Re: [Qemu-devel] [PATCH] pc_piix: enable legacy hotplug for Xen

[Stefano Stabellini]

On Wed, 5 Feb 2014, Paolo Bonzini wrote:
> Il 05/02/2014 17:54, Stefano Stabellini ha scritto:
> > > > I'm not sure how this is related to fw_cfg?  fw_cfg is just a simple
> > > key-value
> > > > store.  If hvmloader doesn't use it, it should be a burden.
> > I was referring to the fact that QEMU might not have all the info that
> > need to be written to fw_cfg when running on Xen: some of the info might
> > be in the hypervisor and some other in another QEMU instance.
> > Or do you think that fw_cfg could be written by multiple entities
> > simultaneously?
> 
> Wouldn't it be possible to fetch the necessary information via hypercalls or
> in xenstore?

Probably, at least for the single QEMU case.


> It's possible that some particular fw_cfg entries will be skipped for Xen, but
> most of them should apply.  fw_cfg support would also make it possible to use
> -kernel/-initrd in Xen HVM machines, for example.