[PATCH RFC 05/15] vhost: Don't merge unmergeable memory sections

[David Hildenbrand <david@redhat.com>]

Memory sections that are marked unmergeable should not be merged, to
allow for atomic removal later.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/virtio/vhost.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 2707972870..49a1074097 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -620,7 +620,7 @@ static void vhost_region_add_section(struct vhost_dev *dev,
                                                mrs_size, mrs_host);
     }
 
-    if (dev->n_tmp_sections) {
+    if (dev->n_tmp_sections && !section->unmergeable) {
         /* Since we already have at least one section, lets see if
          * this extends it; since we're scanning in order, we only
          * have to look at the last one, and the FlatView that calls
@@ -653,7 +653,7 @@ static void vhost_region_add_section(struct vhost_dev *dev,
             size_t offset = mrs_gpa - prev_gpa_start;
 
             if (prev_host_start + offset == mrs_host &&
-                section->mr == prev_sec->mr &&
+                section->mr == prev_sec->mr && !prev_sec->unmergeable &&
                 (!dev->vhost_ops->vhost_backend_can_merge ||
                  dev->vhost_ops->vhost_backend_can_merge(dev,
                     mrs_host, mrs_size,
-- 
2.31.1