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

["Andreas Färber" <afaerber@suse.de>]

Am 19.08.2013 14:29, 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
> +             * 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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