diff options
| -rw-r--r-- | include/migration/migration.h | 1 | ||||
| -rw-r--r-- | migration/migration.c | 23 | ||||
| -rw-r--r-- | qapi-schema.json | 6 |
3 files changed, 29 insertions, 1 deletions
diff --git a/include/migration/migration.h b/include/migration/migration.h index 3dc95f49da..4ed7931d5f 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -186,6 +186,7 @@ void migrate_add_blocker(Error *reason); */ void migrate_del_blocker(Error *reason); +bool migrate_postcopy_ram(void); bool migrate_zero_blocks(void); bool migrate_auto_converge(void); diff --git a/migration/migration.c b/migration/migration.c index e4f91a98f4..f849f890d9 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -578,6 +578,20 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, for (cap = params; cap; cap = cap->next) { s->enabled_capabilities[cap->value->capability] = cap->value->state; } + + if (migrate_postcopy_ram()) { + if (migrate_use_compression()) { + /* The decompression threads asynchronously write into RAM + * rather than use the atomic copies needed to avoid + * userfaulting. It should be possible to fix the decompression + * threads for compatibility in future. + */ + error_report("Postcopy is not currently compatible with " + "compression"); + s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM] = + false; + } + } } void qmp_migrate_set_parameters(bool has_compress_level, @@ -956,6 +970,15 @@ void qmp_migrate_set_downtime(double value, Error **errp) max_downtime = (uint64_t)value; } +bool migrate_postcopy_ram(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM]; +} + bool migrate_auto_converge(void) { MigrationState *s; diff --git a/qapi-schema.json b/qapi-schema.json index e18f14c88e..8638d428b9 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -540,11 +540,15 @@ # @auto-converge: If enabled, QEMU will automatically throttle down the guest # to speed up convergence of RAM migration. (since 1.6) # +# @x-postcopy-ram: Start executing on the migration target before all of RAM has +# been migrated, pulling the remaining pages along as needed. NOTE: If +# the migration fails during postcopy the VM will fail. (since 2.5) +# # Since: 1.2 ## { 'enum': 'MigrationCapability', 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', - 'compress', 'events'] } + 'compress', 'events', 'x-postcopy-ram'] } ## # @MigrationCapabilityStatus |