migration: Postcopy recover with preempt enabled

[qemu.git] / migration / migration.h

diff --git a/migration/migration.h b/migration/migration.h
index ff714c235f8415e1a24afa7b66f5183389c9d280..9220cec6bddf5a5e8f11ade7398a44fe4676eb17 100644 (file)
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -118,6 +118,18 @@ struct MigrationIncomingState {
     /* Postcopy priority thread is used to receive postcopy requested pages */
     QemuThread postcopy_prio_thread;
     bool postcopy_prio_thread_created;
+    /*
+     * Used to sync between the ram load main thread and the fast ram load
+     * thread.  It protects postcopy_qemufile_dst, which is the postcopy
+     * fast channel.
+     *
+     * The ram fast load thread will take it mostly for the whole lifecycle
+     * because it needs to continuously read data from the channel, and
+     * it'll only release this mutex if postcopy is interrupted, so that
+     * the ram load main thread will take this mutex over and properly
+     * release the broken channel.
+     */
+    QemuMutex postcopy_prio_thread_mutex;
     /*
      * An array of temp host huge pages to be used, one for each postcopy
      * channel.
@@ -147,6 +159,13 @@ struct MigrationIncomingState {
     /* notify PAUSED postcopy incoming migrations to try to continue */
     QemuSemaphore postcopy_pause_sem_dst;
     QemuSemaphore postcopy_pause_sem_fault;
+    /*
+     * This semaphore is used to allow the ram fast load thread (only when
+     * postcopy preempt is enabled) fall into sleep when there's network
+     * interruption detected.  When the recovery is done, the main load
+     * thread will kick the fast ram load thread using this semaphore.
+     */
+    QemuSemaphore postcopy_pause_sem_fast_load;
 
     /* List of listening socket addresses  */
     SocketAddressList *socket_address_list;