vhost: allow backends to filter memory sections

This patch introduces a vhost op for vhost backends to allow
them to filter the memory sections that they can handle.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b08290036d..624ade9682 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -386,7 +386,7 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev,
     return r;
 }
 
-static bool vhost_section(MemoryRegionSection *section)
+static bool vhost_section(struct vhost_dev *dev, MemoryRegionSection *section)
 {
     bool result;
     bool log_dirty = memory_region_get_dirty_log_mask(section->mr) &
@@ -399,6 +399,11 @@ static bool vhost_section(MemoryRegionSection *section)
      */
     result &= !log_dirty;
 
+    if (result && dev->vhost_ops->vhost_backend_mem_section_filter) {
+        result &=
+            dev->vhost_ops->vhost_backend_mem_section_filter(dev, section);
+    }
+
     trace_vhost_section(section->mr->name, result);
     return result;
 }
@@ -632,7 +637,7 @@ static void vhost_region_addnop(MemoryListener *listener,
     struct vhost_dev *dev = container_of(listener, struct vhost_dev,
                                          memory_listener);
 
-    if (!vhost_section(section)) {
+    if (!vhost_section(dev, section)) {
         return;
     }
     vhost_region_add_section(dev, section);