Re: [PATCH] intel-iommu: Turn off translations at shutdown

[Deepa Dinamani]

On Fri, Nov 8, 2019 at 2:48 PM Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote:
>
> > > > For VMM live update case, we should be able to detect and bypass
> > > > the shutdown that Deepa introduced here, so keep IOMMU still operating?
> > >
> > > Is that a 'yes' to Deepa's "if someone wants to make it conditional, we
> > > can do that" ?
> >
> > Yes, I think so. Thanks!
>
> Are these changes already part of the kernel like avoiding shutdown of
> the passthrough devices? device_shutdown() doesn't seem to be doing
> anything selectively as of now.

I've posted the v2 without the conditional for now:
https://lore.kernel.org/patchwork/patch/1151225/

As a side topic, I'm trying to support https://www.linuxboot.org/. I
have a couple of more such cleanups coming. The VMM live updates and
linuxboot seem to have contradicting requirements and they both use
kexec. So kexec_in_progress doesn't seem like a sufficient indicator
to distinguish between the two. Do you already have an idea on how to
distiguish between them? Does a separate sys_reboot() command
parameter sound ok? Or, we could use the flags in the sys_kexec_load()
depending on how the live update feature is implemented.

-Deepa