arm/arm64: KVM: support for un-queuing active IRQs

Migrating active interrupts causes the active state to be lost
completely. This implements some additional bitmaps to track the active
state on the distributor and export this to user space.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

include/kvm/arm_vgic.h

@@ -195,6 +195,9 @@ struct vgic_dist {
 	/* Level-triggered interrupt queued on VCPU interface */
 	struct vgic_bitmap	irq_queued;
 
+	/* Interrupt was active when unqueue from VCPU interface */
+	struct vgic_bitmap	irq_active;
+
 	/* Interrupt priority. Not used yet. */
 	struct vgic_bytemap	irq_priority;
 
@@ -235,6 +238,9 @@ struct vgic_dist {
 	/* Bitmap indicating which CPU has something pending */
 	unsigned long		*irq_pending_on_cpu;
 
+	/* Bitmap indicating which CPU has active IRQs */
+	unsigned long		*irq_active_on_cpu;
+
 	struct vgic_vm_ops	vm_ops;
 };
 
@@ -266,9 +272,15 @@ struct vgic_cpu {
 	/* per IRQ to LR mapping */
 	u8		*vgic_irq_lr_map;
 
-	/* Pending interrupts on this VCPU */
+	/* Pending/active/both interrupts on this VCPU */
 	DECLARE_BITMAP(	pending_percpu, VGIC_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(	active_percpu, VGIC_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(	pend_act_percpu, VGIC_NR_PRIVATE_IRQS);
+
+	/* Pending/active/both shared interrupts, dynamically sized */
 	unsigned long	*pending_shared;
+	unsigned long   *active_shared;
+	unsigned long   *pend_act_shared;
 
 	/* Bitmap of used/free list registers */
 	DECLARE_BITMAP(	lr_used, VGIC_V2_MAX_LRS);
@@ -306,6 +318,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
 			bool level);
 void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
+int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu);
 bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		      struct kvm_exit_mmio *mmio);
 

virt/kvm/arm/vgic-v2-emul.c

@@ -107,6 +107,22 @@ static bool handle_mmio_clear_pending_reg(struct kvm_vcpu *vcpu,
 					     vcpu->vcpu_id);
 }
 
+static bool handle_mmio_set_active_reg(struct kvm_vcpu *vcpu,
+				       struct kvm_exit_mmio *mmio,
+				       phys_addr_t offset)
+{
+	return vgic_handle_set_active_reg(vcpu->kvm, mmio, offset,
+					  vcpu->vcpu_id);
+}
+
+static bool handle_mmio_clear_active_reg(struct kvm_vcpu *vcpu,
+					 struct kvm_exit_mmio *mmio,
+					 phys_addr_t offset)
+{
+	return vgic_handle_clear_active_reg(vcpu->kvm, mmio, offset,
+					    vcpu->vcpu_id);
+}
+
 static bool handle_mmio_priority_reg(struct kvm_vcpu *vcpu,
 				     struct kvm_exit_mmio *mmio,
 				     phys_addr_t offset)
@@ -344,13 +360,13 @@ static const struct kvm_mmio_range vgic_dist_ranges[] = {
 		.base		= GIC_DIST_ACTIVE_SET,
 		.len		= VGIC_MAX_IRQS / 8,
 		.bits_per_irq	= 1,
-		.handle_mmio	= handle_mmio_raz_wi,
+		.handle_mmio	= handle_mmio_set_active_reg,
 	},
 	{
 		.base		= GIC_DIST_ACTIVE_CLEAR,
 		.len		= VGIC_MAX_IRQS / 8,
 		.bits_per_irq	= 1,
-		.handle_mmio	= handle_mmio_raz_wi,
+		.handle_mmio	= handle_mmio_clear_active_reg,
 	},
 	{
 		.base		= GIC_DIST_PRI,

virt/kvm/arm/vgic.h

@@ -107,6 +107,14 @@ bool vgic_handle_set_pending_reg(struct kvm *kvm, struct kvm_exit_mmio *mmio,
 bool vgic_handle_clear_pending_reg(struct kvm *kvm, struct kvm_exit_mmio *mmio,
 				   phys_addr_t offset, int vcpu_id);
 
+bool vgic_handle_set_active_reg(struct kvm *kvm,
+				struct kvm_exit_mmio *mmio,
+				phys_addr_t offset, int vcpu_id);
+
+bool vgic_handle_clear_active_reg(struct kvm *kvm,
+				  struct kvm_exit_mmio *mmio,
+				  phys_addr_t offset, int vcpu_id);
+
 bool vgic_handle_cfg_reg(u32 *reg, struct kvm_exit_mmio *mmio,
 			 phys_addr_t offset);