On 27.01.2013, at 15:07, Anthony Liguori wrote:
Anup Patel anup.patel@linaro.org writes:
Hi All,
How about having a generic Virtio-based machine for emulating a virtual desktop ?
I know folks have already thought about this and probably also tried something or other on this front but, it will be good to know the downsides.
Virtio-desktop can be a separate specification describing a virtual desktop. Of-course we cannot avoid few architecture dependent virtual devices in but the Virtio-desktop specification will try to keep minimum possible architecture dependent devices.
There's a lot of reasons why a pure PV machine type is a bad idea. Lots of people have enumerated them in this thread.
But let me mention some things that I think we don't have covered today with PV:
- Graphics. Yes, I know QXL exists but it's (a) dependent on PCI (b) lacks the ability to gracefully degrade making it hopelessly tied to spice.
There was a QXL-on-virtio port in the works a while ago IIRC:
- Input. PS/2 mouse provides relative input which sucks in guests. For absolute input, we have VMMouse which is x86-specific, USB tablets (which are expensive to emulate) or the spice mouse which is intimately tied to the full Spice stack.
I thought the USB tablet is ok today thanks to auto-suspend of the bus? Or was that only with ehci?
- Guest interaction. Copy/paste, drag and drop, etc. In theory this is covered in spice agents but it's all again hopelessly tied to Spice which makes it non-portable.
- Keyboard. When running with VNC, the 3 stacks involved in converting keyboard layouts back and forth are really confusing to users.
So there's good work todo but it's almost certainly in working with the Spice community to try to make what they already have more accessible to non-x86 architectures.
Hooray :)
Alex