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 __section(.hyp.text) kvm_vgic_global_state = {.gicv3_cpuif = STATIC_KEY_FALSE_INIT,};
  33
  34 /*
  35  * Locking order is always:
  36  * its->cmd_lock (mutex)
  37  *   its->its_lock (mutex)
  38  *     vgic_cpu->ap_list_lock
  39  *       kvm->lpi_list_lock
  40  *         vgic_irq->irq_lock
  41  *
  42  * If you need to take multiple locks, always take the upper lock first,
  43  * then the lower ones, e.g. first take the its_lock, then the irq_lock.
  44  * If you are already holding a lock and need to take a higher one, you
  45  * have to drop the lower ranking lock first and re-aquire it after having
  46  * taken the upper one.
  47  *
  48  * When taking more than one ap_list_lock at the same time, always take the
  49  * lowest numbered VCPU's ap_list_lock first, so:
  50  *   vcpuX->vcpu_id < vcpuY->vcpu_id:
  51  *     spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock);
  52  *     spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock);
  53  */
  54
  55 /*
  56  * Iterate over the VM's list of mapped LPIs to find the one with a
  57  * matching interrupt ID and return a reference to the IRQ structure.
  58  */
  59 static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
  60 {
  61         struct vgic_dist *dist = &kvm->arch.vgic;
  62         struct vgic_irq *irq = NULL;
  63
  64         spin_lock(&dist->lpi_list_lock);
  65
  66         list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
  67                 if (irq->intid != intid)
  68                         continue;
  69
  70                 /*
  71                  * This increases the refcount, the caller is expected to
  72                  * call vgic_put_irq() later once it's finished with the IRQ.
  73                  */
  74                 vgic_get_irq_kref(irq);
  75                 goto out_unlock;
  76         }
  77         irq = NULL;
  78
  79 out_unlock:
  80         spin_unlock(&dist->lpi_list_lock);
  81
  82         return irq;
  83 }
  84
  85 /*
  86  * This looks up the virtual interrupt ID to get the corresponding
  87  * struct vgic_irq. It also increases the refcount, so any caller is expected
  88  * to call vgic_put_irq() once it's finished with this IRQ.
  89  */
  90 struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
  91                               u32 intid)
  92 {
  93         /* SGIs and PPIs */
  94         if (intid <= VGIC_MAX_PRIVATE)
  95                 return &vcpu->arch.vgic_cpu.private_irqs[intid];
  96
  97         /* SPIs */
  98         if (intid <= VGIC_MAX_SPI)
  99                 return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
 100
 101         /* LPIs */
 102         if (intid >= VGIC_MIN_LPI)
 103                 return vgic_get_lpi(kvm, intid);
 104
 105         WARN(1, "Looking up struct vgic_irq for reserved INTID");
 106         return NULL;
 107 }
 108
 109 /*
 110  * We can't do anything in here, because we lack the kvm pointer to
 111  * lock and remove the item from the lpi_list. So we keep this function
 112  * empty and use the return value of kref_put() to trigger the freeing.
 113  */
 114 static void vgic_irq_release(struct kref *ref)
 115 {
 116 }
 117
 118 void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 119 {
 120         struct vgic_dist *dist = &kvm->arch.vgic;
 121
 122         if (irq->intid < VGIC_MIN_LPI)
 123                 return;
 124
 125         spin_lock(&dist->lpi_list_lock);
 126         if (!kref_put(&irq->refcount, vgic_irq_release)) {
 127                 spin_unlock(&dist->lpi_list_lock);
 128                 return;
 129         };
 130
 131         list_del(&irq->lpi_list);
 132         dist->lpi_list_count--;
 133         spin_unlock(&dist->lpi_list_lock);
 134
 135         kfree(irq);
 136 }
 137
 138 /**
 139  * kvm_vgic_target_oracle - compute the target vcpu for an irq
 140  *
 141  * @irq:        The irq to route. Must be already locked.
 142  *
 143  * Based on the current state of the interrupt (enabled, pending,
 144  * active, vcpu and target_vcpu), compute the next vcpu this should be
 145  * given to. Return NULL if this shouldn't be injected at all.
 146  *
 147  * Requires the IRQ lock to be held.
 148  */
 149 static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq)
 150 {
 151         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 152
 153         /* If the interrupt is active, it must stay on the current vcpu */
 154         if (irq->active)
 155                 return irq->vcpu ? : irq->target_vcpu;
 156
 157         /*
 158          * If the IRQ is not active but enabled and pending, we should direct
 159          * it to its configured target VCPU.
 160          * If the distributor is disabled, pending interrupts shouldn't be
 161          * forwarded.
 162          */
 163         if (irq->enabled && irq->pending) {
 164                 if (unlikely(irq->target_vcpu &&
 165                              !irq->target_vcpu->kvm->arch.vgic.enabled))
 166                         return NULL;
 167
 168                 return irq->target_vcpu;
 169         }
 170
 171         /* If neither active nor pending and enabled, then this IRQ should not
 172          * be queued to any VCPU.
 173          */
 174         return NULL;
 175 }
 176
 177 /*
 178  * The order of items in the ap_lists defines how we'll pack things in LRs as
 179  * well, the first items in the list being the first things populated in the
 180  * LRs.
 181  *
 182  * A hard rule is that active interrupts can never be pushed out of the LRs
 183  * (and therefore take priority) since we cannot reliably trap on deactivation
 184  * of IRQs and therefore they have to be present in the LRs.
 185  *
 186  * Otherwise things should be sorted by the priority field and the GIC
 187  * hardware support will take care of preemption of priority groups etc.
 188  *
 189  * Return negative if "a" sorts before "b", 0 to preserve order, and positive
 190  * to sort "b" before "a".
 191  */
 192 static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b)
 193 {
 194         struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list);
 195         struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list);
 196         bool penda, pendb;
 197         int ret;
 198
 199         spin_lock(&irqa->irq_lock);
 200         spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING);
 201
 202         if (irqa->active || irqb->active) {
 203                 ret = (int)irqb->active - (int)irqa->active;
 204                 goto out;
 205         }
 206
 207         penda = irqa->enabled && irqa->pending;
 208         pendb = irqb->enabled && irqb->pending;
 209
 210         if (!penda || !pendb) {
 211                 ret = (int)pendb - (int)penda;
 212                 goto out;
 213         }
 214
 215         /* Both pending and enabled, sort by priority */
 216         ret = irqa->priority - irqb->priority;
 217 out:
 218         spin_unlock(&irqb->irq_lock);
 219         spin_unlock(&irqa->irq_lock);
 220         return ret;
 221 }
 222
 223 /* Must be called with the ap_list_lock held */
 224 static void vgic_sort_ap_list(struct kvm_vcpu *vcpu)
 225 {
 226         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 227
 228         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 229
 230         list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp);
 231 }
 232
 233 /*
 234  * Only valid injection if changing level for level-triggered IRQs or for a
 235  * rising edge.
 236  */
 237 static bool vgic_validate_injection(struct vgic_irq *irq, bool level)
 238 {
 239         switch (irq->config) {
 240         case VGIC_CONFIG_LEVEL:
 241                 return irq->line_level != level;
 242         case VGIC_CONFIG_EDGE:
 243                 return level;
 244         }
 245
 246         return false;
 247 }
 248
 249 /*
 250  * Check whether an IRQ needs to (and can) be queued to a VCPU's ap list.
 251  * Do the queuing if necessary, taking the right locks in the right order.
 252  * Returns true when the IRQ was queued, false otherwise.
 253  *
 254  * Needs to be entered with the IRQ lock already held, but will return
 255  * with all locks dropped.
 256  */
 257 bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq)
 258 {
 259         struct kvm_vcpu *vcpu;
 260
 261         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 262
 263 retry:
 264         vcpu = vgic_target_oracle(irq);
 265         if (irq->vcpu || !vcpu) {
 266                 /*
 267                  * If this IRQ is already on a VCPU's ap_list, then it
 268                  * cannot be moved or modified and there is no more work for
 269                  * us to do.
 270                  *
 271                  * Otherwise, if the irq is not pending and enabled, it does
 272                  * not need to be inserted into an ap_list and there is also
 273                  * no more work for us to do.
 274                  */
 275                 spin_unlock(&irq->irq_lock);
 276
 277                 /*
 278                  * We have to kick the VCPU here, because we could be
 279                  * queueing an edge-triggered interrupt for which we
 280                  * get no EOI maintenance interrupt. In that case,
 281                  * while the IRQ is already on the VCPU's AP list, the
 282                  * VCPU could have EOI'ed the original interrupt and
 283                  * won't see this one until it exits for some other
 284                  * reason.
 285                  */
 286                 if (vcpu)
 287                         kvm_vcpu_kick(vcpu);
 288                 return false;
 289         }
 290
 291         /*
 292          * We must unlock the irq lock to take the ap_list_lock where
 293          * we are going to insert this new pending interrupt.
 294          */
 295         spin_unlock(&irq->irq_lock);
 296
 297         /* someone can do stuff here, which we re-check below */
 298
 299         spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
 300         spin_lock(&irq->irq_lock);
 301
 302         /*
 303          * Did something change behind our backs?
 304          *
 305          * There are two cases:
 306          * 1) The irq lost its pending state or was disabled behind our
 307          *    backs and/or it was queued to another VCPU's ap_list.
 308          * 2) Someone changed the affinity on this irq behind our
 309          *    backs and we are now holding the wrong ap_list_lock.
 310          *
 311          * In both cases, drop the locks and retry.
 312          */
 313
 314         if (unlikely(irq->vcpu || vcpu != vgic_target_oracle(irq))) {
 315                 spin_unlock(&irq->irq_lock);
 316                 spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 317
 318                 spin_lock(&irq->irq_lock);
 319                 goto retry;
 320         }
 321
 322         /*
 323          * Grab a reference to the irq to reflect the fact that it is
 324          * now in the ap_list.
 325          */
 326         vgic_get_irq_kref(irq);
 327         list_add_tail(&irq->ap_list, &vcpu->arch.vgic_cpu.ap_list_head);
 328         irq->vcpu = vcpu;
 329
 330         spin_unlock(&irq->irq_lock);
 331         spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 332
 333         kvm_vcpu_kick(vcpu);
 334
 335         return true;
 336 }
 337
 338 static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
 339                                    unsigned int intid, bool level,
 340                                    bool mapped_irq)
 341 {
 342         struct kvm_vcpu *vcpu;
 343         struct vgic_irq *irq;
 344         int ret;
 345
 346         trace_vgic_update_irq_pending(cpuid, intid, level);
 347
 348         ret = vgic_lazy_init(kvm);
 349         if (ret)
 350                 return ret;
 351
 352         vcpu = kvm_get_vcpu(kvm, cpuid);
 353         if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
 354                 return -EINVAL;
 355
 356         irq = vgic_get_irq(kvm, vcpu, intid);
 357         if (!irq)
 358                 return -EINVAL;
 359
 360         if (irq->hw != mapped_irq) {
 361                 vgic_put_irq(kvm, irq);
 362                 return -EINVAL;
 363         }
 364
 365         spin_lock(&irq->irq_lock);
 366
 367         if (!vgic_validate_injection(irq, level)) {
 368                 /* Nothing to see here, move along... */
 369                 spin_unlock(&irq->irq_lock);
 370                 vgic_put_irq(kvm, irq);
 371                 return 0;
 372         }
 373
 374         if (irq->config == VGIC_CONFIG_LEVEL) {
 375                 irq->line_level = level;
 376                 irq->pending = level || irq->soft_pending;
 377         } else {
 378                 irq->pending = true;
 379         }
 380
 381         vgic_queue_irq_unlock(kvm, irq);
 382         vgic_put_irq(kvm, irq);
 383
 384         return 0;
 385 }
 386
 387 /**
 388  * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic
 389  * @kvm:     The VM structure pointer
 390  * @cpuid:   The CPU for PPIs
 391  * @intid:   The INTID to inject a new state to.
 392  * @level:   Edge-triggered:  true:  to trigger the interrupt
 393  *                            false: to ignore the call
 394  *           Level-sensitive  true:  raise the input signal
 395  *                            false: lower the input signal
 396  *
 397  * The VGIC is not concerned with devices being active-LOW or active-HIGH for
 398  * level-sensitive interrupts.  You can think of the level parameter as 1
 399  * being HIGH and 0 being LOW and all devices being active-HIGH.
 400  */
 401 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
 402                         bool level)
 403 {
 404         return vgic_update_irq_pending(kvm, cpuid, intid, level, false);
 405 }
 406
 407 int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid, unsigned int intid,
 408                                bool level)
 409 {
 410         return vgic_update_irq_pending(kvm, cpuid, intid, level, true);
 411 }
 412
 413 int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq)
 414 {
 415         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 416
 417         BUG_ON(!irq);
 418
 419         spin_lock(&irq->irq_lock);
 420
 421         irq->hw = true;
 422         irq->hwintid = phys_irq;
 423
 424         spin_unlock(&irq->irq_lock);
 425         vgic_put_irq(vcpu->kvm, irq);
 426
 427         return 0;
 428 }
 429
 430 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq)
 431 {
 432         struct vgic_irq *irq;
 433
 434         if (!vgic_initialized(vcpu->kvm))
 435                 return -EAGAIN;
 436
 437         irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 438         BUG_ON(!irq);
 439
 440         spin_lock(&irq->irq_lock);
 441
 442         irq->hw = false;
 443         irq->hwintid = 0;
 444
 445         spin_unlock(&irq->irq_lock);
 446         vgic_put_irq(vcpu->kvm, irq);
 447
 448         return 0;
 449 }
 450
 451 /**
 452  * vgic_prune_ap_list - Remove non-relevant interrupts from the list
 453  *
 454  * @vcpu: The VCPU pointer
 455  *
 456  * Go over the list of "interesting" interrupts, and prune those that we
 457  * won't have to consider in the near future.
 458  */
 459 static void vgic_prune_ap_list(struct kvm_vcpu *vcpu)
 460 {
 461         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 462         struct vgic_irq *irq, *tmp;
 463
 464 retry:
 465         spin_lock(&vgic_cpu->ap_list_lock);
 466
 467         list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
 468                 struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB;
 469
 470                 spin_lock(&irq->irq_lock);
 471
 472                 BUG_ON(vcpu != irq->vcpu);
 473
 474                 target_vcpu = vgic_target_oracle(irq);
 475
 476                 if (!target_vcpu) {
 477                         /*
 478                          * We don't need to process this interrupt any
 479                          * further, move it off the list.
 480                          */
 481                         list_del(&irq->ap_list);
 482                         irq->vcpu = NULL;
 483                         spin_unlock(&irq->irq_lock);
 484
 485                         /*
 486                          * This vgic_put_irq call matches the
 487                          * vgic_get_irq_kref in vgic_queue_irq_unlock,
 488                          * where we added the LPI to the ap_list. As
 489                          * we remove the irq from the list, we drop
 490                          * also drop the refcount.
 491                          */
 492                         vgic_put_irq(vcpu->kvm, irq);
 493                         continue;
 494                 }
 495
 496                 if (target_vcpu == vcpu) {
 497                         /* We're on the right CPU */
 498                         spin_unlock(&irq->irq_lock);
 499                         continue;
 500                 }
 501
 502                 /* This interrupt looks like it has to be migrated. */
 503
 504                 spin_unlock(&irq->irq_lock);
 505                 spin_unlock(&vgic_cpu->ap_list_lock);
 506
 507                 /*
 508                  * Ensure locking order by always locking the smallest
 509                  * ID first.
 510                  */
 511                 if (vcpu->vcpu_id < target_vcpu->vcpu_id) {
 512                         vcpuA = vcpu;
 513                         vcpuB = target_vcpu;
 514                 } else {
 515                         vcpuA = target_vcpu;
 516                         vcpuB = vcpu;
 517                 }
 518
 519                 spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock);
 520                 spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock,
 521                                  SINGLE_DEPTH_NESTING);
 522                 spin_lock(&irq->irq_lock);
 523
 524                 /*
 525                  * If the affinity has been preserved, move the
 526                  * interrupt around. Otherwise, it means things have
 527                  * changed while the interrupt was unlocked, and we
 528                  * need to replay this.
 529                  *
 530                  * In all cases, we cannot trust the list not to have
 531                  * changed, so we restart from the beginning.
 532                  */
 533                 if (target_vcpu == vgic_target_oracle(irq)) {
 534                         struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu;
 535
 536                         list_del(&irq->ap_list);
 537                         irq->vcpu = target_vcpu;
 538                         list_add_tail(&irq->ap_list, &new_cpu->ap_list_head);
 539                 }
 540
 541                 spin_unlock(&irq->irq_lock);
 542                 spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock);
 543                 spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock);
 544                 goto retry;
 545         }
 546
 547         spin_unlock(&vgic_cpu->ap_list_lock);
 548 }
 549
 550 static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu)
 551 {
 552         if (kvm_vgic_global_state.type == VGIC_V2)
 553                 vgic_v2_process_maintenance(vcpu);
 554         else
 555                 vgic_v3_process_maintenance(vcpu);
 556 }
 557
 558 static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
 559 {
 560         if (kvm_vgic_global_state.type == VGIC_V2)
 561                 vgic_v2_fold_lr_state(vcpu);
 562         else
 563                 vgic_v3_fold_lr_state(vcpu);
 564 }
 565
 566 /* Requires the irq_lock to be held. */
 567 static inline void vgic_populate_lr(struct kvm_vcpu *vcpu,
 568                                     struct vgic_irq *irq, int lr)
 569 {
 570         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 571
 572         if (kvm_vgic_global_state.type == VGIC_V2)
 573                 vgic_v2_populate_lr(vcpu, irq, lr);
 574         else
 575                 vgic_v3_populate_lr(vcpu, irq, lr);
 576 }
 577
 578 static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr)
 579 {
 580         if (kvm_vgic_global_state.type == VGIC_V2)
 581                 vgic_v2_clear_lr(vcpu, lr);
 582         else
 583                 vgic_v3_clear_lr(vcpu, lr);
 584 }
 585
 586 static inline void vgic_set_underflow(struct kvm_vcpu *vcpu)
 587 {
 588         if (kvm_vgic_global_state.type == VGIC_V2)
 589                 vgic_v2_set_underflow(vcpu);
 590         else
 591                 vgic_v3_set_underflow(vcpu);
 592 }
 593
 594 /* Requires the ap_list_lock to be held. */
 595 static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
 596 {
 597         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 598         struct vgic_irq *irq;
 599         int count = 0;
 600
 601         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 602
 603         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 604                 spin_lock(&irq->irq_lock);
 605                 /* GICv2 SGIs can count for more than one... */
 606                 if (vgic_irq_is_sgi(irq->intid) && irq->source)
 607                         count += hweight8(irq->source);
 608                 else
 609                         count++;
 610                 spin_unlock(&irq->irq_lock);
 611         }
 612         return count;
 613 }
 614
 615 /* Requires the VCPU's ap_list_lock to be held. */
 616 static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 617 {
 618         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 619         struct vgic_irq *irq;
 620         int count = 0;
 621
 622         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 623
 624         if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) {
 625                 vgic_set_underflow(vcpu);
 626                 vgic_sort_ap_list(vcpu);
 627         }
 628
 629         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 630                 spin_lock(&irq->irq_lock);
 631
 632                 if (unlikely(vgic_target_oracle(irq) != vcpu))
 633                         goto next;
 634
 635                 /*
 636                  * If we get an SGI with multiple sources, try to get
 637                  * them in all at once.
 638                  */
 639                 do {
 640                         vgic_populate_lr(vcpu, irq, count++);
 641                 } while (irq->source && count < kvm_vgic_global_state.nr_lr);
 642
 643 next:
 644                 spin_unlock(&irq->irq_lock);
 645
 646                 if (count == kvm_vgic_global_state.nr_lr)
 647                         break;
 648         }
 649
 650         vcpu->arch.vgic_cpu.used_lrs = count;
 651
 652         /* Nuke remaining LRs */
 653         for ( ; count < kvm_vgic_global_state.nr_lr; count++)
 654                 vgic_clear_lr(vcpu, count);
 655 }
 656
 657 /* Sync back the hardware VGIC state into our emulation after a guest's run. */
 658 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 659 {
 660         if (unlikely(!vgic_initialized(vcpu->kvm)))
 661                 return;
 662
 663         vgic_process_maintenance_interrupt(vcpu);
 664         vgic_fold_lr_state(vcpu);
 665         vgic_prune_ap_list(vcpu);
 666 }
 667
 668 /* Flush our emulation state into the GIC hardware before entering the guest. */
 669 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 670 {
 671         if (unlikely(!vgic_initialized(vcpu->kvm)))
 672                 return;
 673
 674         spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
 675         vgic_flush_lr_state(vcpu);
 676         spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 677 }
 678
 679 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 680 {
 681         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 682         struct vgic_irq *irq;
 683         bool pending = false;
 684
 685         if (!vcpu->kvm->arch.vgic.enabled)
 686                 return false;
 687
 688         spin_lock(&vgic_cpu->ap_list_lock);
 689
 690         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 691                 spin_lock(&irq->irq_lock);
 692                 pending = irq->pending && irq->enabled;
 693                 spin_unlock(&irq->irq_lock);
 694
 695                 if (pending)
 696                         break;
 697         }
 698
 699         spin_unlock(&vgic_cpu->ap_list_lock);
 700
 701         return pending;
 702 }
 703
 704 void vgic_kick_vcpus(struct kvm *kvm)
 705 {
 706         struct kvm_vcpu *vcpu;
 707         int c;
 708
 709         /*
 710          * We've injected an interrupt, time to find out who deserves
 711          * a good kick...
 712          */
 713         kvm_for_each_vcpu(c, vcpu, kvm) {
 714                 if (kvm_vgic_vcpu_pending_irq(vcpu))
 715                         kvm_vcpu_kick(vcpu);
 716         }
 717 }
 718
 719 bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq)
 720 {
 721         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
 722         bool map_is_active;
 723
 724         spin_lock(&irq->irq_lock);
 725         map_is_active = irq->hw && irq->active;
 726         spin_unlock(&irq->irq_lock);
 727         vgic_put_irq(vcpu->kvm, irq);
 728
 729         return map_is_active;
 730 }
 731