diff --git a/include/uapi/linux/vm_sockets.h b/include/uapi/linux/vm_sockets.h
index c2eac3d0a9f0..46918a1852d7 100644
--- a/include/uapi/linux/vm_sockets.h
+++ b/include/uapi/linux/vm_sockets.h
@@ -115,6 +115,26 @@
 
 #define VMADDR_CID_HOST 2
 
+/* The current default use case for the vsock channel is the following:
+ * local vsock communication between guest and host and nested VMs setup.
+ * In addition to this, implicitly, the vsock packets are forwarded to the host
+ * if no host->guest vsock transport is set.
+ *
+ * Set this flag value in the sockaddr_vm corresponding field if the vsock
+ * packets need to be always forwarded to the host. Using this behavior,
+ * vsock communication between sibling VMs can be setup.
+ *
+ * This way can explicitly distinguish between vsock channels created for
+ * different use cases, such as nested VMs (or local communication between
+ * guest and host) and sibling VMs.
+ *
+ * The flag can be set in the connect logic in the user space application flow.
+ * In the listen logic (from kernel space) the flag is set on the remote peer
+ * address. This happens for an incoming connection when it is routed from the
+ * host and comes from the guest (local CID and remote CID > VMADDR_CID_HOST).
+ */
+#define VMADDR_FLAG_TO_HOST 0x01
+
 /* Invalid vSockets version. */
 
 #define VM_SOCKETS_INVALID_VERSION -1U