On Wed, Apr 4, 2012 at 12:44 PM, Izik Eidus <izik.ei...@ravellosystems.com> wrote: > What about this patch?, everything that was asked from Dmitry was > accomplished... > What prevent us from progressing with merging this patch?
Hang on, I asked what the point of the VMware paravirt device models is. I don't think that was ever answered fully. I know it makes migration of existing VMware guests easy, but now we have the burden of maintaining these device models, whose feature set and performance will never be equivalent to virtio. The reason is because we cannot extend the device spec without breaking guests (we don't control the device specification and therefore cannot add new features) and we now have twice as much performance optimization work if we want the same level of performance as virtio devices. For these reasons, I think that VMware device models can only ever be 2nd class device models in QEMU. And I wonder if the effort isn't better invested in good v2v migration tooling instead of adding this to QEMU. I'm not strongly against VMware device models in QEMU, I do see the benefit too, but please explain what the plan here is. Stefan