From: Andrew Jones <drjones@redhat.com>
To: kvmarm@lists.cs.columbia.edu
Cc: marc.zyngier@arm.com
Subject: [PATCH] KVM: arm/arm64: fix emulated ptimer irq injection
Date: Mon, 27 May 2019 13:46:19 +0200 [thread overview]
Message-ID: <20190527114619.16252-1-drjones@redhat.com> (raw)
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@redhat.com>
---
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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next reply other threads:[~2019-05-27 11:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-27 11:46 Andrew Jones [this message]
2019-05-28 11:01 ` [PATCH] KVM: arm/arm64: fix emulated ptimer irq injection Christoffer Dall
2019-05-28 12:25 ` Marc Zyngier
2019-05-28 13:12 ` Christoffer Dall
2019-05-28 13:40 ` Andrew Jones
2019-05-28 16:08 ` Marc Zyngier
2019-05-29 5:19 ` Andrew Jones
2019-05-29 9:08 ` Christoffer Dall
2019-05-29 9:13 ` Marc Zyngier
2019-05-29 10:03 ` Christoffer Dall
2019-06-03 12:14 ` Andrew Jones
2019-06-13 10:01 ` Marc Zyngier
2019-06-13 15:45 ` Christoffer Dall
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