Re: [libvirt] [PATCH] Ignore qemu STOP event when stopping CPUs

On Tue, 27 Apr 2010 11:20:39 +0200 jdenemar(a)redhat.com wrote: > From: Jiri Denemark <jdenemar(a)redhat.com&gt; > > With JSON qemu monitor, we get a STOP event from qemu whenever qemu > stops guests CPUs. The downside of it is that vm->state is changed to > PAUSED and a new generic paused event is send to applications. However, > when we ask qemu to stop the CPUs we are not really interested in qemu > event and we usually want to issue a more specific event. Can you give an example? Say, "guest is suspended"? If this is the case, something you have to consider is whether libvirt should add high-level events on top of low-level ones. Or, to make it more general, what should libvirt report to applications wrt events? > By setting vm->status to PAUSED before actually sending the request to > qemu (and resetting it back if the request fails) we can ignore the > event since the event handler does nothing when the guest is already > paused. This solution is quite hacky but unfortunately it's the best > solution which I was able to come up with and it doesn't introduce a > race condition. You could extend the low-level driver to accept a mask of events to be ignored.