Re: [RFC PATCH] PCI MMCONFIG: add validation against ACPI motherboard resources

Robert Hancock
2007-05-02T14:35:31Z

Jesse Barnes wrote:
> On Tuesday, May 01, 2007, Jesse Barnes wrote:
>>> I'm testing it now on my 965...
>> Bah... nevermind Robert, I see you're doing this already in
>> pci_mmcfg_reject_broken. I'm about to reboot & test now.
>
> Ok, I've tested a bit on my 965 (after re-adding my old patch to support
> it) and the new checks are more complete, but my BIOS still appears to be
> buggy.
>
> The extended config space (as defined by the register) is at 0xf0000000
> (full value is 0xf0000003 indicating 128M enabled). The ACPI MCFG table
> has this space reserved according to Robert's new code, but the machine
> hangs due to the address space aliasing Olivier mentioned awhile back. I
> don't have a PCIe card to test with (or any devices that require extended
> config space that I know of) so I can't really tell if Windows supports
> PCIe on this platform, but if it does I don't see how it would w/o having
> a full bridge driver and sophisticated address space allocation builtin.

Windows XP doesn't use MMCONFIG or any extended configuration space. I
believe Vista is supposed to, though. Not sure how they are handling
this issue.

>
> I'm going to try updating my BIOS, but if that doesn't solve this problem,
> I'm not sure what we can do about it. Should pci_mmcfg_insert_resources
> check for conflicts? Should we just blacklist certain boards? I can try
> pinging our BIOS folks about this board to see what was intended, but I'm
> sure this won't be the only board we have problems with, so we'll need to
> address it generically somehow.

Can you post what your board has for PNPACPI reserved resources (I
believe they're in /sys/devices/pnp0/*/resources IIRC, don't have a
Linux box handy right now). Full dmesg would also be useful, I think it
dumps out those reservations at boot nowadays..

--
Robert Hancock Saskatoon, SK, Canada
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