Re: [Xen-devel] Correct format for HVM graphics

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Thu, 5 Apr 2012, Stefan Bader wrote:
> > In any case, as I said before, if the alternatives are keeping the wait
> > time or patching xend, I would go for patching xend.
> > If we don't think we can fix Linux and backport the fix in a reasonable
> > time, patching xend might be the only option.
> 
> My impression is that you (the generic you) would not really want to modify 
> xend
> too much as it and the xm stack should go away anyway.
> Instead I would fix libvirt's use of xend when it is known that it is not
> working well (if using "vfb = [ 'vnc=1, ...' ]" or similar for sxpr is 
> creating
> a vkbd and xend/the xm stack does not support it, then just don't use it).
> 
> The question of removing the delays is not so much (well yes it is too, but 
> not
> always in ones own hands) whether it can be done or how quickly. Providing the
> means to run guests is something rather under our control. Be it Ubuntu as 
> dom0
> or Xenserver. But which kernels are run as guests is not.
> 
> So, as long as xend does not change its behavior, then changing libvirt in a 
> way
> that does never use the configuration format which causes a vkbd to be created
> (for HVM) is ok. And if it gets picked up upstream it helps all users of 
> libvirt
> the same.
> But if xend would change to allow using a vkbd, then it would be good if that
> could be synced with a xend version change which could be used inside libvirt 
> to
> modify its config output (as it does now but in some way with the wrong 
> version).
> 
> The kernel change to remove delays imo is a completely separate issue. And if
> just as an additional "pre-caution".

So the argument is that ATM libvirt uses a vfb config line with HVM
guests and that is wrong.
I agree with you there, the vfb config line is for PV guests only and
should be removed from any HVM guests configurations.
In fact, even if we add a vfb frontend/backend pair for HVM guests, it
probably won't go through a vfb config line, because the vnc/sdl
configuration would be shared between the vfb and vga devices.

So you convinced me that is OK to remove it from libvirt :-)

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel