Re: [PATCH v3 3/4] migration: Deprecate block migration

It is obsolete. It is better to use driver-mirror with 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; --- docs/about/deprecated.rst | 10 ++++++++++ qapi/migration.json | 30 +++++++++++++++++++++++++----- migration/block.c | 3 +++ migration/options.c | 9 ++++++++- 4 files changed, 46 insertions(+), 6 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index b2b7e11742..e46f3df376 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -431,3 +431,13 @@ The new way to modify migration is using migration parameters. ``blk`` functionality can be achieved by setting the ``block`` migration capability to ``true``. +block migration (since 8.2) +''''''''''''''''''''''''''' + +Block migration is too inflexible. It needs to migrate all block +devices or none. + +Please see "QMP invocation for live storage migration with +``driver-mirror`` + NBD" in docs/interop/live-block-operations.rst for +a detailed explanation. + diff --git a/qapi/migration.json b/qapi/migration.json index e4949e0d8e..bf6e1ac5b5 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -269,11 +269,16 @@ # average memory load of the virtual CPU indirectly. Note that # zero means guest doesn't dirty memory. (Since 8.1) # +# Features: +# +# @deprecated: @disk migration is deprecated. Use driver-mirror +# with 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', @@ -526,6 +531,9 @@ # # Features: # +# @deprecated: @block migration is deprecated. Use driver-mirror +# with NBD instead. +#

# @unstable: Members @x-colo and @x-ignore-shared are experimental. # # Since: 1.2 @@ -535,7 +543,8 @@ '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', @@ -826,6 +835,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver-mirror with NBD instead. +#

# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period # are experimental. # @@ -841,7 +853,7 @@ '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', @@ -992,6 +1004,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver-mirror with NBD instead. +# # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period # are experimental. # @@ -1020,7 +1035,8 @@ '*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', @@ -1195,6 +1211,9 @@ # # Features: # +# @deprecated: Member @block-incremental is obsolete. Use +# driver-mirror with NBD instead. +# # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period # are experimental. # @@ -1220,7 +1239,8 @@ '*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', diff --git a/migration/block.c b/migration/block.c index 5f930870a5..46bb431ed3 100644 --- a/migration/block.c +++ b/migration/block.c @@ -729,6 +729,9 @@ 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 driver-mirror with" + "NBD instead."); + qemu_mutex_lock_iothread(); ret = init_blk_migration(f); if (ret < 0) { diff --git a/migration/options.c b/migration/options.c index 6bbfd4853d..48cbbd682a 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" @@ -464,10 +465,14 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp) if (new_caps[MIGRATION_CAPABILITY_BLOCK]) { error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) " "block migration"); - error_append_hint(errp, "Use drive_mirror+NBD instead.\n"); + error_append_hint(errp, "Use driver-mirror with NBD instead.\n"); return false; } #endif + if (new_caps[MIGRATION_CAPABILITY_BLOCK]) { + warn_report("Block migration is deprecated. " + "Use driver-mirror with NBD instead."); + } #ifndef CONFIG_REPLICATION if (new_caps[MIGRATION_CAPABILITY_X_COLO]) { @@ -1351,6 +1356,8 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) } if (params->has_block_incremental) { + warn_report("Block migration is deprecated. " + "Use driver-mirror with NBD instead."); s->parameters.block_incremental = params->block_incremental; } if (params->has_multifd_channels) {