Thread (13 messages) 13 messages, 3 authors, 2015-03-09

[PATCH v2 2/5] arm/arm64: KVM: Implement support for unqueueing active IRQs

From: Alex Bennée <hidden>
Date: 2015-03-09 16:41:04
Also in: kvm, kvmarm, lkml

Christoffer Dall [off-list ref] writes:
On Mon, Mar 02, 2015 at 01:29:01PM +0000, Alex Benn?e wrote:
quoted
From: Christoffer Dall <redacted>

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 <redacted>
Signed-off-by: Alex Benn?e <redacted>

---
AJB:
   - fixed merge conflicts
   - moved additional shared bitmaps to be dynamically allocated
   - make irq_active_on_cpu dynamically allocated as well
   - in vgic_queue_irq don't queue pending if already active
   - in __kvm_vgic_flush_hwstate use pr_shared when checking SPIs
   - vgic: clear active on CPU bit
   - checkpatch, remove extraneous braces
   - checkpatch, remove debug, fix overflows
   - move register access fns to re-factored vgic-v2-emul.c
v2
   - doc: unqueue and update_state
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 7c55dd5..7042251 100644
<snip>
if you respin:                         the active state
if you respin:     Mark the
OK

<snip>
quoted
 
@@ -1030,39 +1113,49 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+	unsigned long *pa_percpu, *pa_shared;
 	int i, vcpu_id;
 	int overflow = 0;
+	int nr_shared = vgic_nr_shared_irqs(dist);
 
 	vcpu_id = vcpu->vcpu_id;
 
+	pa_percpu = vcpu->arch.vgic_cpu.pend_act_percpu;
+	pa_shared = vcpu->arch.vgic_cpu.pend_act_shared;
+
+	bitmap_or(pa_percpu, vgic_cpu->pending_percpu, vgic_cpu->active_percpu,
+		  VGIC_NR_PRIVATE_IRQS);
+	bitmap_or(pa_shared, vgic_cpu->pending_shared, vgic_cpu->active_shared,
+		  nr_shared);
 	/*
 	 * We may not have any pending interrupt, or the interrupts
 	 * may have been serviced from another vcpu. In all cases,
 	 * move along.
 	 */
-	if (!kvm_vgic_vcpu_pending_irq(vcpu)) {
-		pr_debug("CPU%d has no pending interrupt\n", vcpu_id);
+	if (!kvm_vgic_vcpu_pending_irq(vcpu) && !kvm_vgic_vcpu_active_irq(vcpu))
 		goto epilog;
-	}
 
 	/* SGIs */
-	for_each_set_bit(i, vgic_cpu->pending_percpu, VGIC_NR_SGIS) {
+	for_each_set_bit(i, pa_percpu, VGIC_NR_SGIS) {
 		if (!queue_sgi(vcpu, i))
 			overflow = 1;
 	}
 
 	/* PPIs */
-	for_each_set_bit_from(i, vgic_cpu->pending_percpu, VGIC_NR_PRIVATE_IRQS) {
+	for_each_set_bit_from(i, pa_percpu, VGIC_NR_PRIVATE_IRQS) {
 		if (!vgic_queue_hwirq(vcpu, i))
 			overflow = 1;
 	}
 
 	/* SPIs */
-	for_each_set_bit(i, vgic_cpu->pending_shared, vgic_nr_shared_irqs(dist)) {
+	for_each_set_bit(i, pa_shared, nr_shared) {
 		if (!vgic_queue_hwirq(vcpu, i + VGIC_NR_PRIVATE_IRQS))
 			overflow = 1;
 	}
meh, these changes will now produce a quite strange result if one
bisects at this specific patch, since we will be setting pending
interrupts to active....  I thought it was more clear as one patch
containing the changes to vgic_queue_... imho.
I split the re-factor off by Marc's request but your right it becomes a
little weird. Now the horror of dealing with the merge conflicts is done
I could split the next patch and add it before this one:

* add a common vgic_queue_irq_to_lr fn (just deal with pending)
* Implement support for unqueuing active IRQs (expand vgic_queue_irq_to_lr)
Thoughts?
quoted
 
+
+
+
 epilog:
 	if (overflow) {
 		vgic_enable_underflow(vcpu);
@@ -1209,6 +1302,17 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 	return test_bit(vcpu->vcpu_id, dist->irq_pending_on_cpu);
 }
 
+int kvm_vgic_vcpu_active_irq(struct kvm_vcpu *vcpu)
+{
+	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	if (!irqchip_in_kernel(vcpu->kvm))
+		return 0;
+
+	return test_bit(vcpu->vcpu_id, dist->irq_active_on_cpu);
+}
+
+
 void vgic_kick_vcpus(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu;
@@ -1381,8 +1485,12 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
 
 	kfree(vgic_cpu->pending_shared);
+	kfree(vgic_cpu->active_shared);
+	kfree(vgic_cpu->pend_act_shared);
 	kfree(vgic_cpu->vgic_irq_lr_map);
 	vgic_cpu->pending_shared = NULL;
+	vgic_cpu->active_shared = NULL;
+	vgic_cpu->pend_act_shared = NULL;
 	vgic_cpu->vgic_irq_lr_map = NULL;
 }
 
@@ -1392,9 +1500,14 @@ static int vgic_vcpu_init_maps(struct kvm_vcpu *vcpu, int nr_irqs)
 
 	int sz = (nr_irqs - VGIC_NR_PRIVATE_IRQS) / 8;
 	vgic_cpu->pending_shared = kzalloc(sz, GFP_KERNEL);
+	vgic_cpu->active_shared = kzalloc(sz, GFP_KERNEL);
+	vgic_cpu->pend_act_shared = kzalloc(sz, GFP_KERNEL);
 	vgic_cpu->vgic_irq_lr_map = kmalloc(nr_irqs, GFP_KERNEL);
 
-	if (!vgic_cpu->pending_shared || !vgic_cpu->vgic_irq_lr_map) {
+	if (!vgic_cpu->pending_shared
+		|| !vgic_cpu->active_shared
+		|| !vgic_cpu->pend_act_shared
+		|| !vgic_cpu->vgic_irq_lr_map) {
 		kvm_vgic_vcpu_destroy(vcpu);
 		return -ENOMEM;
 	}
@@ -1447,10 +1560,12 @@ void kvm_vgic_destroy(struct kvm *kvm)
 	kfree(dist->irq_spi_mpidr);
 	kfree(dist->irq_spi_target);
 	kfree(dist->irq_pending_on_cpu);
+	kfree(dist->irq_active_on_cpu);
 	dist->irq_sgi_sources = NULL;
 	dist->irq_spi_cpu = NULL;
 	dist->irq_spi_target = NULL;
 	dist->irq_pending_on_cpu = NULL;
+	dist->irq_active_on_cpu = NULL;
 	dist->nr_cpus = 0;
 }
 
@@ -1486,6 +1601,7 @@ int vgic_init(struct kvm *kvm)
 	ret |= vgic_init_bitmap(&dist->irq_pending, nr_cpus, nr_irqs);
 	ret |= vgic_init_bitmap(&dist->irq_soft_pend, nr_cpus, nr_irqs);
 	ret |= vgic_init_bitmap(&dist->irq_queued, nr_cpus, nr_irqs);
+	ret |= vgic_init_bitmap(&dist->irq_active, nr_cpus, nr_irqs);
 	ret |= vgic_init_bitmap(&dist->irq_cfg, nr_cpus, nr_irqs);
 	ret |= vgic_init_bytemap(&dist->irq_priority, nr_cpus, nr_irqs);
 
@@ -1498,10 +1614,13 @@ int vgic_init(struct kvm *kvm)
 				       GFP_KERNEL);
 	dist->irq_pending_on_cpu = kzalloc(BITS_TO_LONGS(nr_cpus) * sizeof(long),
 					   GFP_KERNEL);
+	dist->irq_active_on_cpu = kzalloc(BITS_TO_LONGS(nr_cpus) * sizeof(long),
+					   GFP_KERNEL);
 	if (!dist->irq_sgi_sources ||
 	    !dist->irq_spi_cpu ||
 	    !dist->irq_spi_target ||
-	    !dist->irq_pending_on_cpu) {
+	    !dist->irq_pending_on_cpu ||
+	    !dist->irq_active_on_cpu) {
 		ret = -ENOMEM;
 		goto out;
 	}
diff --git a/virt/kvm/arm/vgic.h b/virt/kvm/arm/vgic.h
index 1e83bdf..1e5a381 100644
--- a/virt/kvm/arm/vgic.h
+++ b/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);
 
-- 
2.3.0
-- 
Alex Benn?e
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