debian/patches/pve/0040-PVE-savevm-async-set-up-migration-state.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Stefan Reiter <s.reiter@proxmox.com>
   3 Date: Wed, 8 Apr 2020 15:29:03 +0200
   4 Subject: [PATCH] PVE: savevm-async: set up migration state
   5
   6 code mostly adapted from upstream savevm.c
   7
   8 Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
   9 ---
  10  savevm-async.c | 30 ++++++++++++++++++++++++++++--
  11  1 file changed, 28 insertions(+), 2 deletions(-)
  12
  13 diff --git a/savevm-async.c b/savevm-async.c
  14 index 790e27ae37..a38b15d652 100644
  15 --- a/savevm-async.c
  16 +++ b/savevm-async.c
  17 @@ -225,6 +225,7 @@ static void *process_savevm_thread(void *opaque)
  18  {
  19      int ret;
  20      int64_t maxlen;
  21 +    MigrationState *ms = migrate_get_current();
  22
  23      rcu_register_thread();
  24
  25 @@ -234,8 +235,7 @@ static void *process_savevm_thread(void *opaque)
  26
  27      if (ret < 0) {
  28          save_snapshot_error("qemu_savevm_state_setup failed");
  29 -        rcu_unregister_thread();
  30 -        return NULL;
  31 +        goto out;
  32      }
  33
  34      while (snap_state.state == SAVE_STATE_ACTIVE) {
  35 @@ -287,6 +287,12 @@ static void *process_savevm_thread(void *opaque)
  36      qemu_bh_schedule(snap_state.cleanup_bh);
  37      qemu_mutex_unlock_iothread();
  38
  39 +out:
  40 +    /* set migration state accordingly and clear soon-to-be stale file */
  41 +    migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP,
  42 +                      ret ? MIGRATION_STATUS_FAILED : MIGRATION_STATUS_COMPLETED);
  43 +    ms->to_dst_file = NULL;
  44 +
  45      rcu_unregister_thread();
  46      return NULL;
  47  }
  48 @@ -294,6 +300,7 @@ static void *process_savevm_thread(void *opaque)
  49  void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
  50  {
  51      Error *local_err = NULL;
  52 +    MigrationState *ms = migrate_get_current();
  53
  54      int bdrv_oflags = BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH;
  55
  56 @@ -303,6 +310,17 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
  57          return;
  58      }
  59
  60 +    if (migration_is_running(ms->state)) {
  61 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR, QERR_MIGRATION_ACTIVE);
  62 +        return;
  63 +    }
  64 +
  65 +    if (migrate_use_block()) {
  66 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
  67 +                  "Block migration and snapshots are incompatible");
  68 +        return;
  69 +    }
  70 +
  71      /* initialize snapshot info */
  72      snap_state.saved_vm_running = runstate_is_running();
  73      snap_state.bs_pos = 0;
  74 @@ -341,6 +359,14 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
  75          goto restart;
  76      }
  77
  78 +    /*
  79 +     * qemu_savevm_* paths use migration code and expect a migration state.
  80 +     * State is cleared in process_savevm_thread, but has to be initialized
  81 +     * here (blocking main thread, from QMP) to avoid race conditions.
  82 +     */
  83 +    migrate_init(ms);
  84 +    memset(&ram_counters, 0, sizeof(ram_counters));
  85 +    ms->to_dst_file = snap_state.file;
  86
  87      error_setg(&snap_state.blocker, "block device is in use by savevm");
  88      blk_op_block_all(snap_state.target, snap_state.blocker);