Re: [Qemu-devel] [PATCH v2 21/21] q35: add acpi-based pci hotplug.

[Jason Baron]

On Thu, Oct 11, 2012 at 04:54:53PM +0200, Paolo Bonzini wrote:
> Il 11/10/2012 16:46, Michael S. Tsirkin ha scritto:
> > Yes. Reason I ask is because q35 is adding bridges by default now.
> > Would it be possible to only add them if requested on command line by user
> > instead?
> 
> Can you just use shpc or pcie hotplug on those bridges?
> 

Yes, I've tested pcie hotplug minimally, but it seems to work so far.

> > I realize some guests expect devices at specific slots
> > but this does not apply to bridges I think?
> > 
> > It would also be nice to add comments explaining why
> > specific slots were selected e.g. /* BSD XYZ fails to boot unless ahci is 
> > at alow 2 */
> > etc.
> > 
> > Also - will adding this code now mean that when adding bridges
> > we'll need to add compatibility code in bios/qemu in the future?
> 
> It will need SSDT changes.  One ugliness of Jason's patch was that it
> introduced a massive chain of 32*32 Ifs in the SSDT.  Changing it to use
> LoadTable shouldn't be hard.  Then you can patch out the LoadTable (e.g.
> _INI -> INI_) based on what QEMU tells you is a bridge or not.
> 
> Paolo
>