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

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Fri, 2013-07-19 at 14:33 -0700, Mukesh Rathor wrote:
> On Fri, 19 Jul 2013 10:16:00 +0100
> Ian Campbell <Ian.Campbell@xxxxxxxxxx> 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?

Being a whole new arch we had the luxury of being pretty fluid about how
things we going to work and were correspondingly slack about writing
them down. Things have settled down now and it really is about time we
had something, I've just posted
<1374517040-10822-1-git-send-email-ijc@xxxxxxxxxxxxxx>. It's a bit lame
but it is a start.

> > >  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.

Thanks.

> > 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.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel