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; 29 int idx = srcu_read_lock(&kvm->srcu); 30 31 ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache, 32 gpa, PAGE_SIZE); 33 if (ret) 34 goto out; 35 36 kvm->arch.xen.shinfo_set = true; 37 38 /* Paranoia checks on the 32-bit struct layout */ 39 BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900); 40 BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924); 41 BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0); 42 43 /* 32-bit location by default */ 44 wc_ofs = offsetof(struct compat_shared_info, wc); 45 sec_hi_ofs = offsetof(struct compat_shared_info, arch.wc_sec_hi); 46 47 #ifdef CONFIG_X86_64 48 /* Paranoia checks on the 64-bit struct layout */ 49 BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00); 50 BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c); 51 52 if (kvm->arch.xen.long_mode) { 53 wc_ofs = offsetof(struct shared_info, wc); 54 sec_hi_ofs = offsetof(struct shared_info, wc_sec_hi); 55 } 56 #endif 57 58 kvm_write_wall_clock(kvm, gpa + wc_ofs, sec_hi_ofs - wc_ofs); 59 kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE); 60 61 out: 62 srcu_read_unlock(&kvm->srcu, idx); 63 return ret; 64 } 65 66 static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state) 67 { 68 struct kvm_vcpu_xen *vx = &v->arch.xen; 69 u64 now = get_kvmclock_ns(v->kvm); 70 u64 delta_ns = now - vx->runstate_entry_time; 71 u64 run_delay = current->sched_info.run_delay; 72 73 if (unlikely(!vx->runstate_entry_time)) 74 vx->current_runstate = RUNSTATE_offline; 75 76 /* 77 * Time waiting for the scheduler isn't "stolen" if the 78 * vCPU wasn't running anyway. 79 */ 80 if (vx->current_runstate == RUNSTATE_running) { 81 u64 steal_ns = run_delay - vx->last_steal; 82 83 delta_ns -= steal_ns; 84 85 vx->runstate_times[RUNSTATE_runnable] += steal_ns; 86 } 87 vx->last_steal = run_delay; 88 89 vx->runstate_times[vx->current_runstate] += delta_ns; 90 vx->current_runstate = state; 91 vx->runstate_entry_time = now; 92 } 93 94 void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) 95 { 96 struct kvm_vcpu_xen *vx = &v->arch.xen; 97 uint64_t state_entry_time; 98 unsigned int offset; 99 100 kvm_xen_update_runstate(v, state); 101 102 if (!vx->runstate_set) 103 return; 104 105 BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c); 106 107 offset = offsetof(struct compat_vcpu_runstate_info, state_entry_time); 108 #ifdef CONFIG_X86_64 109 /* 110 * The only difference is alignment of uint64_t in 32-bit. 111 * So the first field 'state' is accessed directly using 112 * offsetof() (where its offset happens to be zero), while the 113 * remaining fields which are all uint64_t, start at 'offset' 114 * which we tweak here by adding 4. 115 */ 116 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) != 117 offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4); 118 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) != 119 offsetof(struct compat_vcpu_runstate_info, time) + 4); 120 121 if (v->kvm->arch.xen.long_mode) 122 offset = offsetof(struct vcpu_runstate_info, state_entry_time); 123 #endif 124 /* 125 * First write the updated state_entry_time at the appropriate 126 * location determined by 'offset'. 127 */ 128 state_entry_time = vx->runstate_entry_time; 129 state_entry_time |= XEN_RUNSTATE_UPDATE; 130 131 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state_entry_time) != 132 sizeof(state_entry_time)); 133 BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state_entry_time) != 134 sizeof(state_entry_time)); 135 136 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, 137 &state_entry_time, offset, 138 sizeof(state_entry_time))) 139 return; 140 smp_wmb(); 141 142 /* 143 * Next, write the new runstate. This is in the *same* place 144 * for 32-bit and 64-bit guests, asserted here for paranoia. 145 */ 146 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 147 offsetof(struct compat_vcpu_runstate_info, state)); 148 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state) != 149 sizeof(vx->current_runstate)); 150 BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state) != 151 sizeof(vx->current_runstate)); 152 153 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, 154 &vx->current_runstate, 155 offsetof(struct vcpu_runstate_info, state), 156 sizeof(vx->current_runstate))) 157 return; 158 159 /* 160 * Write the actual runstate times immediately after the 161 * runstate_entry_time. 162 */ 163 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) != 164 offsetof(struct vcpu_runstate_info, time) - sizeof(u64)); 165 BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) != 166 offsetof(struct compat_vcpu_runstate_info, time) - sizeof(u64)); 167 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) != 168 sizeof(((struct compat_vcpu_runstate_info *)0)->time)); 169 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) != 170 sizeof(vx->runstate_times)); 171 172 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, 173 &vx->runstate_times[0], 174 offset + sizeof(u64), 175 sizeof(vx->runstate_times))) 176 return; 177 178 smp_wmb(); 179 180 /* 181 * Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's 182 * runstate_entry_time field. 183 */ 184 185 state_entry_time &= ~XEN_RUNSTATE_UPDATE; 186 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache, 187 &state_entry_time, offset, 188 sizeof(state_entry_time))) 189 return; 190 } 191 192 int __kvm_xen_has_interrupt(struct kvm_vcpu *v) 193 { 194 u8 rc = 0; 195 196 /* 197 * If the global upcall vector (HVMIRQ_callback_vector) is set and 198 * the vCPU's evtchn_upcall_pending flag is set, the IRQ is pending. 199 */ 200 struct gfn_to_hva_cache *ghc = &v->arch.xen.vcpu_info_cache; 201 struct kvm_memslots *slots = kvm_memslots(v->kvm); 202 unsigned int offset = offsetof(struct vcpu_info, evtchn_upcall_pending); 203 204 /* No need for compat handling here */ 205 BUILD_BUG_ON(offsetof(struct vcpu_info, evtchn_upcall_pending) != 206 offsetof(struct compat_vcpu_info, evtchn_upcall_pending)); 207 BUILD_BUG_ON(sizeof(rc) != 208 sizeof(((struct vcpu_info *)0)->evtchn_upcall_pending)); 209 BUILD_BUG_ON(sizeof(rc) != 210 sizeof(((struct compat_vcpu_info *)0)->evtchn_upcall_pending)); 211 212 /* 213 * For efficiency, this mirrors the checks for using the valid 214 * cache in kvm_read_guest_offset_cached(), but just uses 215 * __get_user() instead. And falls back to the slow path. 216 */ 217 if (likely(slots->generation == ghc->generation && 218 !kvm_is_error_hva(ghc->hva) && ghc->memslot)) { 219 /* Fast path */ 220 __get_user(rc, (u8 __user *)ghc->hva + offset); 221 } else { 222 /* Slow path */ 223 kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset, 224 sizeof(rc)); 225 } 226 227 return rc; 228 } 229 230 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) 231 { 232 int r = -ENOENT; 233 234 mutex_lock(&kvm->lock); 235 236 switch (data->type) { 237 case KVM_XEN_ATTR_TYPE_LONG_MODE: 238 if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) { 239 r = -EINVAL; 240 } else { 241 kvm->arch.xen.long_mode = !!data->u.long_mode; 242 r = 0; 243 } 244 break; 245 246 case KVM_XEN_ATTR_TYPE_SHARED_INFO: 247 if (data->u.shared_info.gfn == GPA_INVALID) { 248 kvm->arch.xen.shinfo_set = false; 249 r = 0; 250 break; 251 } 252 r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn); 253 break; 254 255 256 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: 257 if (data->u.vector && data->u.vector < 0x10) 258 r = -EINVAL; 259 else { 260 kvm->arch.xen.upcall_vector = data->u.vector; 261 r = 0; 262 } 263 break; 264 265 default: 266 break; 267 } 268 269 mutex_unlock(&kvm->lock); 270 return r; 271 } 272 273 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) 274 { 275 int r = -ENOENT; 276 277 mutex_lock(&kvm->lock); 278 279 switch (data->type) { 280 case KVM_XEN_ATTR_TYPE_LONG_MODE: 281 data->u.long_mode = kvm->arch.xen.long_mode; 282 r = 0; 283 break; 284 285 case KVM_XEN_ATTR_TYPE_SHARED_INFO: 286 if (kvm->arch.xen.shinfo_set) 287 data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa); 288 else 289 data->u.shared_info.gfn = GPA_INVALID; 290 r = 0; 291 break; 292 293 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: 294 data->u.vector = kvm->arch.xen.upcall_vector; 295 r = 0; 296 break; 297 298 default: 299 break; 300 } 301 302 mutex_unlock(&kvm->lock); 303 return r; 304 } 305 306 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) 307 { 308 int idx, r = -ENOENT; 309 310 mutex_lock(&vcpu->kvm->lock); 311 idx = srcu_read_lock(&vcpu->kvm->srcu); 312 313 switch (data->type) { 314 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO: 315 /* No compat necessary here. */ 316 BUILD_BUG_ON(sizeof(struct vcpu_info) != 317 sizeof(struct compat_vcpu_info)); 318 BUILD_BUG_ON(offsetof(struct vcpu_info, time) != 319 offsetof(struct compat_vcpu_info, time)); 320 321 if (data->u.gpa == GPA_INVALID) { 322 vcpu->arch.xen.vcpu_info_set = false; 323 r = 0; 324 break; 325 } 326 327 r = kvm_gfn_to_hva_cache_init(vcpu->kvm, 328 &vcpu->arch.xen.vcpu_info_cache, 329 data->u.gpa, 330 sizeof(struct vcpu_info)); 331 if (!r) { 332 vcpu->arch.xen.vcpu_info_set = true; 333 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); 334 } 335 break; 336 337 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO: 338 if (data->u.gpa == GPA_INVALID) { 339 vcpu->arch.xen.vcpu_time_info_set = false; 340 r = 0; 341 break; 342 } 343 344 r = kvm_gfn_to_hva_cache_init(vcpu->kvm, 345 &vcpu->arch.xen.vcpu_time_info_cache, 346 data->u.gpa, 347 sizeof(struct pvclock_vcpu_time_info)); 348 if (!r) { 349 vcpu->arch.xen.vcpu_time_info_set = true; 350 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); 351 } 352 break; 353 354 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR: 355 if (!sched_info_on()) { 356 r = -EOPNOTSUPP; 357 break; 358 } 359 if (data->u.gpa == GPA_INVALID) { 360 vcpu->arch.xen.runstate_set = false; 361 r = 0; 362 break; 363 } 364 365 r = kvm_gfn_to_hva_cache_init(vcpu->kvm, 366 &vcpu->arch.xen.runstate_cache, 367 data->u.gpa, 368 sizeof(struct vcpu_runstate_info)); 369 if (!r) { 370 vcpu->arch.xen.runstate_set = true; 371 } 372 break; 373 374 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT: 375 if (!sched_info_on()) { 376 r = -EOPNOTSUPP; 377 break; 378 } 379 if (data->u.runstate.state > RUNSTATE_offline) { 380 r = -EINVAL; 381 break; 382 } 383 384 kvm_xen_update_runstate(vcpu, data->u.runstate.state); 385 r = 0; 386 break; 387 388 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA: 389 if (!sched_info_on()) { 390 r = -EOPNOTSUPP; 391 break; 392 } 393 if (data->u.runstate.state > RUNSTATE_offline) { 394 r = -EINVAL; 395 break; 396 } 397 if (data->u.runstate.state_entry_time != 398 (data->u.runstate.time_running + 399 data->u.runstate.time_runnable + 400 data->u.runstate.time_blocked + 401 data->u.runstate.time_offline)) { 402 r = -EINVAL; 403 break; 404 } 405 if (get_kvmclock_ns(vcpu->kvm) < 406 data->u.runstate.state_entry_time) { 407 r = -EINVAL; 408 break; 409 } 410 411 vcpu->arch.xen.current_runstate = data->u.runstate.state; 412 vcpu->arch.xen.runstate_entry_time = 413 data->u.runstate.state_entry_time; 414 vcpu->arch.xen.runstate_times[RUNSTATE_running] = 415 data->u.runstate.time_running; 416 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] = 417 data->u.runstate.time_runnable; 418 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] = 419 data->u.runstate.time_blocked; 420 vcpu->arch.xen.runstate_times[RUNSTATE_offline] = 421 data->u.runstate.time_offline; 422 vcpu->arch.xen.last_steal = current->sched_info.run_delay; 423 r = 0; 424 break; 425 426 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST: 427 if (!sched_info_on()) { 428 r = -EOPNOTSUPP; 429 break; 430 } 431 if (data->u.runstate.state > RUNSTATE_offline && 432 data->u.runstate.state != (u64)-1) { 433 r = -EINVAL; 434 break; 435 } 436 /* The adjustment must add up */ 437 if (data->u.runstate.state_entry_time != 438 (data->u.runstate.time_running + 439 data->u.runstate.time_runnable + 440 data->u.runstate.time_blocked + 441 data->u.runstate.time_offline)) { 442 r = -EINVAL; 443 break; 444 } 445 446 if (get_kvmclock_ns(vcpu->kvm) < 447 (vcpu->arch.xen.runstate_entry_time + 448 data->u.runstate.state_entry_time)) { 449 r = -EINVAL; 450 break; 451 } 452 453 vcpu->arch.xen.runstate_entry_time += 454 data->u.runstate.state_entry_time; 455 vcpu->arch.xen.runstate_times[RUNSTATE_running] += 456 data->u.runstate.time_running; 457 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] += 458 data->u.runstate.time_runnable; 459 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] += 460 data->u.runstate.time_blocked; 461 vcpu->arch.xen.runstate_times[RUNSTATE_offline] += 462 data->u.runstate.time_offline; 463 464 if (data->u.runstate.state <= RUNSTATE_offline) 465 kvm_xen_update_runstate(vcpu, data->u.runstate.state); 466 r = 0; 467 break; 468 469 default: 470 break; 471 } 472 473 srcu_read_unlock(&vcpu->kvm->srcu, idx); 474 mutex_unlock(&vcpu->kvm->lock); 475 return r; 476 } 477 478 int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) 479 { 480 int r = -ENOENT; 481 482 mutex_lock(&vcpu->kvm->lock); 483 484 switch (data->type) { 485 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO: 486 if (vcpu->arch.xen.vcpu_info_set) 487 data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa; 488 else 489 data->u.gpa = GPA_INVALID; 490 r = 0; 491 break; 492 493 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO: 494 if (vcpu->arch.xen.vcpu_time_info_set) 495 data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa; 496 else 497 data->u.gpa = GPA_INVALID; 498 r = 0; 499 break; 500 501 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR: 502 if (!sched_info_on()) { 503 r = -EOPNOTSUPP; 504 break; 505 } 506 if (vcpu->arch.xen.runstate_set) { 507 data->u.gpa = vcpu->arch.xen.runstate_cache.gpa; 508 r = 0; 509 } 510 break; 511 512 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT: 513 if (!sched_info_on()) { 514 r = -EOPNOTSUPP; 515 break; 516 } 517 data->u.runstate.state = vcpu->arch.xen.current_runstate; 518 r = 0; 519 break; 520 521 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA: 522 if (!sched_info_on()) { 523 r = -EOPNOTSUPP; 524 break; 525 } 526 data->u.runstate.state = vcpu->arch.xen.current_runstate; 527 data->u.runstate.state_entry_time = 528 vcpu->arch.xen.runstate_entry_time; 529 data->u.runstate.time_running = 530 vcpu->arch.xen.runstate_times[RUNSTATE_running]; 531 data->u.runstate.time_runnable = 532 vcpu->arch.xen.runstate_times[RUNSTATE_runnable]; 533 data->u.runstate.time_blocked = 534 vcpu->arch.xen.runstate_times[RUNSTATE_blocked]; 535 data->u.runstate.time_offline = 536 vcpu->arch.xen.runstate_times[RUNSTATE_offline]; 537 r = 0; 538 break; 539 540 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST: 541 r = -EINVAL; 542 break; 543 544 default: 545 break; 546 } 547 548 mutex_unlock(&vcpu->kvm->lock); 549 return r; 550 } 551 552 int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data) 553 { 554 struct kvm *kvm = vcpu->kvm; 555 u32 page_num = data & ~PAGE_MASK; 556 u64 page_addr = data & PAGE_MASK; 557 bool lm = is_long_mode(vcpu); 558 559 /* Latch long_mode for shared_info pages etc. */ 560 vcpu->kvm->arch.xen.long_mode = lm; 561 562 /* 563 * If Xen hypercall intercept is enabled, fill the hypercall 564 * page with VMCALL/VMMCALL instructions since that's what 565 * we catch. Else the VMM has provided the hypercall pages 566 * with instructions of its own choosing, so use those. 567 */ 568 if (kvm_xen_hypercall_enabled(kvm)) { 569 u8 instructions[32]; 570 int i; 571 572 if (page_num) 573 return 1; 574 575 /* mov imm32, %eax */ 576 instructions[0] = 0xb8; 577 578 /* vmcall / vmmcall */ 579 kvm_x86_ops.patch_hypercall(vcpu, instructions + 5); 580 581 /* ret */ 582 instructions[8] = 0xc3; 583 584 /* int3 to pad */ 585 memset(instructions + 9, 0xcc, sizeof(instructions) - 9); 586 587 for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) { 588 *(u32 *)&instructions[1] = i; 589 if (kvm_vcpu_write_guest(vcpu, 590 page_addr + (i * sizeof(instructions)), 591 instructions, sizeof(instructions))) 592 return 1; 593 } 594 } else { 595 /* 596 * Note, truncation is a non-issue as 'lm' is guaranteed to be 597 * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes. 598 */ 599 hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64 600 : kvm->arch.xen_hvm_config.blob_addr_32; 601 u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64 602 : kvm->arch.xen_hvm_config.blob_size_32; 603 u8 *page; 604 605 if (page_num >= blob_size) 606 return 1; 607 608 blob_addr += page_num * PAGE_SIZE; 609 610 page = memdup_user((u8 __user *)blob_addr, PAGE_SIZE); 611 if (IS_ERR(page)) 612 return PTR_ERR(page); 613 614 if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) { 615 kfree(page); 616 return 1; 617 } 618 } 619 return 0; 620 } 621 622 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc) 623 { 624 if (xhc->flags & ~KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) 625 return -EINVAL; 626 627 /* 628 * With hypercall interception the kernel generates its own 629 * hypercall page so it must not be provided. 630 */ 631 if ((xhc->flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) && 632 (xhc->blob_addr_32 || xhc->blob_addr_64 || 633 xhc->blob_size_32 || xhc->blob_size_64)) 634 return -EINVAL; 635 636 mutex_lock(&kvm->lock); 637 638 if (xhc->msr && !kvm->arch.xen_hvm_config.msr) 639 static_branch_inc(&kvm_xen_enabled.key); 640 else if (!xhc->msr && kvm->arch.xen_hvm_config.msr) 641 static_branch_slow_dec_deferred(&kvm_xen_enabled); 642 643 memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc)); 644 645 mutex_unlock(&kvm->lock); 646 return 0; 647 } 648 649 void kvm_xen_destroy_vm(struct kvm *kvm) 650 { 651 if (kvm->arch.xen_hvm_config.msr) 652 static_branch_slow_dec_deferred(&kvm_xen_enabled); 653 } 654 655 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result) 656 { 657 kvm_rax_write(vcpu, result); 658 return kvm_skip_emulated_instruction(vcpu); 659 } 660 661 static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu) 662 { 663 struct kvm_run *run = vcpu->run; 664 665 if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip))) 666 return 1; 667 668 return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result); 669 } 670 671 int kvm_xen_hypercall(struct kvm_vcpu *vcpu) 672 { 673 bool longmode; 674 u64 input, params[6]; 675 676 input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX); 677 678 /* Hyper-V hypercalls get bit 31 set in EAX */ 679 if ((input & 0x80000000) && 680 kvm_hv_hypercall_enabled(vcpu)) 681 return kvm_hv_hypercall(vcpu); 682 683 longmode = is_64_bit_mode(vcpu); 684 if (!longmode) { 685 params[0] = (u32)kvm_rbx_read(vcpu); 686 params[1] = (u32)kvm_rcx_read(vcpu); 687 params[2] = (u32)kvm_rdx_read(vcpu); 688 params[3] = (u32)kvm_rsi_read(vcpu); 689 params[4] = (u32)kvm_rdi_read(vcpu); 690 params[5] = (u32)kvm_rbp_read(vcpu); 691 } 692 #ifdef CONFIG_X86_64 693 else { 694 params[0] = (u64)kvm_rdi_read(vcpu); 695 params[1] = (u64)kvm_rsi_read(vcpu); 696 params[2] = (u64)kvm_rdx_read(vcpu); 697 params[3] = (u64)kvm_r10_read(vcpu); 698 params[4] = (u64)kvm_r8_read(vcpu); 699 params[5] = (u64)kvm_r9_read(vcpu); 700 } 701 #endif 702 trace_kvm_xen_hypercall(input, params[0], params[1], params[2], 703 params[3], params[4], params[5]); 704 705 vcpu->run->exit_reason = KVM_EXIT_XEN; 706 vcpu->run->xen.type = KVM_EXIT_XEN_HCALL; 707 vcpu->run->xen.u.hcall.longmode = longmode; 708 vcpu->run->xen.u.hcall.cpl = kvm_x86_ops.get_cpl(vcpu); 709 vcpu->run->xen.u.hcall.input = input; 710 vcpu->run->xen.u.hcall.params[0] = params[0]; 711 vcpu->run->xen.u.hcall.params[1] = params[1]; 712 vcpu->run->xen.u.hcall.params[2] = params[2]; 713 vcpu->run->xen.u.hcall.params[3] = params[3]; 714 vcpu->run->xen.u.hcall.params[4] = params[4]; 715 vcpu->run->xen.u.hcall.params[5] = params[5]; 716 vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu); 717 vcpu->arch.complete_userspace_io = 718 kvm_xen_hypercall_complete_userspace; 719 720 return 0; 721 } 722