Re: [Qemu-devel] [PATCH -V2 1/4] target-ppc: Update slb array with correct index values.

[Alexander Graf]

Am 22.08.2013 um 18:58 schrieb Andreas Färber <address@hidden>:

> Am 20.08.2013 12:49, schrieb Aneesh Kumar K.V:
>> From: "Aneesh Kumar K.V" <address@hidden>
>> 
>> Without this, a value of rb=0 and rs=0 results in replacing the 0th
>> 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 0xc000000000085330
>> 
>> Signed-off-by: Aneesh Kumar K.V <address@hidden>
>> ---
>> 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..a629447 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;
>> +            /*
>> +             * KVM_GET_SREGS doesn't retun slb entry with slot information
> 
> Still has the "return" typo - maybe Alex can fix if he applies it.

No, this patch is wrong. I merely picked that one trivial patch for now :)

Alex

> 
> Andreas
> 
>> +             * 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
> 
> 
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