[PATCH v6] KVM: arm/arm64: Route vtimer events to user space

On 23/09/2016 14:36, Alexander Graf wrote:

quoted

quoted

+        if ((ret == 1) && timer_ret) {
+            /*
+             * We have to exit straight away to ensure that we only
+             * ever notify user space once about a level change
+             */

Is this really a requirement?  It complicates the logic noticeably.

The alternative would be to track the state on ioctl entry, which
Christoffer disliked :).

Ok, I see.  Maybe he's convinced by the ugly code. :)

It's not an architectural concept, it's a KVM API concept.  Tracking the
state on entry just the equivalent of making this vmexit edge-triggered
(both rising and falling edge).

Paolo