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

Alex Williamson
2017-04-06T15:35:31Z

On Thu, 6 Apr 2017 16:53:44 +0800
Cao jin <caoj.fnst@cn.fujitsu.com> wrote:

> On 04/06/2017 06:36 AM, Michael S. Tsirkin wrote:
> > On Wed, Apr 05, 2017 at 04:19:10PM -0600, Alex Williamson wrote:
> >> 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
> >
> > Some things can be tested within a VM. What would you
> > say would be sufficient on a VM and what has to be
> > tested on bare metal?
> >
>
> Does the "bare metal" here mean something like XenServer?

No, bare metal means the non-virtualized host OS. I think Michael was
trying to facilitate testing by proposing to do it in a VM such that we
can create strange and interesting topologies that aren't bound by a
system in a remote lab having only one NIC port connected. Thanks,

Alex