Re: [PATCH v2 2/2] virtio-iommu-pci: force virtio version 1

[Cornelia Huck]

On Fri, 18 Sep 2020 12:24:02 +0200
Auger Eric <eric.auger@redhat.com> wrote:

> Hi Connie,
> 
> On 9/18/20 11:29 AM, Cornelia Huck wrote:
> > On Tue,  8 Sep 2020 21:33:09 +0200
> > Eric Auger <eric.auger@redhat.com> wrote:
> >   
> >> Commit 9b3a35ec82 ("virtio: verify that legacy support is not
> >> accidentally on") added a safety check that requires to set
> >> 'disable-legacy=on' on virtio-iommu-pci:
> >>
> >> qemu-system-aarch64: -device virtio-iommu-pci: device is modern-only,
> >> use disable-legacy=on
> >>
> >> virtio-iommu was introduced after the release of VIRTIO 1.0
> >> specifications, so it should be 'modern-only'.
> >>
> >> This patch forces virtio version 1 and removes the 'transitional_name'
> >> property removing the need to specify 'disable-legacy=on' on
> >> virtio-iommu-pci device.  
> > 
> > Not sure whether this patch has been queued already, and how much we
> > care about migration compatibility for virtio-iommu, but would it make
> > sense to force modern on 5.1+ compat machines only? (see
> > 20200918074710.27810-1-sgarzare@redhat.com/">https://lore.kernel.org/qemu-devel/20200918074710.27810-1-sgarzare@redhat.com/)
> >   
> 
> I don't think it was pulled yet.
> >   
> >>
> >> Cc: qemu-stable@nongnu.org  
> 
> The virtio-iommu-pci device only is usable on ARM in dt mode so I don't
> think it has production users at the moment.

OK, then we can keep this patch here, I guess.