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authorMarc Zyngier <marc.zyngier@arm.com>2018-04-18 12:39:04 +0300
committerMarc Zyngier <marc.zyngier@arm.com>2018-04-27 14:39:09 +0300
commit53692908b0f594285aba18ab848318262332ed25 (patch)
treed486da77b3dc691e89c2ab1fbe8942991fe14e84 /virt/kvm/arm/vgic/vgic-mmio.c
parent85bd0ba1ff9875798fad94218b627ea9f768f3c3 (diff)
downloadlinux-53692908b0f594285aba18ab848318262332ed25.tar.xz
KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGI
Now that we make sure we don't inject multiple instances of the same GICv2 SGI at the same time, we've made another bug more obvious: If we exit with an active SGI, we completely lose track of which vcpu it came from. On the next entry, we restore it with 0 as a source, and if that wasn't the right one, too bad. While this doesn't seem to trouble GIC-400, the architectural model gets offended and doesn't deactivate the interrupt on EOI. Another connected issue is that we will happilly make pending an interrupt from another vcpu, overriding the above zero with something that is just as inconsistent. Don't do that. The final issue is that we signal a maintenance interrupt when no pending interrupts are present in the LR. Assuming we've fixed the two issues above, we end-up in a situation where we keep exiting as soon as we've reached the active state, and not be able to inject the following pending. The fix comes in 3 parts: - GICv2 SGIs have their source vcpu saved if they are active on exit, and restored on entry - Multi-SGIs cannot go via the Pending+Active state, as this would corrupt the source field - Multi-SGIs are converted to using MI on EOI instead of NPIE Fixes: 16ca6a607d84bef0 ("KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid") Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio.c')
-rw-r--r--virt/kvm/arm/vgic/vgic-mmio.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index dbe99d635c80..ff9655cfeb2f 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -289,10 +289,16 @@ static void vgic_mmio_change_active(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
irq->vcpu->cpu != -1) /* VCPU thread is running */
cond_resched_lock(&irq->irq_lock);
- if (irq->hw)
+ if (irq->hw) {
vgic_hw_irq_change_active(vcpu, irq, active, !requester_vcpu);
- else
+ } else {
+ u32 model = vcpu->kvm->arch.vgic.vgic_model;
+
irq->active = active;
+ if (model == KVM_DEV_TYPE_ARM_VGIC_V2 &&
+ active && vgic_irq_is_sgi(irq->intid))
+ irq->active_source = requester_vcpu->vcpu_id;
+ }
if (irq->active)
vgic_queue_irq_unlock(vcpu->kvm, irq, flags);