Cédric Le Goater <c...@kaod.org> writes:
> On 09/02/2016 08:32 AM, Nikunj A Dadhania wrote:
>> The series is a first attempt at enabling Multi-Threaded TCG on PowerPC.
>> Changes that were needed to enable PowerPC are pretty simple;
>>
>> Patch 01: Take a iothread lock during hcall, as hcall can generate io
>> requests
>> 02: For TCG, we were harcoding smt as 1, this gets rid of the
>> limitation
>> 03: Use atomic_cmpxchg in store conditional
>> 04: With more threads, flush the entry from each cpu.
>> This can be optimized further.
>>
>> The patches are based on the Alex Bennee's base enabling patches for
>> MTTCG[1] and Emilios's cmpxchg atomics. The consolidated tree of the
>> above patches is here:
>>
>> https://github.com/stsquad/qemu/tree/mttcg/base-patches-v4-with-cmpxchg-atomics-v2
>>
>> Apart from the above, PPC patches are based out of ppc-for-2.8 and
>> load/store consolidation patches [2]
>>
>> Series with all dependent patches available here:
>> https://github.com/nikunjad/qemu/tree/ppc_mttcg_v1
>>
>> Testing:
>> ========
>>
>> -smp 4,cores=1,threads=4 -accel tcg,thread=multi
>>
>> TODO
>> ====
>> Implement msgsndp instructions(door-bell), newer kernels enable it
>> depending on the PVR. I have been using following workaround to boot.
>> https://github.com/nikunjad/qemu/commit/2c10052c5f93418a6b920e6ba3ce1813fcf50bc4
>
> You could also introduce a Power8 DD1 in qemu. From the kernel cputable :
I see this as a temporary workaround, need to fix it.
> { /* Power8 DD1: Does not support doorbell IPIs */
> .pvr_mask = 0xffffff00,
> .pvr_value = 0x004d0100,
> .cpu_name = "POWER8 (raw)",
> .cpu_features = CPU_FTRS_POWER8_DD1,
> ...
Regards
Nikunj
