Re: [Qemu-devel] Questions about hvm domU default devices with upstream qemu

[Stefano Stabellini]

On Wed, 4 Sep 2013, Fabio Fantoni wrote:
> Il 04/07/2013 15:51, Fabio Fantoni ha scritto:
> > Last year I posted a question about default devices of upstream qemu that
> > differ from qemu traditional, like empty floppy and cdrom in particular.
> > About empty floppy now is disabled as workaround.
> > About empty cdrom Stabellini tells that is useful, so I tried to use it but
> > cd-insert was failing,and I must define other empty cdrom on xl
> > configuration file, for example with: ',raw,hdb,ro,cdrom'.
> > It seem that there isn't default devices usable without define them in xen,
> > and I think that probably need to revise the definition of the devices to
> > avoid empty and unusable ones and to do everything as best as possible (also
> > with possibly reviewing qemu side).
> > Another good thing is also consider pv domU case and possible future support
> > of spice and/or other useful features.
> > Thanks for any reply.
> 
> I seen no replies about this, I think is important improve upstream qemu
> support and remove the traditional ASA upstream will be equivalent or superior
> in all features.
> 
> I also think is good idea add q35 support on xen.
> Seem that hvm domUs have performance limits, in particular on windows domUs
> (also with pv drivers) caused probably by old hardware emulation by qemu
> and/or xen support limited on some instruction sets.
> I don't know how to add essential q35 support on hvmloader to do some tests
> and have effective data about improvements.
> Anyone on this?

I agree that this is important and thanks for raising the issue.
It would be nice if somebody stepped up to do the q35 work.