diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 7d8e61fa9928e5cc77fbbab3c5d46da30b75515c..f074539c6ac585e1c5715b09ce5590f2dd605076 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -140,9 +140,23 @@ struct vgic_dist {
/* Interrupt enabled (one bit per IRQ) */
struct vgic_bitmap irq_enabled;
- /* Interrupt state is pending on the distributor */
+ /* Level-triggered interrupt external input is asserted */
+ struct vgic_bitmap irq_level;
+
+ /*
+ * Interrupt state is pending on the distributor
+ */
struct vgic_bitmap irq_pending;
+ /*
+ * Tracks writes to GICD_ISPENDRn and GICD_ICPENDRn for level-triggered
+ * interrupts. Essentially holds the state of the flip-flop in
+ * Figure 4-10 on page 4-101 in ARM IHI 0048B.b.
+ * Once set, it is only cleared for level-triggered interrupts on
+ * guest ACKs (when we queue it) or writes to GICD_ICPENDRn.
+ */
+ struct vgic_bitmap irq_soft_pend;
+
/* Level-triggered interrupt queued on VCPU interface */
struct vgic_bitmap irq_queued;
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 2026b6147805eaf387d6197e55d9b09dbee84eae..435d8e7ad13721d722ebf839110327876f7cc51c 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -67,6 +67,11 @@
* - When the interrupt is EOIed, the maintenance interrupt fires,
* and clears the corresponding bit in irq_queued. This allows the
* interrupt line to be sampled again.
+ * - Note that level-triggered interrupts can also be set to pending from
+ * writes to GICD_ISPENDRn and lowering the external input line does not
+ * cause the interrupt to become inactive in such a situation.
+ * Conversely, writes to GICD_ICPENDRn do not cause the interrupt to become
+ * inactive as long as the external input line is held high.
*/
#define VGIC_ADDR_UNDEF (-1)
@@ -217,6 +222,41 @@ static void vgic_irq_clear_queued(struct kvm_vcpu *vcpu, int irq)
vgic_bitmap_set_irq_val(&dist->irq_queued, vcpu->vcpu_id, irq, 0);
}
+static int vgic_dist_irq_get_level(struct kvm_vcpu *vcpu, int irq)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ return vgic_bitmap_get_irq_val(&dist->irq_level, vcpu->vcpu_id, irq);
+}
+
+static void vgic_dist_irq_set_level(struct kvm_vcpu *vcpu, int irq)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ vgic_bitmap_set_irq_val(&dist->irq_level, vcpu->vcpu_id, irq, 1);
+}
+
+static void vgic_dist_irq_clear_level(struct kvm_vcpu *vcpu, int irq)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ vgic_bitmap_set_irq_val(&dist->irq_level, vcpu->vcpu_id, irq, 0);
+}
+
+static int vgic_dist_irq_soft_pend(struct kvm_vcpu *vcpu, int irq)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ return vgic_bitmap_get_irq_val(&dist->irq_soft_pend, vcpu->vcpu_id, irq);
+}
+
+static void vgic_dist_irq_clear_soft_pend(struct kvm_vcpu *vcpu, int irq)
+{
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ vgic_bitmap_set_irq_val(&dist->irq_soft_pend, vcpu->vcpu_id, irq, 0);
+}
+
static int vgic_dist_irq_is_pending(struct kvm_vcpu *vcpu, int irq)
{
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
@@ -414,11 +454,26 @@ static bool handle_mmio_set_pending_reg(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
- u32 *reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_pending,
- vcpu->vcpu_id, offset);
+ u32 *reg;
+ u32 level_mask;
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ reg = vgic_bitmap_get_reg(&dist->irq_cfg, vcpu->vcpu_id, offset);
+ level_mask = (~(*reg));
+
+ /* Mark both level and edge triggered irqs as pending */
+ reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu->vcpu_id, offset);
vgic_reg_access(mmio, reg, offset,
ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT);
+
if (mmio->is_write) {
+ /* Set the soft-pending flag only for level-triggered irqs */
+ reg = vgic_bitmap_get_reg(&dist->irq_soft_pend,
+ vcpu->vcpu_id, offset);
+ vgic_reg_access(mmio, reg, offset,
+ ACCESS_READ_VALUE | ACCESS_WRITE_SETBIT);
+ *reg &= level_mask;
+
vgic_update_state(vcpu->kvm);
return true;
}
@@ -430,11 +485,27 @@ static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
struct kvm_exit_mmio *mmio,
phys_addr_t offset)
{
- u32 *reg = vgic_bitmap_get_reg(&vcpu->kvm->arch.vgic.irq_pending,
- vcpu->vcpu_id, offset);
+ u32 *level_active;
+ u32 *reg;
+ struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+ reg = vgic_bitmap_get_reg(&dist->irq_pending, vcpu->vcpu_id, offset);
vgic_reg_access(mmio, reg, offset,
ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);
if (mmio->is_write) {
+ /* Re-set level triggered level-active interrupts */
+ level_active = vgic_bitmap_get_reg(&dist->irq_level,
+ vcpu->vcpu_id, offset);
+ reg = vgic_bitmap_get_reg(&dist->irq_pending,
+ vcpu->vcpu_id, offset);
+ *reg |= *level_active;
+
+ /* Clear soft-pending flags */
+ reg = vgic_bitmap_get_reg(&dist->irq_soft_pend,
+ vcpu->vcpu_id, offset);
+ vgic_reg_access(mmio, reg, offset,
+ ACCESS_READ_VALUE | ACCESS_WRITE_CLEARBIT);
+
vgic_update_state(vcpu->kvm);
return true;
}
@@ -1268,17 +1339,32 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
for_each_set_bit(lr, eisr_ptr, vgic->nr_lr) {
struct vgic_lr vlr = vgic_get_lr(vcpu, lr);
+ WARN_ON(vgic_irq_is_edge(vcpu, vlr.irq));
vgic_irq_clear_queued(vcpu, vlr.irq);
WARN_ON(vlr.state & LR_STATE_MASK);
vlr.state = 0;
vgic_set_lr(vcpu, lr, vlr);
+ /*
+ * If the IRQ was EOIed it was also ACKed and we we
+ * therefore assume we can clear the soft pending
+ * state (should it had been set) for this interrupt.
+ *
+ * Note: if the IRQ soft pending state was set after
+ * the IRQ was acked, it actually shouldn't be
+ * cleared, but we have no way of knowing that unless
+ * we start trapping ACKs when the soft-pending state
+ * is set.
+ */
+ vgic_dist_irq_clear_soft_pend(vcpu, vlr.irq);
+
/* Any additional pending interrupt? */
- if (vgic_dist_irq_is_pending(vcpu, vlr.irq)) {
+ if (vgic_dist_irq_get_level(vcpu, vlr.irq)) {
vgic_cpu_irq_set(vcpu, vlr.irq);
level_pending = true;
} else {
+ vgic_dist_irq_clear_pending(vcpu, vlr.irq);
vgic_cpu_irq_clear(vcpu, vlr.irq);
}
@@ -1384,17 +1470,19 @@ static void vgic_kick_vcpus(struct kvm *kvm)
static int vgic_validate_injection(struct kvm_vcpu *vcpu, int irq, int level)
{
int edge_triggered = vgic_irq_is_edge(vcpu, irq);
- int state = vgic_dist_irq_is_pending(vcpu, irq);
/*
* Only inject an interrupt if:
* - edge triggered and we have a rising edge
* - level triggered and we change level
*/
- if (edge_triggered)
+ if (edge_triggered) {
+ int state = vgic_dist_irq_is_pending(vcpu, irq);
return level > state;
- else
+ } else {
+ int state = vgic_dist_irq_get_level(vcpu, irq);
return level != state;
+ }
}
static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
@@ -1424,10 +1512,19 @@ static bool vgic_update_irq_pending(struct kvm *kvm, int cpuid,
kvm_debug("Inject IRQ%d level %d CPU%d\n", irq_num, level, cpuid);
- if (level)
+ if (level) {
+ if (level_triggered)
+ vgic_dist_irq_set_level(vcpu, irq_num);
vgic_dist_irq_set_pending(vcpu, irq_num);
- else
- vgic_dist_irq_clear_pending(vcpu, irq_num);
+ } else {
+ if (level_triggered) {
+ vgic_dist_irq_clear_level(vcpu, irq_num);
+ if (!vgic_dist_irq_soft_pend(vcpu, irq_num))
+ vgic_dist_irq_clear_pending(vcpu, irq_num);
+ } else {
+ vgic_dist_irq_clear_pending(vcpu, irq_num);
+ }
+ }
enabled = vgic_irq_is_enabled(vcpu, irq_num);