Re: [Qemu-devel] [PATCH] PPC: Bump qemu-system-ppc to 64-bit physical address space

["Andreas Färber" <afaerber@suse.de>]

Am 05.01.2012 17:00, schrieb Andreas Färber:
> Am 05.01.2012 16:52, schrieb Alexander Graf:
>>
>> On 05.01.2012, at 12:41, Andreas Färber wrote:
>>
>>> Am 18.10.2011 01:52, schrieb Alexander Graf:
>>>> Some 32-bit PPC CPUs can use up to 36 bit of physicall address space.
>>>> Treat them accordingly in the qemu-system-ppc binary type.
>>>
>>> This change broke the prep machine. :(
>>>
>>> With -nographic I see:
>>>
>>> ERROR: BUG caught...
>>> BIOS execution exception
>>> nip=0x05800000 msr=0x00002000 dar=0x00000000 dsisr=0x00000000
>>> Stopping execution

>>>> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
>>>> index 8e5c85c..f36f375 100644
>>>> --- a/target-ppc/cpu.h
>>>> +++ b/target-ppc/cpu.h
>>>> @@ -66,7 +66,7 @@
>>>> #define TARGET_PAGE_BITS 12
>>>> #endif /* defined(TARGET_PPCEMB) */
>>>>
>>>> -#define TARGET_PHYS_ADDR_SPACE_BITS 32
>>>> +#define TARGET_PHYS_ADDR_SPACE_BITS 36
>>>
>>> If I revert this part, previous behavior is restored.
>>>
>>> So it's not about libhw64 or target_phys_addr_t.
>>>
>>> Any idea? Is 6xx TLB maybe unable to cope with the larger address space?
>>> Or is this an OHW limitation?
>>
>> That is very confusing tbh.
> 
> It is... Having fixed Avi's Memory API conversion, despite reverting the
> phys addr space bits as above I get the same breakage again.
> Bisecting had clearly pointed out this change. I'll try if bisecting
> with the Memory API patch on top gives any new conclusions.

Yep, new suspect:

0fb56ffc5edd66f12ccfc0d71af5f9c79c0a2612 is the first bad commit
commit 0fb56ffc5edd66f12ccfc0d71af5f9c79c0a2612
Author: Blue Swirl <blauwirbel@gmail.com>
Date:   Sat Oct 15 07:57:49 2011 +0000

    m48t59: drop obsolete address base arithmetic

    Remove now incorrect address base arithmetic, missed by
    9936d6e42392f1440505dfa9df065eabd251cadf. Fixes Sparc64 boot.

    Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

:040000 040000 5a38b3f01bb5afd29660755df2622fcf6d5397ce
5a54e03e2d8af7e4a2e9254ae83b0191730e5ee1 M	hw

with MemoryRegion fix on top.

Andreas

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