The emulated ptimer needs to track the level changes, otherwise the
the interrupt will never get deasserted, resulting in the guest getting
stuck in an interrupt storm if it enables ptimer interrupts. This was
found with kvm-unit-tests; the ptimer tests hung as soon as interrupts
were enabled. Typical Linux guests don't have a problem as they prefer
using the virtual timer.
Fixes: bee038a674875 ("KVM: arm/arm64: Rework the timer code to use a timer_map")
Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
---
virt/kvm/arm/arch_timer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 7fc272ecae16..9f5d8cc8b5e5 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -324,10 +324,15 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
static void timer_emulate(struct arch_timer_context *ctx)
{
bool should_fire = kvm_timer_should_fire(ctx);
+ struct timer_map map;
+
+ get_timer_map(ctx->vcpu, &map);
trace_kvm_timer_emulate(ctx, should_fire);
- if (should_fire) {
+ if (ctx == map.emul_ptimer && should_fire != ctx->irq.level) {
+ kvm_timer_update_irq(ctx->vcpu, !ctx->irq.level, ctx);
+ } else if (should_fire) {
kvm_timer_update_irq(ctx->vcpu, true, ctx);
return;
}
--
2.18.1
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