Commit 4a2c4da1 authored by Christoffer Dall's avatar Christoffer Dall

arm/arm64: KVM: Load the timer state when enabling the timer

After being lazy with saving/restoring the timer state, we defer that
work to vcpu_load and vcpu_put, which ensure that the timer state is
loaded on the hardware timers whenever the VCPU runs.

Unfortunately, we are failing to do that the first time vcpu_load()
runs, because the timer has not yet been enabled at that time.  As long
as the initialized timer state matches what happens to be in the
hardware (a disabled timer, because we never leave the timer screaming),
this does not show up as a problem, but is nevertheless incorrect.

The solution is simple; disable preemption while setting the timer to be
enabled, and call the timer load function when first enabling the timer.
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 1c88ab7e
......@@ -861,7 +861,11 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
return ret;
no_vgic:
preempt_disable();
timer->enabled = 1;
kvm_timer_vcpu_load_vgic(vcpu);
preempt_enable();
return 0;
}
......
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