Re: [Qemu-devel] [PATCH 1/2] virtio-9p: print error message and exit instead of BUG_ON()

[Cornelia Huck]

On Thu, 8 Sep 2016 19:55:16 +0300
"Michael S. Tsirkin" <address@hidden> wrote:

> On Thu, Sep 08, 2016 at 06:26:52PM +0200, Greg Kurz wrote:
> > On Thu, 8 Sep 2016 18:19:27 +0300
> > "Michael S. Tsirkin" <address@hidden> wrote:
> > 
> > > On Thu, Sep 08, 2016 at 05:04:47PM +0200, Cornelia Huck wrote:
> > > > On Thu, 8 Sep 2016 18:00:28 +0300
> > > > "Michael S. Tsirkin" <address@hidden> wrote:
> > > >   
> > > > > On Thu, Sep 08, 2016 at 11:12:16AM +0200, Greg Kurz wrote:  

> > If it continues
> > execution, this means we're expecting the guest or the host to do something
> > to fix the error condition. This requires QEMU to emit an event of some
> > sort, but not necessarily to log an error message in a file. I guess this
> > depends if QEMU is run by some tooling, or by a human.
> 
> I'm not sure we need an event if tools are not expected to
> do anything with it. If we limit # of times error
> is printed, tools will need to reset this counter,
> so we will need an event on overflow.

If the device goes into a broken state, it should be discoverable from
outside. I'm not sure we need an actual event signalling this if this
happens due to the guest doing something wrong: That would be a task
for tools monitoring _inside_ the guest. For tools monitoring the
health of the machine (from the host perspective), the discovery
interface would probably be enough?