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

[Paolo Bonzini]

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?

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.

Paolo