[SeaBIOS] [Xen-devel] Ideas for PV on SeaBIOS

[James Harper]

> 
> On Sat, 2011-05-21 at 09:44 +0100, James Harper wrote:
> > Am I understanding right that the OS would need to be completely put on
> > hold in the middle of the hypercall while the BIOS took over and did
> > it's shutdown sequence, which presumably involves xenstore activity?
> 
> Correct, or at least that is one suggestion (probably the front runner
> at the moment).
> 
> In theory it's no worse than SMM, which Windows presumably already copes
> with, but perhaps the latency from having to do the xenstore interaction
> is far greater than any real SMM operation.
> 

How hard would it be to create a better mechanism for going forward and implement the above as a fallback if the DomU doesn't support the new mechanism?

James