Re: [Qemu-devel] Hang when using 9p mounts after last Seabios update

[Chris Krumme]

On 10/11/2011 03:30 AM, Daniel P. Berrange wrote:
> On Sat, Oct 01, 2011 at 12:50:43PM -0400, Kevin O'Connor wrote:
> > On Thu, Sep 22, 2011 at 12:45:11PM +0100, Daniel P. Berrange wrote:
> > > On 0.14, 0.15 releaes, this all works just fine. On current GIT master,
> > > the guest OS will hang during boot.
> > [...]
> > > To reproduce this you will need my custom initrd for mounting 9p filesystems
> > > as the root FS. You can get that here:
> > >
> > >    http://berrange.com/~dan/qemu-serial-hang-demo.tar.gz
> > Thanks for the detailed report.
> >
> > I've confirmed the issue and tracked it down.  The current SeaBIOS
> > code gets confused during alignment checking if there are no prefmem
> > regions found.
> >
> > The patch below should fix the issue.
> Thanks, I have tested Seabios 1.6.3 which includes that patch, and
> can confirm that it does fix the hang I saw.
>
> Anthony/Gerd: we can get QEMU master updated to Seabios 1.6.3 before
> the 1.0 release ?
>
> > Author: Kevin O'Connor<address@hidden>
> > Date:   Sat Oct 1 12:35:32 2011 -0400
> >
> >      Fix alignment bug in pci_bios_init_root_regions().
> >
> >      If there are no memory allocations for a given type then the "max" bar
> >      size is zero.  However, ALIGN_DOWN does not handle an alignment of
> >      zero properly.  Catch and handle the zero case.
> >
> >      Signed-off-by: Kevin O'Connor<address@hidden>
> >
> > diff --git a/src/pciinit.c b/src/pciinit.c
> > index a857da0..0d8758e 100644
> > --- a/src/pciinit.c
> > +++ b/src/pciinit.c
> > @@ -536,7 +536,7 @@ static void pci_bios_init_bus_bases(struct pci_bus *bus)
> >       }
> >   }
> >
> > -#define ROOT_BASE(top, sum, align) ALIGN_DOWN((top)-(sum),(align))
> > +#define ROOT_BASE(top, sum, max) ALIGN_DOWN((top)-(sum),(max) ?: 1)

Hello,

This is adding a GNUism, can this be:  (max)?(max):1

Thanks

Chris

> >   static int pci_bios_init_root_regions(u32 start, u32 end)
> >   {
> Regards,
> Daniel