Re: [Qemu-devel] [RfC PATCH 2/4] memory: add support getting and using a dirty bitmap copy.

[Paolo Bonzini]

On 30/03/2017 08:55, Gerd Hoffmann wrote:
> +        bitmap_copy(copy->dirty + dest,
> +                    blocks->blocks[idx] + (offset >> BITS_PER_LEVEL),
> +                    num);
> +        bitmap_zero(blocks->blocks[idx] + (offset >> BITS_PER_LEVEL),
> +                    num);
> +

This needs to access the bitmap atomically, so you'll need a new function

  bool bitmap_copy_and_clear_atomic(unsigned long *dest,
                                    unsigned long *src, long nr)

Paolo