On 09/09/2016 01:20 PM, Cornelia Huck wrote:
On Fri, 9 Sep 2016 14:04:55 +0300
Marcel Apfelbaum <mar...@redhat.com> wrote:
On 09/09/2016 01:40 PM, Cornelia Huck wrote:
On Fri, 9 Sep 2016 12:14:32 +0200
Maxime Coquelin <maxime.coque...@redhat.com> wrote:
This patch makes pci devices plugging more robust, by not confusing
guest with modern interface when the backend doesn't support
VIRTIO_F_VERSION_1.
Cc: Marcel Apfelbaum <mar...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Cc: qemu-sta...@nongnu.org
Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
---
hw/virtio/virtio-pci.c | 15 +++++++++++++++
hw/virtio/virtio-pci.h | 5 +++++
2 files changed, 20 insertions(+)
Note that 11380b361 ("virtio: handle non-virtio-1-capable backend for
ccw") fixes this issue for ccw via the introduction of a
->post_plugged() callback. Unfortunately, we did not find a good way to
make it work for pci back then.
It seems that for ccw is enough to rewind dev->rev_max,
sadly for pci we need to rewind a lot of settings/resources.
Yes, that what I meant with 'more flexibility for ccw'.
Maybe we could replace post_plugged with a pre_plugged approach?
In ->pre_plugged(), cww and pci would specify which features it can
support using virtio_add_feature().
Then we could call get_features() before ->device_plugged().
Doing this, both ccw and pci would have the needed information without
having to rewind any settings.
Does that make sense?
But for now, I think it would be better to merge something in the spirit
of this series (taking into account to remarks).
Indeed, I think we want this fixed in stable, but the above proposal
would be too huge for stable.
Thanks,
Maxime
