Re: [PATCH v2 03/10] PCI/LUO: Forward prepare()/freeze()/cancel() callbacks to driver

[Chris Li <chrisl@kernel.org>]

On Fri, Oct 3, 2025 at 5:26 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Oct 03, 2025 at 12:26:01AM -0700, Chris Li wrote:
>
> > It is more than just one driver, we have vfio-pci, idpf, pci-pf-stub
> > and possible nvme driver.
>
> Why is nvme considered a "GPU" that needs context saved?

NVME is not a GPU. The internal reason to have NVME participate in the
liveupdate is because the NVME shutdown of the IO queue is very slow,
it contributes the largest chunk of delay in the black out window for
liveupdate. The NVME participation is just an optimization to avoid
resetting the NVME queue. Consider it as (optional ) speed
optimization.

> > The change needs to happen in the PCI enumeration and probing as well,
> > that is outside of the driver code.
>
> So all just PCI drivers?  Then keep this in PCI-only please, and don't
> touch the driver core.

Ack. Will do.

>
> > > was that you were claiming it was a PCI change, yet it was actually only
> > > touching the driver core which means that all devices in the systems for
> >
> > In theory all the devices can be liveupdate preserved. But now we only
> > support PCI.
>
> Then for now, only focus on PCI.

Agree, thanks for the alignment.

Chris