* Michael S. Tsirkin (m...@redhat.com) wrote: > On Wed, Oct 06, 2021 at 02:29:37PM +0100, Dr. David Alan Gilbert wrote: > > * Michael S. Tsirkin (m...@redhat.com) wrote: > > > On Wed, Oct 06, 2021 at 09:43:52AM +0100, Dr. David Alan Gilbert wrote: > > > > * Michael S. Tsirkin (m...@redhat.com) wrote: > > > > > On Wed, Oct 06, 2021 at 09:28:50AM +0100, Dr. David Alan Gilbert > > > > > wrote: > > > > > > To me it feels the same as the distinction between vhost-kernel and > > > > > > qemu > > > > > > backended virtio that we get in net and others - in principal it's > > > > > > just > > > > > > another implementation. > > > > > > > > > > In net it's actually like this. Same -device, a different netdev. > > > > > > > > > > > A tricky part is guaranteeing the set of visible virtio features > > > > > > between > > > > > > implementations; we have that problem when we use vhost-kernel and > > > > > > run > > > > > > on a newer/older kernel and gain virtio features; the same will be > > > > > > true > > > > > > with vhost-user implementations. > > > > > > > > > > That's not new but yes we need to work on this. > > > > > > > > > > > But this would make the structure of a vhost-user implementation > > > > > > quite > > > > > > different. > > > > > > > > > > > > Dave > > > > > > > > > > Right. That's why I'm reluctant to just add a new device type that > > > > > has special compatibility requirements. > > > > > > > > Hmm but there's already another layer of hack^Wabstraction in there > > > > isn't there - > > > > there's already: > > > > virtio-blk-pci > > > > virtio-blk-device > > > > > > > > created when the user specifies a virtio-blk device? > > > > > > > > Dave > > > > > > virtio-*-pci is there because it was felt these devices look > > > differently from e.g. virtio-ccw so should have a different name. > > > virtio-blk-device is an internal thingy, users and guests have no idea. > > > > Right, so to do what we're asking here, should we keep the > > virtio-blk-pci and instantiate virtio-blk-vhost-user instead of > > virtio-blk-device? > > > > Dave > > I guess that's possible, but we need to pass a bunch of parameters. > -drive is probably the right want to do that, right?
I'm not sure about -drive - isn't that very tied into the block layer? Dave > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > MST > > > > > > > > > > > > > > > > > -- > > > > > > > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > > > > > > > > > > > -- > > > > > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > > > > > > > -- > > > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > > > -- > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
