diff options
| author | Maxime Coquelin <maxime.coquelin@redhat.com> | 2016-09-13 15:30:30 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-09-15 17:30:03 +0300 |
| commit | d1b4259f1ab18af24e6a297edb6a8f71691f3256 (patch) | |
| tree | bad5cbf06d5085c33a14b9f4a4f7d654e06772ec /include/hw/virtio | |
| parent | d1eb8f2acba579830cf3798c3c15ce51be852c56 (diff) | |
| download | qemu-d1b4259f1ab18af24e6a297edb6a8f71691f3256.tar.gz | |
virtio-bus: Plug devices after features are negotiated
Currently, devices are plugged before features are negotiated.
If the backend doesn't support VIRTIO_F_VERSION_1, the transport
needs to rewind some settings.
This is the case for CCW, for which a post_plugged callback had
been introduced, where max_rev field is just updated if
VIRTIO_F_VERSION_1 is not supported by the backend.
For PCI, implementing post_plugged would be much more
complicated, so it needs to know whether the backend supports
VIRTIO_F_VERSION_1 at plug time.
Currently, nothing is done for PCI. Modern capabilities get
exposed to the guest even if VIRTIO_F_VERSION_1 is not supported
by the backend, which confuses the guest.
This patch replaces existing post_plugged solution with an
approach that fits with both transports.
Features negotiation is performed before ->device_plugged() call.
A pre_plugged callback is introduced so that the transports can
set their supported features.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com> [ccw]
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Diffstat (limited to 'include/hw/virtio')
| -rw-r--r-- | include/hw/virtio/virtio-bus.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h index f3e5ef3f5b..24caa0a6e5 100644 --- a/include/hw/virtio/virtio-bus.h +++ b/include/hw/virtio/virtio-bus.h @@ -54,16 +54,16 @@ typedef struct VirtioBusClass { int (*set_guest_notifiers)(DeviceState *d, int nvqs, bool assign); void (*vmstate_change)(DeviceState *d, bool running); /* + * Expose the features the transport layer supports before + * the negotiation takes place. + */ + void (*pre_plugged)(DeviceState *d, Error **errp); + /* * transport independent init function. * This is called by virtio-bus just after the device is plugged. */ void (*device_plugged)(DeviceState *d, Error **errp); /* - * Re-evaluate setup after feature bits have been validated - * by the device backend. - */ - void (*post_plugged)(DeviceState *d, Error **errp); - /* * transport independent exit function. * This is called by virtio-bus just before the device is unplugged. */ |