Re: [Qemu-devel] [PATCH 01/22] memory: add memory_region_ram_resize

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Mar 26, 2015 at 06:38:19PM +0100, Paolo Bonzini wrote:
> This is a simple MemoryRegion wrapper for qemu_ram_resize.
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  include/exec/memory.h | 12 ++++++++++++
>  memory.c              |  7 +++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 06ffa1d..a2ea587 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -605,6 +605,18 @@ int memory_region_get_fd(MemoryRegion *mr);
>   */
>  void *memory_region_get_ram_ptr(MemoryRegion *mr);
>  
> +/* memory_region_ram_resize: Resize a RAM region.
> + *
> + * Only legal before guest might have detected the memory size: e.g. on
> + * incoming migration, or right after reset.
> + *
> + * @mr: a memory region created with @memory_region_init_resizeable_ram.
> + * @newsize: the new size the region
> + * @errp: pointer to Error*, to store an error if it happens.
> + */
> +void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
> +                              Error **errp);
> +
>  /**
>   * memory_region_set_log: Turn dirty logging on or off for a region.
>   *
> diff --git a/memory.c b/memory.c
> index ee3f2a8..a11e9bf 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1452,6 +1452,13 @@ void *memory_region_get_ram_ptr(MemoryRegion *mr)
>      return qemu_get_ram_ptr(mr->ram_addr & TARGET_PAGE_MASK);
>  }
>  
> +void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize, Error **errp)
> +{
> +    assert(mr->terminates);

Why? Does "terminates" guarantee that ram_addr
is valid? In any case, I think this needs a comment.

> +
> +    qemu_ram_resize(mr->ram_addr, newsize, errp);
> +}
> +
>  static void memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpace *as)
>  {
>      FlatView *view;
> -- 
> 2.3.3
>