Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20190514b' into staging

Migration pull 2019-05-14

Small fixes/cleanups
One HMP/monitor fix

# gpg: Signature made Tue 14 May 2019 19:03:53 BST
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20190514b:
  monitor: Call mon_get_cpu() only once at hmp_gva2gpa()
  migration/ram.c: fix typos in comments
  migration: Fix use-after-free during process exit
  migration/savevm: wrap into qemu_loadvm_state_header()
  migration/savevm: load_header before load_setup
  migration/savevm: remove duplicate check of migration_is_blocked
  migration: update comments of migration bitmap
  migration/ram.c: start of migration_bitmap_sync_range is always 0
  qemu-option.hx: Update missed parameter for colo-compare
  migration/colo.h: Remove obsolete codes
  migration/colo.c: Remove redundant input parameter
  migration: savevm: fix error code with migration blockers
  vmstate: check subsection_found is enough
  migration: remove not used field xfer_limit
  migration: not necessary to check ops again
  migration: comment VMSTATE_UNUSED*() properly

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 20 insertions, 6 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 609e0df5d0..d0a0f68f11 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1495,10 +1495,8 @@ static void block_cleanup_parameters(MigrationState *s)
     }
 }
 
-static void migrate_fd_cleanup(void *opaque)
+static void migrate_fd_cleanup(MigrationState *s)
 {
-    MigrationState *s = opaque;
-
     qemu_bh_delete(s->cleanup_bh);
     s->cleanup_bh = NULL;
 
@@ -1543,6 +1541,23 @@ static void migrate_fd_cleanup(void *opaque)
     block_cleanup_parameters(s);
 }
 
+static void migrate_fd_cleanup_schedule(MigrationState *s)
+{
+    /*
+     * Ref the state for bh, because it may be called when
+     * there're already no other refs
+     */
+    object_ref(OBJECT(s));
+    qemu_bh_schedule(s->cleanup_bh);
+}
+
+static void migrate_fd_cleanup_bh(void *opaque)
+{
+    MigrationState *s = opaque;
+    migrate_fd_cleanup(s);
+    object_unref(OBJECT(s));
+}
+
 void migrate_set_error(MigrationState *s, const Error *error)
 {
     qemu_mutex_lock(&s->error_mutex);
@@ -1681,7 +1696,6 @@ void migrate_init(MigrationState *s)
      * locks.
      */
     s->bytes_xfer = 0;
-    s->xfer_limit = 0;
     s->cleanup_bh = 0;
     s->to_dst_file = NULL;
     s->state = MIGRATION_STATUS_NONE;
@@ -3144,7 +3158,7 @@ static void migration_iteration_finish(MigrationState *s)
         error_report("%s: Unknown ending state %d", __func__, s->state);
         break;
     }
-    qemu_bh_schedule(s->cleanup_bh);
+    migrate_fd_cleanup_schedule(s);
     qemu_mutex_unlock_iothread();
 }
 
@@ -3279,7 +3293,7 @@ void migrate_fd_connect(MigrationState *s, Error *error_in)
     bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
 
     s->expected_downtime = s->parameters.downtime_limit;
-    s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
+    s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup_bh, s);
     if (error_in) {
         migrate_fd_error(s, error_in);
         migrate_fd_cleanup(s);