[Qemu-devel] Re: [PATCH 2/3] PPC64: Implement slbmte

[Blue Swirl <blauwirbel@gmail.com>]

On 3/2/09, Alexander Graf <agraf@suse.de> wrote:
> In order to modify SLB entries on recent PPC64 machines, the slbmte
>  instruction is used.
>
>  This patch implements the slbmte instruction and makes the "bridge"
>  mode code use the slb set functions, so we can move the SLB into
>  the CPU struct later.
>
>  This is required for Linux to run on PPC64.
>
>  Signed-off-by: Alexander Graf <alex@csgraf.de>

>   void ppc_store_sr (CPUPPCState *env, int srnum, target_ulong value)
>   {
>      LOG_MMU("%s: reg=%d " ADDRX " " ADDRX "\n",
>                  __func__, srnum, value, env->sr[srnum]);
>  -    if (env->sr[srnum] != value) {
>  +    if (env->mmu_model & POWERPC_MMU_64) {

>   target_ulong helper_load_sr (target_ulong sr_num)
>   {
>  +    if (env->mmu_model & POWERPC_MMU_64)
>  +        return ppc_load_sr(env, sr_num);
>      return env->sr[sr_num];
>   }

It would be faster to move the MMU model checks to translation time.