summaryrefslogtreecommitdiff
path: root/virt/kvm/arm/vgic/vgic.c
diff options
context:
space:
mode:
Diffstat (limited to 'virt/kvm/arm/vgic/vgic.c')
-rw-r--r--virt/kvm/arm/vgic/vgic.c619
1 files changed, 619 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
new file mode 100644
index 000000000..69b61abef
--- /dev/null
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -0,0 +1,619 @@
+/*
+ * Copyright (C) 2015, 2016 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/list_sort.h>
+
+#include "vgic.h"
+
+#define CREATE_TRACE_POINTS
+#include "../trace.h"
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+#define DEBUG_SPINLOCK_BUG_ON(p) BUG_ON(p)
+#else
+#define DEBUG_SPINLOCK_BUG_ON(p)
+#endif
+
+struct vgic_global __section(.hyp.text) kvm_vgic_global_state;
+
+/*
+ * Locking order is always:
+ * vgic_cpu->ap_list_lock
+ * vgic_irq->irq_lock
+ *
+ * (that is, always take the ap_list_lock before the struct vgic_irq lock).
+ *
+ * When taking more than one ap_list_lock at the same time, always take the
+ * lowest numbered VCPU's ap_list_lock first, so:
+ * vcpuX->vcpu_id < vcpuY->vcpu_id:
+ * spin_lock(vcpuX->arch.vgic_cpu.ap_list_lock);
+ * spin_lock(vcpuY->arch.vgic_cpu.ap_list_lock);
+ */
+
+struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
+ u32 intid)
+{
+ /* SGIs and PPIs */
+ if (intid <= VGIC_MAX_PRIVATE)
+ return &vcpu->arch.vgic_cpu.private_irqs[intid];
+
+ /* SPIs */
+ if (intid <= VGIC_MAX_SPI)
+ return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
+
+ /* LPIs are not yet covered */
+ if (intid >= VGIC_MIN_LPI)
+ return NULL;
+
+ WARN(1, "Looking up struct vgic_irq for reserved INTID");
+ return NULL;
+}
+
+/**
+ * kvm_vgic_target_oracle - compute the target vcpu for an irq
+ *
+ * @irq: The irq to route. Must be already locked.
+ *
+ * Based on the current state of the interrupt (enabled, pending,
+ * active, vcpu and target_vcpu), compute the next vcpu this should be
+ * given to. Return NULL if this shouldn't be injected at all.
+ *
+ * Requires the IRQ lock to be held.
+ */
+static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq)
+{
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
+
+ /* If the interrupt is active, it must stay on the current vcpu */
+ if (irq->active)
+ return irq->vcpu ? : irq->target_vcpu;
+
+ /*
+ * If the IRQ is not active but enabled and pending, we should direct
+ * it to its configured target VCPU.
+ * If the distributor is disabled, pending interrupts shouldn't be
+ * forwarded.
+ */
+ if (irq->enabled && irq->pending) {
+ if (unlikely(irq->target_vcpu &&
+ !irq->target_vcpu->kvm->arch.vgic.enabled))
+ return NULL;
+
+ return irq->target_vcpu;
+ }
+
+ /* If neither active nor pending and enabled, then this IRQ should not
+ * be queued to any VCPU.
+ */
+ return NULL;
+}
+
+/*
+ * The order of items in the ap_lists defines how we'll pack things in LRs as
+ * well, the first items in the list being the first things populated in the
+ * LRs.
+ *
+ * A hard rule is that active interrupts can never be pushed out of the LRs
+ * (and therefore take priority) since we cannot reliably trap on deactivation
+ * of IRQs and therefore they have to be present in the LRs.
+ *
+ * Otherwise things should be sorted by the priority field and the GIC
+ * hardware support will take care of preemption of priority groups etc.
+ *
+ * Return negative if "a" sorts before "b", 0 to preserve order, and positive
+ * to sort "b" before "a".
+ */
+static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list);
+ struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list);
+ bool penda, pendb;
+ int ret;
+
+ spin_lock(&irqa->irq_lock);
+ spin_lock_nested(&irqb->irq_lock, SINGLE_DEPTH_NESTING);
+
+ if (irqa->active || irqb->active) {
+ ret = (int)irqb->active - (int)irqa->active;
+ goto out;
+ }
+
+ penda = irqa->enabled && irqa->pending;
+ pendb = irqb->enabled && irqb->pending;
+
+ if (!penda || !pendb) {
+ ret = (int)pendb - (int)penda;
+ goto out;
+ }
+
+ /* Both pending and enabled, sort by priority */
+ ret = irqa->priority - irqb->priority;
+out:
+ spin_unlock(&irqb->irq_lock);
+ spin_unlock(&irqa->irq_lock);
+ return ret;
+}
+
+/* Must be called with the ap_list_lock held */
+static void vgic_sort_ap_list(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
+
+ list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp);
+}
+
+/*
+ * Only valid injection if changing level for level-triggered IRQs or for a
+ * rising edge.
+ */
+static bool vgic_validate_injection(struct vgic_irq *irq, bool level)
+{
+ switch (irq->config) {
+ case VGIC_CONFIG_LEVEL:
+ return irq->line_level != level;
+ case VGIC_CONFIG_EDGE:
+ return level;
+ }
+
+ return false;
+}
+
+/*
+ * Check whether an IRQ needs to (and can) be queued to a VCPU's ap list.
+ * Do the queuing if necessary, taking the right locks in the right order.
+ * Returns true when the IRQ was queued, false otherwise.
+ *
+ * Needs to be entered with the IRQ lock already held, but will return
+ * with all locks dropped.
+ */
+bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq)
+{
+ struct kvm_vcpu *vcpu;
+
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
+
+retry:
+ vcpu = vgic_target_oracle(irq);
+ if (irq->vcpu || !vcpu) {
+ /*
+ * If this IRQ is already on a VCPU's ap_list, then it
+ * cannot be moved or modified and there is no more work for
+ * us to do.
+ *
+ * Otherwise, if the irq is not pending and enabled, it does
+ * not need to be inserted into an ap_list and there is also
+ * no more work for us to do.
+ */
+ spin_unlock(&irq->irq_lock);
+ return false;
+ }
+
+ /*
+ * We must unlock the irq lock to take the ap_list_lock where
+ * we are going to insert this new pending interrupt.
+ */
+ spin_unlock(&irq->irq_lock);
+
+ /* someone can do stuff here, which we re-check below */
+
+ spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
+ spin_lock(&irq->irq_lock);
+
+ /*
+ * Did something change behind our backs?
+ *
+ * There are two cases:
+ * 1) The irq lost its pending state or was disabled behind our
+ * backs and/or it was queued to another VCPU's ap_list.
+ * 2) Someone changed the affinity on this irq behind our
+ * backs and we are now holding the wrong ap_list_lock.
+ *
+ * In both cases, drop the locks and retry.
+ */
+
+ if (unlikely(irq->vcpu || vcpu != vgic_target_oracle(irq))) {
+ spin_unlock(&irq->irq_lock);
+ spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+
+ spin_lock(&irq->irq_lock);
+ goto retry;
+ }
+
+ list_add_tail(&irq->ap_list, &vcpu->arch.vgic_cpu.ap_list_head);
+ irq->vcpu = vcpu;
+
+ spin_unlock(&irq->irq_lock);
+ spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+
+ kvm_vcpu_kick(vcpu);
+
+ return true;
+}
+
+static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
+ unsigned int intid, bool level,
+ bool mapped_irq)
+{
+ struct kvm_vcpu *vcpu;
+ struct vgic_irq *irq;
+ int ret;
+
+ trace_vgic_update_irq_pending(cpuid, intid, level);
+
+ ret = vgic_lazy_init(kvm);
+ if (ret)
+ return ret;
+
+ vcpu = kvm_get_vcpu(kvm, cpuid);
+ if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
+ return -EINVAL;
+
+ irq = vgic_get_irq(kvm, vcpu, intid);
+ if (!irq)
+ return -EINVAL;
+
+ if (irq->hw != mapped_irq)
+ return -EINVAL;
+
+ spin_lock(&irq->irq_lock);
+
+ if (!vgic_validate_injection(irq, level)) {
+ /* Nothing to see here, move along... */
+ spin_unlock(&irq->irq_lock);
+ return 0;
+ }
+
+ if (irq->config == VGIC_CONFIG_LEVEL) {
+ irq->line_level = level;
+ irq->pending = level || irq->soft_pending;
+ } else {
+ irq->pending = true;
+ }
+
+ vgic_queue_irq_unlock(kvm, irq);
+
+ return 0;
+}
+
+/**
+ * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic
+ * @kvm: The VM structure pointer
+ * @cpuid: The CPU for PPIs
+ * @intid: The INTID to inject a new state to.
+ * @level: Edge-triggered: true: to trigger the interrupt
+ * false: to ignore the call
+ * Level-sensitive true: raise the input signal
+ * false: lower the input signal
+ *
+ * The VGIC is not concerned with devices being active-LOW or active-HIGH for
+ * level-sensitive interrupts. You can think of the level parameter as 1
+ * being HIGH and 0 being LOW and all devices being active-HIGH.
+ */
+int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
+ bool level)
+{
+ return vgic_update_irq_pending(kvm, cpuid, intid, level, false);
+}
+
+int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid, unsigned int intid,
+ bool level)
+{
+ return vgic_update_irq_pending(kvm, cpuid, intid, level, true);
+}
+
+int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, u32 virt_irq, u32 phys_irq)
+{
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
+
+ BUG_ON(!irq);
+
+ spin_lock(&irq->irq_lock);
+
+ irq->hw = true;
+ irq->hwintid = phys_irq;
+
+ spin_unlock(&irq->irq_lock);
+
+ return 0;
+}
+
+int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq)
+{
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
+
+ BUG_ON(!irq);
+
+ if (!vgic_initialized(vcpu->kvm))
+ return -EAGAIN;
+
+ spin_lock(&irq->irq_lock);
+
+ irq->hw = false;
+ irq->hwintid = 0;
+
+ spin_unlock(&irq->irq_lock);
+
+ return 0;
+}
+
+/**
+ * vgic_prune_ap_list - Remove non-relevant interrupts from the list
+ *
+ * @vcpu: The VCPU pointer
+ *
+ * Go over the list of "interesting" interrupts, and prune those that we
+ * won't have to consider in the near future.
+ */
+static void vgic_prune_ap_list(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ struct vgic_irq *irq, *tmp;
+
+retry:
+ spin_lock(&vgic_cpu->ap_list_lock);
+
+ list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
+ struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB;
+
+ spin_lock(&irq->irq_lock);
+
+ BUG_ON(vcpu != irq->vcpu);
+
+ target_vcpu = vgic_target_oracle(irq);
+
+ if (!target_vcpu) {
+ /*
+ * We don't need to process this interrupt any
+ * further, move it off the list.
+ */
+ list_del(&irq->ap_list);
+ irq->vcpu = NULL;
+ spin_unlock(&irq->irq_lock);
+ continue;
+ }
+
+ if (target_vcpu == vcpu) {
+ /* We're on the right CPU */
+ spin_unlock(&irq->irq_lock);
+ continue;
+ }
+
+ /* This interrupt looks like it has to be migrated. */
+
+ spin_unlock(&irq->irq_lock);
+ spin_unlock(&vgic_cpu->ap_list_lock);
+
+ /*
+ * Ensure locking order by always locking the smallest
+ * ID first.
+ */
+ if (vcpu->vcpu_id < target_vcpu->vcpu_id) {
+ vcpuA = vcpu;
+ vcpuB = target_vcpu;
+ } else {
+ vcpuA = target_vcpu;
+ vcpuB = vcpu;
+ }
+
+ spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock);
+ spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock,
+ SINGLE_DEPTH_NESTING);
+ spin_lock(&irq->irq_lock);
+
+ /*
+ * If the affinity has been preserved, move the
+ * interrupt around. Otherwise, it means things have
+ * changed while the interrupt was unlocked, and we
+ * need to replay this.
+ *
+ * In all cases, we cannot trust the list not to have
+ * changed, so we restart from the beginning.
+ */
+ if (target_vcpu == vgic_target_oracle(irq)) {
+ struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu;
+
+ list_del(&irq->ap_list);
+ irq->vcpu = target_vcpu;
+ list_add_tail(&irq->ap_list, &new_cpu->ap_list_head);
+ }
+
+ spin_unlock(&irq->irq_lock);
+ spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock);
+ spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock);
+ goto retry;
+ }
+
+ spin_unlock(&vgic_cpu->ap_list_lock);
+}
+
+static inline void vgic_process_maintenance_interrupt(struct kvm_vcpu *vcpu)
+{
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_process_maintenance(vcpu);
+ else
+ vgic_v3_process_maintenance(vcpu);
+}
+
+static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
+{
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_fold_lr_state(vcpu);
+ else
+ vgic_v3_fold_lr_state(vcpu);
+}
+
+/* Requires the irq_lock to be held. */
+static inline void vgic_populate_lr(struct kvm_vcpu *vcpu,
+ struct vgic_irq *irq, int lr)
+{
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&irq->irq_lock));
+
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_populate_lr(vcpu, irq, lr);
+ else
+ vgic_v3_populate_lr(vcpu, irq, lr);
+}
+
+static inline void vgic_clear_lr(struct kvm_vcpu *vcpu, int lr)
+{
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_clear_lr(vcpu, lr);
+ else
+ vgic_v3_clear_lr(vcpu, lr);
+}
+
+static inline void vgic_set_underflow(struct kvm_vcpu *vcpu)
+{
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_set_underflow(vcpu);
+ else
+ vgic_v3_set_underflow(vcpu);
+}
+
+/* Requires the ap_list_lock to be held. */
+static int compute_ap_list_depth(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ struct vgic_irq *irq;
+ int count = 0;
+
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
+
+ list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
+ spin_lock(&irq->irq_lock);
+ /* GICv2 SGIs can count for more than one... */
+ if (vgic_irq_is_sgi(irq->intid) && irq->source)
+ count += hweight8(irq->source);
+ else
+ count++;
+ spin_unlock(&irq->irq_lock);
+ }
+ return count;
+}
+
+/* Requires the VCPU's ap_list_lock to be held. */
+static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ struct vgic_irq *irq;
+ int count = 0;
+
+ DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock));
+
+ if (compute_ap_list_depth(vcpu) > kvm_vgic_global_state.nr_lr) {
+ vgic_set_underflow(vcpu);
+ vgic_sort_ap_list(vcpu);
+ }
+
+ list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
+ spin_lock(&irq->irq_lock);
+
+ if (unlikely(vgic_target_oracle(irq) != vcpu))
+ goto next;
+
+ /*
+ * If we get an SGI with multiple sources, try to get
+ * them in all at once.
+ */
+ do {
+ vgic_populate_lr(vcpu, irq, count++);
+ } while (irq->source && count < kvm_vgic_global_state.nr_lr);
+
+next:
+ spin_unlock(&irq->irq_lock);
+
+ if (count == kvm_vgic_global_state.nr_lr)
+ break;
+ }
+
+ vcpu->arch.vgic_cpu.used_lrs = count;
+
+ /* Nuke remaining LRs */
+ for ( ; count < kvm_vgic_global_state.nr_lr; count++)
+ vgic_clear_lr(vcpu, count);
+}
+
+/* Sync back the hardware VGIC state into our emulation after a guest's run. */
+void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
+{
+ vgic_process_maintenance_interrupt(vcpu);
+ vgic_fold_lr_state(vcpu);
+ vgic_prune_ap_list(vcpu);
+}
+
+/* Flush our emulation state into the GIC hardware before entering the guest. */
+void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
+{
+ spin_lock(&vcpu->arch.vgic_cpu.ap_list_lock);
+ vgic_flush_lr_state(vcpu);
+ spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
+}
+
+int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ struct vgic_irq *irq;
+ bool pending = false;
+
+ if (!vcpu->kvm->arch.vgic.enabled)
+ return false;
+
+ spin_lock(&vgic_cpu->ap_list_lock);
+
+ list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
+ spin_lock(&irq->irq_lock);
+ pending = irq->pending && irq->enabled;
+ spin_unlock(&irq->irq_lock);
+
+ if (pending)
+ break;
+ }
+
+ spin_unlock(&vgic_cpu->ap_list_lock);
+
+ return pending;
+}
+
+void vgic_kick_vcpus(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int c;
+
+ /*
+ * We've injected an interrupt, time to find out who deserves
+ * a good kick...
+ */
+ kvm_for_each_vcpu(c, vcpu, kvm) {
+ if (kvm_vgic_vcpu_pending_irq(vcpu))
+ kvm_vcpu_kick(vcpu);
+ }
+}
+
+bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq)
+{
+ struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, virt_irq);
+ bool map_is_active;
+
+ spin_lock(&irq->irq_lock);
+ map_is_active = irq->hw && irq->active;
+ spin_unlock(&irq->irq_lock);
+
+ return map_is_active;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-15 21:24:53 +0000