virtio-devices: vhost_user: Fully implement Migratable trait

All vhost-user devices are now equipped to support migration.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

virtio-devices/src/vhost_user/blk.rs

@@ -29,9 +29,10 @@ use virtio_bindings::bindings::virtio_blk::{
     VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_SEG_MAX,
     VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_WRITE_ZEROES,
 };
-use vm_memory::{ByteValued, GuestAddressSpace, GuestMemoryAtomic};
+use vm_memory::{Address, ByteValued, GuestAddressSpace, GuestMemory, GuestMemoryAtomic};
 use vm_migration::{
-    Migratable, MigratableError, Pausable, Snapshot, Snapshottable, Transportable, VersionMapped,
+    protocol::MemoryRangeTable, Migratable, MigratableError, Pausable, Snapshot, Snapshottable,
+    Transportable, VersionMapped,
 };
 use vmm_sys_util::eventfd::EventFd;
 
@@ -399,4 +400,54 @@ impl Snapshottable for Blk {
     }
 }
 impl Transportable for Blk {}
-impl Migratable for Blk {}
+
+impl Migratable for Blk {
+    fn start_dirty_log(&mut self) -> std::result::Result<(), MigratableError> {
+        if let Some(guest_memory) = &self.guest_memory {
+            let last_ram_addr = guest_memory.memory().last_addr().raw_value();
+            self.vu
+                .lock()
+                .unwrap()
+                .start_dirty_log(last_ram_addr)
+                .map_err(|e| {
+                    MigratableError::MigrateStart(anyhow!(
+                        "Error starting migration for vhost-user-blk backend: {:?}",
+                        e
+                    ))
+                })
+        } else {
+            Err(MigratableError::MigrateStart(anyhow!(
+                "Missing guest memory"
+            )))
+        }
+    }
+
+    fn stop_dirty_log(&mut self) -> std::result::Result<(), MigratableError> {
+        self.vu.lock().unwrap().stop_dirty_log().map_err(|e| {
+            MigratableError::MigrateStop(anyhow!(
+                "Error stopping migration for vhost-user-blk backend: {:?}",
+                e
+            ))
+        })
+    }
+
+    fn dirty_log(&mut self) -> std::result::Result<MemoryRangeTable, MigratableError> {
+        if let Some(guest_memory) = &self.guest_memory {
+            let last_ram_addr = guest_memory.memory().last_addr().raw_value();
+            self.vu
+                .lock()
+                .unwrap()
+                .dirty_log(last_ram_addr)
+                .map_err(|e| {
+                    MigratableError::MigrateDirtyRanges(anyhow!(
+                        "Error retrieving dirty ranges from vhost-user-blk backend: {:?}",
+                        e
+                    ))
+                })
+        } else {
+            Err(MigratableError::MigrateDirtyRanges(anyhow!(
+                "Missing guest memory"
+            )))
+        }
+    }
+}