vmm: Allow receiving information about changing MemoryZones

It is possible to migrate a VM to a host that might have a different
but compatible NUMA configuration. For example, it should be possible
to move a `MemoryZone` from NUMA node 2 and 3 of the sender to nodes
0 and 1 on the receiver, given sender and receiver nodes are compatible
with respect to available memory.

In such a case, we need to adjust the mapping of guest memory to host
nodes. We need this information for live migration as well as for
snapshot (when performing cold migration). We consume this information
in the following commit.

Signed-off-by: Pascal Scholz <pascal.scholz@cyberus-technology.de>
On-behalf-of: SAP pascal.scholz@sap.com

vmm/src/lib.rs

@@ -3082,9 +3082,10 @@ impl RequestHandler for Vmm {
             .map_err(MigratableError::MigrateReceive)?;
 
         info!(
-            "Receiving migration: receiver_url={},tls={}",
+            "Receiving migration: receiver_url={},tls={},zone_updates={:?}",
             receive_data_migration.receiver_url,
-            receive_data_migration.tls_dir.is_some()
+            receive_data_migration.tls_dir.is_some(),
+            receive_data_migration.zone_updates,
         );
 
         let mut listener = transport::receive_migration_listener(
@@ -3927,6 +3928,7 @@ mod unit_tests {
             memory_mode: MigrationMode::default(),
             vfio_fds,
             iommufd_fd,
+            zone_updates: vec![],
         }
     }