On Tue, 16 Feb 2021 12:18:30 +0100
Cornelia Huck <coh...@redhat.com> wrote:
> The virtio standard specifies that any non-transitional device must
> reject commands prior to revision setting (which we do) and else
> assume revision 0 (legacy) if the driver sends a non-revision-setting
> command first. We neglected to do the latter.
>
> Fortunately, nearly everything worked as intended anyway; the only
> problem was not properly rejecting revision setting after some other
> command had been issued. Easy to fix by setting revision to 0 if
> we see a non-revision command on a legacy-capable revision-less
> device.
>
> Signed-off-by: Cornelia Huck <coh...@redhat.com>
> ---
> hw/s390x/virtio-ccw.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
I now have:
Author: Cornelia Huck <coh...@redhat.com>
Date: Tue Feb 16 12:18:30 2021 +0100
virtio-ccw: commands on revision-less devices
The virtio standard specifies that any non-transitional device must
reject commands prior to revision setting (which we do). Devices
that are transitional need to assume revision 0 (legacy) if the
driver sends a non-revision-setting command first in order to
support legacy drivers. We neglected to do the latter.
Fortunately, nearly everything worked as intended anyway; the only
problem was not properly rejecting revision setting after some other
command had been issued. Easy to fix by setting revision to 0 if
we see a non-revision command on a legacy-capable revision-less
device.
Found by code inspection, not observed in the wild.
Signed-off-by: Cornelia Huck <coh...@redhat.com>
Reviewed-by: Thomas Huth <th...@redhat.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Acked-by: Halil Pasic <pa...@linux.ibm.com>
Message-Id: <20210216111830.1087847-1-coh...@redhat.com>
Any objections?
