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KVM: arm64: GICv3: Drop LPI active state when folding LRs

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Despite LPIs not having an active state, *virtual* LPIs do have
one, which gets cleared on EOI. So far, so good.

However, this leads to a small problem: when an active LPI is not
in the LRs, that EOImode==0 and that the guest EOIs it, EOIcount
doesn't get bumped up. Which means that in these condition, the
LPI would stay active forever.

Clearly, we can't have that. So if we spot an active LPI, we drop
that state. It's pretty pointless anyway, and only serves as a way
to trip SW over.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-11-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
This commit is contained in:
Marc Zyngier
2025-11-20 17:25:00 +00:00
committed by Oliver Upton
parent 0dc433e79a
commit 73c9726975
1 changed files with 3 additions and 1 deletions
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4
arch/arm64/kvm/vgic/vgic-v3.c
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@@ -72,7 +72,9 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu)
raw_spin_lock(&irq->irq_lock);
/* Always preserve the active bit, note deactivation */
/* Always preserve the active bit for !LPIs, note deactivation */
if (irq->intid >= VGIC_MIN_LPI)
val &= ~ICH_LR_ACTIVE_BIT;
deactivated = irq->active && !(val & ICH_LR_ACTIVE_BIT);
irq->active = !!(val & ICH_LR_ACTIVE_BIT);