Re: [Qemu-devel] [PATCH] pci: fix bridge IO/BASE

[Avi Kivity <avi@redhat.com>]

On 03/04/2012 12:27 PM, Blue Swirl wrote:
> On Sun, Mar 4, 2012 at 09:46, Michael S. Tsirkin <mst@redhat.com> wrote:
> > commit 5caef97a16010f818ea8b950e2ee24ba876643ad introduced
> > a regression: we do not make IO base/limit upper 16
> > bit registers writeable, so we should report a 16 bit
> > IO range type, not a 32 bit one.
> > Note that PCI_PREF_RANGE_TYPE_32 is 0x0, but PCI_IO_RANGE_TYPE_32 is 0x1.
> >
> > In particular, this broke sparc64.
> >
> > Note: this just reverts to behaviour prior to the patch.
> > Making PCI_IO_BASE_UPPER16 and PCI_IO_LIMIT_UPPER16
> > registers writeable should, and seems to, work just as well, but
> > as no system seems to actually be interested in 32 bit IO,
> > let's not make unnecessary changes.
> >
> > Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >
> > Mark, can you confirm that this fixes the bug for you?
>
> No, running
> qemu-system-sparc64 -serial stdio
> still shows black screen and the following on console:
> OpenBIOS for Sparc64
> Unhandled Exception 0x0000000000000032
> PC = 0x00000000ffd19e18 NPC = 0x00000000ffd19e1c
> Stopping execution
>
> This unassigned memory exception is triggered because CMD646 IDE I/O
> registers are not accessible:
>
> (qemu) info pci
>   Bus  0, device   5, function 0:
>     IDE controller: PCI device 1095:0646
>       IRQ 1.
>       BAR0: I/O at 0xffffffffffffffff [0x0006].
>       BAR1: I/O at 0xffffffffffffffff [0x0002].
>       BAR2: I/O at 0xffffffffffffffff [0x0006].
>       BAR3: I/O at 0xffffffffffffffff [0x0002].
>       BAR4: I/O at 0xffffffffffffffff [0x000e].
>       id ""

The BARs are not initialized, so they aren't accessible.

But perhaps the dump was not taken at the point of failure, can you
provide a relevant dump if so?


-- 
error compiling committee.c: too many arguments to function