Re: [PATCH v6] vfio error recovery: kernel support

Alex Williamson
2017-04-05T22:19:22Z

On Thu, 6 Apr 2017 00:50:22 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Wed, Apr 05, 2017 at 01:38:22PM -0600, Alex Williamson wrote:
> > The previous intention of trying to handle all sorts of AER faults
> > clearly had more value, though even there the implementation and
> > configuration requirements restricted the practicality. For instance
> > is AER support actually useful to a customer if it requires all ports
> > of a multifunction device assigned to the VM? This seems more like a
> > feature targeting whole system partitioning rather than general VM
> > device assignment use cases. Maybe that's ok, but it should be a clear
> > design decision.
>
> Alex, what kind of testing do you expect to be necessary?
> Would you say testing on real hardware and making it trigger
> AER errors is a requirement?

Testing various fatal, non-fatal, and corrected errors with aer-inject,
especially in multfunction configurations (where more than one port
is actually usable) would certainly be required. If we have cases where
the driver for a companion function can escalate a non-fatal error to a
bus reset, that should be tested, even if it requires temporary hacks to
the host driver for the companion function to trigger that case. AER
handling is not something that the typical user is going to experience,
so it should to be thoroughly tested to make sure it works when needed
or there's little point to doing it at all. Thanks,

Alex