arch/x86/kvm/xen.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
   4  * Copyright © 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
   5  *
   6  * KVM Xen emulation
   7  */
   8
   9 #include "x86.h"
  10 #include "xen.h"
  11 #include "hyperv.h"
  12
  13 #include <linux/kvm_host.h>
  14 #include <linux/sched/stat.h>
  15
  16 #include <trace/events/kvm.h>
  17 #include <xen/interface/xen.h>
  18 #include <xen/interface/vcpu.h>
  19
  20 #include "trace.h"
  21
  22 DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ);
  23
  24 static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
  25 {
  26         gpa_t gpa = gfn_to_gpa(gfn);
  27         int wc_ofs, sec_hi_ofs;
  28         int ret = 0;
  29         int idx = srcu_read_lock(&kvm->srcu);
  30
  31         if (kvm_is_error_hva(gfn_to_hva(kvm, gfn))) {
  32                 ret = -EFAULT;
  33                 goto out;
  34         }
  35         kvm->arch.xen.shinfo_gfn = gfn;
  36
  37         /* Paranoia checks on the 32-bit struct layout */
  38         BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900);
  39         BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924);
  40         BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
  41
  42         /* 32-bit location by default */
  43         wc_ofs = offsetof(struct compat_shared_info, wc);
  44         sec_hi_ofs = offsetof(struct compat_shared_info, arch.wc_sec_hi);
  45
  46 #ifdef CONFIG_X86_64
  47         /* Paranoia checks on the 64-bit struct layout */
  48         BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00);
  49         BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c);
  50
  51         if (kvm->arch.xen.long_mode) {
  52                 wc_ofs = offsetof(struct shared_info, wc);
  53                 sec_hi_ofs = offsetof(struct shared_info, wc_sec_hi);
  54         }
  55 #endif
  56
  57         kvm_write_wall_clock(kvm, gpa + wc_ofs, sec_hi_ofs - wc_ofs);
  58         kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE);
  59
  60 out:
  61         srcu_read_unlock(&kvm->srcu, idx);
  62         return ret;
  63 }
  64
  65 static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state)
  66 {
  67         struct kvm_vcpu_xen *vx = &v->arch.xen;
  68         u64 now = get_kvmclock_ns(v->kvm);
  69         u64 delta_ns = now - vx->runstate_entry_time;
  70         u64 run_delay = current->sched_info.run_delay;
  71
  72         if (unlikely(!vx->runstate_entry_time))
  73                 vx->current_runstate = RUNSTATE_offline;
  74
  75         /*
  76          * Time waiting for the scheduler isn't "stolen" if the
  77          * vCPU wasn't running anyway.
  78          */
  79         if (vx->current_runstate == RUNSTATE_running) {
  80                 u64 steal_ns = run_delay - vx->last_steal;
  81
  82                 delta_ns -= steal_ns;
  83
  84                 vx->runstate_times[RUNSTATE_runnable] += steal_ns;
  85         }
  86         vx->last_steal = run_delay;
  87
  88         vx->runstate_times[vx->current_runstate] += delta_ns;
  89         vx->current_runstate = state;
  90         vx->runstate_entry_time = now;
  91 }
  92
  93 void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
  94 {
  95         struct kvm_vcpu_xen *vx = &v->arch.xen;
  96         struct gfn_to_hva_cache *ghc = &vx->runstate_cache;
  97         struct kvm_memslots *slots = kvm_memslots(v->kvm);
  98         bool atomic = (state == RUNSTATE_runnable);
  99         uint64_t state_entry_time;
 100         int __user *user_state;
 101         uint64_t __user *user_times;
 102
 103         kvm_xen_update_runstate(v, state);
 104
 105         if (!vx->runstate_set)
 106                 return;
 107
 108         if (unlikely(slots->generation != ghc->generation || kvm_is_error_hva(ghc->hva)) &&
 109             kvm_gfn_to_hva_cache_init(v->kvm, ghc, ghc->gpa, ghc->len))
 110                 return;
 111
 112         /* We made sure it fits in a single page */
 113         BUG_ON(!ghc->memslot);
 114
 115         if (atomic)
 116                 pagefault_disable();
 117
 118         /*
 119          * The only difference between 32-bit and 64-bit versions of the
 120          * runstate struct us the alignment of uint64_t in 32-bit, which
 121          * means that the 64-bit version has an additional 4 bytes of
 122          * padding after the first field 'state'.
 123          *
 124          * So we use 'int __user *user_state' to point to the state field,
 125          * and 'uint64_t __user *user_times' for runstate_entry_time. So
 126          * the actual array of time[] in each state starts at user_times[1].
 127          */
 128         BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 0);
 129         BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state) != 0);
 130         user_state = (int __user *)ghc->hva;
 131
 132         BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c);
 133
 134         user_times = (uint64_t __user *)(ghc->hva +
 135                                          offsetof(struct compat_vcpu_runstate_info,
 136                                                   state_entry_time));
 137 #ifdef CONFIG_X86_64
 138         BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
 139                      offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4);
 140         BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) !=
 141                      offsetof(struct compat_vcpu_runstate_info, time) + 4);
 142
 143         if (v->kvm->arch.xen.long_mode)
 144                 user_times = (uint64_t __user *)(ghc->hva +
 145                                                  offsetof(struct vcpu_runstate_info,
 146                                                           state_entry_time));
 147 #endif
 148         /*
 149          * First write the updated state_entry_time at the appropriate
 150          * location determined by 'offset'.
 151          */
 152         state_entry_time = vx->runstate_entry_time;
 153         state_entry_time |= XEN_RUNSTATE_UPDATE;
 154
 155         BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state_entry_time) !=
 156                      sizeof(state_entry_time));
 157         BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state_entry_time) !=
 158                      sizeof(state_entry_time));
 159
 160         if (__put_user(state_entry_time, user_times))
 161                 goto out;
 162         smp_wmb();
 163
 164         /*
 165          * Next, write the new runstate. This is in the *same* place
 166          * for 32-bit and 64-bit guests, asserted here for paranoia.
 167          */
 168         BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) !=
 169                      offsetof(struct compat_vcpu_runstate_info, state));
 170         BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state) !=
 171                      sizeof(vx->current_runstate));
 172         BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state) !=
 173                      sizeof(vx->current_runstate));
 174
 175         if (__put_user(vx->current_runstate, user_state))
 176                 goto out;
 177
 178         /*
 179          * Write the actual runstate times immediately after the
 180          * runstate_entry_time.
 181          */
 182         BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
 183                      offsetof(struct vcpu_runstate_info, time) - sizeof(u64));
 184         BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) !=
 185                      offsetof(struct compat_vcpu_runstate_info, time) - sizeof(u64));
 186         BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) !=
 187                      sizeof(((struct compat_vcpu_runstate_info *)0)->time));
 188         BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) !=
 189                      sizeof(vx->runstate_times));
 190
 191         if (__copy_to_user(user_times + 1, vx->runstate_times, sizeof(vx->runstate_times)))
 192                 goto out;
 193         smp_wmb();
 194
 195         /*
 196          * Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's
 197          * runstate_entry_time field.
 198          */
 199         state_entry_time &= ~XEN_RUNSTATE_UPDATE;
 200         __put_user(state_entry_time, user_times);
 201         smp_wmb();
 202
 203  out:
 204         mark_page_dirty_in_slot(v->kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
 205
 206         if (atomic)
 207                 pagefault_enable();
 208 }
 209
 210 int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
 211 {
 212         int err;
 213         u8 rc = 0;
 214
 215         /*
 216          * If the global upcall vector (HVMIRQ_callback_vector) is set and
 217          * the vCPU's evtchn_upcall_pending flag is set, the IRQ is pending.
 218          */
 219         struct gfn_to_hva_cache *ghc = &v->arch.xen.vcpu_info_cache;
 220         struct kvm_memslots *slots = kvm_memslots(v->kvm);
 221         unsigned int offset = offsetof(struct vcpu_info, evtchn_upcall_pending);
 222
 223         /* No need for compat handling here */
 224         BUILD_BUG_ON(offsetof(struct vcpu_info, evtchn_upcall_pending) !=
 225                      offsetof(struct compat_vcpu_info, evtchn_upcall_pending));
 226         BUILD_BUG_ON(sizeof(rc) !=
 227                      sizeof(((struct vcpu_info *)0)->evtchn_upcall_pending));
 228         BUILD_BUG_ON(sizeof(rc) !=
 229                      sizeof(((struct compat_vcpu_info *)0)->evtchn_upcall_pending));
 230
 231         /*
 232          * For efficiency, this mirrors the checks for using the valid
 233          * cache in kvm_read_guest_offset_cached(), but just uses
 234          * __get_user() instead. And falls back to the slow path.
 235          */
 236         if (likely(slots->generation == ghc->generation &&
 237                    !kvm_is_error_hva(ghc->hva) && ghc->memslot)) {
 238                 /* Fast path */
 239                 pagefault_disable();
 240                 err = __get_user(rc, (u8 __user *)ghc->hva + offset);
 241                 pagefault_enable();
 242                 if (!err)
 243                         return rc;
 244         }
 245
 246         /* Slow path */
 247
 248         /*
 249          * This function gets called from kvm_vcpu_block() after setting the
 250          * task to TASK_INTERRUPTIBLE, to see if it needs to wake immediately
 251          * from a HLT. So we really mustn't sleep. If the page ended up absent
 252          * at that point, just return 1 in order to trigger an immediate wake,
 253          * and we'll end up getting called again from a context where we *can*
 254          * fault in the page and wait for it.
 255          */
 256         if (in_atomic() || !task_is_running(current))
 257                 return 1;
 258
 259         kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset,
 260                                      sizeof(rc));
 261
 262         return rc;
 263 }
 264
 265 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 266 {
 267         int r = -ENOENT;
 268
 269         mutex_lock(&kvm->lock);
 270
 271         switch (data->type) {
 272         case KVM_XEN_ATTR_TYPE_LONG_MODE:
 273                 if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) {
 274                         r = -EINVAL;
 275                 } else {
 276                         kvm->arch.xen.long_mode = !!data->u.long_mode;
 277                         r = 0;
 278                 }
 279                 break;
 280
 281         case KVM_XEN_ATTR_TYPE_SHARED_INFO:
 282                 if (data->u.shared_info.gfn == GPA_INVALID) {
 283                         kvm->arch.xen.shinfo_gfn = GPA_INVALID;
 284                         r = 0;
 285                         break;
 286                 }
 287                 r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
 288                 break;
 289
 290
 291         case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
 292                 if (data->u.vector && data->u.vector < 0x10)
 293                         r = -EINVAL;
 294                 else {
 295                         kvm->arch.xen.upcall_vector = data->u.vector;
 296                         r = 0;
 297                 }
 298                 break;
 299
 300         default:
 301                 break;
 302         }
 303
 304         mutex_unlock(&kvm->lock);
 305         return r;
 306 }
 307
 308 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 309 {
 310         int r = -ENOENT;
 311
 312         mutex_lock(&kvm->lock);
 313
 314         switch (data->type) {
 315         case KVM_XEN_ATTR_TYPE_LONG_MODE:
 316                 data->u.long_mode = kvm->arch.xen.long_mode;
 317                 r = 0;
 318                 break;
 319
 320         case KVM_XEN_ATTR_TYPE_SHARED_INFO:
 321                 data->u.shared_info.gfn = kvm->arch.xen.shinfo_gfn;
 322                 r = 0;
 323                 break;
 324
 325         case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
 326                 data->u.vector = kvm->arch.xen.upcall_vector;
 327                 r = 0;
 328                 break;
 329
 330         default:
 331                 break;
 332         }
 333
 334         mutex_unlock(&kvm->lock);
 335         return r;
 336 }
 337
 338 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 339 {
 340         int idx, r = -ENOENT;
 341
 342         mutex_lock(&vcpu->kvm->lock);
 343         idx = srcu_read_lock(&vcpu->kvm->srcu);
 344
 345         switch (data->type) {
 346         case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
 347                 /* No compat necessary here. */
 348                 BUILD_BUG_ON(sizeof(struct vcpu_info) !=
 349                              sizeof(struct compat_vcpu_info));
 350                 BUILD_BUG_ON(offsetof(struct vcpu_info, time) !=
 351                              offsetof(struct compat_vcpu_info, time));
 352
 353                 if (data->u.gpa == GPA_INVALID) {
 354                         vcpu->arch.xen.vcpu_info_set = false;
 355                         r = 0;
 356                         break;
 357                 }
 358
 359                 /* It must fit within a single page */
 360                 if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct vcpu_info) > PAGE_SIZE) {
 361                         r = -EINVAL;
 362                         break;
 363                 }
 364
 365                 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
 366                                               &vcpu->arch.xen.vcpu_info_cache,
 367                                               data->u.gpa,
 368                                               sizeof(struct vcpu_info));
 369                 if (!r) {
 370                         vcpu->arch.xen.vcpu_info_set = true;
 371                         kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 372                 }
 373                 break;
 374
 375         case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
 376                 if (data->u.gpa == GPA_INVALID) {
 377                         vcpu->arch.xen.vcpu_time_info_set = false;
 378                         r = 0;
 379                         break;
 380                 }
 381
 382                 /* It must fit within a single page */
 383                 if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct pvclock_vcpu_time_info) > PAGE_SIZE) {
 384                         r = -EINVAL;
 385                         break;
 386                 }
 387
 388                 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
 389                                               &vcpu->arch.xen.vcpu_time_info_cache,
 390                                               data->u.gpa,
 391                                               sizeof(struct pvclock_vcpu_time_info));
 392                 if (!r) {
 393                         vcpu->arch.xen.vcpu_time_info_set = true;
 394                         kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
 395                 }
 396                 break;
 397
 398         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
 399                 if (!sched_info_on()) {
 400                         r = -EOPNOTSUPP;
 401                         break;
 402                 }
 403                 if (data->u.gpa == GPA_INVALID) {
 404                         vcpu->arch.xen.runstate_set = false;
 405                         r = 0;
 406                         break;
 407                 }
 408
 409                 /* It must fit within a single page */
 410                 if ((data->u.gpa & ~PAGE_MASK) + sizeof(struct vcpu_runstate_info) > PAGE_SIZE) {
 411                         r = -EINVAL;
 412                         break;
 413                 }
 414
 415                 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
 416                                               &vcpu->arch.xen.runstate_cache,
 417                                               data->u.gpa,
 418                                               sizeof(struct vcpu_runstate_info));
 419                 if (!r) {
 420                         vcpu->arch.xen.runstate_set = true;
 421                 }
 422                 break;
 423
 424         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
 425                 if (!sched_info_on()) {
 426                         r = -EOPNOTSUPP;
 427                         break;
 428                 }
 429                 if (data->u.runstate.state > RUNSTATE_offline) {
 430                         r = -EINVAL;
 431                         break;
 432                 }
 433
 434                 kvm_xen_update_runstate(vcpu, data->u.runstate.state);
 435                 r = 0;
 436                 break;
 437
 438         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
 439                 if (!sched_info_on()) {
 440                         r = -EOPNOTSUPP;
 441                         break;
 442                 }
 443                 if (data->u.runstate.state > RUNSTATE_offline) {
 444                         r = -EINVAL;
 445                         break;
 446                 }
 447                 if (data->u.runstate.state_entry_time !=
 448                     (data->u.runstate.time_running +
 449                      data->u.runstate.time_runnable +
 450                      data->u.runstate.time_blocked +
 451                      data->u.runstate.time_offline)) {
 452                         r = -EINVAL;
 453                         break;
 454                 }
 455                 if (get_kvmclock_ns(vcpu->kvm) <
 456                     data->u.runstate.state_entry_time) {
 457                         r = -EINVAL;
 458                         break;
 459                 }
 460
 461                 vcpu->arch.xen.current_runstate = data->u.runstate.state;
 462                 vcpu->arch.xen.runstate_entry_time =
 463                         data->u.runstate.state_entry_time;
 464                 vcpu->arch.xen.runstate_times[RUNSTATE_running] =
 465                         data->u.runstate.time_running;
 466                 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] =
 467                         data->u.runstate.time_runnable;
 468                 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] =
 469                         data->u.runstate.time_blocked;
 470                 vcpu->arch.xen.runstate_times[RUNSTATE_offline] =
 471                         data->u.runstate.time_offline;
 472                 vcpu->arch.xen.last_steal = current->sched_info.run_delay;
 473                 r = 0;
 474                 break;
 475
 476         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
 477                 if (!sched_info_on()) {
 478                         r = -EOPNOTSUPP;
 479                         break;
 480                 }
 481                 if (data->u.runstate.state > RUNSTATE_offline &&
 482                     data->u.runstate.state != (u64)-1) {
 483                         r = -EINVAL;
 484                         break;
 485                 }
 486                 /* The adjustment must add up */
 487                 if (data->u.runstate.state_entry_time !=
 488                     (data->u.runstate.time_running +
 489                      data->u.runstate.time_runnable +
 490                      data->u.runstate.time_blocked +
 491                      data->u.runstate.time_offline)) {
 492                         r = -EINVAL;
 493                         break;
 494                 }
 495
 496                 if (get_kvmclock_ns(vcpu->kvm) <
 497                     (vcpu->arch.xen.runstate_entry_time +
 498                      data->u.runstate.state_entry_time)) {
 499                         r = -EINVAL;
 500                         break;
 501                 }
 502
 503                 vcpu->arch.xen.runstate_entry_time +=
 504                         data->u.runstate.state_entry_time;
 505                 vcpu->arch.xen.runstate_times[RUNSTATE_running] +=
 506                         data->u.runstate.time_running;
 507                 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] +=
 508                         data->u.runstate.time_runnable;
 509                 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] +=
 510                         data->u.runstate.time_blocked;
 511                 vcpu->arch.xen.runstate_times[RUNSTATE_offline] +=
 512                         data->u.runstate.time_offline;
 513
 514                 if (data->u.runstate.state <= RUNSTATE_offline)
 515                         kvm_xen_update_runstate(vcpu, data->u.runstate.state);
 516                 r = 0;
 517                 break;
 518
 519         default:
 520                 break;
 521         }
 522
 523         srcu_read_unlock(&vcpu->kvm->srcu, idx);
 524         mutex_unlock(&vcpu->kvm->lock);
 525         return r;
 526 }
 527
 528 int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 529 {
 530         int r = -ENOENT;
 531
 532         mutex_lock(&vcpu->kvm->lock);
 533
 534         switch (data->type) {
 535         case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
 536                 if (vcpu->arch.xen.vcpu_info_set)
 537                         data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa;
 538                 else
 539                         data->u.gpa = GPA_INVALID;
 540                 r = 0;
 541                 break;
 542
 543         case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
 544                 if (vcpu->arch.xen.vcpu_time_info_set)
 545                         data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa;
 546                 else
 547                         data->u.gpa = GPA_INVALID;
 548                 r = 0;
 549                 break;
 550
 551         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
 552                 if (!sched_info_on()) {
 553                         r = -EOPNOTSUPP;
 554                         break;
 555                 }
 556                 if (vcpu->arch.xen.runstate_set) {
 557                         data->u.gpa = vcpu->arch.xen.runstate_cache.gpa;
 558                         r = 0;
 559                 }
 560                 break;
 561
 562         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
 563                 if (!sched_info_on()) {
 564                         r = -EOPNOTSUPP;
 565                         break;
 566                 }
 567                 data->u.runstate.state = vcpu->arch.xen.current_runstate;
 568                 r = 0;
 569                 break;
 570
 571         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
 572                 if (!sched_info_on()) {
 573                         r = -EOPNOTSUPP;
 574                         break;
 575                 }
 576                 data->u.runstate.state = vcpu->arch.xen.current_runstate;
 577                 data->u.runstate.state_entry_time =
 578                         vcpu->arch.xen.runstate_entry_time;
 579                 data->u.runstate.time_running =
 580                         vcpu->arch.xen.runstate_times[RUNSTATE_running];
 581                 data->u.runstate.time_runnable =
 582                         vcpu->arch.xen.runstate_times[RUNSTATE_runnable];
 583                 data->u.runstate.time_blocked =
 584                         vcpu->arch.xen.runstate_times[RUNSTATE_blocked];
 585                 data->u.runstate.time_offline =
 586                         vcpu->arch.xen.runstate_times[RUNSTATE_offline];
 587                 r = 0;
 588                 break;
 589
 590         case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
 591                 r = -EINVAL;
 592                 break;
 593
 594         default:
 595                 break;
 596         }
 597
 598         mutex_unlock(&vcpu->kvm->lock);
 599         return r;
 600 }
 601
 602 int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
 603 {
 604         struct kvm *kvm = vcpu->kvm;
 605         u32 page_num = data & ~PAGE_MASK;
 606         u64 page_addr = data & PAGE_MASK;
 607         bool lm = is_long_mode(vcpu);
 608
 609         /* Latch long_mode for shared_info pages etc. */
 610         vcpu->kvm->arch.xen.long_mode = lm;
 611
 612         /*
 613          * If Xen hypercall intercept is enabled, fill the hypercall
 614          * page with VMCALL/VMMCALL instructions since that's what
 615          * we catch. Else the VMM has provided the hypercall pages
 616          * with instructions of its own choosing, so use those.
 617          */
 618         if (kvm_xen_hypercall_enabled(kvm)) {
 619                 u8 instructions[32];
 620                 int i;
 621
 622                 if (page_num)
 623                         return 1;
 624
 625                 /* mov imm32, %eax */
 626                 instructions[0] = 0xb8;
 627
 628                 /* vmcall / vmmcall */
 629                 kvm_x86_ops.patch_hypercall(vcpu, instructions + 5);
 630
 631                 /* ret */
 632                 instructions[8] = 0xc3;
 633
 634                 /* int3 to pad */
 635                 memset(instructions + 9, 0xcc, sizeof(instructions) - 9);
 636
 637                 for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) {
 638                         *(u32 *)&instructions[1] = i;
 639                         if (kvm_vcpu_write_guest(vcpu,
 640                                                  page_addr + (i * sizeof(instructions)),
 641                                                  instructions, sizeof(instructions)))
 642                                 return 1;
 643                 }
 644         } else {
 645                 /*
 646                  * Note, truncation is a non-issue as 'lm' is guaranteed to be
 647                  * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes.
 648                  */
 649                 hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64
 650                                      : kvm->arch.xen_hvm_config.blob_addr_32;
 651                 u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
 652                                   : kvm->arch.xen_hvm_config.blob_size_32;
 653                 u8 *page;
 654
 655                 if (page_num >= blob_size)
 656                         return 1;
 657
 658                 blob_addr += page_num * PAGE_SIZE;
 659
 660                 page = memdup_user((u8 __user *)blob_addr, PAGE_SIZE);
 661                 if (IS_ERR(page))
 662                         return PTR_ERR(page);
 663
 664                 if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
 665                         kfree(page);
 666                         return 1;
 667                 }
 668         }
 669         return 0;
 670 }
 671
 672 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc)
 673 {
 674         if (xhc->flags & ~KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL)
 675                 return -EINVAL;
 676
 677         /*
 678          * With hypercall interception the kernel generates its own
 679          * hypercall page so it must not be provided.
 680          */
 681         if ((xhc->flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) &&
 682             (xhc->blob_addr_32 || xhc->blob_addr_64 ||
 683              xhc->blob_size_32 || xhc->blob_size_64))
 684                 return -EINVAL;
 685
 686         mutex_lock(&kvm->lock);
 687
 688         if (xhc->msr && !kvm->arch.xen_hvm_config.msr)
 689                 static_branch_inc(&kvm_xen_enabled.key);
 690         else if (!xhc->msr && kvm->arch.xen_hvm_config.msr)
 691                 static_branch_slow_dec_deferred(&kvm_xen_enabled);
 692
 693         memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc));
 694
 695         mutex_unlock(&kvm->lock);
 696         return 0;
 697 }
 698
 699 void kvm_xen_init_vm(struct kvm *kvm)
 700 {
 701         kvm->arch.xen.shinfo_gfn = GPA_INVALID;
 702 }
 703
 704 void kvm_xen_destroy_vm(struct kvm *kvm)
 705 {
 706         if (kvm->arch.xen_hvm_config.msr)
 707                 static_branch_slow_dec_deferred(&kvm_xen_enabled);
 708 }
 709
 710 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
 711 {
 712         kvm_rax_write(vcpu, result);
 713         return kvm_skip_emulated_instruction(vcpu);
 714 }
 715
 716 static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
 717 {
 718         struct kvm_run *run = vcpu->run;
 719
 720         if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip)))
 721                 return 1;
 722
 723         return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result);
 724 }
 725
 726 int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
 727 {
 728         bool longmode;
 729         u64 input, params[6];
 730
 731         input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX);
 732
 733         /* Hyper-V hypercalls get bit 31 set in EAX */
 734         if ((input & 0x80000000) &&
 735             kvm_hv_hypercall_enabled(vcpu))
 736                 return kvm_hv_hypercall(vcpu);
 737
 738         longmode = is_64_bit_hypercall(vcpu);
 739         if (!longmode) {
 740                 params[0] = (u32)kvm_rbx_read(vcpu);
 741                 params[1] = (u32)kvm_rcx_read(vcpu);
 742                 params[2] = (u32)kvm_rdx_read(vcpu);
 743                 params[3] = (u32)kvm_rsi_read(vcpu);
 744                 params[4] = (u32)kvm_rdi_read(vcpu);
 745                 params[5] = (u32)kvm_rbp_read(vcpu);
 746         }
 747 #ifdef CONFIG_X86_64
 748         else {
 749                 params[0] = (u64)kvm_rdi_read(vcpu);
 750                 params[1] = (u64)kvm_rsi_read(vcpu);
 751                 params[2] = (u64)kvm_rdx_read(vcpu);
 752                 params[3] = (u64)kvm_r10_read(vcpu);
 753                 params[4] = (u64)kvm_r8_read(vcpu);
 754                 params[5] = (u64)kvm_r9_read(vcpu);
 755         }
 756 #endif
 757         trace_kvm_xen_hypercall(input, params[0], params[1], params[2],
 758                                 params[3], params[4], params[5]);
 759
 760         vcpu->run->exit_reason = KVM_EXIT_XEN;
 761         vcpu->run->xen.type = KVM_EXIT_XEN_HCALL;
 762         vcpu->run->xen.u.hcall.longmode = longmode;
 763         vcpu->run->xen.u.hcall.cpl = kvm_x86_ops.get_cpl(vcpu);
 764         vcpu->run->xen.u.hcall.input = input;
 765         vcpu->run->xen.u.hcall.params[0] = params[0];
 766         vcpu->run->xen.u.hcall.params[1] = params[1];
 767         vcpu->run->xen.u.hcall.params[2] = params[2];
 768         vcpu->run->xen.u.hcall.params[3] = params[3];
 769         vcpu->run->xen.u.hcall.params[4] = params[4];
 770         vcpu->run->xen.u.hcall.params[5] = params[5];
 771         vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu);
 772         vcpu->arch.complete_userspace_io =
 773                 kvm_xen_hypercall_complete_userspace;
 774
 775         return 0;
 776 }