[PATCH qemu v3 1/4] savevm-async: free migration vmdesc

[Erik Fastermann <e.fastermann@proxmox.com>]

migrate_init() allocates it and only migration_cleanup() frees it, which
savevm-async does not call. Free it with the rest of the migration
state, tens of KiB per snapshot even for a minimal guest.

Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
---
 ...async-for-background-state-snapshots.patch | 31 +++++++++++++------
 ...add-optional-buffer-size-to-QEMUFile.patch |  6 ++--
 ...se-migration-blocker-check-for-snaps.patch |  4 +--
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/debian/patches/pve/0017-PVE-add-savevm-async-for-background-state-snapshots.patch b/debian/patches/pve/0017-PVE-add-savevm-async-for-background-state-snapshots.patch
index f252236..d4c3bb5 100644
--- a/debian/patches/pve/0017-PVE-add-savevm-async-for-background-state-snapshots.patch
+++ b/debian/patches/pve/0017-PVE-add-savevm-async-for-background-state-snapshots.patch
@@ -37,7 +37,8 @@ Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
      add parameter to skip vm start to be used for hibernation
      rebase for 11.0.0]
 Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
-[EF: drop QIOChannel reference]
+[EF: drop QIOChannel reference
+     free migration vmdesc]
 Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
 ---
  hmp-commands-info.hx         |  13 +
@@ -45,13 +46,13 @@ Signed-off-by: Erik Fastermann <e.fastermann@proxmox.com>
  include/migration/snapshot.h |   2 +
  include/monitor/hmp.h        |   3 +
  migration/meson.build        |   1 +
- migration/savevm-async.c     | 600 +++++++++++++++++++++++++++++++++++
+ migration/savevm-async.c     | 612 +++++++++++++++++++++++++++++++++++
  monitor/hmp-cmds.c           |  38 +++
  qapi/migration.json          |  34 ++
  qapi/misc.json               |  25 ++
  qemu-options.hx              |  12 +
  system/vl.c                  |  10 +
- 11 files changed, 755 insertions(+)
+ 11 files changed, 767 insertions(+)
  create mode 100644 migration/savevm-async.c
 
 diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
@@ -149,10 +150,10 @@ index 0222d5ea6e..90d62d5723 100644
  ), gnutls, zlib)
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
 new file mode 100644
-index 0000000000..cab08643ad
+index 0000000000..a0525d62dd
 --- /dev/null
 +++ b/migration/savevm-async.c
-@@ -0,0 +1,600 @@
+@@ -0,0 +1,612 @@
 +#include "qemu/osdep.h"
 +#include "migration/channel-savevm-async.h"
 +#include "migration/migration.h"
@@ -261,6 +262,15 @@ index 0000000000..cab08643ad
 +    return info;
 +}
 +
++static void migration_state_cleanup(MigrationState *ms, bool failed)
++{
++    migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP,
++        failed ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED);
++    ms->to_dst_file = NULL;
++    /* see migration_cleanup_json_writer */
++    g_clear_pointer(&ms->vmdesc, json_writer_free);
++}
++
 +static int save_snapshot_cleanup(void)
 +{
 +    int ret = 0;
@@ -359,10 +369,7 @@ index 0000000000..cab08643ad
 +    DPRINTF("timing: process_savevm_finalize (state saving) took %ld ms\n",
 +        qemu_clock_get_ms(QEMU_CLOCK_REALTIME) - start_time);
 +
-+    /* clear migration state */
-+    migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP,
-+        ret || aborted ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED);
-+    ms->to_dst_file = NULL;
++    migration_state_cleanup(ms, ret || aborted);
 +
 +    /*
 +     * Same as in migration_iteration_finish(): saving RAM might've turned on CPU throttling for
@@ -505,6 +512,7 @@ index 0000000000..cab08643ad
 +{
 +    Error *local_err = NULL;
 +    MigrationState *ms = migrate_get_current();
++    bool migration_initialized = false;
 +    BlockDriverState *target_bs = NULL;
 +    int ret = 0;
 +
@@ -591,6 +599,7 @@ index 0000000000..cab08643ad
 +    }
 +    memset(&mig_stats, 0, sizeof(mig_stats));
 +    ms->to_dst_file = snap_state.file;
++    migration_initialized = true;
 +
 +    error_setg(&snap_state.blocker, "block device is in use by savevm");
 +    bdrv_op_block_all(target_bs, snap_state.blocker);
@@ -618,6 +627,10 @@ index 0000000000..cab08643ad
 +    return;
 +
 +fail:
++    if (migration_initialized) {
++        migration_state_cleanup(ms, true);
++    }
++
 +    savevm_cleanup_iothread();
 +    save_snapshot_error("setup failed");
 +}
diff --git a/debian/patches/pve/0018-PVE-add-optional-buffer-size-to-QEMUFile.patch b/debian/patches/pve/0018-PVE-add-optional-buffer-size-to-QEMUFile.patch
index 39cacf7..06ec32f 100644
--- a/debian/patches/pve/0018-PVE-add-optional-buffer-size-to-QEMUFile.patch
+++ b/debian/patches/pve/0018-PVE-add-optional-buffer-size-to-QEMUFile.patch
@@ -186,10 +186,10 @@ index a390554208..eda093b16a 100644
  
  G_DEFINE_AUTOPTR_CLEANUP_FUNC(QEMUFile, qemu_fclose)
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
-index cab08643ad..f9eaf3b8e6 100644
+index a0525d62dd..7a66ede4d1 100644
 --- a/migration/savevm-async.c
 +++ b/migration/savevm-async.c
-@@ -418,7 +418,7 @@ void qmp_savevm_start(const char *statefile, bool has_skip_vm_start,
+@@ -425,7 +425,7 @@ void qmp_savevm_start(const char *statefile, bool has_skip_vm_start,
  
      QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(snap_state.target,
                                                                 &snap_state.bs_pos));
@@ -198,7 +198,7 @@ index cab08643ad..f9eaf3b8e6 100644
      object_unref(ioc);
  
      if (!snap_state.file) {
-@@ -557,7 +557,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
+@@ -569,7 +569,7 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
  
      /* restore the VM state */
      QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(be, &bs_pos));
diff --git a/debian/patches/pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch b/debian/patches/pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch
index 5cc3893..b1ceef8 100644
--- a/debian/patches/pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch
+++ b/debian/patches/pve/0046-savevm-async-reuse-migration-blocker-check-for-snaps.patch
@@ -136,10 +136,10 @@ index b6888daced..80eb0dcd1f 100644
  bool migration_in_postcopy(void);
  bool migration_postcopy_is_alive(MigrationStatus state);
 diff --git a/migration/savevm-async.c b/migration/savevm-async.c
-index f9eaf3b8e6..51340c5dcd 100644
+index 7a66ede4d1..83548a8a13 100644
 --- a/migration/savevm-async.c
 +++ b/migration/savevm-async.c
-@@ -384,7 +384,7 @@ void qmp_savevm_start(const char *statefile, bool has_skip_vm_start,
+@@ -391,7 +391,7 @@ void qmp_savevm_start(const char *statefile, bool has_skip_vm_start,
          return;
      }
  
-- 
2.47.3