From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Xen 4.1 + Linux compiled with PVH == BOOM
Date: Sat, 21 Dec 2013 11:17:55 -0500
Message-ID: <20131221161754.GB13156@pegasus.dumpdata.com>
References: <20131220175735.GA619@phenom.dumpdata.com>
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To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: xen-devel@lists.xensource.com, JBeulich@suse.com
List-Id: xen-devel@lists.xenproject.org

On Sat, Dec 21, 2013 at 11:09:54AM +0000, Ian Campbell wrote:
> On Fri, 2013-12-20 at 12:57 -0500, Konrad Rzeszutek Wilk wrote:
> 
> > My thought was that we should return 0[...]
> > Like this:
> > 
> > diff --git a/xen/common/libelf/libelf-dominfo.c b/xen/common/libelf/libelf-dominfo.c
> > index fda19e7..c9ff61e 100644
> > --- a/xen/common/libelf/libelf-dominfo.c
> > +++ b/xen/common/libelf/libelf-dominfo.c
> > @@ -83,7 +83,9 @@ elf_errorstatus elf_xen_parse_features(const char *features,
> >              }
> >          }
> >          if ( i == elf_xen_features )
> > -            return -1;
> > +            return 0; /* We don't recognize this feature, and let the
> > +                       * caller figure out if it has all of the needed parts.
> > +                       */
> 
> WRT the comment, if this code doesn't know about the feature then the
> caller is unlikely to know about it either, so silently ignoring it is
> more than likely completely fine.

<nods>
> 
> [...]
> > But perhaps that is not the way to do it and we should just cherry-pick
> > 30832c06a8d1f9caff0987654ef9e24d59469d9a in Xen 4.1?
> 
> I think we should do both, i.e. backport 30832c06a8d1 now to solve the
> immediate problem and then look at fixing unstable to be more accepting
> of new features which it doesn't yet know about. Ultimately perhaps we'd
> want to backport that patch too.

Ok, will crank out a patch after New Year.

Thanks!
> 
> Ian.
>