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

[Alexander Graf]

On 05.01.2012, at 12:41, Andreas Färber wrote:

> Dear Mr. ppc,
> 
> 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
> 
>> Signed-off-by: Alexander Graf <address@hidden>
>> ---
>> configure        |    2 +-
>> target-ppc/cpu.h |    2 +-
>> 2 files changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/configure b/configure
>> index 9b4fe34..3bdb556 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3276,7 +3276,7 @@ case "$target_arch2" in
>>   ;;
>>   ppc)
>>     gdb_xml_files="power-core.xml power-fpu.xml power-altivec.xml 
>> power-spe.xml"
>> -    target_phys_bits=32
>> +    target_phys_bits=64
>>     target_nptl="yes"
>>     target_libs_softmmu="$fdt_libs"
>>   ;;
> 
>> 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. Does qemu-system-ppc64 work with -M prep and -cpu 
<something old>? The constant is only used for QEMU's internal TLB.

Alex