Re: [PATCH v3 6/6] ram: Document migration ram flags

[Eric Blake]

On Wed, Feb 08, 2023 at 02:30:10PM +0100, Juan Quintela wrote:
> 0x80 is RAM_SAVE_FLAG_HOOK, it is in qemu-file now.
> Bigger usable flag is 0x200, noticing that.
> We can reuse RAM_SAVE_FLAG_FULL.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/ram.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 7952d5f01c..d95e26c03c 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -73,16 +73,19 @@
>   * RAM_SSAVE_FLAG_COMPRESS_PAGE just rename it.
>   */
>  
> -#define RAM_SAVE_FLAG_FULL     0x01 /* Obsolete, not used anymore */
> +/* RAM_SAVE_FLAG_FULL has been obsoleted since at least 2009, we can
> + * reuse it */

How about:

/* RAM_SAVE_FLAG_FULL was obsoleted in 2009, it can be reused now */

> +#define RAM_SAVE_FLAG_FULL     0x01
>  #define RAM_SAVE_FLAG_ZERO     0x02
>  #define RAM_SAVE_FLAG_MEM_SIZE 0x04
>  #define RAM_SAVE_FLAG_PAGE     0x08
>  #define RAM_SAVE_FLAG_EOS      0x10
>  #define RAM_SAVE_FLAG_CONTINUE 0x20
>  #define RAM_SAVE_FLAG_XBZRLE   0x40
> -/* 0x80 is reserved in migration.h start with 0x100 next */
> +/* 0x80 is reserved in qemu-file.h for RAM_SAVE_FLAG_HOOK */
>  #define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
>  #define RAM_SAVE_FLAG_MULTIFD_SYNC     0x200
> +/* We can't use any flag that is bigger that 0x200 */

s/that is bigger that/bigger than/

>  
>  XBZRLECacheStats xbzrle_counters;
>  
> -- 
> 2.39.1
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org