindex(vcpu), (unsigned long *)vp_bitmap))
1831                         __set_bit(i, vcpu_mask);
1832         }
1833 }
1834
1835 static bool hv_is_vp_in_sparse_set(u32 vp_id, u64 valid_bank_mask, u64 sparse_banks[])
1836 {
1837         int valid_bit_nr = vp_id / HV_VCPUS_PER_SPARSE_BANK;
1838         unsigned long sbank;
1839
1840         if (!test_bit(valid_bit_nr, (unsigned long *)&valid_bank_mask))
1841                 return false;
1842
1843         /*
1844          * The index into the sparse bank is the number of preceding bits in
1845          * the valid mask.  Optimize for VMs with <64 vCPUs by skipping the
1846          * fancy math if there can't possibly be preceding bits.
1847          */
1848         if (valid_bit_nr)
1849                 sbank = hweight64(valid_bank_mask & GENMASK_ULL(valid_bit_nr - 1, 0));
1850         else
1851                 sbank = 0;
1852
1853         return test_bit(vp_id % HV_VCPUS_PER_SPARSE_BANK,
1854                         (unsigned long *)&sparse_banks[sbank]);
1855 }
1856
1857 struct kvm_hv_hcall {
1858         /* Hypercall input data */
1859         u64 param;
1860         u64 ingpa;
1861         u64 outgpa;
1862         u16 code;
1863         u16 var_cnt;
1864         u16 rep_cnt;
1865         u16 rep_idx;
1866         bool fast;
1867         bool rep;
1868         sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
1869
1870         /*
1871          * Current read offset when KVM reads hypercall input data gradually,
1872          * either offset in bytes from 'ingpa' for regular hypercalls or the
1873          * number of already consumed 'XMM halves' for 'fast' hypercalls.
1874          */
1875         union {
1876                 gpa_t data_offset;
1877                 int consumed_xmm_halves;
1878         };
1879 };
1880
1881
1882 static int kvm_hv_get_hc_data(struct kvm *kvm, struct kvm_hv_hcall *hc,
1883                               u16 orig_cnt, u16 cnt_cap, u64 *data)
1884 {
1885         /*
1886          * Preserve the original count when ignoring entries via a "cap", KVM
1887          * still needs to validate the guest input (though the non-XMM path
1888          * punts on the checks).
1889          */
1890         u16 cnt = min(orig_cnt, cnt_cap);
1891         int i, j;
1892
1893         if (hc->fast) {
1894                 /*
1895                  * Each XMM holds two sparse banks, but do not count halves that
1896                  * have already been consumed for hypercall parameters.
1897                  */
1898                 if (orig_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - hc->consumed_xmm_halves)
1899                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
1900
1901                 for (i = 0; i < cnt; i++) {
1902                         j = i + hc->consumed_xmm_halves;
1903                         if (j % 2)
1904                                 data[i] = sse128_hi(hc->xmm[j / 2]);
1905                         else
1906                                 data[i] = sse128_lo(hc->xmm[j / 2]);
1907                 }
1908                 return 0;
1909         }
1910
1911         return kvm_read_guest(kvm, hc->ingpa + hc->data_offset, data,
1912                               cnt * sizeof(*data));
1913 }
1914
1915 static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,
1916                                  u64 *sparse_banks)
1917 {
1918         if (hc->var_cnt > HV_MAX_SPARSE_VCPU_BANKS)
1919                 return -EINVAL;
1920
1921         /* Cap var_cnt to ignore banks that cannot contain a legal VP index. */
1922         return kvm_hv_get_hc_data(kvm, hc, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS,
1923                                   sparse_banks);
1924 }
1925
1926 static int kvm_hv_get_tlb_flush_entries(struct kvm *kvm, struct kvm_hv_hcall *hc, u64 entries[])
1927 {
1928         return kvm_hv_get_hc_data(kvm, hc, hc->rep_cnt, hc->rep_cnt, entries);
1929 }
1930
1931 static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu,
1932                                  struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo,
1933                                  u64 *entries, int count)
1934 {
1935         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1936         u64 flush_all_entry = KVM_HV_TLB_FLUSHALL_ENTRY;
1937
1938         if (!hv_vcpu)
1939                 return;
1940
1941         spin_lock(&tlb_flush_fifo->write_lock);
1942
1943         /*
1944          * All entries should fit on the fifo leaving one free for 'flush all'
1945          * entry in case another request comes in. In case there's not enough
1946          * space, just put 'flush all' entry there.
1947          */
1948         if (count && entries && count < kfifo_avail(&tlb_flush_fifo->entries)) {
1949                 WARN_ON(kfifo_in(&tlb_flush_fifo->entries, entries, count) != count);
1950                 goto out_unlock;
1951         }
1952
1953         /*
1954          * Note: full fifo always contains 'flush all' entry, no need to check the
1955          * return value.
1956          */
1957         kfifo_in(&tlb_flush_fifo->entries, &flush_all_entry, 1);
1958
1959 out_unlock:
1960         spin_unlock(&tlb_flush_fifo->write_lock);
1961 }
1962
1963 int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu)
1964 {
1965         struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
1966         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
1967         u64 entries[KVM_HV_TLB_FLUSH_FIFO_SIZE];
1968         int i, j, count;
1969         gva_t gva;
1970
1971         if (!tdp_enabled || !hv_vcpu)
1972                 return -EINVAL;
1973
1974         tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu));
1975
1976         count = kfifo_out(&tlb_flush_fifo->entries, entries, KVM_HV_TLB_FLUSH_FIFO_SIZE);
1977
1978         for (i = 0; i < count; i++) {
1979                 if (entries[i] == KVM_HV_TLB_FLUSHALL_ENTRY)
1980                         goto out_flush_all;
1981
1982                 /*
1983                  * Lower 12 bits of 'address' encode the number of additional
1984                  * pages to flush.
1985                  */
1986                 gva = entries[i] & PAGE_MASK;
1987                 for (j = 0; j < (entries[i] & ~PAGE_MASK) + 1; j++)
1988                         static_call(kvm_x86_flush_tlb_gva)(vcpu, gva + j * PAGE_SIZE);
1989
1990                 ++vcpu->stat.tlb_flush;
1991         }
1992         return 0;
1993
1994 out_flush_all:
1995         kfifo_reset_out(&tlb_flush_fifo->entries);
1996
1997         /* Fall back to full flush. */
1998         return -ENOSPC;
1999 }
2000
2001 static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2002 {
2003         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2004         u64 *sparse_banks = hv_vcpu->sparse_banks;
2005         struct kvm *kvm = vcpu->kvm;
2006         struct hv_tlb_flush_ex flush_ex;
2007         struct hv_tlb_flush flush;
2008         DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
2009         struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
2010         /*
2011          * Normally, there can be no more than 'KVM_HV_TLB_FLUSH_FIFO_SIZE'
2012          * entries on the TLB flush fifo. The last entry, however, needs to be
2013          * always left free for 'flush all' entry which gets placed when
2014          * there is not enough space to put all the requested entries.
2015          */
2016         u64 __tlb_flush_entries[KVM_HV_TLB_FLUSH_FIFO_SIZE - 1];
2017         u64 *tlb_flush_entries;
2018         u64 valid_bank_mask;
2019         struct kvm_vcpu *v;
2020         unsigned long i;
2021         bool all_cpus;
2022
2023         /*
2024          * The Hyper-V TLFS doesn't allow more than HV_MAX_SPARSE_VCPU_BANKS
2025          * sparse banks. Fail the build if KVM's max allowed number of
2026          * vCPUs (>4096) exceeds this limit.
2027          */
2028         BUILD_BUG_ON(KVM_HV_MAX_SPARSE_VCPU_SET_BITS > HV_MAX_SPARSE_VCPU_BANKS);
2029
2030         /*
2031          * 'Slow' hypercall's first parameter is the address in guest's memory
2032          * where hypercall parameters are placed. This is either a GPA or a
2033          * nested GPA when KVM is handling the call from L2 ('direct' TLB
2034          * flush).  Translate the address here so the memory can be uniformly
2035          * read with kvm_read_guest().
2036          */
2037         if (!hc->fast && is_guest_mode(vcpu)) {
2038                 hc->ingpa = translate_nested_gpa(vcpu, hc->ingpa, 0, NULL);
2039                 if (unlikely(hc->ingpa == INVALID_GPA))
2040                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
2041         }
2042
2043         if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST ||
2044             hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE) {
2045                 if (hc->fast) {
2046                         flush.address_space = hc->ingpa;
2047                         flush.flags = hc->outgpa;
2048                         flush.processor_mask = sse128_lo(hc->xmm[0]);
2049                         hc->consumed_xmm_halves = 1;
2050                 } else {
2051                         if (unlikely(kvm_read_guest(kvm, hc->ingpa,
2052                                                     &flush, sizeof(flush))))
2053                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2054                         hc->data_offset = sizeof(flush);
2055                 }
2056
2057                 trace_kvm_hv_flush_tlb(flush.processor_mask,
2058                                        flush.address_space, flush.flags,
2059                                        is_guest_mode(vcpu));
2060
2061                 valid_bank_mask = BIT_ULL(0);
2062                 sparse_banks[0] = flush.processor_mask;
2063
2064                 /*
2065                  * Work around possible WS2012 bug: it sends hypercalls
2066                  * with processor_mask = 0x0 and HV_FLUSH_ALL_PROCESSORS clear,
2067                  * while also expecting us to flush something and crashing if
2068                  * we don't. Let's treat processor_mask == 0 same as
2069                  * HV_FLUSH_ALL_PROCESSORS.
2070                  */
2071                 all_cpus = (flush.flags & HV_FLUSH_ALL_PROCESSORS) ||
2072                         flush.processor_mask == 0;
2073         } else {
2074                 if (hc->fast) {
2075                         flush_ex.address_space = hc->ingpa;
2076                         flush_ex.flags = hc->outgpa;
2077                         memcpy(&flush_ex.hv_vp_set,
2078                                &hc->xmm[0], sizeof(hc->xmm[0]));
2079                         hc->consumed_xmm_halves = 2;
2080                 } else {
2081                         if (unlikely(kvm_read_guest(kvm, hc->ingpa, &flush_ex,
2082                                                     sizeof(flush_ex))))
2083                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2084                         hc->data_offset = sizeof(flush_ex);
2085                 }
2086
2087                 trace_kvm_hv_flush_tlb_ex(flush_ex.hv_vp_set.valid_bank_mask,
2088                                           flush_ex.hv_vp_set.format,
2089                                           flush_ex.address_space,
2090                                           flush_ex.flags, is_guest_mode(vcpu));
2091
2092                 valid_bank_mask = flush_ex.hv_vp_set.valid_bank_mask;
2093                 all_cpus = flush_ex.hv_vp_set.format !=
2094                         HV_GENERIC_SET_SPARSE_4K;
2095
2096                 if (hc->var_cnt != hweight64(valid_bank_mask))
2097                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
2098
2099                 if (!all_cpus) {
2100                         if (!hc->var_cnt)
2101                                 goto ret_success;
2102
2103                         if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2104                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2105                 }
2106
2107                 /*
2108                  * Hyper-V TLFS doesn't explicitly forbid non-empty sparse vCPU
2109                  * banks (and, thus, non-zero 'var_cnt') for the 'all vCPUs'
2110                  * case (HV_GENERIC_SET_ALL).  Always adjust data_offset and
2111                  * consumed_xmm_halves to make sure TLB flush entries are read
2112                  * from the correct offset.
2113                  */
2114                 if (hc->fast)
2115                         hc->consumed_xmm_halves += hc->var_cnt;
2116                 else
2117                         hc->data_offset += hc->var_cnt * sizeof(sparse_banks[0]);
2118         }
2119
2120         if (hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE ||
2121             hc->code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX ||
2122             hc->rep_cnt > ARRAY_SIZE(__tlb_flush_entries)) {
2123                 tlb_flush_entries = NULL;
2124         } else {
2125                 if (kvm_hv_get_tlb_flush_entries(kvm, hc, __tlb_flush_entries))
2126                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
2127                 tlb_flush_entries = __tlb_flush_entries;
2128         }
2129
2130         /*
2131          * vcpu->arch.cr3 may not be up-to-date for running vCPUs so we can't
2132          * analyze it here, flush TLB regardless of the specified address space.
2133          */
2134         if (all_cpus && !is_guest_mode(vcpu)) {
2135                 kvm_for_each_vcpu(i, v, kvm) {
2136                         tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2137                         hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2138                                              tlb_flush_entries, hc->rep_cnt);
2139                 }
2140
2141                 kvm_make_all_cpus_request(kvm, KVM_REQ_HV_TLB_FLUSH);
2142         } else if (!is_guest_mode(vcpu)) {
2143                 sparse_set_to_vcpu_mask(kvm, sparse_banks, valid_bank_mask, vcpu_mask);
2144
2145                 for_each_set_bit(i, vcpu_mask, KVM_MAX_VCPUS) {
2146                         v = kvm_get_vcpu(kvm, i);
2147                         if (!v)
2148                                 continue;
2149                         tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, false);
2150                         hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2151                                              tlb_flush_entries, hc->rep_cnt);
2152                 }
2153
2154                 kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2155         } else {
2156                 struct kvm_vcpu_hv *hv_v;
2157
2158                 bitmap_zero(vcpu_mask, KVM_MAX_VCPUS);
2159
2160                 kvm_for_each_vcpu(i, v, kvm) {
2161                         hv_v = to_hv_vcpu(v);
2162
2163                         /*
2164                          * The following check races with nested vCPUs entering/exiting
2165                          * and/or migrating between L1's vCPUs, however the only case when
2166                          * KVM *must* flush the TLB is when the target L2 vCPU keeps
2167                          * running on the same L1 vCPU from the moment of the request until
2168                          * kvm_hv_flush_tlb() returns. TLB is fully flushed in all other
2169                          * cases, e.g. when the target L2 vCPU migrates to a different L1
2170                          * vCPU or when the corresponding L1 vCPU temporary switches to a
2171                          * different L2 vCPU while the request is being processed.
2172                          */
2173                         if (!hv_v || hv_v->nested.vm_id != hv_vcpu->nested.vm_id)
2174                                 continue;
2175
2176                         if (!all_cpus &&
2177                             !hv_is_vp_in_sparse_set(hv_v->nested.vp_id, valid_bank_mask,
2178                                                     sparse_banks))
2179                                 continue;
2180
2181                         __set_bit(i, vcpu_mask);
2182                         tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(v, true);
2183                         hv_tlb_flush_enqueue(v, tlb_flush_fifo,
2184                                              tlb_flush_entries, hc->rep_cnt);
2185                 }
2186
2187                 kvm_make_vcpus_request_mask(kvm, KVM_REQ_HV_TLB_FLUSH, vcpu_mask);
2188         }
2189
2190 ret_success:
2191         /* We always do full TLB flush, set 'Reps completed' = 'Rep Count' */
2192         return (u64)HV_STATUS_SUCCESS |
2193                 ((u64)hc->rep_cnt << HV_HYPERCALL_REP_COMP_OFFSET);
2194 }
2195
2196 static void kvm_hv_send_ipi_to_many(struct kvm *kvm, u32 vector,
2197                                     u64 *sparse_banks, u64 valid_bank_mask)
2198 {
2199         struct kvm_lapic_irq irq = {
2200                 .delivery_mode = APIC_DM_FIXED,
2201                 .vector = vector
2202         };
2203         struct kvm_vcpu *vcpu;
2204         unsigned long i;
2205
2206         kvm_for_each_vcpu(i, vcpu, kvm) {
2207                 if (sparse_banks &&
2208                     !hv_is_vp_in_sparse_set(kvm_hv_get_vpindex(vcpu),
2209                                             valid_bank_mask, sparse_banks))
2210                         continue;
2211
2212                 /* We fail only when APIC is disabled */
2213                 kvm_apic_set_irq(vcpu, &irq, NULL);
2214         }
2215 }
2216
2217 static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2218 {
2219         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2220         u64 *sparse_banks = hv_vcpu->sparse_banks;
2221         struct kvm *kvm = vcpu->kvm;
2222         struct hv_send_ipi_ex send_ipi_ex;
2223         struct hv_send_ipi send_ipi;
2224         u64 valid_bank_mask;
2225         u32 vector;
2226         bool all_cpus;
2227
2228         if (hc->code == HVCALL_SEND_IPI) {
2229                 if (!hc->fast) {
2230                         if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
2231                                                     sizeof(send_ipi))))
2232                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2233                         sparse_banks[0] = send_ipi.cpu_mask;
2234                         vector = send_ipi.vector;
2235                 } else {
2236                         /* 'reserved' part of hv_send_ipi should be 0 */
2237                         if (unlikely(hc->ingpa >> 32 != 0))
2238                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2239                         sparse_banks[0] = hc->outgpa;
2240                         vector = (u32)hc->ingpa;
2241                 }
2242                 all_cpus = false;
2243                 valid_bank_mask = BIT_ULL(0);
2244
2245                 trace_kvm_hv_send_ipi(vector, sparse_banks[0]);
2246         } else {
2247                 if (!hc->fast) {
2248                         if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi_ex,
2249                                                     sizeof(send_ipi_ex))))
2250                                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2251                 } else {
2252                         send_ipi_ex.vector = (u32)hc->ingpa;
2253                         send_ipi_ex.vp_set.format = hc->outgpa;
2254                         send_ipi_ex.vp_set.valid_bank_mask = sse128_lo(hc->xmm[0]);
2255                 }
2256
2257                 trace_kvm_hv_send_ipi_ex(send_ipi_ex.vector,
2258                                          send_ipi_ex.vp_set.format,
2259                                          send_ipi_ex.vp_set.valid_bank_mask);
2260
2261                 vector = send_ipi_ex.vector;
2262                 valid_bank_mask = send_ipi_ex.vp_set.valid_bank_mask;
2263                 all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
2264
2265                 if (hc->var_cnt != hweight64(valid_bank_mask))
2266                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
2267
2268                 if (all_cpus)
2269                         goto check_and_send_ipi;
2270
2271                 if (!hc->var_cnt)
2272                         goto ret_success;
2273
2274                 if (!hc->fast)
2275                         hc->data_offset = offsetof(struct hv_send_ipi_ex,
2276                                                    vp_set.bank_contents);
2277                 else
2278                         hc->consumed_xmm_halves = 1;
2279
2280                 if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks))
2281                         return HV_STATUS_INVALID_HYPERCALL_INPUT;
2282         }
2283
2284 check_and_send_ipi:
2285         if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
2286                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2287
2288         if (all_cpus)
2289                 kvm_hv_send_ipi_to_many(kvm, vector, NULL, 0);
2290         else
2291                 kvm_hv_send_ipi_to_many(kvm, vector, sparse_banks, valid_bank_mask);
2292
2293 ret_success:
2294         return HV_STATUS_SUCCESS;
2295 }
2296
2297 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled)
2298 {
2299         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2300         struct kvm_cpuid_entry2 *entry;
2301
2302         vcpu->arch.hyperv_enabled = hyperv_enabled;
2303
2304         if (!hv_vcpu) {
2305                 /*
2306                  * KVM should have already allocated kvm_vcpu_hv if Hyper-V is
2307                  * enabled in CPUID.
2308                  */
2309                 WARN_ON_ONCE(vcpu->arch.hyperv_enabled);
2310                 return;
2311         }
2312
2313         memset(&hv_vcpu->cpuid_cache, 0, sizeof(hv_vcpu->cpuid_cache));
2314
2315         if (!vcpu->arch.hyperv_enabled)
2316                 return;
2317
2318         entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_FEATURES);
2319         if (entry) {
2320                 hv_vcpu->cpuid_cache.features_eax = entry->eax;
2321                 hv_vcpu->cpuid_cache.features_ebx = entry->ebx;
2322                 hv_vcpu->cpuid_cache.features_edx = entry->edx;
2323         }
2324
2325         entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_ENLIGHTMENT_INFO);
2326         if (entry) {
2327                 hv_vcpu->cpuid_cache.enlightenments_eax = entry->eax;
2328                 hv_vcpu->cpuid_cache.enlightenments_ebx = entry->ebx;
2329         }
2330
2331         entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
2332         if (entry)
2333                 hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
2334
2335         entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES);
2336         if (entry) {
2337                 hv_vcpu->cpuid_cache.nested_eax = entry->eax;
2338                 hv_vcpu->cpuid_cache.nested_ebx = entry->ebx;
2339         }
2340 }
2341
2342 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)
2343 {
2344         struct kvm_vcpu_hv *hv_vcpu;
2345         int ret = 0;
2346
2347         if (!to_hv_vcpu(vcpu)) {
2348                 if (enforce) {
2349                         ret = kvm_hv_vcpu_init(vcpu);
2350                         if (ret)
2351                                 return ret;
2352                 } else {
2353                         return 0;
2354                 }
2355         }
2356
2357         hv_vcpu = to_hv_vcpu(vcpu);
2358         hv_vcpu->enforce_cpuid = enforce;
2359
2360         return ret;
2361 }
2362
2363 static void kvm_hv_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
2364 {
2365         bool longmode;
2366
2367         longmode = is_64_bit_hypercall(vcpu);
2368         if (longmode)
2369                 kvm_rax_write(vcpu, result);
2370         else {
2371                 kvm_rdx_write(vcpu, result >> 32);
2372                 kvm_rax_write(vcpu, result & 0xffffffff);
2373         }
2374 }
2375
2376 static int kvm_hv_hypercall_complete(struct kvm_vcpu *vcpu, u64 result)
2377 {
2378         u32 tlb_lock_count = 0;
2379         int ret;
2380
2381         if (hv_result_success(result) && is_guest_mode(vcpu) &&
2382             kvm_hv_is_tlb_flush_hcall(vcpu) &&
2383             kvm_read_guest(vcpu->kvm, to_hv_vcpu(vcpu)->nested.pa_page_gpa,
2384                            &tlb_lock_count, sizeof(tlb_lock_count)))
2385                 result = HV_STATUS_INVALID_HYPERCALL_INPUT;
2386
2387         trace_kvm_hv_hypercall_done(result);
2388         kvm_hv_hypercall_set_result(vcpu, result);
2389         ++vcpu->stat.hypercalls;
2390
2391         ret = kvm_skip_emulated_instruction(vcpu);
2392
2393         if (tlb_lock_count)
2394                 kvm_x86_ops.nested_ops->hv_inject_synthetic_vmexit_post_tlb_flush(vcpu);
2395
2396         return ret;
2397 }
2398
2399 static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
2400 {
2401         return kvm_hv_hypercall_complete(vcpu, vcpu->run->hyperv.u.hcall.result);
2402 }
2403
2404 static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc)
2405 {
2406         struct kvm_hv *hv = to_kvm_hv(vcpu->kvm);
2407         struct eventfd_ctx *eventfd;
2408
2409         if (unlikely(!hc->fast)) {
2410                 int ret;
2411                 gpa_t gpa = hc->ingpa;
2412
2413                 if ((gpa & (__alignof__(hc->ingpa) - 1)) ||
2414                     offset_in_page(gpa) + sizeof(hc->ingpa) > PAGE_SIZE)
2415                         return HV_STATUS_INVALID_ALIGNMENT;
2416
2417                 ret = kvm_vcpu_read_guest(vcpu, gpa,
2418                                           &hc->ingpa, sizeof(hc->ingpa));
2419                 if (ret < 0)
2420                         return HV_STATUS_INVALID_ALIGNMENT;
2421         }
2422
2423         /*
2424          * Per spec, bits 32-47 contain the extra "flag number".  However, we
2425          * have no use for it, and in all known usecases it is zero, so just
2426          * report lookup failure if it isn't.
2427          */
2428         if (hc->ingpa & 0xffff00000000ULL)
2429                 return HV_STATUS_INVALID_PORT_ID;
2430         /* remaining bits are reserved-zero */
2431         if (hc->ingpa & ~KVM_HYPERV_CONN_ID_MASK)
2432                 return HV_STATUS_INVALID_HYPERCALL_INPUT;
2433
2434         /* the eventfd is protected by vcpu->kvm->srcu, but conn_to_evt isn't */
2435         rcu_read_lock();
2436         eventfd = idr_find(&hv->conn_to_evt, hc->ingpa);
2437         rcu_read_unlock();
2438         if (!eventfd)
2439                 return HV_STATUS_INVALID_PORT_ID;
2440
2441         eventfd_signal(eventfd);
2442         return HV_STATUS_SUCCESS;
2443 }
2444
2445 static bool is_xmm_fast_hypercall(struct kvm_hv_hcall *hc)
2446 {
2447         switch (hc->code) {
2448         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2449         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2450         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2451         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2452         case HVCALL_SEND_IPI_EX:
2453                 return true;
2454         }
2455
2456         return false;
2457 }
2458
2459 static void kvm_hv_hypercall_read_xmm(struct kvm_hv_hcall *hc)
2460 {
2461         int reg;
2462
2463         kvm_fpu_get();
2464         for (reg = 0; reg < HV_HYPERCALL_MAX_XMM_REGISTERS; reg++)
2465                 _kvm_read_sse_reg(reg, &hc->xmm[reg]);
2466         kvm_fpu_put();
2467 }
2468
2469 static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
2470 {
2471         if (!hv_vcpu->enforce_cpuid)
2472                 return true;
2473
2474         switch (code) {
2475         case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2476                 return hv_vcpu->cpuid_cache.enlightenments_ebx &&
2477                         hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
2478         case HVCALL_POST_MESSAGE:
2479                 return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
2480         case HVCALL_SIGNAL_EVENT:
2481                 return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
2482         case HVCALL_POST_DEBUG_DATA:
2483         case HVCALL_RETRIEVE_DEBUG_DATA:
2484         case HVCALL_RESET_DEBUG_SESSION:
2485                 /*
2486                  * Return 'true' when SynDBG is disabled so the resulting code
2487                  * will be HV_STATUS_INVALID_HYPERCALL_CODE.
2488                  */
2489                 return !kvm_hv_is_syndbg_enabled(hv_vcpu->vcpu) ||
2490                         hv_vcpu->cpuid_cache.features_ebx & HV_DEBUGGING;
2491         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2492         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2493                 if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2494                       HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2495                         return false;
2496                 fallthrough;
2497         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2498         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2499                 return hv_vcpu->cpuid_cache.enlightenments_eax &
2500                         HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2501         case HVCALL_SEND_IPI_EX:
2502                 if (!(hv_vcpu->cpuid_cache.enlightenments_eax &
2503                       HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
2504                         return false;
2505                 fallthrough;
2506         case HVCALL_SEND_IPI:
2507                 return hv_vcpu->cpuid_cache.enlightenments_eax &
2508                         HV_X64_CLUSTER_IPI_RECOMMENDED;
2509         case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX:
2510                 return hv_vcpu->cpuid_cache.features_ebx &
2511                         HV_ENABLE_EXTENDED_HYPERCALLS;
2512         default:
2513                 break;
2514         }
2515
2516         return true;
2517 }
2518
2519 int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
2520 {
2521         struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
2522         struct kvm_hv_hcall hc;
2523         u64 ret = HV_STATUS_SUCCESS;
2524
2525         /*
2526          * hypercall generates UD from non zero cpl and real mode
2527          * per HYPER-V spec
2528          */
2529         if (static_call(kvm_x86_get_cpl)(vcpu) != 0 || !is_protmode(vcpu)) {
2530                 kvm_queue_exception(vcpu, UD_VECTOR);
2531                 return 1;
2532         }
2533
2534 #ifdef CONFIG_X86_64
2535         if (is_64_bit_hypercall(vcpu)) {
2536                 hc.param = kvm_rcx_read(vcpu);
2537                 hc.ingpa = kvm_rdx_read(vcpu);
2538                 hc.outgpa = kvm_r8_read(vcpu);
2539         } else
2540 #endif
2541         {
2542                 hc.param = ((u64)kvm_rdx_read(vcpu) << 32) |
2543                             (kvm_rax_read(vcpu) & 0xffffffff);
2544                 hc.ingpa = ((u64)kvm_rbx_read(vcpu) << 32) |
2545                             (kvm_rcx_read(vcpu) & 0xffffffff);
2546                 hc.outgpa = ((u64)kvm_rdi_read(vcpu) << 32) |
2547                              (kvm_rsi_read(vcpu) & 0xffffffff);
2548         }
2549
2550         hc.code = hc.param & 0xffff;
2551         hc.var_cnt = (hc.param & HV_HYPERCALL_VARHEAD_MASK) >> HV_HYPERCALL_VARHEAD_OFFSET;
2552         hc.fast = !!(hc.param & HV_HYPERCALL_FAST_BIT);
2553         hc.rep_cnt = (hc.param >> HV_HYPERCALL_REP_COMP_OFFSET) & 0xfff;
2554         hc.rep_idx = (hc.param >> HV_HYPERCALL_REP_START_OFFSET) & 0xfff;
2555         hc.rep = !!(hc.rep_cnt || hc.rep_idx);
2556
2557         trace_kvm_hv_hypercall(hc.code, hc.fast, hc.var_cnt, hc.rep_cnt,
2558                                hc.rep_idx, hc.ingpa, hc.outgpa);
2559
2560         if (unlikely(!hv_check_hypercall_access(hv_vcpu, hc.code))) {
2561                 ret = HV_STATUS_ACCESS_DENIED;
2562                 goto hypercall_complete;
2563         }
2564
2565         if (unlikely(hc.param & HV_HYPERCALL_RSVD_MASK)) {
2566                 ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2567                 goto hypercall_complete;
2568         }
2569
2570         if (hc.fast && is_xmm_fast_hypercall(&hc)) {
2571                 if (unlikely(hv_vcpu->enforce_cpuid &&
2572                              !(hv_vcpu->cpuid_cache.features_edx &
2573                                HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE))) {
2574                         kvm_queue_exception(vcpu, UD_VECTOR);
2575                         return 1;
2576                 }
2577
2578                 kvm_hv_hypercall_read_xmm(&hc);
2579         }
2580
2581         switch (hc.code) {
2582         case HVCALL_NOTIFY_LONG_SPIN_WAIT:
2583                 if (unlikely(hc.rep || hc.var_cnt)) {
2584                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2585                         break;
2586                 }
2587                 kvm_vcpu_on_spin(vcpu, true);
2588                 break;
2589         case HVCALL_SIGNAL_EVENT:
2590                 if (unlikely(hc.rep || hc.var_cnt)) {
2591                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2592                         break;
2593                 }
2594                 ret = kvm_hvcall_signal_event(vcpu, &hc);
2595                 if (ret != HV_STATUS_INVALID_PORT_ID)
2596                         break;
2597                 fallthrough;    /* maybe userspace knows this conn_id */
2598         case HVCALL_POST_MESSAGE:
2599                 /* don't bother userspace if it has no way to handle it */
2600                 if (unlikely(hc.rep || hc.var_cnt || !to_hv_synic(vcpu)->active)) {
2601                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2602                         break;
2603                 }
2604                 goto hypercall_userspace_exit;
2605         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST:
2606                 if (unlikely(hc.var_cnt)) {
2607                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2608                         break;
2609                 }
2610                 fallthrough;
2611         case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
2612                 if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
2613                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2614                         break;
2615                 }
2616                 ret = kvm_hv_flush_tlb(vcpu, &hc);
2617                 break;
2618         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
2619                 if (unlikely(hc.var_cnt)) {
2620                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2621                         break;
2622                 }
2623                 fallthrough;
2624         case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
2625                 if (unlikely(hc.rep)) {
2626                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2627                         break;
2628                 }
2629                 ret = kvm_hv_flush_tlb(vcpu, &hc);
2630                 break;
2631         case HVCALL_SEND_IPI:
2632                 if (unlikely(hc.var_cnt)) {
2633                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2634                         break;
2635                 }
2636                 fallthrough;
2637         case HVCALL_SEND_IPI_EX:
2638                 if (unlikely(hc.rep)) {
2639                         ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
2640                         break;
2641                 }
2642                 ret = kvm_hv_send_ipi(vcpu, &hc);
2643                 break;
2644         case HVCALL_POST_DEBUG_DATA:
2645         case HVCALL_RETRIEVE_DEBUG_DATA:
2646                 if (unlikely(hc.fast)) {
2647                         ret = HV_STATUS_INVALID_PARAMETER;
2648                         break;
2649                 }
2650                 fallthrough;
2651         case HVCALL_RESET_DEBUG_SESSION: {
2652                 struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
2653
2654                 if (!kvm_hv_is_syndbg_enabled(vcpu)) {
2655                         ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2656                         break;
2657                 }
2658
2659                 if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) {
2660                         ret = HV_STATUS_OPERATION_DENIED;
2661                         break;
2662                 }
2663                 goto hypercall_userspace_exit;
2664         }
2665         case HV_EXT_CALL_QUERY_CAPABILITIES ... HV_EXT_CALL_MAX:
2666                 if (unlikely(hc.fast)) {
2667                         ret = HV_STATUS_INVALID_PARAMETER;
2668                         break;
2669                 }
2670                 goto hypercall_userspace_exit;
2671         default:
2672                 ret = HV_STATUS_INVALID_HYPERCALL_CODE;
2673                 break;
2674         }
2675
2676 hypercall_complete:
2677         return kvm_hv_hypercall_complete(vcpu, ret);
2678
2679 hypercall_userspace_exit:
2680         vcpu->run->exit_reason = KVM_EXIT_HYPERV;
2681         vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
2682         vcpu->run->hyperv.u.hcall.input = hc.param;
2683         vcpu->run->hyperv.u.hcall.params[0] = hc.ingpa;
2684         vcpu->run->hyperv.u.hcall.params[1] = hc.outgpa;
2685         vcpu->arch.complete_userspace_io = kvm_hv_hypercall_complete_userspace;
2686         return 0;
2687 }
2688
2689 void kvm_hv_init_vm(struct kvm *kvm)
2690 {
2691         struct kvm_hv *hv = to_kvm_hv(kvm);
2692
2693         mutex_init(&hv->hv_lock);
2694         idr_init(&hv->conn_to_evt);
2695 }
2696
2697 void kvm_hv_destroy_vm(struct kvm *kvm)
2698 {
2699         struct kvm_hv *hv = to_kvm_hv(kvm);
2700         struct eventfd_ctx *eventfd;
2701         int i;
2702
2703         idr_for_each_entry(&hv->conn_to_evt, eventfd, i)
2704                 eventfd_ctx_put(eventfd);
2705         idr_destroy(&hv->conn_to_evt);
2706 }
2707
2708 static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
2709 {
2710         struct kvm_hv *hv = to_kvm_hv(kvm);
2711         struct eventfd_ctx *eventfd;
2712         int ret;
2713
2714         eventfd = eventfd_ctx_fdget(fd);
2715         if (IS_ERR(eventfd))
2716                 return PTR_ERR(eventfd);
2717
2718         mutex_lock(&hv->hv_lock);
2719         ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
2720                         GFP_KERNEL_ACCOUNT);
2721         mutex_unlock(&hv->hv_lock);
2722
2723         if (ret >= 0)
2724                 return 0;
2725
2726         if (ret == -ENOSPC)
2727                 ret = -EEXIST;
2728         eventfd_ctx_put(eventfd);
2729         return ret;
2730 }
2731
2732 static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
2733 {
2734         struct kvm_hv *hv = to_kvm_hv(kvm);
2735         struct eventfd_ctx *eventfd;
2736
2737         mutex_lock(&hv->hv_lock);
2738         eventfd = idr_remove(&hv->conn_to_evt, conn_id);
2739         mutex_unlock(&hv->hv_lock);
2740
2741         if (!eventfd)
2742                 return -ENOENT;
2743
2744         synchronize_srcu(&kvm->srcu);
2745         eventfd_ctx_put(eventfd);
2746         return 0;
2747 }
2748
2749 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
2750 {
2751         if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
2752             (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
2753                 return -EINVAL;
2754
2755         if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
2756                 return kvm_hv_eventfd_deassign(kvm, args->conn_id);
2757         return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
2758 }
2759
2760 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
2761                      struct kvm_cpuid_entry2 __user *entries)
2762 {
2763         uint16_t evmcs_ver = 0;
2764         struct kvm_cpuid_entry2 cpuid_entries[] = {
2765                 { .function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS },
2766                 { .function = HYPERV_CPUID_INTERFACE },
2767                 { .function = HYPERV_CPUID_VERSION },
2768                 { .function = HYPERV_CPUID_FEATURES },
2769                 { .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
2770                 { .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
2771                 { .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
2772                 { .function = HYPERV_CPUID_SYNDBG_INTERFACE },
2773                 { .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES },
2774                 { .function = HYPERV_CPUID_NESTED_FEATURES },
2775         };
2776         int i, nent = ARRAY_SIZE(cpuid_entries);
2777
2778         if (kvm_x86_ops.nested_ops->get_evmcs_version)
2779                 evmcs_ver = kvm_x86_ops.nested_ops->get_evmcs_version(vcpu);
2780
2781         if (cpuid->nent < nent)
2782                 return -E2BIG;
2783
2784         if (cpuid->nent > nent)
2785                 cpuid->nent = nent;
2786
2787         for (i = 0; i < nent; i++) {
2788                 struct kvm_cpuid_entry2 *ent = &cpuid_entries[i];
2789                 u32 signature[3];
2790
2791                 switch (ent->function) {
2792                 case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
2793                         memcpy(signature, "Linux KVM Hv", 12);
2794
2795                         ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
2796                         ent->ebx = signature[0];
2797                         ent->ecx = signature[1];
2798                         ent->edx = signature[2];
2799                         break;
2800
2801                 case HYPERV_CPUID_INTERFACE:
2802                         ent->eax = HYPERV_CPUID_SIGNATURE_EAX;
2803                         break;
2804
2805                 case HYPERV_CPUID_VERSION:
2806                         /*
2807                          * We implement some Hyper-V 2016 functions so let's use
2808                          * this version.
2809                          */
2810                         ent->eax = 0x00003839;
2811                         ent->ebx = 0x000A0000;
2812                         break;
2813
2814                 case HYPERV_CPUID_FEATURES:
2815                         ent->eax |= HV_MSR_VP_RUNTIME_AVAILABLE;
2816                         ent->eax |= HV_MSR_TIME_REF_COUNT_AVAILABLE;
2817                         ent->eax |= HV_MSR_SYNIC_AVAILABLE;
2818                         ent->eax |= HV_MSR_SYNTIMER_AVAILABLE;
2819                         ent->eax |= HV_MSR_APIC_ACCESS_AVAILABLE;
2820                         ent->eax |= HV_MSR_HYPERCALL_AVAILABLE;
2821                         ent->eax |= HV_MSR_VP_INDEX_AVAILABLE;
2822                         ent->eax |= HV_MSR_RESET_AVAILABLE;
2823                         ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE;
2824                         ent->eax |= HV_ACCESS_FREQUENCY_MSRS;
2825                         ent->eax |= HV_ACCESS_REENLIGHTENMENT;
2826                         ent->eax |= HV_ACCESS_TSC_INVARIANT;
2827
2828                         ent->ebx |= HV_POST_MESSAGES;
2829                         ent->ebx |= HV_SIGNAL_EVENTS;
2830                         ent->ebx |= HV_ENABLE_EXTENDED_HYPERCALLS;
2831
2832                         ent->edx |= HV_X64_HYPERCALL_XMM_INPUT_AVAILABLE;
2833                         ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
2834                         ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
2835
2836                         ent->ebx |= HV_DEBUGGING;
2837                         ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
2838                         ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
2839                         ent->edx |= HV_FEATURE_EXT_GVA_RANGES_FLUSH;
2840
2841                         /*
2842                          * Direct Synthetic timers only make sense with in-kernel
2843                          * LAPIC
2844                          */
2845                         if (!vcpu || lapic_in_kernel(vcpu))
2846                                 ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
2847
2848                         break;
2849
2850                 case HYPERV_CPUID_ENLIGHTMENT_INFO:
2851                         ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED;
2852                         ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED;
2853                         ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED;
2854                         ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED;
2855                         ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED;
2856                         if (evmcs_ver)
2857                                 ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
2858                         if (!cpu_smt_possible())
2859                                 ent->eax |= HV_X64_NO_NONARCH_CORESHARING;
2860
2861                         ent->eax |= HV_DEPRECATING_AEOI_RECOMMENDED;
2862                         /*
2863                          * Default number of spinlock retry attempts, matches
2864                          * HyperV 2016.
2865                          */
2866                         ent->ebx = 0x00000FFF;
2867
2868                         break;
2869
2870                 case HYPERV_CPUID_IMPLEMENT_LIMITS:
2871                         /* Maximum number of virtual processors */
2872                         ent->eax = KVM_MAX_VCPUS;
2873                         /*
2874                          * Maximum number of logical processors, matches
2875                          * HyperV 2016.
2876                          */
2877                         ent->ebx = 64;
2878
2879                         break;
2880
2881                 case HYPERV_CPUID_NESTED_FEATURES:
2882                         ent->eax = evmcs_ver;
2883                         ent->eax |= HV_X64_NESTED_DIRECT_FLUSH;
2884                         ent->eax |= HV_X64_NESTED_MSR_BITMAP;
2885                         ent->ebx |= HV_X64_NESTED_EVMCS1_PERF_GLOBAL_CTRL;
2886                         break;
2887
2888                 case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
2889                         memcpy(signature, "Linux KVM Hv", 12);
2890
2891                         ent->eax = 0;
2892                         ent->ebx = signature[0];
2893                         ent->ecx = signature[1];
2894                         ent->edx = signature[2];
2895                         break;
2896
2897                 case HYPERV_CPUID_SYNDBG_INTERFACE:
2898                         memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
2899                         ent->eax = signature[0];
2900                         break;
2901
2902                 case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
2903                         ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
2904                         break;
2905
2906                 default:
2907                         break;
2908                 }
2909         }
2910
2911         if (copy_to_user(entries, cpuid_entries,
2912                          nent * sizeof(struct kvm_cpuid_entry2)))
2913                 return -EFAULT;
2914
2915         return 0;
2916 }