Re: [Qemu-devel] [PATCH 4/7] Only TCG needs TLB handling

[Orit Wasserman <owasserm@redhat.com>]

On 05/22/2012 09:32 PM, Juan Quintela wrote:
> Refactor the code that is only needed for tcg to an static function.
> Call that only when tcg is enabled.  We can't refactor to a dummy
> function in the kvm case, as qemu can be compiled at the same time
> with tcg and kvm.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  exec.c |   31 +++++++++++++++++++++----------
>  1 files changed, 21 insertions(+), 10 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index a0494c7..b6c7675 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1943,11 +1943,29 @@ void tb_flush_jmp_cache(CPUArchState *env, target_ulong addr)
>              TB_JMP_PAGE_SIZE * sizeof(TranslationBlock *));
>  }
> 
> +static void tlb_reset_dirty_range_all(ram_addr_t start, ram_addr_t end,
> +                                      uintptr_t length)
> +{
> +    uintptr_t start1;
> +
> +    /* we modify the TLB cache so that the dirty bit will be set again
> +       when accessing the range */
> +    start1 = (uintptr_t)qemu_safe_ram_ptr(start);
> +    /* Check that we don't span multiple blocks - this breaks the
> +       address comparisons below.  */
> +    if ((uintptr_t)qemu_safe_ram_ptr(end - 1) - start1
> +            != (end - 1) - start) {
> +        abort();
> +    }
> +    cpu_tlb_reset_dirty_all(start1, length);
> +
> +}
> +
>  /* Note: start and end must be within the same ram block.  */
>  void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end,
>                                       int dirty_flags)
>  {
> -    uintptr_t length, start1;
> +    uintptr_t length;
> 
>      start &= TARGET_PAGE_MASK;
>      end = TARGET_PAGE_ALIGN(end);
> @@ -1957,16 +1975,9 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end,
>          return;
>      cpu_physical_memory_mask_dirty_range(start, length, dirty_flags);
> 
> -    /* we modify the TLB cache so that the dirty bit will be set again
> -       when accessing the range */
> -    start1 = (uintptr_t)qemu_safe_ram_ptr(start);
> -    /* Check that we don't span multiple blocks - this breaks the
> -       address comparisons below.  */
> -    if ((uintptr_t)qemu_safe_ram_ptr(end - 1) - start1
> -            != (end - 1) - start) {
> -        abort();
> +    if (tcg_enabled()) {
> +        tlb_reset_dirty_range_all(start, end, length);
>      }
> -    cpu_tlb_reset_dirty_all(start1, length);
>  }
> 
>  int cpu_physical_memory_set_dirty_tracking(int enable)

Reviewed-by: Orit Wasserman <owasserm@redhat.com>