Add _F_SUSPEND and suspend ioctl.

TODO: This is still not merged in Linux upstream, so it may change.
---
 include/standard-headers/linux/vhost_types.h | 3 +++
 linux-headers/linux/vhost.h                  | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/include/standard-headers/linux/vhost_types.h b/include/standard-headers/linux/vhost_types.h
index ce78551b0f..c93ed1b920 100644
--- a/include/standard-headers/linux/vhost_types.h
+++ b/include/standard-headers/linux/vhost_types.h
@@ -161,5 +161,8 @@ struct vhost_vdpa_iova_range {
  * message
  */
 #define VHOST_BACKEND_F_IOTLB_ASID  0x3
+/* Stop device from processing virtqueue buffers */
+#define VHOST_BACKEND_F_SUSPEND  0x4
+
 
 #endif
diff --git a/linux-headers/linux/vhost.h b/linux-headers/linux/vhost.h
index cab645d4a6..f3f5bea3cb 100644
--- a/linux-headers/linux/vhost.h
+++ b/linux-headers/linux/vhost.h
@@ -171,4 +171,7 @@
 #define VHOST_VDPA_SET_GROUP_ASID	_IOW(VHOST_VIRTIO, 0x7C, \
 					     struct vhost_vring_state)
 
+/* Stop or resume a device so it does not process virtqueue requests anymore */
+#define VHOST_VDPA_SUSPEND              _IO(VHOST_VIRTIO, 0x7D)
+
 #endif
-- 
2.31.1