Re: [Qemu-devel] [PATCH 4/7] ppc: move sdr1 value change detection logic to helper_store_sdr1()

[Paolo Bonzini <pbonzini@redhat.com>]

On 23/12/2014 01:36, Mark Cave-Ayland wrote:
> Otherwise when cpu_post_load calls ppc_store_sdr1() when restoring a VM
> snapshot the value is deemed unchanged and so the internal env->htab*
> variables aren't set correctly.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  target-ppc/misc_helper.c |    7 ++++++-
>  target-ppc/mmu_helper.c  |   35 +++++++++++++++--------------------
>  2 files changed, 21 insertions(+), 21 deletions(-)
> 
> diff --git a/target-ppc/misc_helper.c b/target-ppc/misc_helper.c
> index a577b3a..6b12ca8 100644
> --- a/target-ppc/misc_helper.c
> +++ b/target-ppc/misc_helper.c
> @@ -77,8 +77,13 @@ void helper_msr_facility_check(CPUPPCState *env, uint32_t bit,
>  
>  void helper_store_sdr1(CPUPPCState *env, target_ulong val)
>  {
> +    PowerPCCPU *cpu = ppc_env_get_cpu(env);
> +
>      if (!env->external_htab) {
> -        ppc_store_sdr1(env, val);
> +        if (env->spr[SPR_SDR1] != val) {
> +            ppc_store_sdr1(env, val);
> +            tlb_flush(CPU(cpu), 1);

Possibly stupid question: should this tlb_flush be in ppc_store_sdr1,
maybe guarded by "if (tcg_enabled())"?

Apart from this, the patch is okay.

Paolo

> +        }
>      }
>  }
>  
> diff --git a/target-ppc/mmu_helper.c b/target-ppc/mmu_helper.c
> index 660be7f..527c6ad 100644
> --- a/target-ppc/mmu_helper.c
> +++ b/target-ppc/mmu_helper.c
> @@ -2036,31 +2036,26 @@ void ppc_tlb_invalidate_one(CPUPPCState *env, target_ulong addr)
>  /* Special registers manipulation */
>  void ppc_store_sdr1(CPUPPCState *env, target_ulong value)
>  {
> -    PowerPCCPU *cpu = ppc_env_get_cpu(env);
> -
>      qemu_log_mask(CPU_LOG_MMU, "%s: " TARGET_FMT_lx "\n", __func__, value);
>      assert(!env->external_htab);
> -    if (env->spr[SPR_SDR1] != value) {
> -        env->spr[SPR_SDR1] = value;
> +    env->spr[SPR_SDR1] = value;
>  #if defined(TARGET_PPC64)
> -        if (env->mmu_model & POWERPC_MMU_64) {
> -            target_ulong htabsize = value & SDR_64_HTABSIZE;
> +    if (env->mmu_model & POWERPC_MMU_64) {
> +        target_ulong htabsize = value & SDR_64_HTABSIZE;
>  
> -            if (htabsize > 28) {
> -                fprintf(stderr, "Invalid HTABSIZE 0x" TARGET_FMT_lx
> -                        " stored in SDR1\n", htabsize);
> -                htabsize = 28;
> -            }
> -            env->htab_mask = (1ULL << (htabsize + 18 - 7)) - 1;
> -            env->htab_base = value & SDR_64_HTABORG;
> -        } else
> -#endif /* defined(TARGET_PPC64) */
> -        {
> -            /* FIXME: Should check for valid HTABMASK values */
> -            env->htab_mask = ((value & SDR_32_HTABMASK) << 16) | 0xFFFF;
> -            env->htab_base = value & SDR_32_HTABORG;
> +        if (htabsize > 28) {
> +            fprintf(stderr, "Invalid HTABSIZE 0x" TARGET_FMT_lx
> +                    " stored in SDR1\n", htabsize);
> +            htabsize = 28;
>          }
> -        tlb_flush(CPU(cpu), 1);
> +        env->htab_mask = (1ULL << (htabsize + 18 - 7)) - 1;
> +        env->htab_base = value & SDR_64_HTABORG;
> +    } else
> +#endif /* defined(TARGET_PPC64) */
> +    {
> +        /* FIXME: Should check for valid HTABMASK values */
> +        env->htab_mask = ((value & SDR_32_HTABMASK) << 16) | 0xFFFF;
> +        env->htab_base = value & SDR_32_HTABORG;
>      }
>  }
>  
>