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 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22
  23 #include "vgic.h"
  24
  25 #define CREATE_TRACE_POINTS
  26 #include "trace.h"
  27
  28 #ifdef CONFIG_DEBUG_SPINLOCK
  29 #define DEBUG_SPINLOCK_BUG_ON(p) BUG_ON(p)
  30 #else
  31 #define DEBUG_SPINLOCK_BUG_ON(p)
  32 #endif
  33
  34 struct vgic_global kvm_vgic_global_state __ro_after_init = {
  35         .gicv3_cpuif = STATIC_KEY_FALSE_INIT,
  36 };
  37
  38 /*
  39  * Locking order is always:
  40  * kvm->lock (mutex)
  41  *   its->cmd_lock (mutex)
  42  *     its->its_lock (mutex)
  43  *       vgic_cpu->ap_list_lock
  44  *         kvm->lpi_list_lock
  45  *           vgic_irq->irq_lock
  46  *
  47  * If you need to take multiple locks, always take the upper lock first,
  48  * then the lower ones, e.g. first take the its_lock, then the irq_lock.
  49  * If you are already holding a lock and need to take a higher one, you
  50  * have to drop the lower ranking lock first and re-aquire it after having
  51  * taken the upper one.
  52  *
  53  * When taking more than one ap_list_lock at the same time, always take the
  54  * lowest numbered VCPU's ap_list_lock first, so:
  55  *   vcpuX->vcpu_id < vcpuY->vcpu_id:
  56  *     spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock);
  57  *     spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock);
  58  *
  59  * Since the VGIC must support injecting virtual interrupts from ISRs, we have
  60  * to use the spin_lock_irqsave/spin_unlock_irqrestore versions of outer
  61  * spinlocks for any lock that may be taken while injecting an interrupt.
  62  */
  63
  64 /*
  65  * Iterate over the VM's list of mapped LPIs to find the one with a
  66  * matching interrupt ID and return a reference to the IRQ structure.
  67  */
  68 static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
  69 {
  70         struct vgic_dist *dist = &kvm->arch.vgic;
  71         struct vgic_irq *irq = NULL;
  72
  73         spin_lock(&dist->lpi_list_lock);
  74
  75         list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
  76                 if (irq->intid != intid)
  77                         continue;
  78
  79                 /*
  80                  * This increases the refcount, the caller is expected to
  81                  * call vgic_put_irq() later once it's finished with the IRQ.
  82                  */
  83                 vgic_get_irq_kref(irq);
  84                 goto out_unlock;
  85         }
  86         irq = NULL;
  87
  88 out_unlock:
  89         spin_unlock(&dist->lpi_list_lock);
  90
  91         return irq;
  92 }
  93
  94 /*
  95  * This looks up the virtual interrupt ID to get the corresponding
  96  * struct vgic_irq. It also increases the refcount, so any caller is expected
  97  * to call vgic_put_irq() once it's finished with this IRQ.
  98  */
  99 struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 100                               u32 intid)
 101 {
 102         /* SGIs and PPIs */
 103         if (intid <= VGIC_MAX_PRIVATE)
 104                 return &vcpu->arch.vgic_cpu.private_irqs[intid];
 105
 106         /* SPIs */
 107         if (intid <= VGIC_MAX_SPI)
 108                 return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
 109
 110         /* LPIs */
 111         if (intid >= VGIC_MIN_LPI)
 112                 return vgic_get_lpi(kvm, intid);
 113
 114         WARN(1, "Looking up struct vgic_irq for reserved INTID");
 115         return NULL;
 116 }
 117
 118 /*
 119  * We can't do anything in here, because we lack the kvm pointer to
 120  * lock and remove the item from the lpi_list. So we keep this function
 121  * empty and use the return value of kref_put() to trigger the freeing.
 122  */
 123 static void vgic_irq_release(struct kref *ref)
 124 {
 125 }
 126
 127 void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 128 {
 129         struct vgic_dist *dist = &kvm->arch.vgic;
 130
 131         if (irq->intid < VGIC_MIN_LPI)
 132                 return;
 133
 134         spin_lock(&dist->lpi_list_lock);
 135         if (!kref_put(&irq->refcount, vgic_irq_release)) {
 136                 spin_unlock(&dist->lpi_list_lock);
 137                 return;
 138         };
 139
 140         list_del(&irq->lpi_list);
 141         dist->lpi_list_count--;
 142         spin_unlock(&dist->lpi_list_lock);
 143
 144         kfree(irq);
 145 }
 146
 147 /**
 148  * kvm_vgic_target_oracle - compute the target vcpu for an irq
 149  *
 150  * @irq:        The irq to route. Must be already locked.
 151  *
 152  * Based on the current state of the interrupt (enabled, pending,
 153  * active, vcpu and target_vcpu), compute the next vcpu this should be
 154  * given to. Return NULL if this shouldn't be injected at all.
 155  *
 156  * Requires the IRQ lock to be held.
 157  */
 158 static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq)
 159 {
 160         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 161
 162         /* If the interrupt is active, it must stay on the current vcpu */
 163         if (irq->active)
 164                 return irq->vcpu ? : irq->target_vcpu;
 165
 166         /*
 167          * If the IRQ is not active but enabled and pending, we should direct
 168          * it to its configured target VCPU.
 169          * If the distributor is disabled, pending interrupts shouldn't be
 170          * forwarded.
 171          */
 172         if (irq->enabled && irq_is_pending(irq)) {
 173                 if (unlikely(irq->target_vcpu &&
 174                              !irq->target_vcpu->kvm->arch.vgic.enabled))
 175                         return NULL;
 176
 177                 return irq->target_vcpu;
 178         }
 179
 180         /* If neither active nor pending and enabled, then this IRQ should not
 181          * be queued to any VCPU.
 182          */
 183         return NULL;
 184 }
 185
 186 /*
 187  * The order of items in the ap_lists defines how we'll pack things in LRs as
 188  * well, the first items in the list being the first things populated in the
 189  * LRs.
 190  *
 191  * A hard rule is that active interrupts can never be pushed out of the LRs
 192  * (and therefore take priority) since we cannot reliably trap on deactivation
 193  * of IRQs and therefore they have to be present in the LRs.
 194  *
 195  * Otherwise things should be sorted by the priority field and the GIC
 196  * hardware support will take care of preemption of priority groups etc.
 197  *
 198  * Return negative if "a" sorts before "b", 0 to preserve order, and positive
 199  * to sort "b" before "a".
 200  */
 201 static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b)
 202 {
 203         struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list);
 204         struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list);
 205         bool penda, pendb;
 206         int ret;
 207
 208         spin_lock(&irqa->irq_lock);
 209         spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING);
 210
 211         if (irqa->active || irqb->active) {
 212                 ret = (int)irqb->active - (int)irqa->active;
 213                 goto out;
 214         }
 215
 216         penda = irqa->enabled && irq_is_pending(irqa);
 217         pendb = irqb->enabled && irq_is_pending(irqb);
 218
 219         if (!penda || !pendb) {
 220                 ret = (int)pendb - (int)penda;
 221                 goto out;
 222         }
 223
 224         /* Both pending and enabled, sort by priority */
 225         ret = irqa->priority - irqb->priority;
 226 out:
 227         spin_unlock(&irqb->irq_lock);
 228         spin_unlock(&irqa->irq_lock);
 229         return ret;
 230 }
 231
 232 /* Must be called with the ap_list_lock held */
 233 static void vgic_sort_ap_list(struct kvm_vcpu *vcpu)
 234 {
 235         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 236
 237         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 238
 239         list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp);
 240 }
 241
 242 /*
 243  * Only valid injection if changing level for level-triggered IRQs or for a
 244  * rising edge, and in-kernel connected IRQ lines can only be controlled by
 245  * their owner.
 246  */
 247 static bool vgic_validate_injection(struct vgic_irq *irq, bool level, void *owner)
 248 {
 249         if (irq->owner != owner)
 250                 return false;
 251
 252         switch (irq->config) {
 253         case VGIC_CONFIG_LEVEL:
 254                 return irq->line_level != level;
 255         case VGIC_CONFIG_EDGE:
 256                 return level;
 257         }
 258
 259         return false;
 260 }
 261
 262 /*
 263  * Check whether an IRQ needs to (and can) be queued to a VCPU's ap list.
 264  * Do the queuing if necessary, taking the right locks in the right order.
 265  * Returns true when the IRQ was queued, false otherwise.
 266  *
 267  * Needs to be entered with the IRQ lock already held, but will return
 268  * with all locks dropped.
 269  */
 270 bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
 271                            unsigned long flags)
 272 {
 273         struct kvm_vcpu *vcpu;
 274
 275         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 276
 277 retry:
 278         vcpu = vgic_target_oracle(irq);
 279         if (irq->vcpu || !vcpu) {
 280                 /*
 281                  * If this IRQ is already on a VCPU's ap_list, then it
 282                  * cannot be moved or modified and there is no more work for
 283                  * us to do.
 284                  *
 285                  * Otherwise, if the irq is not pending and enabled, it does
 286                  * not need to be inserted into an ap_list and there is also
 287                  * no more work for us to do.
 288                  */
 289                 spin_unlock_irqrestore(&irq->irq_lock, flags);
 290
 291                 /*
 292                  * We have to kick the VCPU here, because we could be
 293                  * queueing an edge-triggered interrupt for which we
 294                  * get no EOI maintenance interrupt. In that case,
 295                  * while the IRQ is already on the VCPU's AP list, the
 296                  * VCPU could have EOI'ed the original interrupt and
 297                  * won't see this one until it exits for some other
 298                  * reason.
 299                  */
 300                 if (vcpu) {
 301                         kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
 302                         kvm_vcpu_kick(vcpu);
 303                 }
 304                 return false;
 305         }
 306
 307         /*
 308          * We must unlock the irq lock to take the ap_list_lock where
 309          * we are going to insert this new pending interrupt.
 310          */
 311         spin_unlock_irqrestore(&irq->irq_lock, flags);
 312
 313         /* someone can do stuff here, which we re-check below */
 314
 315         spin_lock_irqsave(&vcpu->arch.vgic_cpu.ap_list_lock, flags);
 316         spin_lock(&irq->irq_lock);
 317
 318         /*
 319          * Did something change behind our backs?
 320          *
 321          * There are two cases:
 322          * 1) The irq lost its pending state or was disabled behind our
 323          *    backs and/or it was queued to another VCPU's ap_list.
 324          * 2) Someone changed the affinity on this irq behind our
 325          *    backs and we are now holding the wrong ap_list_lock.
 326          *
 327          * In both cases, drop the locks and retry.
 328          */
 329
 330         if (unlikely(irq->vcpu || vcpu != vgic_target_oracle(irq))) {
 331                 spin_unlock(&irq->irq_lock);
 332                 spin_unlock_irqrestore(&vcpu->arch.vgic_cpu.ap_list_lock, flags);
 333
 334                 spin_lock_irqsave(&irq->irq_lock, flags);
 335                 goto retry;
 336         }
 337
 338         /*
 339          * Grab a reference to the irq to reflect the fact that it is
 340          * now in the ap_list.
 341          */
 342         vgic_get_irq_kref(irq);
 343         list_add_tail(&irq->ap_list, &vcpu->arch.vgic_cpu.ap_list_head);
 344         irq->vcpu = vcpu;
 345
 346         spin_unlock(&irq->irq_lock);
 347         spin_unlock_irqrestore(&vcpu->arch.vgic_cpu.ap_list_lock, flags);
 348
 349         kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
 350         kvm_vcpu_kick(vcpu);
 351
 352         return true;
 353 }
 354
 355 /**
 356  * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic
 357  * @kvm:     The VM structure pointer
 358  * @cpuid:   The CPU for PPIs
 359  * @intid:   The INTID to inject a new state to.
 360  * @level:   Edge-triggered:  true:  to trigger the interrupt
 361  *                            false: to ignore the call
 362  *           Level-sensitive  true:  raise the input signal
 363  *                            false: lower the input signal
 364  * @owner:   The opaque pointer to the owner of the IRQ being raised to verify
 365  *           that the caller is allowed to inject this IRQ.  Userspace
 366  *           injections will have owner == NULL.
 367  *
 368  * The VGIC is not concerned with devices being active-LOW or active-HIGH for
 369  * level-sensitive interrupts.  You can think of the level parameter as 1
 370  * being HIGH and 0 being LOW and all devices being active-HIGH.
 371  */
 372 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
 373                         bool level, void *owner)
 374 {
 375         struct kvm_vcpu *vcpu;
 376         struct vgic_irq *irq;
 377         unsigned long flags;
 378         int ret;
 379
 380         trace_vgic_update_irq_pending(cpuid, intid, level);
 381
 382         ret = vgic_lazy_init(kvm);
 383         if (ret)
 384                 return ret;
 385
 386         vcpu = kvm_get_vcpu(kvm, cpuid);
 387         if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
 388                 return -EINVAL;
 389
 390         irq = vgic_get_irq(kvm, vcpu, intid);
 391         if (!irq)
 392                 return -EINVAL;
 393
 394         spin_lock_irqsave(&irq->irq_lock, flags);
 395
 396         if (!vgic_validate_injection(irq, level, owner)) {
 397                 /* Nothing to see here, move along... */
 398                 spin_unlock_irqrestore(&irq->irq_lock, flags);
 399                 vgic_put_irq(kvm, irq);
 400                 return 0;
 401         }
 402
 403         if (irq->config == VGIC_CONFIG_LEVEL)
 404                 irq->line_level = level;
 405         else
 406                 irq->pending_latch = true;
 407
 408         vgic_queue_irq_unlock(kvm, irq, flags);
 409         vgic_put_irq(kvm, irq);
 410
 411         return 0;
 412 }
 413
 414 /* @irq->irq_lock must be held */
 415 static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
 416                             unsigned int host_irq)
 417 {
 418         struct irq_desc *desc;
 419         struct irq_data *data;
 420
 421         /*
 422          * Find the physical IRQ number corresponding to @host_irq
 423          */
 424         desc = irq_to_desc(host_irq);
 425         if (!desc) {
 426                 kvm_err("%s: no interrupt descriptor\n", __func__);
 427                 return -EINVAL;
 428         }
 429         data = irq_desc_get_irq_data(desc);
 430         while (data->parent_data)
 431                 data = data->parent_data;
 432
 433         irq->hw = true;
 434         irq->host_irq = host_irq;
 435         irq->hwintid = data->hwirq;
 436         return 0;
 437 }
 438
 439 /* @irq->irq_lock must be held */
 440 static inline void kvm_vgic_unmap_irq(struct vgic_irq *irq)
 441 {
 442         irq->hw = false;
 443         irq->hwintid = 0;
 444 }
 445
 446 int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
 447                           u32 vintid)
 448 {
 449         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
 450         unsigned long flags;
 451         int ret;
 452
 453         BUG_ON(!irq);
 454
 455         spin_lock_irqsave(&irq->irq_lock, flags);
 456         ret = kvm_vgic_map_irq(vcpu, irq, host_irq);
 457         spin_unlock_irqrestore(&irq->irq_lock, flags);
 458         vgic_put_irq(vcpu->kvm, irq);
 459
 460         return ret;
 461 }
 462
 463 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid)
 464 {
 465         struct vgic_irq *irq;
 466         unsigned long flags;
 467
 468         if (!vgic_initialized(vcpu->kvm))
 469                 return -EAGAIN;
 470
 471         irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
 472         BUG_ON(!irq);
 473
 474         spin_lock_irqsave(&irq->irq_lock, flags);
 475         kvm_vgic_unmap_irq(irq);
 476         spin_unlock_irqrestore(&irq->irq_lock, flags);
 477         vgic_put_irq(vcpu->kvm, irq);
 478
 479         return 0;
 480 }
 481
 482 /**
 483  * kvm_vgic_set_owner - Set the owner of an interrupt for a VM
 484  *
 485  * @vcpu:   Pointer to the VCPU (used for PPIs)
 486  * @intid:  The virtual INTID identifying the interrupt (PPI or SPI)
 487  * @owner:  Opaque pointer to the owner
 488  *
 489  * Returns 0 if intid is not already used by another in-kernel device and the
 490  * owner is set, otherwise returns an error code.
 491  */
 492 int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner)
 493 {
 494         struct vgic_irq *irq;
 495         int ret = 0;
 496
 497         if (!vgic_initialized(vcpu->kvm))
 498                 return -EAGAIN;
 499
 500         /* SGIs and LPIs cannot be wired up to any device */
 501         if (!irq_is_ppi(intid) && !vgic_valid_spi(vcpu->kvm, intid))
 502                 return -EINVAL;
 503
 504         irq = vgic_get_irq(vcpu->kvm, vcpu, intid);
 505         spin_lock(&irq->irq_lock);
 506         if (irq->owner && irq->owner != owner)
 507                 ret = -EEXIST;
 508         else
 509                 irq->owner = owner;
 510         spin_unlock(&irq->irq_lock);
 511
 512         return ret;
 513 }
 514
 515 /**
 516  * vgic_prune_ap_list - Remove non-relevant interrupts from the list
 517  *
 518  * @vcpu: The VCPU pointer
 519  *
 520  * Go over the list of "interesting" interrupts, and prune those that we
 521  * won't have to consider in the near future.
 522  */
 523 static void vgic_prune_ap_list(struct kvm_vcpu *vcpu)
 524 {
 525         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 526         struct vgic_irq *irq, *tmp;
 527         unsigned long flags;
 528
 529 retry:
 530         spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);
 531
 532         list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
 533                 struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB;
 534
 535                 spin_lock(&irq->irq_lock);
 536
 537                 BUG_ON(vcpu != irq->vcpu);
 538
 539                 target_vcpu = vgic_target_oracle(irq);
 540
 541                 if (!target_vcpu) {
 542                         /*
 543                          * We don't need to process this interrupt any
 544                          * further, move it off the list.
 545                          */
 546                         list_del(&irq->ap_list);
 547                         irq->vcpu = NULL;
 548                         spin_unlock(&irq->irq_lock);
 549
 550                         /*
 551                          * This vgic_put_irq call matches the
 552                          * vgic_get_irq_kref in vgic_queue_irq_unlock,
 553                          * where we added the LPI to the ap_list. As
 554                          * we remove the irq from the list, we drop
 555                          * also drop the refcount.
 556                          */
 557                         vgic_put_irq(vcpu->kvm, irq);
 558                         continue;
 559                 }
 560
 561                 if (target_vcpu == vcpu) {
 562                         /* We're on the right CPU */
 563                         spin_unlock(&irq->irq_lock);
 564                         continue;
 565                 }
 566
 567                 /* This interrupt looks like it has to be migrated. */
 568
 569                 spin_unlock(&irq->irq_lock);
 570                 spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);
 571
 572                 /*
 573                  * Ensure locking order by always locking the smallest
 574                  * ID first.
 575                  */
 576                 if (vcpu->vcpu_id < target_vcpu->vcpu_id) {
 577                         vcpuA = vcpu;
 578                         vcpuB = target_vcpu;
 579                 } else {
 580                         vcpuA = target_vcpu;
 581                         vcpuB = vcpu;
 582                 }
 583
 584                 spin_lock_irqsave(&vcpuA->arch.vgic_cpu.ap_list_lock, flags);
 585                 spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock,
 586                                  SINGLE_DEPTH_NESTING);
 587                 spin_lock(&irq->irq_lock);
 588
 589                 /*
 590                  * If the affinity has been preserved, move the
 591                  * interrupt around. Otherwise, it means things have
 592                  * changed while the interrupt was unlocked, and we
 593                  * need to replay this.
 594                  *
 595                  * In all cases, we cannot trust the list not to have
 596                  * changed, so we restart from the beginning.
 597                  */
 598                 if (target_vcpu == vgic_target_oracle(irq)) {
 599                         struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu;
 600
 601                         list_del(&irq->ap_list);
 602                         irq->vcpu = target_vcpu;
 603                         list_add_tail(&irq->ap_list, &new_cpu->ap_list_head);
 604                 }
 605
 606                 spin_unlock(&irq->irq_lock);
 607                 spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock);
 608                 spin_unlock_irqrestore(&vcpuA->arch.vgic_cpu.ap_list_lock, flags);
 609                 goto retry;
 610         }
 611
 612         spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);
 613 }
 614
 615 static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
 616 {
 617         if (kvm_vgic_global_state.type == VGIC_V2)
 618                 vgic_v2_fold_lr_state(vcpu);
 619         else
 620                 vgic_v3_fold_lr_state(vcpu);
 621 }
 622
 623 /* Requires the irq_lock to be held. */
 624 static inline void vgic_populate_lr(struct kvm_vcpu *vcpu,
 625                                     struct vgic_irq *irq, int lr)
 626 {
 627         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
 628
 629         if (kvm_vgic_global_state.type == VGIC_V2)
 630                 vgic_v2_populate_lr(vcpu, irq, lr);
 631         else
 632                 vgic_v3_populate_lr(vcpu, irq, lr);
 633 }
 634
 635 static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr)
 636 {
 637         if (kvm_vgic_global_state.type == VGIC_V2)
 638                 vgic_v2_clear_lr(vcpu, lr);
 639         else
 640                 vgic_v3_clear_lr(vcpu, lr);
 641 }
 642
 643 static inline void vgic_set_underflow(struct kvm_vcpu *vcpu)
 644 {
 645         if (kvm_vgic_global_state.type == VGIC_V2)
 646                 vgic_v2_set_underflow(vcpu);
 647         else
 648                 vgic_v3_set_underflow(vcpu);
 649 }
 650
 651 /* Requires the ap_list_lock to be held. */
 652 static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
 653 {
 654         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 655         struct vgic_irq *irq;
 656         int count = 0;
 657
 658         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 659
 660         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 661                 spin_lock(&irq->irq_lock);
 662                 /* GICv2 SGIs can count for more than one... */
 663                 if (vgic_irq_is_sgi(irq->intid) && irq->source)
 664                         count += hweight8(irq->source);
 665                 else
 666                         count++;
 667                 spin_unlock(&irq->irq_lock);
 668         }
 669         return count;
 670 }
 671
 672 /* Requires the VCPU's ap_list_lock to be held. */
 673 static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
 674 {
 675         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 676         struct vgic_irq *irq;
 677         int count = 0;
 678
 679         DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
 680
 681         if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr)
 682                 vgic_sort_ap_list(vcpu);
 683
 684         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 685                 spin_lock(&irq->irq_lock);
 686
 687                 if (unlikely(vgic_target_oracle(irq) != vcpu))
 688                         goto next;
 689
 690                 /*
 691                  * If we get an SGI with multiple sources, try to get
 692                  * them in all at once.
 693                  */
 694                 do {
 695                         vgic_populate_lr(vcpu, irq, count++);
 696                 } while (irq->source && count < kvm_vgic_global_state.nr_lr);
 697
 698 next:
 699                 spin_unlock(&irq->irq_lock);
 700
 701                 if (count == kvm_vgic_global_state.nr_lr) {
 702                         if (!list_is_last(&irq->ap_list,
 703                                           &vgic_cpu->ap_list_head))
 704                                 vgic_set_underflow(vcpu);
 705                         break;
 706                 }
 707         }
 708
 709         vcpu->arch.vgic_cpu.used_lrs = count;
 710
 711         /* Nuke remaining LRs */
 712         for ( ; count < kvm_vgic_global_state.nr_lr; count++)
 713                 vgic_clear_lr(vcpu, count);
 714 }
 715
 716 /* Sync back the hardware VGIC state into our emulation after a guest's run. */
 717 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 718 {
 719         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 720
 721         WARN_ON(vgic_v4_sync_hwstate(vcpu));
 722
 723         /* An empty ap_list_head implies used_lrs == 0 */
 724         if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 725                 return;
 726
 727         if (vgic_cpu->used_lrs)
 728                 vgic_fold_lr_state(vcpu);
 729         vgic_prune_ap_list(vcpu);
 730 }
 731
 732 /* Flush our emulation state into the GIC hardware before entering the guest. */
 733 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 734 {
 735         WARN_ON(vgic_v4_flush_hwstate(vcpu));
 736
 737         /*
 738          * If there are no virtual interrupts active or pending for this
 739          * VCPU, then there is no work to do and we can bail out without
 740          * taking any lock.  There is a potential race with someone injecting
 741          * interrupts to the VCPU, but it is a benign race as the VCPU will
 742          * either observe the new interrupt before or after doing this check,
 743          * and introducing additional synchronization mechanism doesn't change
 744          * this.
 745          */
 746         if (list_empty(&vcpu->arch.vgic_cpu.ap_list_head))
 747                 return;
 748
 749         DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
 750
 751         spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
 752         vgic_flush_lr_state(vcpu);
 753         spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 754 }
 755
 756 void kvm_vgic_load(struct kvm_vcpu *vcpu)
 757 {
 758         if (unlikely(!vgic_initialized(vcpu->kvm)))
 759                 return;
 760
 761         if (kvm_vgic_global_state.type == VGIC_V2)
 762                 vgic_v2_load(vcpu);
 763         else
 764                 vgic_v3_load(vcpu);
 765 }
 766
 767 void kvm_vgic_put(struct kvm_vcpu *vcpu)
 768 {
 769         if (unlikely(!vgic_initialized(vcpu->kvm)))
 770                 return;
 771
 772         if (kvm_vgic_global_state.type == VGIC_V2)
 773                 vgic_v2_put(vcpu);
 774         else
 775                 vgic_v3_put(vcpu);
 776 }
 777
 778 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 779 {
 780         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 781         struct vgic_irq *irq;
 782         bool pending = false;
 783         unsigned long flags;
 784
 785         if (!vcpu->kvm->arch.vgic.enabled)
 786                 return false;
 787
 788         if (vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last)
 789                 return true;
 790
 791         spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);
 792
 793         list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
 794                 spin_lock(&irq->irq_lock);
 795                 pending = irq_is_pending(irq) && irq->enabled;
 796                 spin_unlock(&irq->irq_lock);
 797
 798                 if (pending)
 799                         break;
 800         }
 801
 802         spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);
 803
 804         return pending;
 805 }
 806
 807 void vgic_kick_vcpus(struct kvm *kvm)
 808 {
 809         struct kvm_vcpu *vcpu;
 810         int c;
 811
 812         /*
 813          * We've injected an interrupt, time to find out who deserves
 814          * a good kick...
 815          */
 816         kvm_for_each_vcpu(c, vcpu, kvm) {
 817                 if (kvm_vgic_vcpu_pending_irq(vcpu)) {
 818                         kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
 819                         kvm_vcpu_kick(vcpu);
 820                 }
 821         }
 822 }
 823
 824 bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid)
 825 {
 826         struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
 827         bool map_is_active;
 828         unsigned long flags;
 829
 830         if (!vgic_initialized(vcpu->kvm))
 831                 return false;
 832
 833         spin_lock_irqsave(&irq->irq_lock, flags);
 834         map_is_active = irq->hw && irq->active;
 835         spin_unlock_irqrestore(&irq->irq_lock, flags);
 836         vgic_put_irq(vcpu->kvm, irq);
 837
 838         return map_is_active;
 839 }
 840