Re: [Qemu-devel] [PATCH] ppc: Add/Re-introduce MMU model definitions needed by PR KVM

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 11/07/2015 08:12 AM, Benjamin Herrenschmidt wrote:
> On Fri, 2015-11-06 at 13:12 +0530, Bharata B Rao wrote:
>> Commit aa4bb5875231 (ppc: Add mmu_model defines for arch 2.03 and
>> 2.07)
>> removed the mmu_model definition POWERPC_MMU_2_06a which is needed by
>> PR KVM. Reintroduce it and also add POWERPC_MMU_2_07a.
>>
>> This fixes QEMU crash (qemu: fatal: Unknown MMU model) during booting
>> of PR KVM guest.
>
> Hrm, I see... we clear the 1TSEG bit and that causes the switch/cases
> to no long work. Argh....
>
> We should clean up that junk. We are mixing up bit masks and an actual
> model "number" in the same field. We should make that cleaner, using
> a mask to extract the actual version and switch/case on *that*...


I like this and I wonder if Bharata is going to do this, if not, I will, I 
just noticed this this patch made it to the dwg/spapr-next tree so we need 
to hurry...

Bharata, got some time for this? Thanks.



>
>> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> ---
>>   target-ppc/cpu.h        | 6 ++++++
>>   target-ppc/mmu_helper.c | 8 ++++++++
>>   2 files changed, 14 insertions(+)
>>
>> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
>> index b34aed6..31c6fee 100644
>> --- a/target-ppc/cpu.h
>> +++ b/target-ppc/cpu.h
>> @@ -122,9 +122,15 @@ enum powerpc_mmu_t {
>>       /* Architecture 2.06 variant                               */
>>       POWERPC_MMU_2_06       = POWERPC_MMU_64 | POWERPC_MMU_1TSEG
>>                                | POWERPC_MMU_AMR | 0x00000003,
>> +    /* Architecture 2.06 "degraded" (no 1T segments)           */
>> +    POWERPC_MMU_2_06a      = POWERPC_MMU_64 | POWERPC_MMU_AMR
>> +                             | 0x00000003,
>>       /* Architecture 2.07 variant                               */
>>       POWERPC_MMU_2_07       = POWERPC_MMU_64 | POWERPC_MMU_1TSEG
>>                                | POWERPC_MMU_AMR | 0x00000004,
>> +    /* Architecture 2.07 "degraded" (no 1T segments)           */
>> +    POWERPC_MMU_2_07a      = POWERPC_MMU_64 | POWERPC_MMU_AMR
>> +                             | 0x00000004,
>>   #endif /* defined(TARGET_PPC64) */
>>   };
>>
>> diff --git a/target-ppc/mmu_helper.c b/target-ppc/mmu_helper.c
>> index e52d0e5..30298d8 100644
>> --- a/target-ppc/mmu_helper.c
>> +++ b/target-ppc/mmu_helper.c
>> @@ -1295,7 +1295,9 @@ void dump_mmu(FILE *f, fprintf_function
>> cpu_fprintf, CPUPPCState *env)
>>       case POWERPC_MMU_64B:
>>       case POWERPC_MMU_2_03:
>>       case POWERPC_MMU_2_06:
>> +    case POWERPC_MMU_2_06a:
>>       case POWERPC_MMU_2_07:
>> +    case POWERPC_MMU_2_07a:
>>           dump_slb(f, cpu_fprintf, env);
>>           break;
>>   #endif
>> @@ -1435,7 +1437,9 @@ hwaddr ppc_cpu_get_phys_page_debug(CPUState
>> *cs, vaddr addr)
>>       case POWERPC_MMU_64B:
>>       case POWERPC_MMU_2_03:
>>       case POWERPC_MMU_2_06:
>> +    case POWERPC_MMU_2_06a:
>>       case POWERPC_MMU_2_07:
>> +    case POWERPC_MMU_2_07a:
>>           return ppc_hash64_get_phys_page_debug(env, addr);
>>   #endif
>>
>> @@ -1939,7 +1943,9 @@ void ppc_tlb_invalidate_all(CPUPPCState *env)
>>       case POWERPC_MMU_64B:
>>       case POWERPC_MMU_2_03:
>>       case POWERPC_MMU_2_06:
>> +    case POWERPC_MMU_2_06a:
>>       case POWERPC_MMU_2_07:
>> +    case POWERPC_MMU_2_07a:
>>   #endif /* defined(TARGET_PPC64) */
>>           tlb_flush(CPU(cpu), 1);
>>           break;
>> @@ -2013,7 +2019,9 @@ void ppc_tlb_invalidate_one(CPUPPCState *env,
>> target_ulong addr)
>>       case POWERPC_MMU_64B:
>>       case POWERPC_MMU_2_03:
>>       case POWERPC_MMU_2_06:
>> +    case POWERPC_MMU_2_06a:
>>       case POWERPC_MMU_2_07:
>> +    case POWERPC_MMU_2_07a:
>>           /* tlbie invalidate TLBs for all segments */
>>           /* XXX: given the fact that there are too many segments to
>> invalidate,
>>            *      and we still don't have a tlb_flush_mask(env, n,
>> mask) in QEMU,


-- 
Alexey