From: Marc Zyngier <marc.zyngier@arm.com>
Date: Fri, 27 Oct 2017 15:28:44 +0100
Subject: KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE
Patch-mainline: v4.15-rc1
Git-commit: ff9c114394aaed2061df112b75be9835a1394be4
References: bsc#1077761

The current implementation of MOVALL doesn't allow us to call
into the core ITS code as we hold a number of spinlocks.

Let's try a method used in other parts of the code, were we copy
the intids of the candicate interrupts, and then do whatever
we need to do with them outside of the critical section.

This allows us to move the interrupts one by one, at the expense
of a bit of CPU time. Who cares? MOVALL is such a stupid command
anyway...

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Alexander Graf <agraf@suse.de>
---
 virt/kvm/arm/vgic/vgic-its.c |   19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1169,11 +1169,12 @@
 static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
 				      u64 *its_cmd)
 {
-	struct vgic_dist *dist = &kvm->arch.vgic;
 	u32 target1_addr = its_cmd_get_target_addr(its_cmd);
 	u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
 	struct kvm_vcpu *vcpu1, *vcpu2;
 	struct vgic_irq *irq;
+	u32 *intids;
+	int irq_count, i;
 
 	if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
 	    target2_addr >= atomic_read(&kvm->online_vcpus))
@@ -1185,19 +1186,19 @@
 	vcpu1 = kvm_get_vcpu(kvm, target1_addr);
 	vcpu2 = kvm_get_vcpu(kvm, target2_addr);
 
-	spin_lock(&dist->lpi_list_lock);
+	irq_count = vgic_copy_lpi_list(vcpu1, &intids);
+	if (irq_count < 0)
+		return irq_count;
 
-	list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
-		spin_lock(&irq->irq_lock);
+	for (i = 0; i < irq_count; i++) {
+		irq = vgic_get_irq(kvm, NULL, intids[i]);
 
-		if (irq->target_vcpu == vcpu1)
-			irq->target_vcpu = vcpu2;
+		update_affinity(irq, vcpu2);
 
-		spin_unlock(&irq->irq_lock);
+		vgic_put_irq(kvm, irq);
 	}
 
-	spin_unlock(&dist->lpi_list_lock);
-
+	kfree(intids);
 	return 0;
 }