From: Christoffer Dall christoffer.dall@arm.com

When the VCPU is blocked (for example from WFI) we don't inject the physical timer interrupt if it should fire while the CPU is blocked, but instead we just wake up the VCPU and expect kvm_timer_vcpu_load to take care of injecting the interrupt.

Unfortunately, kvm_timer_vcpu_load() doesn't actually do that, it only has support to schedule a soft timer if the emulated phys timer is expected to fire in the future.

Follow the same pattern as kvm_timer_update_state() and update the irq state after potentially scheduling a soft timer.

Reported-by: Andre Przywara andre.przywara@arm.com Cc: Stable stable@vger.kernel.org # 4.15+ Fixes: bbdd52cfcba29 ("KVM: arm/arm64: Avoid phys timer emulation in vcpu entry/exit") Signed-off-by: Christoffer Dall christoffer.dall@arm.com --- virt/kvm/arm/arch_timer.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 18ff6203079d..17cecc96f735 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -487,6 +487,7 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu) { struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

if (unlikely(!timer->enabled)) return; @@ -502,6 +503,10 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)

/* Set the background timer for the physical timer emulation. */ phys_timer_emulate(vcpu); + + /* If the timer fired while we weren't running, inject it now */ + if (kvm_timer_should_fire(ptimer) != ptimer->irq.level) + kvm_timer_update_irq(vcpu, !ptimer->irq.level, ptimer); }

bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)