[Qemu-devel] [PATCH v3] vhost: Cancel migration when vhost-user process restarted during migration

[fangying]

QEMU will abort when vhost-user process is restarted during migration
and vhost_log_global_start/stop is called. The reason is clear that
vhost_dev_set_log returns -1 because network connection is temporarily
lost. To handle this situation, let's cancel migration here.

Signed-off-by: Ying Fang <address@hidden>
---
 hw/virtio/vhost.c     | 15 +++++++++++++--
 migration/migration.c |  2 +-
 migration/migration.h |  2 +-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ddc42f0..e2ade93 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -26,6 +26,7 @@
 #include "hw/virtio/virtio-bus.h"
 #include "hw/virtio/virtio-access.h"
 #include "migration/blocker.h"
+#include "migration/migration.h"
 #include "sysemu/dma.h"
 
 /* enabled until disconnected backend stabilizes */
@@ -882,20 +883,30 @@ static int vhost_migration_log(MemoryListener *listener, 
int enable)
 static void vhost_log_global_start(MemoryListener *listener)
 {
     int r;
+    MigrationState *s = NULL;
 
     r = vhost_migration_log(listener, true);
     if (r < 0) {
-        abort();
+        error_report("Failed to start vhost dirty log");
+        s = migrate_get_current();
+        if (s->migration_thread_running) {
+            migrate_fd_cancel(s);
+        }
     }
 }
 
 static void vhost_log_global_stop(MemoryListener *listener)
 {
     int r;
+    MigrationState *s = NULL;
 
     r = vhost_migration_log(listener, false);
     if (r < 0) {
-        abort();
+        error_report("Failed to stop vhost dirty log");
+        s = migrate_get_current();
+        if (s->migration_thread_running) {
+            migrate_fd_cancel(s);
+        }
     }
 }
 
diff --git a/migration/migration.c b/migration/migration.c
index 4de3b55..6d2b7df 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1131,7 +1131,7 @@ void migrate_fd_error(MigrationState *s, const Error 
*error)
     block_cleanup_parameters(s);
 }
 
-static void migrate_fd_cancel(MigrationState *s)
+void migrate_fd_cancel(MigrationState *s)
 {
     int old_state ;
     QEMUFile *f = migrate_get_current()->to_dst_file;
diff --git a/migration/migration.h b/migration/migration.h
index 663415f..f0261e3 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -167,7 +167,7 @@ uint64_t migrate_max_downtime(void);
 
 void migrate_set_error(MigrationState *s, const Error *error);
 void migrate_fd_error(MigrationState *s, const Error *error);
-
+void migrate_fd_cancel(MigrationState *s);
 void migrate_fd_connect(MigrationState *s);
 
 MigrationState *migrate_init(void);
-- 
1.8.3.1