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 #include "lapic.h" 13 14 #include <linux/eventfd.h> 15 #include <linux/kvm_host.h> 16 #include <linux/sched/stat.h> 17 18 #include <trace/events/kvm.h> 19 #include <xen/interface/xen.h> 20 #include <xen/interface/vcpu.h> 21 #include <xen/interface/version.h> 22 #include <xen/interface/event_channel.h> 23 #include <xen/interface/sched.h> 24 25 #include "trace.h" 26 27 static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm); 28 static int kvm_xen_setattr_evtchn(struct kvm *kvm, struct kvm_xen_hvm_attr *data); 29 static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r); 30 31 DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ); 32 33 static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn) 34 { 35 struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; 36 struct pvclock_wall_clock *wc; 37 gpa_t gpa = gfn_to_gpa(gfn); 38 u32 *wc_sec_hi; 39 u32 wc_version; 40 u64 wall_nsec; 41 int ret = 0; 42 int idx = srcu_read_lock(&kvm->srcu); 43 44 if (gfn == GPA_INVALID) { 45 kvm_gfn_to_pfn_cache_destroy(kvm, gpc); 46 goto out; 47 } 48 49 do { 50 ret = kvm_gfn_to_pfn_cache_init(kvm, gpc, NULL, KVM_HOST_USES_PFN, 51 gpa, PAGE_SIZE); 52 if (ret) 53 goto out; 54 55 /* 56 * This code mirrors kvm_write_wall_clock() except that it writes 57 * directly through the pfn cache and doesn't mark the page dirty. 58 */ 59 wall_nsec = ktime_get_real_ns() - get_kvmclock_ns(kvm); 60 61 /* It could be invalid again already, so we need to check */ 62 read_lock_irq(&gpc->lock); 63 64 if (gpc->valid) 65 break; 66 67 read_unlock_irq(&gpc->lock); 68 } while (1); 69 70 /* Paranoia checks on the 32-bit struct layout */ 71 BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900); 72 BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924); 73 BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0); 74 75 #ifdef CONFIG_X86_64 76 /* Paranoia checks on the 64-bit struct layout */ 77 BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00); 78 BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c); 79 80 if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { 81 struct shared_info *shinfo = gpc->khva; 82 83 wc_sec_hi = &shinfo->wc_sec_hi; 84 wc = &shinfo->wc; 85 } else 86 #endif 87 { 88 struct compat_shared_info *shinfo = gpc->khva; 89 90 wc_sec_hi = &shinfo->arch.wc_sec_hi; 91 wc = &shinfo->wc; 92 } 93 94 /* Increment and ensure an odd value */ 95 wc_version = wc->version = (wc->version + 1) | 1; 96 smp_wmb(); 97 98 wc->nsec = do_div(wall_nsec, 1000000000); 99 wc->sec = (u32)wall_nsec; 100 *wc_sec_hi = wall_nsec >> 32; 101 smp_wmb(); 102 103 wc->version = wc_version + 1; 104 read_unlock_irq(&gpc->lock); 105 106 kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE); 107 108 out: 109 srcu_read_unlock(&kvm->srcu, idx); 110 return ret; 111 } 112 113 void kvm_xen_inject_timer_irqs(struct kvm_vcpu *vcpu) 114 { 115 if (atomic_read(&vcpu->arch.xen.timer_pending) > 0) { 116 struct kvm_xen_evtchn e; 117 118 e.vcpu_id = vcpu->vcpu_id; 119 e.vcpu_idx = vcpu->vcpu_idx; 120 e.port = vcpu->arch.xen.timer_virq; 121 e.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL; 122 123 kvm_xen_set_evtchn(&e, vcpu->kvm); 124 125 vcpu->arch.xen.timer_expires = 0; 126 atomic_set(&vcpu->arch.xen.timer_pending, 0); 127 } 128 } 129 130 static enum hrtimer_restart xen_timer_callback(struct hrtimer *timer) 131 { 132 struct kvm_vcpu *vcpu = container_of(timer, struct kvm_vcpu, 133 arch.xen.timer); 134 if (atomic_read(&vcpu->arch.xen.timer_pending)) 135 return HRTIMER_NORESTART; 136 137 atomic_inc(&vcpu->arch.xen.timer_pending); 138 kvm_make_request(KVM_REQ_UNBLOCK, vcpu); 139 kvm_vcpu_kick(vcpu); 140 141 return HRTIMER_NORESTART; 142 } 143 144 static void kvm_xen_start_timer(struct kvm_vcpu *vcpu, u64 guest_abs, s64 delta_ns) 145 { 146 atomic_set(&vcpu->arch.xen.timer_pending, 0); 147 vcpu->arch.xen.timer_expires = guest_abs; 148 149 if (delta_ns <= 0) { 150 xen_timer_callback(&vcpu->arch.xen.timer); 151 } else { 152 ktime_t ktime_now = ktime_get(); 153 hrtimer_start(&vcpu->arch.xen.timer, 154 ktime_add_ns(ktime_now, delta_ns), 155 HRTIMER_MODE_ABS_HARD); 156 } 157 } 158 159 static void kvm_xen_stop_timer(struct kvm_vcpu *vcpu) 160 { 161 hrtimer_cancel(&vcpu->arch.xen.timer); 162 vcpu->arch.xen.timer_expires = 0; 163 atomic_set(&vcpu->arch.xen.timer_pending, 0); 164 } 165 166 static void kvm_xen_init_timer(struct kvm_vcpu *vcpu) 167 { 168 hrtimer_init(&vcpu->arch.xen.timer, CLOCK_MONOTONIC, 169 HRTIMER_MODE_ABS_HARD); 170 vcpu->arch.xen.timer.function = xen_timer_callback; 171 } 172 173 static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state) 174 { 175 struct kvm_vcpu_xen *vx = &v->arch.xen; 176 u64 now = get_kvmclock_ns(v->kvm); 177 u64 delta_ns = now - vx->runstate_entry_time; 178 u64 run_delay = current->sched_info.run_delay; 179 180 if (unlikely(!vx->runstate_entry_time)) 181 vx->current_runstate = RUNSTATE_offline; 182 183 /* 184 * Time waiting for the scheduler isn't "stolen" if the 185 * vCPU wasn't running anyway. 186 */ 187 if (vx->current_runstate == RUNSTATE_running) { 188 u64 steal_ns = run_delay - vx->last_steal; 189 190 delta_ns -= steal_ns; 191 192 vx->runstate_times[RUNSTATE_runnable] += steal_ns; 193 } 194 vx->last_steal = run_delay; 195 196 vx->runstate_times[vx->current_runstate] += delta_ns; 197 vx->current_runstate = state; 198 vx->runstate_entry_time = now; 199 } 200 201 void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state) 202 { 203 struct kvm_vcpu_xen *vx = &v->arch.xen; 204 struct gfn_to_pfn_cache *gpc = &vx->runstate_cache; 205 uint64_t *user_times; 206 unsigned long flags; 207 size_t user_len; 208 int *user_state; 209 210 kvm_xen_update_runstate(v, state); 211 212 if (!vx->runstate_cache.active) 213 return; 214 215 if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode) 216 user_len = sizeof(struct vcpu_runstate_info); 217 else 218 user_len = sizeof(struct compat_vcpu_runstate_info); 219 220 read_lock_irqsave(&gpc->lock, flags); 221 while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa, 222 user_len)) { 223 read_unlock_irqrestore(&gpc->lock, flags); 224 225 /* When invoked from kvm_sched_out() we cannot sleep */ 226 if (state == RUNSTATE_runnable) 227 return; 228 229 if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa, user_len)) 230 return; 231 232 read_lock_irqsave(&gpc->lock, flags); 233 } 234 235 /* 236 * The only difference between 32-bit and 64-bit versions of the 237 * runstate struct us the alignment of uint64_t in 32-bit, which 238 * means that the 64-bit version has an additional 4 bytes of 239 * padding after the first field 'state'. 240 * 241 * So we use 'int __user *user_state' to point to the state field, 242 * and 'uint64_t __user *user_times' for runstate_entry_time. So 243 * the actual array of time[] in each state starts at user_times[1]. 244 */ 245 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 0); 246 BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state) != 0); 247 BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c); 248 #ifdef CONFIG_X86_64 249 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) != 250 offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4); 251 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) != 252 offsetof(struct compat_vcpu_runstate_info, time) + 4); 253 #endif 254 255 user_state = gpc->khva; 256 257 if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode) 258 user_times = gpc->khva + offsetof(struct vcpu_runstate_info, 259 state_entry_time); 260 else 261 user_times = gpc->khva + offsetof(struct compat_vcpu_runstate_info, 262 state_entry_time); 263 264 /* 265 * First write the updated state_entry_time at the appropriate 266 * location determined by 'offset'. 267 */ 268 BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, state_entry_time) != 269 sizeof(user_times[0])); 270 BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state_entry_time) != 271 sizeof(user_times[0])); 272 273 user_times[0] = vx->runstate_entry_time | XEN_RUNSTATE_UPDATE; 274 smp_wmb(); 275 276 /* 277 * Next, write the new runstate. This is in the *same* place 278 * for 32-bit and 64-bit guests, asserted here for paranoia. 279 */ 280 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) != 281 offsetof(struct compat_vcpu_runstate_info, state)); 282 BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, state) != 283 sizeof(vx->current_runstate)); 284 BUILD_BUG_ON(sizeof_field(struct compat_vcpu_runstate_info, state) != 285 sizeof(vx->current_runstate)); 286 287 *user_state = vx->current_runstate; 288 289 /* 290 * Write the actual runstate times immediately after the 291 * runstate_entry_time. 292 */ 293 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) != 294 offsetof(struct vcpu_runstate_info, time) - sizeof(u64)); 295 BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) != 296 offsetof(struct compat_vcpu_runstate_info, time) - sizeof(u64)); 297 BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, time) != 298 sizeof_field(struct compat_vcpu_runstate_info, time)); 299 BUILD_BUG_ON(sizeof_field(struct vcpu_runstate_info, time) != 300 sizeof(vx->runstate_times)); 301 302 memcpy(user_times + 1, vx->runstate_times, sizeof(vx->runstate_times)); 303 smp_wmb(); 304 305 /* 306 * Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's 307 * runstate_entry_time field. 308 */ 309 user_times[0] &= ~XEN_RUNSTATE_UPDATE; 310 smp_wmb(); 311 312 read_unlock_irqrestore(&gpc->lock, flags); 313 314 mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); 315 } 316 317 static void kvm_xen_inject_vcpu_vector(struct kvm_vcpu *v) 318 { 319 struct kvm_lapic_irq irq = { }; 320 int r; 321 322 irq.dest_id = v->vcpu_id; 323 irq.vector = v->arch.xen.upcall_vector; 324 irq.dest_mode = APIC_DEST_PHYSICAL; 325 irq.shorthand = APIC_DEST_NOSHORT; 326 irq.delivery_mode = APIC_DM_FIXED; 327 irq.level = 1; 328 329 /* The fast version will always work for physical unicast */ 330 WARN_ON_ONCE(!kvm_irq_delivery_to_apic_fast(v->kvm, NULL, &irq, &r, NULL)); 331 } 332 333 /* 334 * On event channel delivery, the vcpu_info may not have been accessible. 335 * In that case, there are bits in vcpu->arch.xen.evtchn_pending_sel which 336 * need to be marked into the vcpu_info (and evtchn_upcall_pending set). 337 * Do so now that we can sleep in the context of the vCPU to bring the 338 * page in, and refresh the pfn cache for it. 339 */ 340 void kvm_xen_inject_pending_events(struct kvm_vcpu *v) 341 { 342 unsigned long evtchn_pending_sel = READ_ONCE(v->arch.xen.evtchn_pending_sel); 343 struct gfn_to_pfn_cache *gpc = &v->arch.xen.vcpu_info_cache; 344 unsigned long flags; 345 346 if (!evtchn_pending_sel) 347 return; 348 349 /* 350 * Yes, this is an open-coded loop. But that's just what put_user() 351 * does anyway. Page it in and retry the instruction. We're just a 352 * little more honest about it. 353 */ 354 read_lock_irqsave(&gpc->lock, flags); 355 while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa, 356 sizeof(struct vcpu_info))) { 357 read_unlock_irqrestore(&gpc->lock, flags); 358 359 if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa, 360 sizeof(struct vcpu_info))) 361 return; 362 363 read_lock_irqsave(&gpc->lock, flags); 364 } 365 366 /* Now gpc->khva is a valid kernel address for the vcpu_info */ 367 if (IS_ENABLED(CONFIG_64BIT) && v->kvm->arch.xen.long_mode) { 368 struct vcpu_info *vi = gpc->khva; 369 370 asm volatile(LOCK_PREFIX "orq %0, %1\n" 371 "notq %0\n" 372 LOCK_PREFIX "andq %0, %2\n" 373 : "=r" (evtchn_pending_sel), 374 "+m" (vi->evtchn_pending_sel), 375 "+m" (v->arch.xen.evtchn_pending_sel) 376 : "0" (evtchn_pending_sel)); 377 WRITE_ONCE(vi->evtchn_upcall_pending, 1); 378 } else { 379 u32 evtchn_pending_sel32 = evtchn_pending_sel; 380 struct compat_vcpu_info *vi = gpc->khva; 381 382 asm volatile(LOCK_PREFIX "orl %0, %1\n" 383 "notl %0\n" 384 LOCK_PREFIX "andl %0, %2\n" 385 : "=r" (evtchn_pending_sel32), 386 "+m" (vi->evtchn_pending_sel), 387 "+m" (v->arch.xen.evtchn_pending_sel) 388 : "0" (evtchn_pending_sel32)); 389 WRITE_ONCE(vi->evtchn_upcall_pending, 1); 390 } 391 read_unlock_irqrestore(&gpc->lock, flags); 392 393 /* For the per-vCPU lapic vector, deliver it as MSI. */ 394 if (v->arch.xen.upcall_vector) 395 kvm_xen_inject_vcpu_vector(v); 396 397 mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT); 398 } 399 400 int __kvm_xen_has_interrupt(struct kvm_vcpu *v) 401 { 402 struct gfn_to_pfn_cache *gpc = &v->arch.xen.vcpu_info_cache; 403 unsigned long flags; 404 u8 rc = 0; 405 406 /* 407 * If the global upcall vector (HVMIRQ_callback_vector) is set and 408 * the vCPU's evtchn_upcall_pending flag is set, the IRQ is pending. 409 */ 410 411 /* No need for compat handling here */ 412 BUILD_BUG_ON(offsetof(struct vcpu_info, evtchn_upcall_pending) != 413 offsetof(struct compat_vcpu_info, evtchn_upcall_pending)); 414 BUILD_BUG_ON(sizeof(rc) != 415 sizeof_field(struct vcpu_info, evtchn_upcall_pending)); 416 BUILD_BUG_ON(sizeof(rc) != 417 sizeof_field(struct compat_vcpu_info, evtchn_upcall_pending)); 418 419 read_lock_irqsave(&gpc->lock, flags); 420 while (!kvm_gfn_to_pfn_cache_check(v->kvm, gpc, gpc->gpa, 421 sizeof(struct vcpu_info))) { 422 read_unlock_irqrestore(&gpc->lock, flags); 423 424 /* 425 * This function gets called from kvm_vcpu_block() after setting the 426 * task to TASK_INTERRUPTIBLE, to see if it needs to wake immediately 427 * from a HLT. So we really mustn't sleep. If the page ended up absent 428 * at that point, just return 1 in order to trigger an immediate wake, 429 * and we'll end up getting called again from a context where we *can* 430 * fault in the page and wait for it. 431 */ 432 if (in_atomic() || !task_is_running(current)) 433 return 1; 434 435 if (kvm_gfn_to_pfn_cache_refresh(v->kvm, gpc, gpc->gpa, 436 sizeof(struct vcpu_info))) { 437 /* 438 * If this failed, userspace has screwed up the 439 * vcpu_info mapping. No interrupts for you. 440 */ 441 return 0; 442 } 443 read_lock_irqsave(&gpc->lock, flags); 444 } 445 446 rc = ((struct vcpu_info *)gpc->khva)->evtchn_upcall_pending; 447 read_unlock_irqrestore(&gpc->lock, flags); 448 return rc; 449 } 450 451 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) 452 { 453 int r = -ENOENT; 454 455 456 switch (data->type) { 457 case KVM_XEN_ATTR_TYPE_LONG_MODE: 458 if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) { 459 r = -EINVAL; 460 } else { 461 mutex_lock(&kvm->lock); 462 kvm->arch.xen.long_mode = !!data->u.long_mode; 463 mutex_unlock(&kvm->lock); 464 r = 0; 465 } 466 break; 467 468 case KVM_XEN_ATTR_TYPE_SHARED_INFO: 469 mutex_lock(&kvm->lock); 470 r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn); 471 mutex_unlock(&kvm->lock); 472 break; 473 474 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: 475 if (data->u.vector && data->u.vector < 0x10) 476 r = -EINVAL; 477 else { 478 mutex_lock(&kvm->lock); 479 kvm->arch.xen.upcall_vector = data->u.vector; 480 mutex_unlock(&kvm->lock); 481 r = 0; 482 } 483 break; 484 485 case KVM_XEN_ATTR_TYPE_EVTCHN: 486 r = kvm_xen_setattr_evtchn(kvm, data); 487 break; 488 489 case KVM_XEN_ATTR_TYPE_XEN_VERSION: 490 mutex_lock(&kvm->lock); 491 kvm->arch.xen.xen_version = data->u.xen_version; 492 mutex_unlock(&kvm->lock); 493 r = 0; 494 break; 495 496 default: 497 break; 498 } 499 500 return r; 501 } 502 503 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) 504 { 505 int r = -ENOENT; 506 507 mutex_lock(&kvm->lock); 508 509 switch (data->type) { 510 case KVM_XEN_ATTR_TYPE_LONG_MODE: 511 data->u.long_mode = kvm->arch.xen.long_mode; 512 r = 0; 513 break; 514 515 case KVM_XEN_ATTR_TYPE_SHARED_INFO: 516 if (kvm->arch.xen.shinfo_cache.active) 517 data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa); 518 else 519 data->u.shared_info.gfn = GPA_INVALID; 520 r = 0; 521 break; 522 523 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR: 524 data->u.vector = kvm->arch.xen.upcall_vector; 525 r = 0; 526 break; 527 528 case KVM_XEN_ATTR_TYPE_XEN_VERSION: 529 data->u.xen_version = kvm->arch.xen.xen_version; 530 r = 0; 531 break; 532 533 default: 534 break; 535 } 536 537 mutex_unlock(&kvm->lock); 538 return r; 539 } 540 541 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) 542 { 543 int idx, r = -ENOENT; 544 545 mutex_lock(&vcpu->kvm->lock); 546 idx = srcu_read_lock(&vcpu->kvm->srcu); 547 548 switch (data->type) { 549 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO: 550 /* No compat necessary here. */ 551 BUILD_BUG_ON(sizeof(struct vcpu_info) != 552 sizeof(struct compat_vcpu_info)); 553 BUILD_BUG_ON(offsetof(struct vcpu_info, time) != 554 offsetof(struct compat_vcpu_info, time)); 555 556 if (data->u.gpa == GPA_INVALID) { 557 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, &vcpu->arch.xen.vcpu_info_cache); 558 r = 0; 559 break; 560 } 561 562 r = kvm_gfn_to_pfn_cache_init(vcpu->kvm, 563 &vcpu->arch.xen.vcpu_info_cache, 564 NULL, KVM_HOST_USES_PFN, data->u.gpa, 565 sizeof(struct vcpu_info)); 566 if (!r) 567 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); 568 569 break; 570 571 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO: 572 if (data->u.gpa == GPA_INVALID) { 573 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, 574 &vcpu->arch.xen.vcpu_time_info_cache); 575 r = 0; 576 break; 577 } 578 579 r = kvm_gfn_to_pfn_cache_init(vcpu->kvm, 580 &vcpu->arch.xen.vcpu_time_info_cache, 581 NULL, KVM_HOST_USES_PFN, data->u.gpa, 582 sizeof(struct pvclock_vcpu_time_info)); 583 if (!r) 584 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); 585 break; 586 587 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR: 588 if (!sched_info_on()) { 589 r = -EOPNOTSUPP; 590 break; 591 } 592 if (data->u.gpa == GPA_INVALID) { 593 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, 594 &vcpu->arch.xen.runstate_cache); 595 r = 0; 596 break; 597 } 598 599 r = kvm_gfn_to_pfn_cache_init(vcpu->kvm, 600 &vcpu->arch.xen.runstate_cache, 601 NULL, KVM_HOST_USES_PFN, data->u.gpa, 602 sizeof(struct vcpu_runstate_info)); 603 break; 604 605 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT: 606 if (!sched_info_on()) { 607 r = -EOPNOTSUPP; 608 break; 609 } 610 if (data->u.runstate.state > RUNSTATE_offline) { 611 r = -EINVAL; 612 break; 613 } 614 615 kvm_xen_update_runstate(vcpu, data->u.runstate.state); 616 r = 0; 617 break; 618 619 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA: 620 if (!sched_info_on()) { 621 r = -EOPNOTSUPP; 622 break; 623 } 624 if (data->u.runstate.state > RUNSTATE_offline) { 625 r = -EINVAL; 626 break; 627 } 628 if (data->u.runstate.state_entry_time != 629 (data->u.runstate.time_running + 630 data->u.runstate.time_runnable + 631 data->u.runstate.time_blocked + 632 data->u.runstate.time_offline)) { 633 r = -EINVAL; 634 break; 635 } 636 if (get_kvmclock_ns(vcpu->kvm) < 637 data->u.runstate.state_entry_time) { 638 r = -EINVAL; 639 break; 640 } 641 642 vcpu->arch.xen.current_runstate = data->u.runstate.state; 643 vcpu->arch.xen.runstate_entry_time = 644 data->u.runstate.state_entry_time; 645 vcpu->arch.xen.runstate_times[RUNSTATE_running] = 646 data->u.runstate.time_running; 647 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] = 648 data->u.runstate.time_runnable; 649 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] = 650 data->u.runstate.time_blocked; 651 vcpu->arch.xen.runstate_times[RUNSTATE_offline] = 652 data->u.runstate.time_offline; 653 vcpu->arch.xen.last_steal = current->sched_info.run_delay; 654 r = 0; 655 break; 656 657 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST: 658 if (!sched_info_on()) { 659 r = -EOPNOTSUPP; 660 break; 661 } 662 if (data->u.runstate.state > RUNSTATE_offline && 663 data->u.runstate.state != (u64)-1) { 664 r = -EINVAL; 665 break; 666 } 667 /* The adjustment must add up */ 668 if (data->u.runstate.state_entry_time != 669 (data->u.runstate.time_running + 670 data->u.runstate.time_runnable + 671 data->u.runstate.time_blocked + 672 data->u.runstate.time_offline)) { 673 r = -EINVAL; 674 break; 675 } 676 677 if (get_kvmclock_ns(vcpu->kvm) < 678 (vcpu->arch.xen.runstate_entry_time + 679 data->u.runstate.state_entry_time)) { 680 r = -EINVAL; 681 break; 682 } 683 684 vcpu->arch.xen.runstate_entry_time += 685 data->u.runstate.state_entry_time; 686 vcpu->arch.xen.runstate_times[RUNSTATE_running] += 687 data->u.runstate.time_running; 688 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] += 689 data->u.runstate.time_runnable; 690 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] += 691 data->u.runstate.time_blocked; 692 vcpu->arch.xen.runstate_times[RUNSTATE_offline] += 693 data->u.runstate.time_offline; 694 695 if (data->u.runstate.state <= RUNSTATE_offline) 696 kvm_xen_update_runstate(vcpu, data->u.runstate.state); 697 r = 0; 698 break; 699 700 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID: 701 if (data->u.vcpu_id >= KVM_MAX_VCPUS) 702 r = -EINVAL; 703 else { 704 vcpu->arch.xen.vcpu_id = data->u.vcpu_id; 705 r = 0; 706 } 707 break; 708 709 case KVM_XEN_VCPU_ATTR_TYPE_TIMER: 710 if (data->u.timer.port && 711 data->u.timer.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) { 712 r = -EINVAL; 713 break; 714 } 715 716 if (!vcpu->arch.xen.timer.function) 717 kvm_xen_init_timer(vcpu); 718 719 /* Stop the timer (if it's running) before changing the vector */ 720 kvm_xen_stop_timer(vcpu); 721 vcpu->arch.xen.timer_virq = data->u.timer.port; 722 723 /* Start the timer if the new value has a valid vector+expiry. */ 724 if (data->u.timer.port && data->u.timer.expires_ns) 725 kvm_xen_start_timer(vcpu, data->u.timer.expires_ns, 726 data->u.timer.expires_ns - 727 get_kvmclock_ns(vcpu->kvm)); 728 729 r = 0; 730 break; 731 732 case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: 733 if (data->u.vector && data->u.vector < 0x10) 734 r = -EINVAL; 735 else { 736 vcpu->arch.xen.upcall_vector = data->u.vector; 737 r = 0; 738 } 739 break; 740 741 default: 742 break; 743 } 744 745 srcu_read_unlock(&vcpu->kvm->srcu, idx); 746 mutex_unlock(&vcpu->kvm->lock); 747 return r; 748 } 749 750 int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data) 751 { 752 int r = -ENOENT; 753 754 mutex_lock(&vcpu->kvm->lock); 755 756 switch (data->type) { 757 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO: 758 if (vcpu->arch.xen.vcpu_info_cache.active) 759 data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa; 760 else 761 data->u.gpa = GPA_INVALID; 762 r = 0; 763 break; 764 765 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO: 766 if (vcpu->arch.xen.vcpu_time_info_cache.active) 767 data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa; 768 else 769 data->u.gpa = GPA_INVALID; 770 r = 0; 771 break; 772 773 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR: 774 if (!sched_info_on()) { 775 r = -EOPNOTSUPP; 776 break; 777 } 778 if (vcpu->arch.xen.runstate_cache.active) { 779 data->u.gpa = vcpu->arch.xen.runstate_cache.gpa; 780 r = 0; 781 } 782 break; 783 784 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT: 785 if (!sched_info_on()) { 786 r = -EOPNOTSUPP; 787 break; 788 } 789 data->u.runstate.state = vcpu->arch.xen.current_runstate; 790 r = 0; 791 break; 792 793 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA: 794 if (!sched_info_on()) { 795 r = -EOPNOTSUPP; 796 break; 797 } 798 data->u.runstate.state = vcpu->arch.xen.current_runstate; 799 data->u.runstate.state_entry_time = 800 vcpu->arch.xen.runstate_entry_time; 801 data->u.runstate.time_running = 802 vcpu->arch.xen.runstate_times[RUNSTATE_running]; 803 data->u.runstate.time_runnable = 804 vcpu->arch.xen.runstate_times[RUNSTATE_runnable]; 805 data->u.runstate.time_blocked = 806 vcpu->arch.xen.runstate_times[RUNSTATE_blocked]; 807 data->u.runstate.time_offline = 808 vcpu->arch.xen.runstate_times[RUNSTATE_offline]; 809 r = 0; 810 break; 811 812 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST: 813 r = -EINVAL; 814 break; 815 816 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID: 817 data->u.vcpu_id = vcpu->arch.xen.vcpu_id; 818 r = 0; 819 break; 820 821 case KVM_XEN_VCPU_ATTR_TYPE_TIMER: 822 data->u.timer.port = vcpu->arch.xen.timer_virq; 823 data->u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL; 824 data->u.timer.expires_ns = vcpu->arch.xen.timer_expires; 825 r = 0; 826 break; 827 828 case KVM_XEN_VCPU_ATTR_TYPE_UPCALL_VECTOR: 829 data->u.vector = vcpu->arch.xen.upcall_vector; 830 r = 0; 831 break; 832 833 default: 834 break; 835 } 836 837 mutex_unlock(&vcpu->kvm->lock); 838 return r; 839 } 840 841 int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data) 842 { 843 struct kvm *kvm = vcpu->kvm; 844 u32 page_num = data & ~PAGE_MASK; 845 u64 page_addr = data & PAGE_MASK; 846 bool lm = is_long_mode(vcpu); 847 848 /* Latch long_mode for shared_info pages etc. */ 849 vcpu->kvm->arch.xen.long_mode = lm; 850 851 /* 852 * If Xen hypercall intercept is enabled, fill the hypercall 853 * page with VMCALL/VMMCALL instructions since that's what 854 * we catch. Else the VMM has provided the hypercall pages 855 * with instructions of its own choosing, so use those. 856 */ 857 if (kvm_xen_hypercall_enabled(kvm)) { 858 u8 instructions[32]; 859 int i; 860 861 if (page_num) 862 return 1; 863 864 /* mov imm32, %eax */ 865 instructions[0] = 0xb8; 866 867 /* vmcall / vmmcall */ 868 static_call(kvm_x86_patch_hypercall)(vcpu, instructions + 5); 869 870 /* ret */ 871 instructions[8] = 0xc3; 872 873 /* int3 to pad */ 874 memset(instructions + 9, 0xcc, sizeof(instructions) - 9); 875 876 for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) { 877 *(u32 *)&instructions[1] = i; 878 if (kvm_vcpu_write_guest(vcpu, 879 page_addr + (i * sizeof(instructions)), 880 instructions, sizeof(instructions))) 881 return 1; 882 } 883 } else { 884 /* 885 * Note, truncation is a non-issue as 'lm' is guaranteed to be 886 * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes. 887 */ 888 hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64 889 : kvm->arch.xen_hvm_config.blob_addr_32; 890 u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64 891 : kvm->arch.xen_hvm_config.blob_size_32; 892 u8 *page; 893 894 if (page_num >= blob_size) 895 return 1; 896 897 blob_addr += page_num * PAGE_SIZE; 898 899 page = memdup_user((u8 __user *)blob_addr, PAGE_SIZE); 900 if (IS_ERR(page)) 901 return PTR_ERR(page); 902 903 if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) { 904 kfree(page); 905 return 1; 906 } 907 } 908 return 0; 909 } 910 911 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc) 912 { 913 /* Only some feature flags need to be *enabled* by userspace */ 914 u32 permitted_flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL | 915 KVM_XEN_HVM_CONFIG_EVTCHN_SEND; 916 917 if (xhc->flags & ~permitted_flags) 918 return -EINVAL; 919 920 /* 921 * With hypercall interception the kernel generates its own 922 * hypercall page so it must not be provided. 923 */ 924 if ((xhc->flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) && 925 (xhc->blob_addr_32 || xhc->blob_addr_64 || 926 xhc->blob_size_32 || xhc->blob_size_64)) 927 return -EINVAL; 928 929 mutex_lock(&kvm->lock); 930 931 if (xhc->msr && !kvm->arch.xen_hvm_config.msr) 932 static_branch_inc(&kvm_xen_enabled.key); 933 else if (!xhc->msr && kvm->arch.xen_hvm_config.msr) 934 static_branch_slow_dec_deferred(&kvm_xen_enabled); 935 936 memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc)); 937 938 mutex_unlock(&kvm->lock); 939 return 0; 940 } 941 942 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result) 943 { 944 kvm_rax_write(vcpu, result); 945 return kvm_skip_emulated_instruction(vcpu); 946 } 947 948 static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu) 949 { 950 struct kvm_run *run = vcpu->run; 951 952 if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip))) 953 return 1; 954 955 return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result); 956 } 957 958 static bool wait_pending_event(struct kvm_vcpu *vcpu, int nr_ports, 959 evtchn_port_t *ports) 960 { 961 struct kvm *kvm = vcpu->kvm; 962 struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; 963 unsigned long *pending_bits; 964 unsigned long flags; 965 bool ret = true; 966 int idx, i; 967 968 read_lock_irqsave(&gpc->lock, flags); 969 idx = srcu_read_lock(&kvm->srcu); 970 if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, PAGE_SIZE)) 971 goto out_rcu; 972 973 ret = false; 974 if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { 975 struct shared_info *shinfo = gpc->khva; 976 pending_bits = (unsigned long *)&shinfo->evtchn_pending; 977 } else { 978 struct compat_shared_info *shinfo = gpc->khva; 979 pending_bits = (unsigned long *)&shinfo->evtchn_pending; 980 } 981 982 for (i = 0; i < nr_ports; i++) { 983 if (test_bit(ports[i], pending_bits)) { 984 ret = true; 985 break; 986 } 987 } 988 989 out_rcu: 990 srcu_read_unlock(&kvm->srcu, idx); 991 read_unlock_irqrestore(&gpc->lock, flags); 992 993 return ret; 994 } 995 996 static bool kvm_xen_schedop_poll(struct kvm_vcpu *vcpu, bool longmode, 997 u64 param, u64 *r) 998 { 999 int idx, i; 1000 struct sched_poll sched_poll; 1001 evtchn_port_t port, *ports; 1002 gpa_t gpa; 1003 1004 if (!longmode || !lapic_in_kernel(vcpu) || 1005 !(vcpu->kvm->arch.xen_hvm_config.flags & KVM_XEN_HVM_CONFIG_EVTCHN_SEND)) 1006 return false; 1007 1008 idx = srcu_read_lock(&vcpu->kvm->srcu); 1009 gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL); 1010 srcu_read_unlock(&vcpu->kvm->srcu, idx); 1011 1012 if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, &sched_poll, 1013 sizeof(sched_poll))) { 1014 *r = -EFAULT; 1015 return true; 1016 } 1017 1018 if (unlikely(sched_poll.nr_ports > 1)) { 1019 /* Xen (unofficially) limits number of pollers to 128 */ 1020 if (sched_poll.nr_ports > 128) { 1021 *r = -EINVAL; 1022 return true; 1023 } 1024 1025 ports = kmalloc_array(sched_poll.nr_ports, 1026 sizeof(*ports), GFP_KERNEL); 1027 if (!ports) { 1028 *r = -ENOMEM; 1029 return true; 1030 } 1031 } else 1032 ports = &port; 1033 1034 for (i = 0; i < sched_poll.nr_ports; i++) { 1035 idx = srcu_read_lock(&vcpu->kvm->srcu); 1036 gpa = kvm_mmu_gva_to_gpa_system(vcpu, 1037 (gva_t)(sched_poll.ports + i), 1038 NULL); 1039 srcu_read_unlock(&vcpu->kvm->srcu, idx); 1040 1041 if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, 1042 &ports[i], sizeof(port))) { 1043 *r = -EFAULT; 1044 goto out; 1045 } 1046 } 1047 1048 if (sched_poll.nr_ports == 1) 1049 vcpu->arch.xen.poll_evtchn = port; 1050 else 1051 vcpu->arch.xen.poll_evtchn = -1; 1052 1053 set_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask); 1054 1055 if (!wait_pending_event(vcpu, sched_poll.nr_ports, ports)) { 1056 vcpu->arch.mp_state = KVM_MP_STATE_HALTED; 1057 1058 if (sched_poll.timeout) 1059 mod_timer(&vcpu->arch.xen.poll_timer, 1060 jiffies + nsecs_to_jiffies(sched_poll.timeout)); 1061 1062 kvm_vcpu_halt(vcpu); 1063 1064 if (sched_poll.timeout) 1065 del_timer(&vcpu->arch.xen.poll_timer); 1066 1067 vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; 1068 kvm_clear_request(KVM_REQ_UNHALT, vcpu); 1069 } 1070 1071 vcpu->arch.xen.poll_evtchn = 0; 1072 *r = 0; 1073 out: 1074 /* Really, this is only needed in case of timeout */ 1075 clear_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask); 1076 1077 if (unlikely(sched_poll.nr_ports > 1)) 1078 kfree(ports); 1079 return true; 1080 } 1081 1082 static void cancel_evtchn_poll(struct timer_list *t) 1083 { 1084 struct kvm_vcpu *vcpu = from_timer(vcpu, t, arch.xen.poll_timer); 1085 1086 kvm_make_request(KVM_REQ_UNBLOCK, vcpu); 1087 kvm_vcpu_kick(vcpu); 1088 } 1089 1090 static bool kvm_xen_hcall_sched_op(struct kvm_vcpu *vcpu, bool longmode, 1091 int cmd, u64 param, u64 *r) 1092 { 1093 switch (cmd) { 1094 case SCHEDOP_poll: 1095 if (kvm_xen_schedop_poll(vcpu, longmode, param, r)) 1096 return true; 1097 fallthrough; 1098 case SCHEDOP_yield: 1099 kvm_vcpu_on_spin(vcpu, true); 1100 *r = 0; 1101 return true; 1102 default: 1103 break; 1104 } 1105 1106 return false; 1107 } 1108 1109 struct compat_vcpu_set_singleshot_timer { 1110 uint64_t timeout_abs_ns; 1111 uint32_t flags; 1112 } __attribute__((packed)); 1113 1114 static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd, 1115 int vcpu_id, u64 param, u64 *r) 1116 { 1117 struct vcpu_set_singleshot_timer oneshot; 1118 s64 delta; 1119 gpa_t gpa; 1120 int idx; 1121 1122 if (!kvm_xen_timer_enabled(vcpu)) 1123 return false; 1124 1125 switch (cmd) { 1126 case VCPUOP_set_singleshot_timer: 1127 if (vcpu->arch.xen.vcpu_id != vcpu_id) { 1128 *r = -EINVAL; 1129 return true; 1130 } 1131 idx = srcu_read_lock(&vcpu->kvm->srcu); 1132 gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL); 1133 srcu_read_unlock(&vcpu->kvm->srcu, idx); 1134 1135 /* 1136 * The only difference for 32-bit compat is the 4 bytes of 1137 * padding after the interesting part of the structure. So 1138 * for a faithful emulation of Xen we have to *try* to copy 1139 * the padding and return -EFAULT if we can't. Otherwise we 1140 * might as well just have copied the 12-byte 32-bit struct. 1141 */ 1142 BUILD_BUG_ON(offsetof(struct compat_vcpu_set_singleshot_timer, timeout_abs_ns) != 1143 offsetof(struct vcpu_set_singleshot_timer, timeout_abs_ns)); 1144 BUILD_BUG_ON(sizeof_field(struct compat_vcpu_set_singleshot_timer, timeout_abs_ns) != 1145 sizeof_field(struct vcpu_set_singleshot_timer, timeout_abs_ns)); 1146 BUILD_BUG_ON(offsetof(struct compat_vcpu_set_singleshot_timer, flags) != 1147 offsetof(struct vcpu_set_singleshot_timer, flags)); 1148 BUILD_BUG_ON(sizeof_field(struct compat_vcpu_set_singleshot_timer, flags) != 1149 sizeof_field(struct vcpu_set_singleshot_timer, flags)); 1150 1151 if (!gpa || 1152 kvm_vcpu_read_guest(vcpu, gpa, &oneshot, longmode ? sizeof(oneshot) : 1153 sizeof(struct compat_vcpu_set_singleshot_timer))) { 1154 *r = -EFAULT; 1155 return true; 1156 } 1157 1158 delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm); 1159 if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) { 1160 *r = -ETIME; 1161 return true; 1162 } 1163 1164 kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta); 1165 *r = 0; 1166 return true; 1167 1168 case VCPUOP_stop_singleshot_timer: 1169 if (vcpu->arch.xen.vcpu_id != vcpu_id) { 1170 *r = -EINVAL; 1171 return true; 1172 } 1173 kvm_xen_stop_timer(vcpu); 1174 *r = 0; 1175 return true; 1176 } 1177 1178 return false; 1179 } 1180 1181 static bool kvm_xen_hcall_set_timer_op(struct kvm_vcpu *vcpu, uint64_t timeout, 1182 u64 *r) 1183 { 1184 if (!kvm_xen_timer_enabled(vcpu)) 1185 return false; 1186 1187 if (timeout) { 1188 uint64_t guest_now = get_kvmclock_ns(vcpu->kvm); 1189 int64_t delta = timeout - guest_now; 1190 1191 /* Xen has a 'Linux workaround' in do_set_timer_op() which 1192 * checks for negative absolute timeout values (caused by 1193 * integer overflow), and for values about 13 days in the 1194 * future (2^50ns) which would be caused by jiffies 1195 * overflow. For those cases, it sets the timeout 100ms in 1196 * the future (not *too* soon, since if a guest really did 1197 * set a long timeout on purpose we don't want to keep 1198 * churning CPU time by waking it up). 1199 */ 1200 if (unlikely((int64_t)timeout < 0 || 1201 (delta > 0 && (uint32_t) (delta >> 50) != 0))) { 1202 delta = 100 * NSEC_PER_MSEC; 1203 timeout = guest_now + delta; 1204 } 1205 1206 kvm_xen_start_timer(vcpu, timeout, delta); 1207 } else { 1208 kvm_xen_stop_timer(vcpu); 1209 } 1210 1211 *r = 0; 1212 return true; 1213 } 1214 1215 int kvm_xen_hypercall(struct kvm_vcpu *vcpu) 1216 { 1217 bool longmode; 1218 u64 input, params[6], r = -ENOSYS; 1219 bool handled = false; 1220 1221 input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX); 1222 1223 /* Hyper-V hypercalls get bit 31 set in EAX */ 1224 if ((input & 0x80000000) && 1225 kvm_hv_hypercall_enabled(vcpu)) 1226 return kvm_hv_hypercall(vcpu); 1227 1228 longmode = is_64_bit_hypercall(vcpu); 1229 if (!longmode) { 1230 params[0] = (u32)kvm_rbx_read(vcpu); 1231 params[1] = (u32)kvm_rcx_read(vcpu); 1232 params[2] = (u32)kvm_rdx_read(vcpu); 1233 params[3] = (u32)kvm_rsi_read(vcpu); 1234 params[4] = (u32)kvm_rdi_read(vcpu); 1235 params[5] = (u32)kvm_rbp_read(vcpu); 1236 } 1237 #ifdef CONFIG_X86_64 1238 else { 1239 params[0] = (u64)kvm_rdi_read(vcpu); 1240 params[1] = (u64)kvm_rsi_read(vcpu); 1241 params[2] = (u64)kvm_rdx_read(vcpu); 1242 params[3] = (u64)kvm_r10_read(vcpu); 1243 params[4] = (u64)kvm_r8_read(vcpu); 1244 params[5] = (u64)kvm_r9_read(vcpu); 1245 } 1246 #endif 1247 trace_kvm_xen_hypercall(input, params[0], params[1], params[2], 1248 params[3], params[4], params[5]); 1249 1250 switch (input) { 1251 case __HYPERVISOR_xen_version: 1252 if (params[0] == XENVER_version && vcpu->kvm->arch.xen.xen_version) { 1253 r = vcpu->kvm->arch.xen.xen_version; 1254 handled = true; 1255 } 1256 break; 1257 case __HYPERVISOR_event_channel_op: 1258 if (params[0] == EVTCHNOP_send) 1259 handled = kvm_xen_hcall_evtchn_send(vcpu, params[1], &r); 1260 break; 1261 case __HYPERVISOR_sched_op: 1262 handled = kvm_xen_hcall_sched_op(vcpu, longmode, params[0], 1263 params[1], &r); 1264 break; 1265 case __HYPERVISOR_vcpu_op: 1266 handled = kvm_xen_hcall_vcpu_op(vcpu, longmode, params[0], params[1], 1267 params[2], &r); 1268 break; 1269 case __HYPERVISOR_set_timer_op: { 1270 u64 timeout = params[0]; 1271 /* In 32-bit mode, the 64-bit timeout is in two 32-bit params. */ 1272 if (!longmode) 1273 timeout |= params[1] << 32; 1274 handled = kvm_xen_hcall_set_timer_op(vcpu, timeout, &r); 1275 break; 1276 } 1277 default: 1278 break; 1279 } 1280 1281 if (handled) 1282 return kvm_xen_hypercall_set_result(vcpu, r); 1283 1284 vcpu->run->exit_reason = KVM_EXIT_XEN; 1285 vcpu->run->xen.type = KVM_EXIT_XEN_HCALL; 1286 vcpu->run->xen.u.hcall.longmode = longmode; 1287 vcpu->run->xen.u.hcall.cpl = static_call(kvm_x86_get_cpl)(vcpu); 1288 vcpu->run->xen.u.hcall.input = input; 1289 vcpu->run->xen.u.hcall.params[0] = params[0]; 1290 vcpu->run->xen.u.hcall.params[1] = params[1]; 1291 vcpu->run->xen.u.hcall.params[2] = params[2]; 1292 vcpu->run->xen.u.hcall.params[3] = params[3]; 1293 vcpu->run->xen.u.hcall.params[4] = params[4]; 1294 vcpu->run->xen.u.hcall.params[5] = params[5]; 1295 vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu); 1296 vcpu->arch.complete_userspace_io = 1297 kvm_xen_hypercall_complete_userspace; 1298 1299 return 0; 1300 } 1301 1302 static inline int max_evtchn_port(struct kvm *kvm) 1303 { 1304 if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) 1305 return EVTCHN_2L_NR_CHANNELS; 1306 else 1307 return COMPAT_EVTCHN_2L_NR_CHANNELS; 1308 } 1309 1310 static void kvm_xen_check_poller(struct kvm_vcpu *vcpu, int port) 1311 { 1312 int poll_evtchn = vcpu->arch.xen.poll_evtchn; 1313 1314 if ((poll_evtchn == port || poll_evtchn == -1) && 1315 test_and_clear_bit(vcpu->vcpu_idx, vcpu->kvm->arch.xen.poll_mask)) { 1316 kvm_make_request(KVM_REQ_UNBLOCK, vcpu); 1317 kvm_vcpu_kick(vcpu); 1318 } 1319 } 1320 1321 /* 1322 * The return value from this function is propagated to kvm_set_irq() API, 1323 * so it returns: 1324 * < 0 Interrupt was ignored (masked or not delivered for other reasons) 1325 * = 0 Interrupt was coalesced (previous irq is still pending) 1326 * > 0 Number of CPUs interrupt was delivered to 1327 * 1328 * It is also called directly from kvm_arch_set_irq_inatomic(), where the 1329 * only check on its return value is a comparison with -EWOULDBLOCK'. 1330 */ 1331 int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe, struct kvm *kvm) 1332 { 1333 struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; 1334 struct kvm_vcpu *vcpu; 1335 unsigned long *pending_bits, *mask_bits; 1336 unsigned long flags; 1337 int port_word_bit; 1338 bool kick_vcpu = false; 1339 int vcpu_idx, idx, rc; 1340 1341 vcpu_idx = READ_ONCE(xe->vcpu_idx); 1342 if (vcpu_idx >= 0) 1343 vcpu = kvm_get_vcpu(kvm, vcpu_idx); 1344 else { 1345 vcpu = kvm_get_vcpu_by_id(kvm, xe->vcpu_id); 1346 if (!vcpu) 1347 return -EINVAL; 1348 WRITE_ONCE(xe->vcpu_idx, vcpu->vcpu_idx); 1349 } 1350 1351 if (!vcpu->arch.xen.vcpu_info_cache.active) 1352 return -EINVAL; 1353 1354 if (xe->port >= max_evtchn_port(kvm)) 1355 return -EINVAL; 1356 1357 rc = -EWOULDBLOCK; 1358 1359 idx = srcu_read_lock(&kvm->srcu); 1360 1361 read_lock_irqsave(&gpc->lock, flags); 1362 if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, PAGE_SIZE)) 1363 goto out_rcu; 1364 1365 if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { 1366 struct shared_info *shinfo = gpc->khva; 1367 pending_bits = (unsigned long *)&shinfo->evtchn_pending; 1368 mask_bits = (unsigned long *)&shinfo->evtchn_mask; 1369 port_word_bit = xe->port / 64; 1370 } else { 1371 struct compat_shared_info *shinfo = gpc->khva; 1372 pending_bits = (unsigned long *)&shinfo->evtchn_pending; 1373 mask_bits = (unsigned long *)&shinfo->evtchn_mask; 1374 port_word_bit = xe->port / 32; 1375 } 1376 1377 /* 1378 * If this port wasn't already set, and if it isn't masked, then 1379 * we try to set the corresponding bit in the in-kernel shadow of 1380 * evtchn_pending_sel for the target vCPU. And if *that* wasn't 1381 * already set, then we kick the vCPU in question to write to the 1382 * *real* evtchn_pending_sel in its own guest vcpu_info struct. 1383 */ 1384 if (test_and_set_bit(xe->port, pending_bits)) { 1385 rc = 0; /* It was already raised */ 1386 } else if (test_bit(xe->port, mask_bits)) { 1387 rc = -ENOTCONN; /* Masked */ 1388 kvm_xen_check_poller(vcpu, xe->port); 1389 } else { 1390 rc = 1; /* Delivered to the bitmap in shared_info. */ 1391 /* Now switch to the vCPU's vcpu_info to set the index and pending_sel */ 1392 read_unlock_irqrestore(&gpc->lock, flags); 1393 gpc = &vcpu->arch.xen.vcpu_info_cache; 1394 1395 read_lock_irqsave(&gpc->lock, flags); 1396 if (!kvm_gfn_to_pfn_cache_check(kvm, gpc, gpc->gpa, sizeof(struct vcpu_info))) { 1397 /* 1398 * Could not access the vcpu_info. Set the bit in-kernel 1399 * and prod the vCPU to deliver it for itself. 1400 */ 1401 if (!test_and_set_bit(port_word_bit, &vcpu->arch.xen.evtchn_pending_sel)) 1402 kick_vcpu = true; 1403 goto out_rcu; 1404 } 1405 1406 if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode) { 1407 struct vcpu_info *vcpu_info = gpc->khva; 1408 if (!test_and_set_bit(port_word_bit, &vcpu_info->evtchn_pending_sel)) { 1409 WRITE_ONCE(vcpu_info->evtchn_upcall_pending, 1); 1410 kick_vcpu = true; 1411 } 1412 } else { 1413 struct compat_vcpu_info *vcpu_info = gpc->khva; 1414 if (!test_and_set_bit(port_word_bit, 1415 (unsigned long *)&vcpu_info->evtchn_pending_sel)) { 1416 WRITE_ONCE(vcpu_info->evtchn_upcall_pending, 1); 1417 kick_vcpu = true; 1418 } 1419 } 1420 1421 /* For the per-vCPU lapic vector, deliver it as MSI. */ 1422 if (kick_vcpu && vcpu->arch.xen.upcall_vector) { 1423 kvm_xen_inject_vcpu_vector(vcpu); 1424 kick_vcpu = false; 1425 } 1426 } 1427 1428 out_rcu: 1429 read_unlock_irqrestore(&gpc->lock, flags); 1430 srcu_read_unlock(&kvm->srcu, idx); 1431 1432 if (kick_vcpu) { 1433 kvm_make_request(KVM_REQ_UNBLOCK, vcpu); 1434 kvm_vcpu_kick(vcpu); 1435 } 1436 1437 return rc; 1438 } 1439 1440 static int kvm_xen_set_evtchn(struct kvm_xen_evtchn *xe, struct kvm *kvm) 1441 { 1442 bool mm_borrowed = false; 1443 int rc; 1444 1445 rc = kvm_xen_set_evtchn_fast(xe, kvm); 1446 if (rc != -EWOULDBLOCK) 1447 return rc; 1448 1449 if (current->mm != kvm->mm) { 1450 /* 1451 * If not on a thread which already belongs to this KVM, 1452 * we'd better be in the irqfd workqueue. 1453 */ 1454 if (WARN_ON_ONCE(current->mm)) 1455 return -EINVAL; 1456 1457 kthread_use_mm(kvm->mm); 1458 mm_borrowed = true; 1459 } 1460 1461 /* 1462 * For the irqfd workqueue, using the main kvm->lock mutex is 1463 * fine since this function is invoked from kvm_set_irq() with 1464 * no other lock held, no srcu. In future if it will be called 1465 * directly from a vCPU thread (e.g. on hypercall for an IPI) 1466 * then it may need to switch to using a leaf-node mutex for 1467 * serializing the shared_info mapping. 1468 */ 1469 mutex_lock(&kvm->lock); 1470 1471 /* 1472 * It is theoretically possible for the page to be unmapped 1473 * and the MMU notifier to invalidate the shared_info before 1474 * we even get to use it. In that case, this looks like an 1475 * infinite loop. It was tempting to do it via the userspace 1476 * HVA instead... but that just *hides* the fact that it's 1477 * an infinite loop, because if a fault occurs and it waits 1478 * for the page to come back, it can *still* immediately 1479 * fault and have to wait again, repeatedly. 1480 * 1481 * Conversely, the page could also have been reinstated by 1482 * another thread before we even obtain the mutex above, so 1483 * check again *first* before remapping it. 1484 */ 1485 do { 1486 struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache; 1487 int idx; 1488 1489 rc = kvm_xen_set_evtchn_fast(xe, kvm); 1490 if (rc != -EWOULDBLOCK) 1491 break; 1492 1493 idx = srcu_read_lock(&kvm->srcu); 1494 rc = kvm_gfn_to_pfn_cache_refresh(kvm, gpc, gpc->gpa, PAGE_SIZE); 1495 srcu_read_unlock(&kvm->srcu, idx); 1496 } while(!rc); 1497 1498 mutex_unlock(&kvm->lock); 1499 1500 if (mm_borrowed) 1501 kthread_unuse_mm(kvm->mm); 1502 1503 return rc; 1504 } 1505 1506 /* This is the version called from kvm_set_irq() as the .set function */ 1507 static int evtchn_set_fn(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm, 1508 int irq_source_id, int level, bool line_status) 1509 { 1510 if (!level) 1511 return -EINVAL; 1512 1513 return kvm_xen_set_evtchn(&e->xen_evtchn, kvm); 1514 } 1515 1516 /* 1517 * Set up an event channel interrupt from the KVM IRQ routing table. 1518 * Used for e.g. PIRQ from passed through physical devices. 1519 */ 1520 int kvm_xen_setup_evtchn(struct kvm *kvm, 1521 struct kvm_kernel_irq_routing_entry *e, 1522 const struct kvm_irq_routing_entry *ue) 1523 1524 { 1525 struct kvm_vcpu *vcpu; 1526 1527 if (ue->u.xen_evtchn.port >= max_evtchn_port(kvm)) 1528 return -EINVAL; 1529 1530 /* We only support 2 level event channels for now */ 1531 if (ue->u.xen_evtchn.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) 1532 return -EINVAL; 1533 1534 /* 1535 * Xen gives us interesting mappings from vCPU index to APIC ID, 1536 * which means kvm_get_vcpu_by_id() has to iterate over all vCPUs 1537 * to find it. Do that once at setup time, instead of every time. 1538 * But beware that on live update / live migration, the routing 1539 * table might be reinstated before the vCPU threads have finished 1540 * recreating their vCPUs. 1541 */ 1542 vcpu = kvm_get_vcpu_by_id(kvm, ue->u.xen_evtchn.vcpu); 1543 if (vcpu) 1544 e->xen_evtchn.vcpu_idx = vcpu->vcpu_idx; 1545 else 1546 e->xen_evtchn.vcpu_idx = -1; 1547 1548 e->xen_evtchn.port = ue->u.xen_evtchn.port; 1549 e->xen_evtchn.vcpu_id = ue->u.xen_evtchn.vcpu; 1550 e->xen_evtchn.priority = ue->u.xen_evtchn.priority; 1551 e->set = evtchn_set_fn; 1552 1553 return 0; 1554 } 1555 1556 /* 1557 * Explicit event sending from userspace with KVM_XEN_HVM_EVTCHN_SEND ioctl. 1558 */ 1559 int kvm_xen_hvm_evtchn_send(struct kvm *kvm, struct kvm_irq_routing_xen_evtchn *uxe) 1560 { 1561 struct kvm_xen_evtchn e; 1562 int ret; 1563 1564 if (!uxe->port || uxe->port >= max_evtchn_port(kvm)) 1565 return -EINVAL; 1566 1567 /* We only support 2 level event channels for now */ 1568 if (uxe->priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) 1569 return -EINVAL; 1570 1571 e.port = uxe->port; 1572 e.vcpu_id = uxe->vcpu; 1573 e.vcpu_idx = -1; 1574 e.priority = uxe->priority; 1575 1576 ret = kvm_xen_set_evtchn(&e, kvm); 1577 1578 /* 1579 * None of that 'return 1 if it actually got delivered' nonsense. 1580 * We don't care if it was masked (-ENOTCONN) either. 1581 */ 1582 if (ret > 0 || ret == -ENOTCONN) 1583 ret = 0; 1584 1585 return ret; 1586 } 1587 1588 /* 1589 * Support for *outbound* event channel events via the EVTCHNOP_send hypercall. 1590 */ 1591 struct evtchnfd { 1592 u32 send_port; 1593 u32 type; 1594 union { 1595 struct kvm_xen_evtchn port; 1596 struct { 1597 u32 port; /* zero */ 1598 struct eventfd_ctx *ctx; 1599 } eventfd; 1600 } deliver; 1601 }; 1602 1603 /* 1604 * Update target vCPU or priority for a registered sending channel. 1605 */ 1606 static int kvm_xen_eventfd_update(struct kvm *kvm, 1607 struct kvm_xen_hvm_attr *data) 1608 { 1609 u32 port = data->u.evtchn.send_port; 1610 struct evtchnfd *evtchnfd; 1611 1612 if (!port || port >= max_evtchn_port(kvm)) 1613 return -EINVAL; 1614 1615 mutex_lock(&kvm->lock); 1616 evtchnfd = idr_find(&kvm->arch.xen.evtchn_ports, port); 1617 mutex_unlock(&kvm->lock); 1618 1619 if (!evtchnfd) 1620 return -ENOENT; 1621 1622 /* For an UPDATE, nothing may change except the priority/vcpu */ 1623 if (evtchnfd->type != data->u.evtchn.type) 1624 return -EINVAL; 1625 1626 /* 1627 * Port cannot change, and if it's zero that was an eventfd 1628 * which can't be changed either. 1629 */ 1630 if (!evtchnfd->deliver.port.port || 1631 evtchnfd->deliver.port.port != data->u.evtchn.deliver.port.port) 1632 return -EINVAL; 1633 1634 /* We only support 2 level event channels for now */ 1635 if (data->u.evtchn.deliver.port.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) 1636 return -EINVAL; 1637 1638 mutex_lock(&kvm->lock); 1639 evtchnfd->deliver.port.priority = data->u.evtchn.deliver.port.priority; 1640 if (evtchnfd->deliver.port.vcpu_id != data->u.evtchn.deliver.port.vcpu) { 1641 evtchnfd->deliver.port.vcpu_id = data->u.evtchn.deliver.port.vcpu; 1642 evtchnfd->deliver.port.vcpu_idx = -1; 1643 } 1644 mutex_unlock(&kvm->lock); 1645 return 0; 1646 } 1647 1648 /* 1649 * Configure the target (eventfd or local port delivery) for sending on 1650 * a given event channel. 1651 */ 1652 static int kvm_xen_eventfd_assign(struct kvm *kvm, 1653 struct kvm_xen_hvm_attr *data) 1654 { 1655 u32 port = data->u.evtchn.send_port; 1656 struct eventfd_ctx *eventfd = NULL; 1657 struct evtchnfd *evtchnfd = NULL; 1658 int ret = -EINVAL; 1659 1660 if (!port || port >= max_evtchn_port(kvm)) 1661 return -EINVAL; 1662 1663 evtchnfd = kzalloc(sizeof(struct evtchnfd), GFP_KERNEL); 1664 if (!evtchnfd) 1665 return -ENOMEM; 1666 1667 switch(data->u.evtchn.type) { 1668 case EVTCHNSTAT_ipi: 1669 /* IPI must map back to the same port# */ 1670 if (data->u.evtchn.deliver.port.port != data->u.evtchn.send_port) 1671 goto out; /* -EINVAL */ 1672 break; 1673 1674 case EVTCHNSTAT_interdomain: 1675 if (data->u.evtchn.deliver.port.port) { 1676 if (data->u.evtchn.deliver.port.port >= max_evtchn_port(kvm)) 1677 goto out; /* -EINVAL */ 1678 } else { 1679 eventfd = eventfd_ctx_fdget(data->u.evtchn.deliver.eventfd.fd); 1680 if (IS_ERR(eventfd)) { 1681 ret = PTR_ERR(eventfd); 1682 goto out; 1683 } 1684 } 1685 break; 1686 1687 case EVTCHNSTAT_virq: 1688 case EVTCHNSTAT_closed: 1689 case EVTCHNSTAT_unbound: 1690 case EVTCHNSTAT_pirq: 1691 default: /* Unknown event channel type */ 1692 goto out; /* -EINVAL */ 1693 } 1694 1695 evtchnfd->send_port = data->u.evtchn.send_port; 1696 evtchnfd->type = data->u.evtchn.type; 1697 if (eventfd) { 1698 evtchnfd->deliver.eventfd.ctx = eventfd; 1699 } else { 1700 /* We only support 2 level event channels for now */ 1701 if (data->u.evtchn.deliver.port.priority != KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL) 1702 goto out; /* -EINVAL; */ 1703 1704 evtchnfd->deliver.port.port = data->u.evtchn.deliver.port.port; 1705 evtchnfd->deliver.port.vcpu_id = data->u.evtchn.deliver.port.vcpu; 1706 evtchnfd->deliver.port.vcpu_idx = -1; 1707 evtchnfd->deliver.port.priority = data->u.evtchn.deliver.port.priority; 1708 } 1709 1710 mutex_lock(&kvm->lock); 1711 ret = idr_alloc(&kvm->arch.xen.evtchn_ports, evtchnfd, port, port + 1, 1712 GFP_KERNEL); 1713 mutex_unlock(&kvm->lock); 1714 if (ret >= 0) 1715 return 0; 1716 1717 if (ret == -ENOSPC) 1718 ret = -EEXIST; 1719 out: 1720 if (eventfd) 1721 eventfd_ctx_put(eventfd); 1722 kfree(evtchnfd); 1723 return ret; 1724 } 1725 1726 static int kvm_xen_eventfd_deassign(struct kvm *kvm, u32 port) 1727 { 1728 struct evtchnfd *evtchnfd; 1729 1730 mutex_lock(&kvm->lock); 1731 evtchnfd = idr_remove(&kvm->arch.xen.evtchn_ports, port); 1732 mutex_unlock(&kvm->lock); 1733 1734 if (!evtchnfd) 1735 return -ENOENT; 1736 1737 if (kvm) 1738 synchronize_srcu(&kvm->srcu); 1739 if (!evtchnfd->deliver.port.port) 1740 eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx); 1741 kfree(evtchnfd); 1742 return 0; 1743 } 1744 1745 static int kvm_xen_eventfd_reset(struct kvm *kvm) 1746 { 1747 struct evtchnfd *evtchnfd; 1748 int i; 1749 1750 mutex_lock(&kvm->lock); 1751 idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) { 1752 idr_remove(&kvm->arch.xen.evtchn_ports, evtchnfd->send_port); 1753 synchronize_srcu(&kvm->srcu); 1754 if (!evtchnfd->deliver.port.port) 1755 eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx); 1756 kfree(evtchnfd); 1757 } 1758 mutex_unlock(&kvm->lock); 1759 1760 return 0; 1761 } 1762 1763 static int kvm_xen_setattr_evtchn(struct kvm *kvm, struct kvm_xen_hvm_attr *data) 1764 { 1765 u32 port = data->u.evtchn.send_port; 1766 1767 if (data->u.evtchn.flags == KVM_XEN_EVTCHN_RESET) 1768 return kvm_xen_eventfd_reset(kvm); 1769 1770 if (!port || port >= max_evtchn_port(kvm)) 1771 return -EINVAL; 1772 1773 if (data->u.evtchn.flags == KVM_XEN_EVTCHN_DEASSIGN) 1774 return kvm_xen_eventfd_deassign(kvm, port); 1775 if (data->u.evtchn.flags == KVM_XEN_EVTCHN_UPDATE) 1776 return kvm_xen_eventfd_update(kvm, data); 1777 if (data->u.evtchn.flags) 1778 return -EINVAL; 1779 1780 return kvm_xen_eventfd_assign(kvm, data); 1781 } 1782 1783 static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r) 1784 { 1785 struct evtchnfd *evtchnfd; 1786 struct evtchn_send send; 1787 gpa_t gpa; 1788 int idx; 1789 1790 idx = srcu_read_lock(&vcpu->kvm->srcu); 1791 gpa = kvm_mmu_gva_to_gpa_system(vcpu, param, NULL); 1792 srcu_read_unlock(&vcpu->kvm->srcu, idx); 1793 1794 if (!gpa || kvm_vcpu_read_guest(vcpu, gpa, &send, sizeof(send))) { 1795 *r = -EFAULT; 1796 return true; 1797 } 1798 1799 /* The evtchn_ports idr is protected by vcpu->kvm->srcu */ 1800 evtchnfd = idr_find(&vcpu->kvm->arch.xen.evtchn_ports, send.port); 1801 if (!evtchnfd) 1802 return false; 1803 1804 if (evtchnfd->deliver.port.port) { 1805 int ret = kvm_xen_set_evtchn(&evtchnfd->deliver.port, vcpu->kvm); 1806 if (ret < 0 && ret != -ENOTCONN) 1807 return false; 1808 } else { 1809 eventfd_signal(evtchnfd->deliver.eventfd.ctx, 1); 1810 } 1811 1812 *r = 0; 1813 return true; 1814 } 1815 1816 void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu) 1817 { 1818 vcpu->arch.xen.vcpu_id = vcpu->vcpu_idx; 1819 vcpu->arch.xen.poll_evtchn = 0; 1820 timer_setup(&vcpu->arch.xen.poll_timer, cancel_evtchn_poll, 0); 1821 } 1822 1823 void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu) 1824 { 1825 if (kvm_xen_timer_enabled(vcpu)) 1826 kvm_xen_stop_timer(vcpu); 1827 1828 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, 1829 &vcpu->arch.xen.runstate_cache); 1830 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, 1831 &vcpu->arch.xen.vcpu_info_cache); 1832 kvm_gfn_to_pfn_cache_destroy(vcpu->kvm, 1833 &vcpu->arch.xen.vcpu_time_info_cache); 1834 del_timer_sync(&vcpu->arch.xen.poll_timer); 1835 } 1836 1837 void kvm_xen_init_vm(struct kvm *kvm) 1838 { 1839 idr_init(&kvm->arch.xen.evtchn_ports); 1840 } 1841 1842 void kvm_xen_destroy_vm(struct kvm *kvm) 1843 { 1844 struct evtchnfd *evtchnfd; 1845 int i; 1846 1847 kvm_gfn_to_pfn_cache_destroy(kvm, &kvm->arch.xen.shinfo_cache); 1848 1849 idr_for_each_entry(&kvm->arch.xen.evtchn_ports, evtchnfd, i) { 1850 if (!evtchnfd->deliver.port.port) 1851 eventfd_ctx_put(evtchnfd->deliver.eventfd.ctx); 1852 kfree(evtchnfd); 1853 } 1854 idr_destroy(&kvm->arch.xen.evtchn_ports); 1855 1856 if (kvm->arch.xen_hvm_config.msr) 1857 static_branch_slow_dec_deferred(&kvm_xen_enabled); 1858 } 1859