Re: [Qemu-devel] [PATCH 4/4] xen: Always set the vram dirty during migration.

[Stefano Stabellini]

On Tue, 17 Jul 2012, Anthony PERARD wrote:
> Because the call to track the dirty bit in the video ram during migration 
> won't
> work (it returns -1), we set dirtybit on the all video ram.
> 
> Signed-off-by: Anthony PERARD <address@hidden>
> ---
>  xen-all.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/xen-all.c b/xen-all.c
> index 498883b..00bdb50 100644
> --- a/xen-all.c
> +++ b/xen-all.c
> @@ -502,6 +502,11 @@ static void xen_sync_dirty_bitmap(XenIOState *state,
>          return;
>      }
>  
> +    if (unlikely(xen_in_migration)) {
> +        /* track_dirty_vram does not work during migration */
> +        memory_region_set_dirty(framebuffer, 0, size);
> +        return;
> +    }
>      rc = xc_hvm_track_dirty_vram(xen_xc, xen_domid,
>                                   start_addr >> TARGET_PAGE_BITS, npages,
>                                   bitmap);

Why are you setting the entire framebuffer dirty?
We should set dirty only the actualy region that is supposed to be
dirty.