virt/kvm/arm/vgic/vgic.c

   1 /*
   2  * Copyright (C) 2015, 2016 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16
  17 #include <linux/kvm.h>
  18 #include <linux/kvm_host.h>
  19 #include <linux/list_sort.h>
  20
  21 #include "vgic.h"
  22
  23 #define CREATE_TRACE_POINTS
  24 #include "trace.h"
  25
  26 #ifdef CONFIG_DEBUG_SPINLOCK
  27 #define DEBUG_SPINLOCK_BUG_ON(p) BUG_ON(p)
  28 #else
  29 #define DEBUG_SPINLOCK_BUG_ON(p)
  30 #endif
  31
  32 struct vgic_global kvm_vgic_global_state __ro_after_init = {
  33         .gicv3_cpuif = STATIC_KEY_FALSE_INIT,
  34 };
  35
  36 /*
  37  * Locking order is always:
  38  * its->cmd_lock (mutex)
  39  *   its->its_lock (mutex)
  40  *     vgic_cpu->ap_list_lock
  41  *       kvm->lpi_list_lock
  42  *         vgic_irq->irq_lock
  43  *
  44  * If you need to take multiple locks, always take the upper lock first,
  45  * then the lower ones, e.g. first take the its_lock, then the irq_lock.
  46  * If you are already holding a lock and need to take a higher one, you
  47  * have to drop the lower ranking lock first and re-aquire it after having
  48  * taken the upper one.
  49  *
  50  * When taking more than one ap_list_lock at the same time, always take the
  51  * lowest numbered VCPU's ap_list_lock first, so:
  52  *   vcpuX->vcpu_id < vcpuY->vcpu_id:
  53  *     spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock);
  54  *     spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock);
  55  */
  56
  57 /*
  58  * Iterate over the VM's list of mapped LPIs to find the one with a
  59  * matching interrupt ID and return a reference to the IRQ structure.
  60  */
  61 static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
  62 {
  63         struct vgic_dist *dist = &kvm->arch.vgic;
  64         struct vgic_irq *irq = NULL;
  65
  66         spin_lock(&dist->lpi_list_lock);
  67
  68         list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
  69                 if (irq->intid != intid)
  70                         continue;
  71
  72                 /*
  73                  * This increases the refcount, the caller is expected to
  74                  * call vgic_put_irq() later once it's finished with the IRQ.
  75                  */
  76                 vgic_get_irq_kref(irq);
  77                 goto out_unlock;
  78         }
  79         irq = NULL;
  80
  81 out_unlock:
  82         spin_unlock(&dist->lpi_list_lock);
  83
  84         return irq;
  85 }
  86
  87 /*
  88  * This looks up the virtual interrupt ID to get the corresponding
  89  * struct vgic_irq. It also increases the refcount, so any caller is expected
  90  * to call vgic_put_irq() once it's finished with this IRQ.
  91  */
  92 struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
  93                               u32 intid)
  94 {
  95         /* SGIs and PPIs */
  96         if (intid <= VGIC_MAX_PRIVATE)
  97                 return &vcpu->arch.vgic_cpu.private_irqs[intid];
  98
  99         /* SPIs */
 100         if (intid <= VGIC_MAX_SPI)
 101                 return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
 102
 103         /* LPIs */
 104         if (intid >= VGIC_MIN_LPI)
 105                 return vgic_get_lpi(kvm, intid);
 106
 107         WARN(1, "Looking up struct vgic_irq for reserved INTID");
 108         return NULL;
 109 }
 110
 111 /*
 112  * We can't do anything in here, because we lack the kvm pointer to
 113  * lock and remove the item from the lpi_list. So we keep this function
 114  * empty and use the return value of kref_put() to trigger the freeing.
 115  */
 116 static void vgic_irq_release(struct kref *ref)
 117 {
 118 }
 119
 120 void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 121 {
 122         struct vgic_dist *dist = &kvm->arch.vgic;
 123
 124         if (irq->intid < VGIC_MIN_LPI)
 125                 return;
 126
 127         spin_lock(&dist->lpi_list_lock);
 128         if (!kref_put(&irq->refcount, vgic_irq_release)) {
 129                 spin_unlock(&dist->lpi_list_lock);
 130                 return;
 131         };
 132
 133         list_del(&irq->lpi_list);
 134         dist->lpi_list_count--;
 135         spin_unlock(&dist->lpi_list_lock);
 136
 137         kfree(irq);
 138 }
 139
 140 /**
 141  * kvm_vgic_target_oracle - compute the target vcpu for an irq
 142  *
 143  * @irq:        The irq to route. Must be already locked.
 144  *
 145  * Based on the current state of the interrupt (enabled, pending,
 146  * active, vcpu and target_vcpu), compute the next vcpu this should be
 147  * given to. Return NULL if this shouldn't be injected at all.
 148  *
 149  * Requires the IRQ lock to be held.
 150  */
 151 static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq)
 152 {
 153         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 154
 155         /* If the interrupt is active, it must stay on the current vcpu */
 156         if (irq->active)
 157                 return irq->vcpu ? : irq->target_vcpu;
 158
 159         /*
 160          * If the IRQ is not active but enabled and pending, we should direct
 161          * it to its configured target VCPU.
 162          * If the distributor is disabled, pending interrupts shouldn't be
 163          * forwarded.
 164          */
 165         if (irq->enabled && irq_is_pending(irq)) {
 166                 if (unlikely(irq->target_vcpu &&
 167                              !irq->target_vcpu->kvm->arch.vgic.enabled))
 168                         return NULL;
 169
 170                 return irq->target_vcpu;
 171         }
 172
 173         /* If neither active nor pending and enabled, then this IRQ should not
 174          * be queued to any VCPU.
 175          */
 176         return NULL;
 177 }
 178
 179 /*
 180  * The order of items in the ap_lists defines how we'll pack things in LRs as
 181  * well, the first items in the list being the first things populated in the
 182  * LRs.
 183  *
 184  * A hard rule is that active interrupts can never be pushed out of the LRs
 185  * (and therefore take priority) since we cannot reliably trap on deactivation
 186  * of IRQs and therefore they have to be present in the LRs.
 187  *
 188  * Otherwise things should be sorted by the priority field and the GIC
 189  * hardware support will take care of preemption of priority groups etc.
 190  *
 191  * Return negative if "a" sorts before "b", 0 to preserve order, and positive
 192  * to sort "b" before "a".
 193  */
 194 static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b)
 195 {
 196         struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list);
 197         struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list);
 198         bool penda, pendb;
 199         int ret;
 200
 201         spin_lock(&irqa->irq_lock);
 202         spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING);
 203
 204         if (irqa->active || irqb->active) {
 205                 ret = (int)irqb->active - (int)irqa->active;
 206                 goto out;
 207         }
 208
 209         penda = irqa->enabled && irq_is_pending(irqa);
 210         pendb = irqb->enabled && irq_is_pending(irqb);
 211
 212         if (!penda || !pendb) {
 213                 ret = (int)pendb - (int)penda;
 214                 goto out;
 215         }
 216
 217         /* Both pending and enabled, sort by priority */
 218         ret = irqa->priority - irqb->priority;
 219 out:
 220         spin_unlock(&irqb->irq_lock);
 221         spin_unlock(&irqa->irq_lock);
 222         return ret;
 223 }
 224
 225 /* Must be called with the ap_list_lock held */
 226 static void vgic_sort_ap_list(struct kvm_vcpu *vcpu)
 227 {
 228         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 229
 230         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 231
 232         list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp);
 233 }
 234
 235 /*
 236  * Only valid injection if changing level for level-triggered IRQs or for a
 237  * rising edge.
 238  */
 239 static bool vgic_validate_injection(struct vgic_irq *irq, bool level)
 240 {
 241         switch (irq->config) {
 242         case VGIC_CONFIG_LEVEL:
 243                 return irq->line_level != level;
 244         case VGIC_CONFIG_EDGE:
 245                 return level;
 246         }
 247
 248         return false;
 249 }
 250
 251 /*
 252  * Check whether an IRQ needs to (and can) be queued to a VCPU's ap list.
 253  * Do the queuing if necessary, taking the right locks in the right order.
 254  * Returns true when the IRQ was queued, false otherwise.
 255  *
 256  * Needs to be entered with the IRQ lock already held, but will return
 257  * with all locks dropped.
 258  */
 259 bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq)
 260 {
 261         struct kvm_vcpu *vcpu;
 262
 263         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 264
 265 retry:
 266         vcpu = vgic_target_oracle(irq);
 267         if (irq->vcpu || !vcpu) {
 268                 /*
 269                  * If this IRQ is already on a VCPU's ap_list, then it
 270                  * cannot be moved or modified and there is no more work for
 271                  * us to do.
 272                  *
 273                  * Otherwise, if the irq is not pending and enabled, it does
 274                  * not need to be inserted into an ap_list and there is also
 275                  * no more work for us to do.
 276                  */
 277                 spin_unlock(&irq->irq_lock);
 278
 279                 /*
 280                  * We have to kick the VCPU here, because we could be
 281                  * queueing an edge-triggered interrupt for which we
 282                  * get no EOI maintenance interrupt. In that case,
 283                  * while the IRQ is already on the VCPU's AP list, the
 284                  * VCPU could have EOI'ed the original interrupt and
 285                  * won't see this one until it exits for some other
 286                  * reason.
 287                  */
 288                 if (vcpu)
 289                         kvm_vcpu_kick(vcpu);
 290                 return false;
 291         }
 292
 293         /*
 294          * We must unlock the irq lock to take the ap_list_lock where
 295          * we are going to insert this new pending interrupt.
 296          */
 297         spin_unlock(&irq->irq_lock);
 298
 299         /* someone can do stuff here, which we re-check below */
 300
 301         spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
 302         spin_lock(&irq->irq_lock);
 303
 304         /*
 305          * Did something change behind our backs?
 306          *
 307          * There are two cases:
 308          * 1) The irq lost its pending state or was disabled behind our
 309          *    backs and/or it was queued to another VCPU's ap_list.
 310          * 2) Someone changed the affinity on this irq behind our
 311          *    backs and we are now holding the wrong ap_list_lock.
 312          *
 313          * In both cases, drop the locks and retry.
 314          */
 315
 316         if (unlikely(irq->vcpu || vcpu != vgic_target_oracle(irq))) {
 317                 spin_unlock(&irq->irq_lock);
 318                 spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 319
 320                 spin_lock(&irq->irq_lock);
 321                 goto retry;
 322         }
 323
 324         /*
 325          * Grab a reference to the irq to reflect the fact that it is
 326          * now in the ap_list.
 327          */
 328         vgic_get_irq_kref(irq);
 329         list_add_tail(&irq->ap_list, &vcpu->arch.vgic_cpu.ap_list_head);
 330         irq->vcpu = vcpu;
 331
 332         spin_unlock(&irq->irq_lock);
 333         spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 334
 335         kvm_vcpu_kick(vcpu);
 336
 337         return true;
 338 }
 339
 340 /**
 341  * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic
 342  * @kvm:     The VM structure pointer
 343  * @cpuid:   The CPU for PPIs
 344  * @intid:   The INTID to inject a new state to.
 345  * @level:   Edge-triggered:  true:  to trigger the interrupt
 346  *                            false: to ignore the call
 347  *           Level-sensitive  true:  raise the input signal
 348  *                            false: lower the input signal
 349  *
 350  * The VGIC is not concerned with devices being active-LOW or active-HIGH for
 351  * level-sensitive interrupts.  You can think of the level parameter as 1
 352  * being HIGH and 0 being LOW and all devices being active-HIGH.
 353  */
 354 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
 355                         bool level)
 356 {
 357         struct kvm_vcpu *vcpu;
 358         struct vgic_irq *irq;
 359         int ret;
 360
 361         trace_vgic_update_irq_pending(cpuid, intid, level);
 362
 363         ret = vgic_lazy_init(kvm);
 364         if (ret)
 365                 return ret;
 366
 367         vcpu = kvm_get_vcpu(kvm, cpuid);
 368         if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
 369                 return -EINVAL;
 370
 371         irq = vgic_get_irq(kvm, vcpu, intid);
 372         if (!irq)
 373                 return -EINVAL;
 374
 375         spin_lock(&irq->irq_lock);
 376
 377         if (!vgic_validate_injection(irq, level)) {
 378                 /* Nothing to see here, move along... */
 379                 spin_unlock(&irq->irq_lock);
 380                 vgic_put_irq(kvm, irq);
 381                 return 0;
 382         }
 383
 384         if (irq->config == VGIC_CONFIG_LEVEL)
 385                 irq->line_level = level;
 386         else
 387                 irq->pending_latch = true;
 388
 389         vgic_queue_irq_unlock(kvm, irq);
 390         vgic_put_irq(kvm, irq);
 391
 392         return 0;
 393 }
 394
 395 int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq)
 396 {
 397         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 398
 399         BUG_ON(!irq);
 400
 401         spin_lock(&irq->irq_lock);
 402
 403         irq->hw = true;
 404         irq->hwintid = phys_irq;
 405
 406         spin_unlock(&irq->irq_lock);
 407         vgic_put_irq(vcpu->kvm, irq);
 408
 409         return 0;
 410 }
 411
 412 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq)
 413 {
 414         struct vgic_irq *irq;
 415
 416         if (!vgic_initialized(vcpu->kvm))
 417                 return -EAGAIN;
 418
 419         irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 420         BUG_ON(!irq);
 421
 422         spin_lock(&irq->irq_lock);
 423
 424         irq->hw = false;
 425         irq->hwintid = 0;
 426
 427         spin_unlock(&irq->irq_lock);
 428         vgic_put_irq(vcpu->kvm, irq);
 429
 430         return 0;
 431 }
 432
 433 /**
 434  * vgic_prune_ap_list - Remove non-relevant interrupts from the list
 435  *
 436  * @vcpu: The VCPU pointer
 437  *
 438  * Go over the list of "interesting" interrupts, and prune those that we
 439  * won't have to consider in the near future.
 440  */
 441 static void vgic_prune_ap_list(struct kvm_vcpu *vcpu)
 442 {
 443         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 444         struct vgic_irq *irq, *tmp;
 445
 446 retry:
 447         spin_lock(&vgic_cpu->ap_list_lock);
 448
 449         list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
 450                 struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB;
 451
 452                 spin_lock(&irq->irq_lock);
 453
 454                 BUG_ON(vcpu != irq->vcpu);
 455
 456                 target_vcpu = vgic_target_oracle(irq);
 457
 458                 if (!target_vcpu) {
 459                         /*
 460                          * We don't need to process this interrupt any
 461                          * further, move it off the list.
 462                          */
 463                         list_del(&irq->ap_list);
 464                         irq->vcpu = NULL;
 465                         spin_unlock(&irq->irq_lock);
 466
 467                         /*
 468                          * This vgic_put_irq call matches the
 469                          * vgic_get_irq_kref in vgic_queue_irq_unlock,
 470                          * where we added the LPI to the ap_list. As
 471                          * we remove the irq from the list, we drop
 472                          * also drop the refcount.
 473                          */
 474                         vgic_put_irq(vcpu->kvm, irq);
 475                         continue;
 476                 }
 477
 478                 if (target_vcpu == vcpu) {
 479                         /* We're on the right CPU */
 480                         spin_unlock(&irq->irq_lock);
 481                         continue;
 482                 }
 483
 484                 /* This interrupt looks like it has to be migrated. */
 485
 486                 spin_unlock(&irq->irq_lock);
 487                 spin_unlock(&vgic_cpu->ap_list_lock);
 488
 489                 /*
 490                  * Ensure locking order by always locking the smallest
 491                  * ID first.
 492                  */
 493                 if (vcpu->vcpu_id < target_vcpu->vcpu_id) {
 494                         vcpuA = vcpu;
 495                         vcpuB = target_vcpu;
 496                 } else {
 497                         vcpuA = target_vcpu;
 498                         vcpuB = vcpu;
 499                 }
 500
 501                 spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock);
 502                 spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock,
 503                                  SINGLE_DEPTH_NESTING);
 504                 spin_lock(&irq->irq_lock);
 505
 506                 /*
 507                  * If the affinity has been preserved, move the
 508                  * interrupt around. Otherwise, it means things have
 509                  * changed while the interrupt was unlocked, and we
 510                  * need to replay this.
 511                  *
 512                  * In all cases, we cannot trust the list not to have
 513                  * changed, so we restart from the beginning.
 514                  */
 515                 if (target_vcpu == vgic_target_oracle(irq)) {
 516                         struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu;
 517
 518                         list_del(&irq->ap_list);
 519                         irq->vcpu = target_vcpu;
 520                         list_add_tail(&irq->ap_list, &new_cpu->ap_list_head);
 521                 }
 522
 523                 spin_unlock(&irq->irq_lock);
 524                 spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock);
 525                 spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock);
 526                 goto retry;
 527         }
 528
 529         spin_unlock(&vgic_cpu->ap_list_lock);
 530 }
 531
 532 static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
 533 {
 534         if (kvm_vgic_global_state.type == VGIC_V2)
 535                 vgic_v2_fold_lr_state(vcpu);
 536         else
 537                 vgic_v3_fold_lr_state(vcpu);
 538 }
 539
 540 /* Requires the irq_lock to be held. */
 541 static inline void vgic_populate_lr(struct kvm_vcpu *vcpu,
 542                                     struct vgic_irq *irq, int lr)
 543 {
 544         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 545
 546         if (kvm_vgic_global_state.type == VGIC_V2)
 547                 vgic_v2_populate_lr(vcpu, irq, lr);
 548         else
 549                 vgic_v3_populate_lr(vcpu, irq, lr);
 550 }
 551
 552 static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr)
 553 {
 554         if (kvm_vgic_global_state.type == VGIC_V2)
 555                 vgic_v2_clear_lr(vcpu, lr);
 556         else
 557                 vgic_v3_clear_lr(vcpu, lr);
 558 }
 559
 560 static inline void vgic_set_underflow(struct kvm_vcpu *vcpu)
 561 {
 562         if (kvm_vgic_global_state.type == VGIC_V2)
 563                 vgic_v2_set_underflow(vcpu);
 564         else
 565                 vgic_v3_set_underflow(vcpu);
 566 }
 567
 568 /* Requires the ap_list_lock to be held. */
 569 static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
 570 {
 571         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 572         struct vgic_irq *irq;
 573         int count = 0;
 574
 575         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 576
 577         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 578                 spin_lock(&irq->irq_lock);
 579                 /* GICv2 SGIs can count for more than one... */
 580                 if (vgic_irq_is_sgi(irq->intid) && irq->source)
 581                         count += hweight8(irq->source);
 582                 else
 583                         count++;
 584                 spin_unlock(&irq->irq_lock);
 585         }
 586         return count;
 587 }
 588
 589 /* Requires the VCPU's ap_list_lock to be held. */
 590 static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 591 {
 592         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 593         struct vgic_irq *irq;
 594         int count = 0;
 595
 596         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 597
 598         if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr)
 599                 vgic_sort_ap_list(vcpu);
 600
 601         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 602                 spin_lock(&irq->irq_lock);
 603
 604                 if (unlikely(vgic_target_oracle(irq) != vcpu))
 605                         goto next;
 606
 607                 /*
 608                  * If we get an SGI with multiple sources, try to get
 609                  * them in all at once.
 610                  */
 611                 do {
 612                         vgic_populate_lr(vcpu, irq, count++);
 613                 } while (irq->source && count < kvm_vgic_global_state.nr_lr);
 614
 615 next:
 616                 spin_unlock(&irq->irq_lock);
 617
 618                 if (count == kvm_vgic_global_state.nr_lr) {
 619                         if (!list_is_last(&irq->ap_list,
 620                                           &vgic_cpu->ap_list_head))
 621                                 vgic_set_underflow(vcpu);
 622                         break;
 623                 }
 624         }
 625
 626         vcpu->arch.vgic_cpu.used_lrs = count;
 627
 628         /* Nuke remaining LRs */
 629         for ( ; count < kvm_vgic_global_state.nr_lr; count++)
 630                 vgic_clear_lr(vcpu, count);
 631 }
 632
 633 /* Sync back the hardware VGIC state into our emulation after a guest's run. */
 634 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 635 {
 636         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 637
 638         /* An empty ap_list_head implies used_lrs == 0 */
 639         if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 640                 return;
 641
 642         if (vgic_cpu->used_lrs)
 643                 vgic_fold_lr_state(vcpu);
 644         vgic_prune_ap_list(vcpu);
 645 }
 646
 647 /* Flush our emulation state into the GIC hardware before entering the guest. */
 648 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 649 {
 650         /*
 651          * If there are no virtual interrupts active or pending for this
 652          * VCPU, then there is no work to do and we can bail out without
 653          * taking any lock.  There is a potential race with someone injecting
 654          * interrupts to the VCPU, but it is a benign race as the VCPU will
 655          * either observe the new interrupt before or after doing this check,
 656          * and introducing additional synchronization mechanism doesn't change
 657          * this.
 658          */
 659         if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 660                 return;
 661
 662         spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
 663         vgic_flush_lr_state(vcpu);
 664         spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 665 }
 666
 667 void kvm_vgic_load(struct kvm_vcpu *vcpu)
 668 {
 669         if (unlikely(!vgic_initialized(vcpu->kvm)))
 670                 return;
 671
 672         if (kvm_vgic_global_state.type == VGIC_V2)
 673                 vgic_v2_load(vcpu);
 674         else
 675                 vgic_v3_load(vcpu);
 676 }
 677
 678 void kvm_vgic_put(struct kvm_vcpu *vcpu)
 679 {
 680         if (unlikely(!vgic_initialized(vcpu->kvm)))
 681                 return;
 682
 683         if (kvm_vgic_global_state.type == VGIC_V2)
 684                 vgic_v2_put(vcpu);
 685         else
 686                 vgic_v3_put(vcpu);
 687 }
 688
 689 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 690 {
 691         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 692         struct vgic_irq *irq;
 693         bool pending = false;
 694
 695         if (!vcpu->kvm->arch.vgic.enabled)
 696                 return false;
 697
 698         spin_lock(&vgic_cpu->ap_list_lock);
 699
 700         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 701                 spin_lock(&irq->irq_lock);
 702                 pending = irq_is_pending(irq) && irq->enabled;
 703                 spin_unlock(&irq->irq_lock);
 704
 705                 if (pending)
 706                         break;
 707         }
 708
 709         spin_unlock(&vgic_cpu->ap_list_lock);
 710
 711         return pending;
 712 }
 713
 714 void vgic_kick_vcpus(struct kvm *kvm)
 715 {
 716         struct kvm_vcpu *vcpu;
 717         int c;
 718
 719         /*
 720          * We've injected an interrupt, time to find out who deserves
 721          * a good kick...
 722          */
 723         kvm_for_each_vcpu(c, vcpu, kvm) {
 724                 if (kvm_vgic_vcpu_pending_irq(vcpu))
 725                         kvm_vcpu_kick(vcpu);
 726         }
 727 }
 728
 729 bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq)
 730 {
 731         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 732         bool map_is_active;
 733
 734         spin_lock(&irq->irq_lock);
 735         map_is_active = irq->hw && irq->active;
 736         spin_unlock(&irq->irq_lock);
 737         vgic_put_irq(vcpu->kvm, irq);
 738
 739         return map_is_active;
 740 }
 741