[virtio-dev] RE: [virtio-comment] [PATCH 00/11] Introduce transitional mmr pci device

Parav Pandit
2023-04-03T20:27:42Z

> From: Stefan Hajnoczi <stefanha@redhat.com>
> Sent: Monday, April 3, 2023 3:10 PM

> Maybe call it "Memory-mapped Transitional"? That name would be easier to
> understand.
>
Sounds fine to me.

> > > Modern devices were added to Linux in 2014 and support SR-IOV.
> >
> > > Why is it
> > > important to support Transitional (which really means Legacy
> > > devices, otherwise Modern devices would be sufficient)?
> > >
> > To support guest VMs which only understand legacy devices and
> > unfortunately they are still in much wider use by the users.
>
> I wonder which guest software without Modern VIRTIO support will still be
> supported by the time Transitional MMR software and hardware becomes
> available. Are you aiming for particular guest software versions?

Transitional MMR hardware is available almost now.
Transitional MMR software is also WIP to be available as soon as we ratify the spec via tvq or via mmr or both.
This will be support the guest sw version such as 2.6.32.754 kernel.