[Qemu-devel] SPARC64: unable to boot OpenBIOS from git master

[Qemu-devel] SPARC64: unable to boot OpenBIOS from git master

[Mark Cave-Ayland]

Hi all,

I've been experimenting with SPARC64 under QEMU, and with current git 
master I am unable to boot OpenBIOS at all with the following error:

OpenBIOS for Sparc64
Unhandled Exception 0x0000000000000032
PC = 0x00000000ffd19d84 NPC = 0x00000000ffd19d88
Stopping execution

Using git bisect indicates that the problem lies with the following commit:


commit d5f27e88699f14c802d66c01de70e5ea37b7153a
Author: Michael S. Tsirkin <mst@redhat.com>
Date:   Tue Feb 21 15:57:58 2012 +0200

     pci: set memory type for memory behind the bridge

     As we make upper bits in IO and prefetcheable memory
     registers writeable, we should declare support
     for 64 bit prefetcheable memory and 32 bit io
     in the bridge.

     This changes the default for apb, dec, but I'm guessing
     they got the defaults wrong by accident.
     Alternatively, we could let bridges declare lack of
     64 bit support and make the upper bits read-only zero.

     With this applied, we can drop these bits
     from express code.

     Reported-by: Gerd Hoffmann <kraxel@redhat.com>
     Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

     Could someone familiar with apb,dec ack this please?
     Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


Does anyone have an idea as to whether this is something that needs to 
be fixed in QEMU or OpenBIOS?


Many thanks,

Mark.

Re: [Qemu-devel] SPARC64: unable to boot OpenBIOS from git master

[Blue Swirl]

On Mon, Feb 27, 2012 at 06:36, Mark Cave-Ayland
<mark.cave-ayland@ilande.co.uk> wrote:
> Hi all,
>
> I've been experimenting with SPARC64 under QEMU, and with current git master
> I am unable to boot OpenBIOS at all with the following error:
>
> OpenBIOS for Sparc64
> Unhandled Exception 0x0000000000000032
> PC = 0x00000000ffd19d84 NPC = 0x00000000ffd19d88
> Stopping execution
>
> Using git bisect indicates that the problem lies with the following commit:
>
>
> commit d5f27e88699f14c802d66c01de70e5ea37b7153a
> Author: Michael S. Tsirkin <mst@redhat.com>
> Date:   Tue Feb 21 15:57:58 2012 +0200
>
>    pci: set memory type for memory behind the bridge
>
>    As we make upper bits in IO and prefetcheable memory
>    registers writeable, we should declare support
>    for 64 bit prefetcheable memory and 32 bit io
>    in the bridge.
>
>    This changes the default for apb, dec, but I'm guessing
>    they got the defaults wrong by accident.
>    Alternatively, we could let bridges declare lack of
>    64 bit support and make the upper bits read-only zero.
>
>    With this applied, we can drop these bits
>    from express code.
>
>    Reported-by: Gerd Hoffmann <kraxel@redhat.com>
>    Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>
>    Could someone familiar with apb,dec ack this please?
>    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>
>
> Does anyone have an idea as to whether this is something that needs to be
> fixed in QEMU or OpenBIOS?

No idea. Michael, should the commit be reverted?

It's easy to confirm the bug, just run qemu-system-sparc64 without any
arguments. Bug: black screen, no bug: yellow screen with OpenBIOS boot
text.

In fact, it's pretty annoying to see that even this very minimal
amount of testing effort has not been spent by a critical subsystem
maintainer.

>
> Many thanks,
>
> Mark.
>

Re: [Qemu-devel] SPARC64: unable to boot OpenBIOS from git master

[Michael S. Tsirkin]

On Sat, Mar 03, 2012 at 03:09:16PM +0000, Blue Swirl wrote:
> On Mon, Feb 27, 2012 at 06:36, Mark Cave-Ayland
> <mark.cave-ayland@ilande.co.uk> wrote:
> > Hi all,
> >
> > I've been experimenting with SPARC64 under QEMU, and with current git master
> > I am unable to boot OpenBIOS at all with the following error:
> >
> > OpenBIOS for Sparc64
> > Unhandled Exception 0x0000000000000032
> > PC = 0x00000000ffd19d84 NPC = 0x00000000ffd19d88
> > Stopping execution
> >
> > Using git bisect indicates that the problem lies with the following commit:
> >
> >
> > commit d5f27e88699f14c802d66c01de70e5ea37b7153a
> > Author: Michael S. Tsirkin <mst@redhat.com>
> > Date:   Tue Feb 21 15:57:58 2012 +0200
> >
> >    pci: set memory type for memory behind the bridge
> >
> >    As we make upper bits in IO and prefetcheable memory
> >    registers writeable, we should declare support
> >    for 64 bit prefetcheable memory and 32 bit io
> >    in the bridge.
> >
> >    This changes the default for apb, dec, but I'm guessing
> >    they got the defaults wrong by accident.
> >    Alternatively, we could let bridges declare lack of
> >    64 bit support and make the upper bits read-only zero.
> >
> >    With this applied, we can drop these bits
> >    from express code.
> >
> >    Reported-by: Gerd Hoffmann <kraxel@redhat.com>
> >    Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >
> >    Could someone familiar with apb,dec ack this please?
> >    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
> >
> >
> > Does anyone have an idea as to whether this is something that needs to be
> > fixed in QEMU or OpenBIOS?
> 
> No idea. Michael, should the commit be reverted?
> 
> It's easy to confirm the bug, just run qemu-system-sparc64 without any
> arguments. Bug: black screen, no bug: yellow screen with OpenBIOS boot
> text.
> 
> In fact, it's pretty annoying to see that even this very minimal
> amount of testing effort has not been spent by a critical subsystem
> maintainer.

My bad, I just sent out a fix.

> >
> > Many thanks,
> >
> > Mark.
> >