Re: [Qemu-devel] [PATCH v2 6/7] exec: Factor out section_covers_addr

[Peter Xu]

On Tue, Mar 01, 2016 at 02:18:23PM +0800, Fam Zheng wrote:
> This will be shared by the next patch.
> 
> Also add a comment explaining the unobvious condition on "size.hi".
> 
> Signed-off-by: Fam Zheng <f...@redhat.com>

Reviewed-by: Peter Xu <pet...@redhat.com>

> ---
>  exec.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index ad8b826..b4e2eb5 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -307,6 +307,16 @@ static void phys_page_compact_all(AddressSpaceDispatch 
> *d, int nodes_nb)
>      }
>  }
>  
> +static inline bool section_covers_addr(const MemoryRegionSection *section,
> +                                       hwaddr addr)
> +{
> +    /* Memory topology clips a memory region to 2^64, size.hi >= 0 means the
> +     * section must cover any addr. */
> +    return section->size.hi ||
> +           range_covers_byte(section->offset_within_address_space,
> +                             section->size.lo, addr);
> +}
> +
>  static MemoryRegionSection *phys_page_find(PhysPageEntry lp, hwaddr addr,
>                                             Node *nodes, MemoryRegionSection 
> *sections)
>  {
> @@ -322,9 +332,7 @@ static MemoryRegionSection *phys_page_find(PhysPageEntry 
> lp, hwaddr addr,
>          lp = p[(index >> (i * P_L2_BITS)) & (P_L2_SIZE - 1)];
>      }
>  
> -    if (sections[lp.ptr].size.hi ||
> -        range_covers_byte(sections[lp.ptr].offset_within_address_space,
> -                          sections[lp.ptr].size.lo, addr)) {
> +    if (section_covers_addr(&sections[lp.ptr], addr)) {
>          return &sections[lp.ptr];
>      } else {
>          return &sections[PHYS_SECTION_UNASSIGNED];
> -- 
> 2.4.3
>