> From: Michael S. Tsirkin <mst@xxxxxxxxxx> > Sent: Thursday, October 28, 2021 1:46 AM > > On Wed, Oct 27, 2021 at 03:21:15PM +0000, Parav Pandit wrote: > > Hi Stefano, > > > > > From: Stefano Garzarella <sgarzare@xxxxxxxxxx> > > > Sent: Wednesday, October 27, 2021 8:04 PM > > > > > > Hi folks, > > > I was trying to understand if we have a way to specify which vDPA > > > bus driver (e.g. vhost-vdpa, virtio-vdpa) a device should use. > > > IIUC we don't have it, and the first registered driver is used when > > > a new device is registered. > > > > > > I was thinking if it makes sense to extend the management API to > > > specify which bus driver to use for a device. A use case could be > > > for example a single host handling VMs and bare-metal containers, so > > > we would have both virtio-vdpa and vhost-vdpa loaded and we want to > > > attach some devices to VMs through vhost-vdpa and others to containers > through virtio-vdpa. > > > > > > What do you think? > > > > > One option is, user keeps the drivers_autoprobe disabled for the vdpa > > bus using, > > > > $ vdpa/vdpa dev add mgmtdev vdpasim_net name vdpa0 mac > > 00:11:22:33:44:55 $ echo 0 > /sys/bus/vdpa/drivers_autoprobe > > > > And after vdpa device creation, it manually binds to the desired > > driver such as, > > > > $ echo vdpa0 > /sys/bus/vdpa/drivers/virtio_vdpa/bind > > Or > > $ echo vdpa0 > /sys/bus/vdpa/drivers/vhost_vdpa/bind > > > > In an case of VDUSE, it makes more sense to bind to the one of the above > driver after user space has connected the use space backend to the kernel > device. > > The only annoying thing is that manual bind is not validated. > E.g. if one makes a mistake and binds an incorrect device, it just tends to crash > IIRC. Only a vdpa device can be bind/unbind to a vdpa bus driver. Such checks are done by the kernel core. I didn't follow when can it crash. Can you please share an example when can it crash? _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
