Re: [Qemu-devel] [PATCH 1/3] target-ppc: Update slb array with correct index values.

["Andreas Färber" <afaerber@suse.de>]

Am 19.08.2013 14:42, schrieb Andreas Färber:
> Am 19.08.2013 14:29, schrieb Aneesh Kumar K.V:
>> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>>
>> Without this, a value of rb=0 and rs=0, results in replacing the 0th
> 
> "... rs=0 results in ..."
> 
>> index. This can be observed when using gdb remote debugging support.
>>
>> (gdb) x/10i do_fork
>>    0xc000000000085330 <do_fork>:        Cannot access memory at address 0xc000000000085330
>> (gdb)
>>
>> This is because when we do the slb sync via kvm_cpu_synchronize_state,
>> we overwrite the slb entry (0th entry) for 0xc00000000008533
> 
> Is there a trailing 0 missing here?
> 
>>
>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
>> ---
>>  target-ppc/kvm.c | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
>> index 30a870e..5d4e613 100644
>> --- a/target-ppc/kvm.c
>> +++ b/target-ppc/kvm.c
>> @@ -1034,8 +1034,18 @@ int kvm_arch_get_registers(CPUState *cs)
>>          /* Sync SLB */
>>  #ifdef TARGET_PPC64
>>          for (i = 0; i < 64; i++) {
>> -            ppc_store_slb(env, sregs.u.s.ppc64.slb[i].slbe,
>> -                               sregs.u.s.ppc64.slb[i].slbv);
>> +            target_ulong rb  = sregs.u.s.ppc64.slb[i].slbe;
> 
> Double space.
> 
>> +            /*
>> +             * KVM_GET_SREGS doesn't retun slb entry with slot information

"return"

>> +             * same as index. So don't depend on the slot information in
>> +             * the returned value.
>> +             */
>> +            rb &= ~0xfff;
>> +            /*
>> +             * use the array index as the slot
>> +             */
>> +            rb |= i;
>> +            ppc_store_slb(env, rb, sregs.u.s.ppc64.slb[i].slbv);
>>          }
>>  #endif
>>  
> 
> Regards,
> Andreas
> 


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