On Mon, Sep 21, 2020 at 11:46:02AM +0200, Cornelia Huck wrote:
> On Mon, 21 Sep 2020 10:38:05 +0200
> Stefano Garzarella <sgarz...@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 vhost-vsock-pci device:
> >
> > $ ./qemu-system-x86_64 ... -device vhost-vsock-pci,guest-cid=5
> > qemu-system-x86_64: -device vhost-vsock-pci,guest-cid=5:
> > device is modern-only, use disable-legacy=on
> >
> > virtio-vsock was introduced after the release of VIRTIO 1.0
> > specifications, so it should be 'modern-only'.
> > In addition Cornelia verified that forcing a legacy mode on
> > vhost-vsock-pci device using x86-64 host and s390x guest, so with
> > different endianness, produces strange behaviours.
> >
> > This patch forces virtio version 1 and removes the 'transitional_name'
> > property removing the need to specify 'disable-legacy=on' on
> > vhost-vsock-pci device.
> >
> > To avoid migration issues, we force virtio version 1 only when
> > legacy check is enabled in the new machine types (>= 5.1).
>
> Maybe add
>
> "As the transitional device name is not commonly used, we do not
> provide compatibility handling for it." ?
Yes, I'll add in v5.
>
> >
> > Cc: qemu-sta...@nongnu.org
> > Reported-by: Qian Cai <caiq...@redhat.com>
> > Reported-by: Qinghua Cheng <qch...@redhat.com>
> > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1868449
> > Suggested-by: Cornelia Huck <coh...@redhat.com>
> > Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
> > ---
> > v3:
> > - forced virtio version 1 only with new machine types
> > v2:
> > - fixed commit message [Cornelia]
> > ---
> > hw/virtio/vhost-vsock-pci.c | 10 +++++++++-
> > 1 file changed, 9 insertions(+), 1 deletion(-)
> >
>
> Reviewed-by: Cornelia Huck <coh...@redhat.com>
Thanks,
Stefano
