On Tuesday 18 August 2009 20:35:22 Michael S. Tsirkin wrote: > On Tue, Aug 18, 2009 at 10:27:52AM -0700, Ira W. Snyder wrote: > > Also, in my case I'd like to boot Linux with my rootfs over NFS. Is > > vhost-net capable of this? > > > > I've had Arnd, BenH, and Grant Likely (and others, privately) contact me > > about devices they are working with that would benefit from something > > like virtio-over-PCI. I'd like to see vhost-net be merged with the > > capability to support my use case. There are plenty of others that would > > benefit, not just myself. yes. > > I'm not sure vhost-net is being written with this kind of future use in > > mind. I'd hate to see it get merged, and then have to change the ABI to > > support physical-device-to-device usage. It would be better to keep > > future use in mind now, rather than try and hack it in later. > > I still need to think your usage over. I am not so sure this fits what > vhost is trying to do. If not, possibly it's better to just have a > separate driver for your device. I now think we need both. virtio-over-PCI does it the right way for its purpose and can be rather generic. It could certainly be extended to support virtio-net on both sides (host and guest) of KVM, but I think it better fits the use where a kernel wants to communicate with some other machine where you normally wouldn't think of using qemu. Vhost-net OTOH is great in the way that it serves as an easy way to move the virtio-net code from qemu into the kernel, without changing its behaviour. It should even straightforward to do live-migration between hosts with and without it, something that would be much harder with the virtio-over-PCI logic. Also, its internal state is local to the process owning its file descriptor, which makes it much easier to manage permissions and cleanup of its resources. Arnd <>< -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
