Re: [Qemu-devel] QMP: RFC: I/O error info & query-stop-reason

[Anthony Liguori]

On 06/02/2011 04:06 AM, Daniel P. Berrange wrote:
> On Wed, Jun 01, 2011 at 04:35:03PM -0500, Anthony Liguori wrote:
> > >     "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
> > >
> > > Valid error reasons could be: "enospc", "eio", etc.
> >
> > No etc :-)  Error reasons should we be well known and well documented.
> >
> > > B. query-stop-reason
> > > --------------------
> > >
> > > I also have a simple solution for item 2. The vm_stop() accepts a reason
> > > argument, so we could store it somewhere and return it as a string, like:
> > >
> > > ->   { "execute": "query-stop-reason" }
> > > <- { "return": { "reason": "user" } }
> > >
> > > Valid reasons could be: "user", "debug", "shutdown", "diskfull" (hey,
> > > this should be "ioerror", no?), "watchdog", "panic", "savevm", "loadvm",
> > > "migrate".
> > >
> > > Also note that we have a STOP event. It should be extended with the
> > > stop reason too, for completeness.
> >
> >
> > Can we just extend query-block?
>
> Primarily we want 'query-stop-reason' to tell us what caused the VM
> CPUs to stop. If that reason was 'ioerror', then 'query-block' could
> be used to find out which particular block device(s) caused the IO
> error to occurr&  get the "reason" that was in the BLOCK_IO_ERROR
> event.

My concern is that we're over abstracting here.  We're not going to add 
additional stop reasons in the future.

Maybe just add an 'io-error': True to query-state.

Regards,

Anthony Liguori

> Regards,
> Daniel