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

[Jason Gunthorpe]

On Fri, Oct 03, 2025 at 09:03:36AM -0700, David Matlack wrote:
> > Shutting down enough of the PF kernel driver to safely kexec is almost
> > the same as unbinding it completely.
> 
> I think it's totally fair to tell us to replace pci-pf-stub with
> vfio-pci. That gets rid of one PF driver.
> 
> idpf cannot be easily replaced with vfio-pci, since the PF is also
> used for host networking.

Run host networking on a VF instead?

> Brian Vazquez from Google will be giving a
> talk about the idpf support at LPC so we can revisit this topic there.
> We took the approach of only preserving the SR-IOV configuration in
> the PF, everything else gets reset (so no DMA mapping preservation, no
> driver state preservation, etc.).

Yes, that's pretty much what you'd have to do, it sure would be nice
to have some helper to manage this to minimize driver work. It really
is remove the existing driver and just leave it idle unless luo fails
then rebind it..

> We haven't looked into nvme yet so we'll have to revisit that discussion later.

Put any host storage on a NVMe VF?

Jason