Subject: Re: [PATCH V6 mlx5-next 10/15] vfio: Remove migration protocol v1

From: Jason Gunthorpe <[email-masked]>
Date: Tue, 1 Feb 2022 10:29:30 -0400

On Tue, Feb 01, 2022 at 03:19:18PM +0100, Cornelia Huck wrote:

> - remove the current QEMU implementation of vfio migration for 7.0 (it's
>   experimental, and if there's anybody experimenting with that, they can
>   stay on 6.2)

I think we went from "we clarified how the ABI works and made
something ABI compataible with qemu" to "let's delete the whole thing
from a released qemu" rather quickly..

To be clear this is still all logically compatible with the v1
interface, and we might, or might not, want to use the ABI compatible
version we already built out of tree to support the existing installed
base of qemu.

Dropping the whole thing seems to only make things worse for this
ecosystem, IMHO.

> (- also continue to get the documentation into good shape)

Which items do you see here?

> - have an RFC for QEMU that contains a provisional update of the
>   relevant vfio headers so that we can discuss the QEMU side (and maybe
>   shoot down any potential problems in the uapi before they are merged
>   in the kernel)

This qemu patch is linked in the cover letter.

Jason