On Fri, Mar 23, 2018 at 12:46:37PM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> My rework of section adding combines overlapping or abutting regions,
> but checks they're actually the same underlying RAM block.
> Fix the case where two blocks abut but don't overlap; that new region
> should get added (but not combined), but my previous patch was disallowing it.
>
> Fixes: c1ece84e7c9
>
> Reported-by: Alex Williamson <alex.william...@redhat.com>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
I prefer adjacent and not abutting.
> ---
> hw/virtio/vhost.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 250f886acb..fc9062a89f 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -595,10 +595,15 @@ static void vhost_region_add_section(struct vhost_dev
> *dev,
>
> prev_sec->offset_within_address_space,
> prev_sec->offset_within_region);
> } else {
> - error_report("%s: Overlapping but not coherent sections "
> - "at %"PRIx64,
> - __func__, mrs_gpa);
> - return;
> + /* abutting regions are fine, but overlapping ones with
> + * different blocks/offsets shouldn't happen
> + */
> + if (mrs_gpa != prev_gpa_end + 1) {
> + error_report("%s: Overlapping but not coherent sections "
> + "at %"PRIx64,
> + __func__, mrs_gpa);
> + return;
> + }
> }
> }
> }
> --
> 2.14.3
