Re: [Qemu-devel] [PATCH 1/1] virtio: fail device if set_event_notifier fails

[Halil Pasic <pasic@linux.vnet.ibm.com>]

On 03/03/2017 01:21 PM, Cornelia Huck wrote:
> On Thu,  2 Mar 2017 19:59:42 +0100
> Halil Pasic <pasic@linux.vnet.ibm.com> wrote:
> 
>> The function virtio_notify_irqfd used to ignore the return code of
>> event_notifier_set. Let's fail the device should this occur.
> 
> I'm wondering if there are reasons for event_notifier_set() to fail
> beyond "we've hit an internal race and should make an effort to fix
> that one, or else we have completely messed up in qemu". Marking the
> device broken tells the guest that there's something wrong with the
> device, but I think we want qemu bug reports when there's something
> broken with the irqfd.
>

That's why the error is logged. I understand virtio_error like something
suitable for indicating bugs.

What do you suggest? Forcing a dump? I would rather leave it to the
user to figure out how important is the state sitting in the machine
and the device, and how much effort does (s)he want to put into recovering
from the failure. 

Halil