Re: [Qemu-devel] insmod virtio-blk is broken in qemu 1.0

["Daniel P. Berrange" <berrange@redhat.com>]

On Mon, Dec 19, 2011 at 11:34:13AM -0600, Anthony Liguori wrote:
> On 12/19/2011 04:31 AM, Daniel P. Berrange wrote:
> >On Sat, Dec 17, 2011 at 11:49:56AM -0500, Kevin O'Connor wrote:
> >>On Sat, Dec 17, 2011 at 10:24:07AM -0600, Anthony Liguori wrote:
> >>>On 12/17/2011 09:25 AM, Richard W.M. Jones wrote:
> >>>>On Sat, Dec 17, 2011 at 09:22:45AM -0600, Anthony Liguori wrote:
> >>>>>I've even further narrowed it down to the presents or lack of '-vga
> >>>>>cirrus'.  If you add '-vga cirrus' to the above command line, the
> >>>>>guest will boot successfully.
> >>>>
> >>>>Confirmed: Adding -vga cirrus to the command line cures it too.
> >>>>
> >>>>That's a strange one :-)
> >>>
> >>>vga sticks out a bit because it's one of the few places where we
> >>>treat device memory as ram as a performance optimization.
> >>>
> >>>The only time vga has been touched in between v0.15 and v1.0 was
> >>>during the introduction of the memory API.
> >>>
> >>>It's this commit:
> >>>
> >>>commit d67c3f2cd92aed2247bfa8a9da61a902b7b2ff09
> >>>Author: Gerd Hoffmann<kraxel@redhat.com>
> >>>Date:   Wed Aug 10 17:34:13 2011 +0200
> >>>
> >>>     seabios: update to master
> >>
> >>This looks like the same issue reported at:
> >>
> >>http://lists.nongnu.org/archive/html/qemu-devel/2011-10/msg00029.html
> >>
> >>The SeaBIOS fix for this was in rel-1.6.3.1 - but that didn't make
> >>QEmu 1.0.  Does the problem go away if you upgrade to the newer
> >>SeaBIOS version?
> >
> >Sigh, we really need to be better about updating SeaBIOS in QEMU before
> >release. We had plenty of time to pull in a newer SeaBIOS before 1.0
> >that would have fixed this :-(
> 
> 1.6.3.1 was released on Nov 24th, which was actually after the soft
> feature freeze.  We could have pulled 1.6.3 which was Oct 4th but
> updating the BIOS always results in some interesting things
> happening so it's not something I like to do unless we have to.
> 
> I'd rather have known that this functionality broken before that
> commit event went in to begin with than allowing it to remain broken
> until we happened to update past the bug.
> 
> >We've had multiple releases now where
> >functionality is broken due to QEMU shipping with an older SeaBIOS
> >release than is available upstream.
> 
> I think the real issue here is testing.  -nodefconfig -nodefaults is
> used by both libguestfs and libvirt but I'd wager to say that almost
> noone tests it in QEMU.

I had actually discovered & pointed out this flaw on qemu-devel back
in September, and Kevin had the seabios fix by Oct

http://lists.nongnu.org/archive/html/qemu-devel/2011-10/msg00029.html

I hadn't raised it again, because I had mistakenly assumed QEMU
will automatically pull in the newer SeaBios release before 1.0
came out. I could have more aggresively bugged people on qemu-devel
to update SeaBios, but given your point above about not wanting to
rebase Seabios its not clear that would have helped sort this out
before 1.0

Regards,
Daniel
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