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authorMarc Zyngier <marc.zyngier@arm.com>2015-06-08 16:06:13 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2015-08-12 11:28:25 +0100
commit08fd6461e8752d2db233c1f237fa5771bcefc63f (patch)
tree4c1e5d2ed88eece78975a83cde1995e7e9e36ae4
parent6c3d63c9a26ba56e2ca63a9f68d52f77ae551d91 (diff)
KVM: arm/arm64: vgic: Allow HW interrupts to be queued to a guest
To allow a HW interrupt to be injected into a guest, we lookup the guest virtual interrupt in the irq_phys_map list, and if we have a match, encode both interrupts in the LR. We also mark the interrupt as "active" at the host distributor level. On guest EOI on the virtual interrupt, the host interrupt will be deactivated. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
-rw-r--r--virt/kvm/arm/vgic.c89
1 files changed, 86 insertions, 3 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 51c990075624..9d009d2f92f8 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1140,6 +1140,39 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu *vcpu, int irq,
if (!vgic_irq_is_edge(vcpu, irq))
vlr.state |= LR_EOI_INT;
+ if (vlr.irq >= VGIC_NR_SGIS) {
+ struct irq_phys_map *map;
+ map = vgic_irq_map_search(vcpu, irq);
+
+ /*
+ * If we have a mapping, and the virtual interrupt is
+ * being injected, then we must set the state to
+ * active in the physical world. Otherwise the
+ * physical interrupt will fire and the guest will
+ * exit before processing the virtual interrupt.
+ */
+ if (map) {
+ int ret;
+
+ BUG_ON(!map->active);
+ vlr.hwirq = map->phys_irq;
+ vlr.state |= LR_HW;
+ vlr.state &= ~LR_EOI_INT;
+
+ ret = irq_set_irqchip_state(map->irq,
+ IRQCHIP_STATE_ACTIVE,
+ true);
+ WARN_ON(ret);
+
+ /*
+ * Make sure we're not going to sample this
+ * again, as a HW-backed interrupt cannot be
+ * in the PENDING_ACTIVE stage.
+ */
+ vgic_irq_set_queued(vcpu, irq);
+ }
+ }
+
vgic_set_lr(vcpu, lr_nr, vlr);
vgic_sync_lr_elrsr(vcpu, lr_nr, vlr);
}
@@ -1364,6 +1397,39 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
return level_pending;
}
+/*
+ * Save the physical active state, and reset it to inactive.
+ *
+ * Return 1 if HW interrupt went from active to inactive, and 0 otherwise.
+ */
+static int vgic_sync_hwirq(struct kvm_vcpu *vcpu, struct vgic_lr vlr)
+{
+ struct irq_phys_map *map;
+ int ret;
+
+ if (!(vlr.state & LR_HW))
+ return 0;
+
+ map = vgic_irq_map_search(vcpu, vlr.irq);
+ BUG_ON(!map || !map->active);
+
+ ret = irq_get_irqchip_state(map->irq,
+ IRQCHIP_STATE_ACTIVE,
+ &map->active);
+
+ WARN_ON(ret);
+
+ if (map->active) {
+ ret = irq_set_irqchip_state(map->irq,
+ IRQCHIP_STATE_ACTIVE,
+ false);
+ WARN_ON(ret);
+ return 0;
+ }
+
+ return 1;
+}
+
/* Sync back the VGIC state after a guest run */
static void __kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
{
@@ -1378,14 +1444,31 @@ static void __kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
elrsr = vgic_get_elrsr(vcpu);
elrsr_ptr = u64_to_bitmask(&elrsr);
- /* Clear mappings for empty LRs */
- for_each_set_bit(lr, elrsr_ptr, vgic->nr_lr) {
+ /* Deal with HW interrupts, and clear mappings for empty LRs */
+ for (lr = 0; lr < vgic->nr_lr; lr++) {
struct vgic_lr vlr;
- if (!test_and_clear_bit(lr, vgic_cpu->lr_used))
+ if (!test_bit(lr, vgic_cpu->lr_used))
continue;
vlr = vgic_get_lr(vcpu, lr);
+ if (vgic_sync_hwirq(vcpu, vlr)) {
+ /*
+ * So this is a HW interrupt that the guest
+ * EOI-ed. Clean the LR state and allow the
+ * interrupt to be sampled again.
+ */
+ vlr.state = 0;
+ vlr.hwirq = 0;
+ vgic_set_lr(vcpu, lr, vlr);
+ vgic_irq_clear_queued(vcpu, vlr.irq);
+ set_bit(lr, elrsr_ptr);
+ }
+
+ if (!test_bit(lr, elrsr_ptr))
+ continue;
+
+ clear_bit(lr, vgic_cpu->lr_used);
BUG_ON(vlr.irq >= dist->nr_irqs);
vgic_cpu->vgic_irq_lr_map[vlr.irq] = LR_EMPTY;