Re: PVH questions

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Jan 28, 2013 at 03:09:57PM +0000, Stefano Stabellini wrote:
> On Mon, 28 Jan 2013, Samuel Thibault wrote:
> > Hello,
> > 
> > I've had a look at PVH support, and I have a few questions:
> > 
> > - events are still dispatched the PV way through the callback, right?
> 
> No, they are injected as an X86 vector (0xf3).

This is a non-PVH question, but the X86 vector injection only works
on CPU0 right? Which means that for HVM backends all of the events
are coalesced in one vector and worst yet - they are not perCPU - so
end up with IPI-ing the other CPUs. Stefano, you were the original
author of this - what would be needed to get this to work across
multitple CPUs and such?

> 
> 
> > - I guess FPU errors don't trigger an INT13, so I don't need to handle
> > that?
> 
> I think that's right, but Mukesh can confirm this.
> 
> 
> > - How about the console and store MFNs from the boot info? Are they
> > still MFNs, or actually PFNs?
> 
> PFNs
> 
> 
> > - How about PV network in non-copy mode?  It used to be done
> > with a page transfer, which the frontend would free, does
> > XENMEM_decrease_reservation still use MFNs, or PFNs?
> 
> PFNs
> 
> Mukesh, did I get it right?
> Would you be up for writing down these basic pieces of information
> regarding the PVH interface on a wiki page? 
> So that other kernel hackers like Samuel can port their favourite open
> source kernel to it?
> Maybe add something about the shared_info page and the grant_table too.