diff mbox series

[V9,05/46] migration: migrate-enable-mode option

Message ID 1658851843-236870-6-git-send-email-steven.sistare@oracle.com
State New
Headers show
Series Live Update | expand

Commit Message

Steve Sistare July 26, 2022, 4:10 p.m. UTC 
Add the '-migrate-enable-mode <mode>' command-line option as a
pre-requisite for migration using the mode.  Multiple
-migrate-enable-mode options may be specified, one per mode.

Requiring -migrate-enable-mode allows qemu to initialize objects
differently, if necessary, so that migration for a mode is not blocked.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 include/migration/misc.h |  2 ++
 migration/migration.c    | 31 +++++++++++++++++++++++++++++++
 qemu-options.hx          | 10 ++++++++++
 softmmu/vl.c             |  4 ++++
 4 files changed, 47 insertions(+)
diff mbox series

Patch

diff --git a/include/migration/misc.h b/include/migration/misc.h
index 1e01134..71b6285 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -78,5 +78,7 @@  void dirty_bitmap_mig_init(void);
 
 MigMode migrate_mode(void);
 MigMode migrate_mode_of(MigrationState *s);
+void migrate_enable_mode(MigMode mode);
+bool migrate_mode_enabled(MigMode mode);
 
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index 38584db..5f704a9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -173,6 +173,7 @@  INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
 
 static MigrationState *current_migration;
 static MigrationIncomingState *current_incoming;
+static int migrate_enabled_modes = BIT(MIG_MODE_NORMAL);
 
 static GSList *migration_blockers;
 
@@ -2140,6 +2141,29 @@  bool migration_is_active(MigrationState *s)
             s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
 }
 
+void migrate_enable_mode(MigMode mode)
+{
+    migrate_enabled_modes |= BIT(mode);
+}
+
+bool migrate_mode_enabled(MigMode mode)
+{
+    return !!(migrate_enabled_modes & BIT(mode));
+}
+
+static int migrate_check_enabled(Error **errp)
+{
+    MigMode mode = migrate_mode();
+
+    if (!migrate_mode_enabled(mode)) {
+        error_setg(errp, "migrate mode is not enabled.  "
+                         "Use '-migrate-mode-enable %s'.",
+                   MigMode_str(mode));
+        return -1;
+    }
+    return 0;
+}
+
 void migrate_init(MigrationState *s)
 {
     /*
@@ -2210,6 +2234,9 @@  void qmp_migrate_incoming(const char *uri, Error **errp)
     Error *local_err = NULL;
     static bool once = true;
 
+    if (migrate_check_enabled(errp)) {
+        return;
+    }
     if (!once) {
         error_setg(errp, "The incoming migration has already been started");
         return;
@@ -2356,6 +2383,10 @@  static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
         return false;
     }
 
+    if (migrate_check_enabled(errp)) {
+        return false;
+    }
+
     if (migration_is_blocked(errp)) {
         return false;
     }
diff --git a/qemu-options.hx b/qemu-options.hx
index 5ff47f4..7797d3d 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4491,6 +4491,16 @@  SRST
     an unmigratable state.
 ERST
 
+DEF("migrate-mode-enable", HAS_ARG, QEMU_OPTION_migrate_mode_enable, \
+    "-migrate-mode-enable <mode>    enable the migration mode.\n",
+    QEMU_ARCH_ALL)
+SRST
+``-migrate-mode-enable <mode>``
+    Enable the specified migrate mode.  May be supplied
+    multiple times, once per mode.  This is a pre-requisite for performing a
+    migration using any mode except 'normal'.
+ERST
+
 DEF("nodefaults", 0, QEMU_OPTION_nodefaults, \
     "-nodefaults     don't create default devices\n", QEMU_ARCH_ALL)
 SRST
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 7189eb6..83f3be0 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -3364,6 +3364,10 @@  void qemu_init(int argc, char **argv, char **envp)
             case QEMU_OPTION_only_migratable:
                 only_migratable = 1;
                 break;
+            case QEMU_OPTION_migrate_mode_enable:
+                migrate_enable_mode(qapi_enum_parse(&MigMode_lookup, optarg, -1,
+                                                    &error_fatal));
+                break;
             case QEMU_OPTION_nodefaults:
                 has_defaults = 0;
                 break;