Re: Serious AMD-Vi(?) issue

[Elliott Mitchell <ehem+xen@m5p.com>]

On Thu, Mar 28, 2024 at 07:25:02AM +0100, Jan Beulich wrote:
> On 27.03.2024 18:27, Elliott Mitchell wrote:
> > On Mon, Mar 25, 2024 at 02:43:44PM -0700, Elliott Mitchell wrote:
> >> On Mon, Mar 25, 2024 at 08:55:56AM +0100, Jan Beulich wrote:
> >>>
> >>> In fact when running into trouble, the usual course of action would be to
> >>> increase verbosity in both hypervisor and kernel, just to make sure no
> >>> potentially relevant message is missed.
> >>
> >> More/better information might have been obtained if I'd been engaged
> >> earlier.
> > 
> > This is still true, things are in full mitigation mode and I'll be
> > quite unhappy to go back with experiments at this point.
> 
> Well, it very likely won't work without further experimenting by someone
> able to observe the bad behavior. Recall we're on xen-devel here; it is
> kind of expected that without clear (and practical) repro instructions
> experimenting as well as info collection will remain with the reporter.

After looking at the situation and considering the issues, I /may/ be
able to setup for doing more testing.  I guess I should confirm, which of
those criteria do you think currently provided information fails at?

AMD-IOMMU + Linux MD RAID1 + dual Samsung SATA (or various NVMe) +
dbench; seems a pretty specific setup.

I could see this being criticised as impractical if /new/ devices were
required, but the confirmed flash devices are several generations old.
Difficulty is cheaper candidate devices are being recycled for their
precious metal content, rather than resold as used.


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