Re: [PATCH 01/24] PVH xen: Add readme docs/misc/pvh-readme.txt

[Mukesh Rathor <mukesh.rathor@oracle.com>]

On Fri, 19 Jul 2013 10:16:00 +0100
Ian Campbell <Ian.Campbell@citrix.com> wrote:

> On Thu, 2013-07-18 at 11:21 -0700, Mukesh Rathor wrote:
> > > Is there a description somewhere in the series of what PVH means
> > > in terms of the guest visible ABI? i.e. documentation of the
> > > delta from the regular PV mode? I had a skim through and didn't
> > > spot it.
> > 
> > No. The ABIs are not as affected, thanks to pre-existing auto
> > translate mode.
> 
> Not even a little bit of variation from that?

In the current series, it's a PV domU guest with auto translate, so not
really. There are some changes to the implementation, like in case
of VCPUOP_initialise or XEN_DOMCTL_setvcpucontext for PVH, we must set 
context in VMCS also. The upcoming dom0 patch will introduce a new ABI, 
(unless you already did it for ARM and PVH will just piggyback on it).

BTW, is there such a doc for ARM I can look at for reference?

> >  But, I suppose after all the patches are checked in, I can write
> > up something. 
> 
> I could live with that, but I have heard mutterings that some people
> are finding it hard to review the patches without knowing the
> interface the are supposed to be implementing, which is pretty fair I
> think.

Ah, I see. I will try to enhance the patch comment prolog in the next
version. Hopefully, that will help.

> Could you perhaps enumerate the exact set of XENFEAT flags which
> must/must not be used/supported by a PVH guest in a document
> somewhere? That would hopefully explain the vast majority of the
> differences between trad-PV and PVH and be pretty succinct I think.
> Anything which isn't explained away by a particular feature flag
> might need additional explanation.

Ok, done. I put that in the pvh-readme. 

thanks
Mukesh