[Qemu-devel] Re: [PATCH 04/21] wrap cache flushing functions into accel drivers

[Anthony Liguori <aliguori@us.ibm.com>]

Glauber Costa wrote:
> From: Glauber Costa <gcosta@redhat.com>
>
> Yet another accel field: cache flushing functions
> Signed-off-by: Glauber Costa <glommer@redhat.com>
> ---
>  accel.c |    2 ++
>  accel.h |   11 +++++++++++
>  exec.c  |   15 +++++++--------
>  kqemu.c |   15 +++++++++------
>  4 files changed, 29 insertions(+), 14 deletions(-)
>
> diff --git a/accel.c b/accel.c
> index 3a17dc5..6776244 100644
> --- a/accel.c
> +++ b/accel.c
> @@ -14,5 +14,7 @@ int _accel_nop(void)
>  QEMUAccel noaccel = {
>      .cpu_interrupt = accel_nop,
>      .init_env = accel_nop,
> +    .flush_cache = accel_nop,
> +    .flush_page = accel_nop,
>  };
>
> diff --git a/accel.h b/accel.h
> index 0d916dc..935cfef 100644
> --- a/accel.h
> +++ b/accel.h
> @@ -4,6 +4,8 @@
>  typedef struct QEMUAccel {
>      void (*cpu_interrupt)(CPUState *env);
>      void (*init_env)(CPUState *env);
> +    void (*flush_cache)(CPUState *env, int global);
> +    void (*flush_page)(CPUState *env, target_ulong addr);
>  } QEMUAccel;
>
>  extern QEMUAccel *current_accel;
> @@ -24,4 +26,13 @@ static inline void accel_init_env(CPUState *env)
>      current_accel->init_env(env);
>  }
>
> +static inline void accel_flush_cache(CPUState *env, int global)
> +{
> +    current_accel->flush_cache(env, global);
> +}
> +
> +static inline void accel_flush_page(CPUState *env, target_ulong addr)
> +{
> +    current_accel->flush_page(env, addr);
> +}
>  #endif
> diff --git a/exec.c b/exec.c
> index 21253cc..c761f4a 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1684,10 +1684,10 @@ void tlb_flush(CPUState *env, int flush_global)
>
>      memset (env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *));
>
> -#ifdef USE_KQEMU
> -    if (env->kqemu_enabled) {
> -        kqemu_flush(env, flush_global);
> -    }
> +    accel_flush_cache(env, flush_global);
> +
> +#if !defined(CONFIG_SOFTMMU)
> +    munmap((void *)MMAP_AREA_START, MMAP_AREA_END - MMAP_AREA_START);
>   

Where did this come from??  I understand the rather simple conversion of 
kqemu_flush to accel_flush_cache but it's not at all clear where this 
munmap came from.

>  #endif
>      tlb_flush_count++;
>  }
> @@ -1730,10 +1730,9 @@ void tlb_flush_page(CPUState *env, target_ulong addr)
>
>      tlb_flush_jmp_cache(env, addr);
>
> -#ifdef USE_KQEMU
> -    if (env->kqemu_enabled) {
> -        kqemu_flush_page(env, addr);
> -    }
> +    accel_flush_page(env, addr);
> +#if !defined(CONFIG_SOFTMMU)
> +    if (addr < MMAP_AREA_END)
>   

And what is this if() being added for?


Regards,

Anthony Liguori