Re: [RFC 5/6] migration: Deprecate block migration

It is obsolete. It is better to use driver_mirror+NBD instead. CC: Kevin Wolf <kwolf(a)redhat.com&gt; CC: Eric Blake <eblake(a)redhat.com&gt; CC: Stefan Hajnoczi <stefanha(a)redhat.com&gt; CC: Hanna Czenczek <hreitz(a)redhat.com&gt; Signed-off-by: Juan Quintela <quintela(a)redhat.com&gt; --- Can any of you give one example of how to use driver_mirror+NBD for deprecated.rst?

Thanks, Juan. --- docs/about/deprecated.rst | 6 ++++++ qapi/migration.json | 29 +++++++++++++++++++++++++---- migration/block.c | 2 ++ migration/options.c | 7 +++++++ 4 files changed, 40 insertions(+), 4 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 518672722d..173c5ba5cb 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -454,3 +454,9 @@ Everything except ``-incoming defer`` are deprecated. This allows to setup parameters before launching the proper migration with ``migrate-incoming uri``. +block migration (since 8.1) +''''''''''''''''''''''''''' + +Block migration is too inflexible. It needs to migrate all block +devices or none. Use driver_mirror+NBD instead.

+ diff --git a/qapi/migration.json b/qapi/migration.json index b71e00737e..a8497de48d 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -258,11 +258,16 @@ # blocked. Present and non-empty when migration is blocked. # (since 6.0) # +# Features: +# +# @deprecated: @disk migration is deprecated. Use driver_mirror+NBD

+# instead. +# # Since: 0.14 ## { 'struct': 'MigrationInfo', 'data': {'*status': 'MigrationStatus', '*ram': 'MigrationStats', - '*disk': 'MigrationStats', + '*disk': { 'type': 'MigrationStats', 'features': ['deprecated'] }, '*vfio': 'VfioStats', '*xbzrle-cache': 'XBZRLECacheStats', '*total-time': 'int', @@ -497,6 +502,9 @@ # # Features: # +# @deprecated: @block migration is deprecated. Use driver_mirror+NBD

+# instead. +# # @unstable: Members @x-colo and @x-ignore-shared are experimental. # # Since: 1.2 @@ -506,7 +514,8 @@ 'compress', 'events', 'postcopy-ram', { 'name': 'x-colo', 'features': [ 'unstable' ] }, 'release-ram', - 'block', 'return-path', 'pause-before-switchover', 'multifd', + { 'name': 'block', 'features': [ 'deprecated' ] }, + 'return-path', 'pause-before-switchover', 'multifd', 'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate', { 'name': 'x-ignore-shared', 'features': [ 'unstable' ] }, 'validate-uuid', 'background-snapshot', @@ -789,6 +798,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver_mirror+NBD instead.

+# # @unstable: Member @x-checkpoint-delay is experimental. # # Since: 2.4 @@ -803,7 +815,7 @@ 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', 'downtime-limit', { 'name': 'x-checkpoint-delay', 'features': [ 'unstable' ] }, - 'block-incremental', + { 'name': 'block-incremental', 'features': [ 'deprecated' ] }, 'multifd-channels', 'xbzrle-cache-size', 'max-postcopy-bandwidth', 'max-cpu-throttle', 'multifd-compression', @@ -945,6 +957,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver_mirror+NBD instead.

+# # @unstable: Member @x-checkpoint-delay is experimental. # # TODO: either fuse back into MigrationParameters, or make @@ -972,7 +987,8 @@ '*downtime-limit': 'uint64', '*x-checkpoint-delay': { 'type': 'uint32', 'features': [ 'unstable' ] }, - '*block-incremental': 'bool', + '*block-incremental': { 'type': 'bool', + 'features': [ 'deprecated' ] }, '*multifd-channels': 'uint8', '*xbzrle-cache-size': 'size', '*max-postcopy-bandwidth': 'size', @@ -1137,6 +1153,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver_mirror+NBD instead.

+# # @unstable: Member @x-checkpoint-delay is experimental. # # Since: 2.4 @@ -1161,6 +1180,8 @@ '*downtime-limit': 'uint64', '*x-checkpoint-delay': { 'type': 'uint32', 'features': [ 'unstable' ] }, + '*block-incremental': { 'type': 'bool', + 'features': [ 'deprecated' ] }, '*block-incremental': 'bool', '*multifd-channels': 'uint8', '*xbzrle-cache-size': 'size', diff --git a/migration/block.c b/migration/block.c index b9580a6c7e..2521a22269 100644 --- a/migration/block.c +++ b/migration/block.c @@ -722,6 +722,8 @@ static int block_save_setup(QEMUFile *f, void *opaque) trace_migration_block_save("setup", block_mig_state.submitted, block_mig_state.transferred); + warn_report("block migration is deprecated. Use mirror jobs instead.");

+ qemu_mutex_lock_iothread(); ret = init_blk_migration(f); if (ret < 0) { diff --git a/migration/options.c b/migration/options.c index b62ab30cd5..374dc0767e 100644 --- a/migration/options.c +++ b/migration/options.c @@ -12,6 +12,7 @@ */ #include "qemu/osdep.h" +#include "qemu/error-report.h" #include "exec/target_page.h" #include "qapi/clone-visitor.h" #include "qapi/error.h" @@ -437,6 +438,10 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp) return false; } #endif + if (new_caps[MIGRATION_CAPABILITY_BLOCK]) { + warn_report("Block migration is deprecated. " + "Use driver_mirror+NBD instead.");

+ } #ifndef CONFIG_REPLICATION if (new_caps[MIGRATION_CAPABILITY_X_COLO]) { @@ -1257,6 +1262,8 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) } if (params->has_block_incremental) { + warn_report("Block migration is deprecated. " + "Use driver_mirror+NBD instead.");

s->parameters.block_incremental = params->block_incremental; } if (params->has_multifd_channels) { -- 2.40.1