Re: [Xen-devel] pv-grub guest booting fail with recent qemu-xen

["Hao, Xudong" <xudong.hao@xxxxxxxxx>]

> -----Original Message-----
> From: Xen-devel [mailto:xen-devel-bounces@xxxxxxxxxxxxx] On Behalf Of Konrad
> Rzeszutek Wilk
> Sent: Friday, April 1, 2016 11:55 PM
> To: Hao, Xudong <xudong.hao@xxxxxxxxx>
> Cc: samuel.thibault@xxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxx; Wei Liu
> <wei.liu2@xxxxxxxxxx>; stefano.stabellini@xxxxxxxxxxxxx
> Subject: Re: [Xen-devel] pv-grub guest booting fail with recent qemu-xen
> 
> On Wed, Mar 30, 2016 at 02:05:28AM +0000, Hao, Xudong wrote:
> > > -----Original Message-----
> > > From: Wei Liu [mailto:wei.liu2@xxxxxxxxxx]
> > > Sent: Wednesday, March 30, 2016 12:58 AM
> > > To: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > > Cc: Hao, Xudong <xudong.hao@xxxxxxxxx>; wei.liu2@xxxxxxxxxx;
> > > samuel.thibault@xxxxxxxxxxxx; stefano.stabellini@xxxxxxxxxxxxx; xen-
> > > devel@xxxxxxxxxxxxx
> > > Subject: Re: [Xen-devel] pv-grub guest booting fail with recent
> > > qemu-xen
> > >
> > > On Mon, Mar 28, 2016 at 09:21:14AM -0400, Konrad Rzeszutek Wilk wrote:
> > > > On Mon, Mar 28, 2016 at 02:03:35AM +0000, Hao, Xudong wrote:
> > > > > > -----Original Message-----
> > > > > > From: Xen-devel [mailto:xen-devel-bounces@xxxxxxxxxxxxx] On
> > > > > > Behalf Of Konrad Rzeszutek Wilk
> > > > > > Sent: Saturday, March 26, 2016 2:58 AM
> > > > > > To: Hao, Xudong <xudong.hao@xxxxxxxxx>
> > > > > > Cc: stefano.stabellini@xxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxx
> > > > > > Subject: Re: [Xen-devel] pv-grub guest booting fail with
> > > > > > recent qemu-xen
> > > > > >
> > > > > > On Wed, Mar 02, 2016 at 07:16:40AM +0000, Hao, Xudong wrote:
> > > > > > > Hi,
> > > > > > > For Xen upstream master branch with commit 1949868d, After
> > > > > > > updating qemu-
> > > > > > xen version from fcf6ac57 to 2ce1d30e, booting a pv-grub guest will
> fail.
> > > >
> > >
> > > pv-grub should be using qemu-traditional, not qemu-xen
> > >
> >
> > Never hear this limitation.
> >
> > > The log message you posted in your original post doesn't seem to reveal
> much.
> > > Can you have a look at relevant QEMU logs under /var/log/xen?
> >
> > There is not valuable qemu log, only one line: "qemu: terminating on signal 
> > 1
> from pid 36642".
> >
> > Bisect and the bad commit of qemu-xen is:
> 
> If you use PV-grub without the framebuffer does it boot?

How to disable framebuffer when VM booting.
Reverted this patch, PV-grub guest boot successfully.

> 
> 
> >
> > commit 2ce1d30ef2858dfed72a281872579e5a26b090dd
> > Author: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> > Date:   Wed Jan 6 16:32:22 2016 +0000
> >
> >     xenfb.c: avoid expensive loops when prod <= out_cons
> >
> >     If the frontend sets out_cons to a value higher than out_prod, it will
> >     cause xenfb_handle_events to loop about 2^32 times. Avoid that by using
> >     better checks at the beginning of the function.
> >
> >     upstream-commit-id: ac0487e1d2ae811cd4d035741a109a4ecfb013f1
> >
> >     Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> >     Reported-by: Ling Liu <liuling-it@xxxxxx>
> >
> > diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index
> > 4e2a27a..8eb3046 100644
> > --- a/hw/display/xenfb.c
> > +++ b/hw/display/xenfb.c
> > @@ -789,8 +789,9 @@ static void xenfb_handle_events(struct XenFB
> > *xenfb)
> >
> >      prod = page->out_prod;
> >      out_cons = page->out_cons;
> > -    if (prod == out_cons)
> > -       return;
> > +    if (prod - out_cons >= XENFB_OUT_RING_LEN) {
> > +        return;
> > +    }
> >      xen_rmb();         /* ensure we see ring contents up to prod */
> >      for (cons = out_cons; cons != prod; cons++) {
> >         union xenfb_out_event *event = &XENFB_OUT_RING_REF(page,
> > cons);
> >
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel