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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-v3.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-v3.c')
-rw-r--r--virt/kvm/arm/vgic/vgic-v3.c49
1 files changed, 29 insertions, 20 deletions
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 8195f52ae6f0..c7423f3768e5 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -27,13 +27,6 @@ static bool group1_trap;
static bool common_trap;
static bool gicv4_enable;
-void vgic_v3_set_npie(struct kvm_vcpu *vcpu)
-{
- struct vgic_v3_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v3;
-
- cpuif->vgic_hcr |= ICH_HCR_NPIE;
-}
-
void vgic_v3_set_underflow(struct kvm_vcpu *vcpu)
{
struct vgic_v3_cpu_if *cpuif = &vcpu->arch.vgic_cpu.vgic_v3;
@@ -55,17 +48,23 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
int lr;
unsigned long flags;
- cpuif->vgic_hcr &= ~(ICH_HCR_UIE | ICH_HCR_NPIE);
+ cpuif->vgic_hcr &= ~ICH_HCR_UIE;
for (lr = 0; lr < vgic_cpu->used_lrs; lr++) {
u64 val = cpuif->vgic_lr[lr];
- u32 intid;
+ u32 intid, cpuid;
struct vgic_irq *irq;
+ bool is_v2_sgi = false;
- if (model == KVM_DEV_TYPE_ARM_VGIC_V3)
+ cpuid = val & GICH_LR_PHYSID_CPUID;
+ cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT;
+
+ if (model == KVM_DEV_TYPE_ARM_VGIC_V3) {
intid = val & ICH_LR_VIRTUAL_ID_MASK;
- else
+ } else {
intid = val & GICH_LR_VIRTUALID;
+ is_v2_sgi = vgic_irq_is_sgi(intid);
+ }
/* Notify fds when the guest EOI'ed a level-triggered IRQ */
if (lr_signals_eoi_mi(val) && vgic_valid_spi(vcpu->kvm, intid))
@@ -81,18 +80,16 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
/* Always preserve the active bit */
irq->active = !!(val & ICH_LR_ACTIVE_BIT);
+ if (irq->active && is_v2_sgi)
+ irq->active_source = cpuid;
+
/* Edge is the only case where we preserve the pending bit */
if (irq->config == VGIC_CONFIG_EDGE &&
(val & ICH_LR_PENDING_BIT)) {
irq->pending_latch = true;
- if (vgic_irq_is_sgi(intid) &&
- model == KVM_DEV_TYPE_ARM_VGIC_V2) {
- u32 cpuid = val & GICH_LR_PHYSID_CPUID;
-
- cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT;
+ if (is_v2_sgi)
irq->source |= (1 << cpuid);
- }
}
/*
@@ -133,10 +130,20 @@ void vgic_v3_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr)
{
u32 model = vcpu->kvm->arch.vgic.vgic_model;
u64 val = irq->intid;
- bool allow_pending = true;
+ bool allow_pending = true, is_v2_sgi;
- if (irq->active)
+ is_v2_sgi = (vgic_irq_is_sgi(irq->intid) &&
+ model == KVM_DEV_TYPE_ARM_VGIC_V2);
+
+ if (irq->active) {
val |= ICH_LR_ACTIVE_BIT;
+ if (is_v2_sgi)
+ val |= irq->active_source << GICH_LR_PHYSID_CPUID_SHIFT;
+ if (vgic_irq_is_multi_sgi(irq)) {
+ allow_pending = false;
+ val |= ICH_LR_EOI;
+ }
+ }
if (irq->hw) {
val |= ICH_LR_HW;
@@ -174,8 +181,10 @@ void vgic_v3_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr)
BUG_ON(!src);
val |= (src - 1) << GICH_LR_PHYSID_CPUID_SHIFT;
irq->source &= ~(1 << (src - 1));
- if (irq->source)
+ if (irq->source) {
irq->pending_latch = true;
+ val |= ICH_LR_EOI;
+ }
}
}