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Wed, 22 Jul 2020 09:06:55 +0000 (UTC) Date: Wed, 22 Jul 2020 10:06:53 +0100 From: "Dr. David Alan Gilbert" To: Max Reitz Subject: Re: [PATCH v2 1/3] migration: Add block-bitmap-mapping parameter Message-ID: <20200722090653.GB2660@work-vm> References: <20200716135303.319502-1-mreitz@redhat.com> <20200716135303.319502-2-mreitz@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200716135303.319502-2-mreitz@redhat.com> User-Agent: Mutt/1.14.5 (2020-06-23) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.120; envelope-from=dgilbert@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/21 23:27:14 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, Juan Quintela , John Snow , qemu-devel@nongnu.org, Peter Krempa Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Max Reitz (mreitz@redhat.com) wrote: > This migration parameter allows mapping block node names and bitmap > names to aliases for the purpose of block dirty bitmap migration. > > This way, management tools can use different node and bitmap names on > the source and destination and pass the mapping of how bitmaps are to be > transferred to qemu (on the source, the destination, or even both with > arbitrary aliases in the migration stream). > > Suggested-by: Vladimir Sementsov-Ogievskiy > Signed-off-by: Max Reitz For both HMP and migration stuff: Acked-by: Dr. David Alan Gilbert > --- > Vladimir noted in v1 that it would be better to ignore bitmaps whose > names aren't mapped, or that are on nodes whose names aren't mapped. > One of the reasons he gave was that bitmap migration is inherently a > form of postcopy migration, and we should not break the target when it > is already running because of a bitmap issue. > > So in this version, I changed the behavior to just ignore bitmaps > without a mapping on the source side. On the destination, however, I > kept it an error when an incoming bitmap or node alias is unknown. > > This is in violation of Vladimir's (rightful) reasoning that such > errors should never break the already running target, but I decided to > do so anyway for a couple of reasons: > > - Ignoring unmapped bitmaps on the source is trivial: We just have to > not put them into the migration stream. > On the destination, it isn't so easy: We (I think) would have to > modify the code to actively skip the bitmap in the stream. > (On the other hand, erroring out is always easy.) > > - Incoming bitmaps with unknown names are already an error before this > series. So this isn't introducing new breakage. > > - I think it makes sense to drop all bitmaps you don't want to migrate > (or implicitly drop them by just not specifying them if you don't care > about them) on the source. I can't imagine a scenario where it would > be really useful if the destination could silently drop unknown > bitmaps. Unknown bitmaps should just be dropped on the source. > > - Choosing to make it an error now doesn't prevent us from relaxing that > restriction in the future. > --- > qapi/migration.json | 92 +++++++- > migration/migration.h | 3 + > migration/block-dirty-bitmap.c | 373 ++++++++++++++++++++++++++++----- > migration/migration.c | 30 +++ > monitor/hmp-cmds.c | 30 +++ > 5 files changed, 473 insertions(+), 55 deletions(-) > > diff --git a/qapi/migration.json b/qapi/migration.json > index d5000558c6..1b0fbcef96 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -507,6 +507,44 @@ > 'data': [ 'none', 'zlib', > { 'name': 'zstd', 'if': 'defined(CONFIG_ZSTD)' } ] } > > +## > +# @BitmapMigrationBitmapAlias: > +# > +# @name: The name of the bitmap. > +# > +# @alias: An alias name for migration (for example the bitmap name on > +# the opposite site). > +# > +# Since: 5.1 > +## > +{ 'struct': 'BitmapMigrationBitmapAlias', > + 'data': { > + 'name': 'str', > + 'alias': 'str' > + } } > + > +## > +# @BitmapMigrationNodeAlias: > +# > +# Maps a block node name and the bitmaps it has to aliases for dirty > +# bitmap migration. > +# > +# @node-name: A block node name. > +# > +# @alias: An alias block node name for migration (for example the > +# node name on the opposite site). > +# > +# @bitmaps: Mappings for the bitmaps on this node. > +# > +# Since: 5.1 > +## > +{ 'struct': 'BitmapMigrationNodeAlias', > + 'data': { > + 'node-name': 'str', > + 'alias': 'str', > + 'bitmaps': [ 'BitmapMigrationBitmapAlias' ] > + } } > + > ## > # @MigrationParameter: > # > @@ -641,6 +679,21 @@ > # will consume more CPU. > # Defaults to 1. (Since 5.0) > # > +# @block-bitmap-mapping: Maps block nodes and bitmaps on them to > +# aliases for the purpose of dirty bitmap migration. Such > +# aliases may for example be the corresponding names on the > +# opposite site. > +# The mapping must be one-to-one, and on the destination also > +# complete: On the source, bitmaps on nodes where either the > +# bitmap or the node is not mapped will be ignored. In > +# contrast, on the destination, receiving a bitmap (by alias) > +# from a node (by alias) when either alias is not mapped will > +# result in an error. > +# By default (when this parameter has never been set), bitmap > +# names are mapped to themselves. Nodes are mapped to their > +# block device name if there is one, and to their node name > +# otherwise. (Since 5.2) > +# > # Since: 2.4 > ## > { 'enum': 'MigrationParameter', > @@ -655,7 +708,8 @@ > 'multifd-channels', > 'xbzrle-cache-size', 'max-postcopy-bandwidth', > 'max-cpu-throttle', 'multifd-compression', > - 'multifd-zlib-level' ,'multifd-zstd-level' ] } > + 'multifd-zlib-level' ,'multifd-zstd-level', > + 'block-bitmap-mapping' ] } > > ## > # @MigrateSetParameters: > @@ -781,6 +835,21 @@ > # will consume more CPU. > # Defaults to 1. (Since 5.0) > # > +# @block-bitmap-mapping: Maps block nodes and bitmaps on them to > +# aliases for the purpose of dirty bitmap migration. Such > +# aliases may for example be the corresponding names on the > +# opposite site. > +# The mapping must be one-to-one, and on the destination also > +# complete: On the source, bitmaps on nodes where either the > +# bitmap or the node is not mapped will be ignored. In > +# contrast, on the destination, receiving a bitmap (by alias) > +# from a node (by alias) when either alias is not mapped will > +# result in an error. > +# By default (when this parameter has never been set), bitmap > +# names are mapped to themselves. Nodes are mapped to their > +# block device name if there is one, and to their node name > +# otherwise. (Since 5.2) > +# > # Since: 2.4 > ## > # TODO either fuse back into MigrationParameters, or make > @@ -811,7 +880,8 @@ > '*max-cpu-throttle': 'int', > '*multifd-compression': 'MultiFDCompression', > '*multifd-zlib-level': 'int', > - '*multifd-zstd-level': 'int' } } > + '*multifd-zstd-level': 'int', > + '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } > > ## > # @migrate-set-parameters: > @@ -957,6 +1027,21 @@ > # will consume more CPU. > # Defaults to 1. (Since 5.0) > # > +# @block-bitmap-mapping: Maps block nodes and bitmaps on them to > +# aliases for the purpose of dirty bitmap migration. Such > +# aliases may for example be the corresponding names on the > +# opposite site. > +# The mapping must be one-to-one, and on the destination also > +# complete: On the source, bitmaps on nodes where either the > +# bitmap or the node is not mapped will be ignored. In > +# contrast, on the destination, receiving a bitmap (by alias) > +# from a node (by alias) when either alias is not mapped will > +# result in an error. > +# By default (when this parameter has never been set), bitmap > +# names are mapped to themselves. Nodes are mapped to their > +# block device name if there is one, and to their node name > +# otherwise. (Since 5.2) > +# > # Since: 2.4 > ## > { 'struct': 'MigrationParameters', > @@ -985,7 +1070,8 @@ > '*max-cpu-throttle': 'uint8', > '*multifd-compression': 'MultiFDCompression', > '*multifd-zlib-level': 'uint8', > - '*multifd-zstd-level': 'uint8' } } > + '*multifd-zstd-level': 'uint8', > + '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } > > ## > # @query-migrate-parameters: > diff --git a/migration/migration.h b/migration/migration.h > index f617960522..038c318b92 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -336,6 +336,9 @@ void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value); > > void dirty_bitmap_mig_before_vm_start(void); > void init_dirty_bitmap_incoming_migration(void); > +bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, > + Error **errp); > + > void migrate_add_address(SocketAddress *address); > > int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque); > diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c > index b0dbf9eeed..c7945c631b 100644 > --- a/migration/block-dirty-bitmap.c > +++ b/migration/block-dirty-bitmap.c > @@ -29,10 +29,10 @@ > * > * # Header (shared for different chunk types) > * 1, 2 or 4 bytes: flags (see qemu_{put,put}_flags) > - * [ 1 byte: node name size ] \ flags & DEVICE_NAME > - * [ n bytes: node name ] / > - * [ 1 byte: bitmap name size ] \ flags & BITMAP_NAME > - * [ n bytes: bitmap name ] / > + * [ 1 byte: node alias size ] \ flags & DEVICE_NAME > + * [ n bytes: node alias ] / > + * [ 1 byte: bitmap alias size ] \ flags & BITMAP_NAME > + * [ n bytes: bitmap alias ] / > * > * # Start of bitmap migration (flags & START) > * header > @@ -72,7 +72,9 @@ > #include "migration/register.h" > #include "qemu/hbitmap.h" > #include "qemu/cutils.h" > +#include "qemu/id.h" > #include "qapi/error.h" > +#include "qapi/qapi-commands-migration.h" > #include "trace.h" > > #define CHUNK_SIZE (1 << 10) > @@ -103,7 +105,8 @@ > typedef struct DirtyBitmapMigBitmapState { > /* Written during setup phase. */ > BlockDriverState *bs; > - const char *node_name; > + char *node_alias; > + char *bitmap_alias; > BdrvDirtyBitmap *bitmap; > uint64_t total_sectors; > uint64_t sectors_per_chunk; > @@ -128,7 +131,8 @@ typedef struct DirtyBitmapMigState { > > typedef struct DirtyBitmapLoadState { > uint32_t flags; > - char node_name[256]; > + char node_alias[256]; > + char bitmap_alias[256]; > char bitmap_name[256]; > BlockDriverState *bs; > BdrvDirtyBitmap *bitmap; > @@ -144,6 +148,162 @@ typedef struct DirtyBitmapLoadBitmapState { > static GSList *enabled_bitmaps; > QemuMutex finish_lock; > > +/* For hash tables that map node/bitmap names to aliases */ > +typedef struct AliasMapInnerNode { > + char *string; > + GHashTable *subtree; > +} AliasMapInnerNode; > + > +static void free_alias_map_inner_node(void *amin_ptr) > +{ > + AliasMapInnerNode *amin = amin_ptr; > + > + g_free(amin->string); > + g_hash_table_unref(amin->subtree); > + g_free(amin); > +} > + > +/** > + * Construct an alias map based on the given QMP structure. > + * > + * (Note that we cannot store such maps in the MigrationParameters > + * object, because that struct is defined by the QAPI schema, which > + * makes it basically impossible to have dicts with arbitrary keys. > + * Therefore, we instead have to construct these maps when migration > + * starts.) > + * > + * @bbm is the block_bitmap_mapping from the migration parameters. > + * > + * If @name_to_alias is true, the returned hash table will map node > + * and bitmap names to their respective aliases (for outgoing > + * migration). > + * > + * If @name_to_alias is false, the returned hash table will map node > + * and bitmap aliases to their respective names (for incoming > + * migration). > + * > + * The hash table maps node names/aliases to AliasMapInnerNode > + * objects, whose .string is the respective node alias/name, and whose > + * .subtree table maps bitmap names/aliases to the respective bitmap > + * alias/name. > + */ > +static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm, > + bool name_to_alias, > + Error **errp) > +{ > + GHashTable *alias_map; > + > + alias_map = g_hash_table_new_full(g_str_hash, g_str_equal, > + g_free, free_alias_map_inner_node); > + > + for (; bbm; bbm = bbm->next) { > + const BitmapMigrationNodeAlias *bmna = bbm->value; > + const BitmapMigrationBitmapAliasList *bmbal; > + AliasMapInnerNode *amin; > + GHashTable *bitmaps_map; > + const char *node_map_from, *node_map_to; > + > + if (!id_wellformed(bmna->alias)) { > + error_setg(errp, "The node alias %s is not well-formed", > + bmna->alias); > + goto fail; > + } > + > + if (name_to_alias) { > + if (g_hash_table_contains(alias_map, bmna->node_name)) { > + error_setg(errp, "The node name %s is mapped twice", > + bmna->node_name); > + goto fail; > + } > + > + node_map_from = bmna->node_name; > + node_map_to = bmna->alias; > + } else { > + if (g_hash_table_contains(alias_map, bmna->alias)) { > + error_setg(errp, "The node alias %s is used twice", > + bmna->alias); > + goto fail; > + } > + > + node_map_from = bmna->alias; > + node_map_to = bmna->node_name; > + } > + > + bitmaps_map = g_hash_table_new_full(g_str_hash, g_str_equal, > + g_free, g_free); > + > + amin = g_new(AliasMapInnerNode, 1); > + *amin = (AliasMapInnerNode){ > + .string = g_strdup(node_map_to), > + .subtree = bitmaps_map, > + }; > + > + g_hash_table_insert(alias_map, g_strdup(node_map_from), amin); > + > + for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) { > + const BitmapMigrationBitmapAlias *bmba = bmbal->value; > + const char *bmap_map_from, *bmap_map_to; > + > + if (name_to_alias) { > + bmap_map_from = bmba->name; > + bmap_map_to = bmba->alias; > + > + if (g_hash_table_contains(bitmaps_map, bmba->name)) { > + error_setg(errp, "The bitmap %s/%s is mapped twice", > + bmna->node_name, bmba->name); > + goto fail; > + } > + } else { > + bmap_map_from = bmba->alias; > + bmap_map_to = bmba->name; > + > + if (g_hash_table_contains(bitmaps_map, bmba->alias)) { > + error_setg(errp, "The bitmap alias %s/%s is used twice", > + bmna->alias, bmba->alias); > + goto fail; > + } > + } > + > + g_hash_table_insert(bitmaps_map, > + g_strdup(bmap_map_from), g_strdup(bmap_map_to)); > + } > + } > + > + return alias_map; > + > +fail: > + g_hash_table_destroy(alias_map); > + return NULL; > +} > + > +/** > + * Run construct_alias_map() in both directions to check whether @bbm > + * is valid. > + * (This function is to be used by migration/migration.c to validate > + * the user-specified block-bitmap-mapping migration parameter.) > + * > + * Returns true if and only if the mapping is valid. > + */ > +bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, > + Error **errp) > +{ > + GHashTable *alias_map; > + > + alias_map = construct_alias_map(bbm, true, errp); > + if (!alias_map) { > + return false; > + } > + g_hash_table_destroy(alias_map); > + > + alias_map = construct_alias_map(bbm, false, errp); > + if (!alias_map) { > + return false; > + } > + g_hash_table_destroy(alias_map); > + > + return true; > +} > + > void init_dirty_bitmap_incoming_migration(void) > { > qemu_mutex_init(&finish_lock); > @@ -191,11 +351,11 @@ static void send_bitmap_header(QEMUFile *f, DirtyBitmapMigBitmapState *dbms, > qemu_put_bitmap_flags(f, flags); > > if (flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { > - qemu_put_counted_string(f, dbms->node_name); > + qemu_put_counted_string(f, dbms->node_alias); > } > > if (flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { > - qemu_put_counted_string(f, bdrv_dirty_bitmap_name(bitmap)); > + qemu_put_counted_string(f, dbms->bitmap_alias); > } > } > > @@ -263,17 +423,25 @@ static void dirty_bitmap_mig_cleanup(void) > QSIMPLEQ_REMOVE_HEAD(&dirty_bitmap_mig_state.dbms_list, entry); > bdrv_dirty_bitmap_set_busy(dbms->bitmap, false); > bdrv_unref(dbms->bs); > + g_free(dbms->node_alias); > + g_free(dbms->bitmap_alias); > g_free(dbms); > } > } > > /* Called with iothread lock taken. */ > -static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name) > +static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name, > + GHashTable *alias_map) > { > BdrvDirtyBitmap *bitmap; > DirtyBitmapMigBitmapState *dbms; > + GHashTable *bitmap_aliases; > + const char *node_alias, *bitmap_name, *bitmap_alias; > Error *local_err = NULL; > > + /* When an alias map is given, @bs_name must be @bs's node name */ > + assert(!alias_map || !strcmp(bs_name, bdrv_get_node_name(bs))); > + > FOR_EACH_DIRTY_BITMAP(bs, bitmap) { > if (bdrv_dirty_bitmap_name(bitmap)) { > break; > @@ -283,21 +451,39 @@ static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name) > return 0; > } > > + bitmap_name = bdrv_dirty_bitmap_name(bitmap); > + > if (!bs_name || strcmp(bs_name, "") == 0) { > error_report("Bitmap '%s' in unnamed node can't be migrated", > - bdrv_dirty_bitmap_name(bitmap)); > + bitmap_name); > return -1; > } > > - if (bs_name[0] == '#') { > + if (alias_map) { > + const AliasMapInnerNode *amin = g_hash_table_lookup(alias_map, bs_name); > + > + if (!amin) { > + /* Skip bitmaps on nodes with no alias */ > + return 0; > + } > + > + node_alias = amin->string; > + bitmap_aliases = amin->subtree; > + } else { > + node_alias = bs_name; > + bitmap_aliases = NULL; > + } > + > + if (node_alias[0] == '#') { > error_report("Bitmap '%s' in a node with auto-generated " > "name '%s' can't be migrated", > - bdrv_dirty_bitmap_name(bitmap), bs_name); > + bitmap_name, node_alias); > return -1; > } > > FOR_EACH_DIRTY_BITMAP(bs, bitmap) { > - if (!bdrv_dirty_bitmap_name(bitmap)) { > + bitmap_name = bdrv_dirty_bitmap_name(bitmap); > + if (!bitmap_name) { > continue; > } > > @@ -306,12 +492,23 @@ static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name) > return -1; > } > > + if (bitmap_aliases) { > + bitmap_alias = g_hash_table_lookup(bitmap_aliases, bitmap_name); > + if (!bitmap_alias) { > + /* Skip bitmaps with no alias */ > + continue; > + } > + } else { > + bitmap_alias = bitmap_name; > + } > + > bdrv_ref(bs); > bdrv_dirty_bitmap_set_busy(bitmap, true); > > dbms = g_new0(DirtyBitmapMigBitmapState, 1); > dbms->bs = bs; > - dbms->node_name = bs_name; > + dbms->node_alias = g_strdup(node_alias); > + dbms->bitmap_alias = g_strdup(bitmap_alias); > dbms->bitmap = bitmap; > dbms->total_sectors = bdrv_nb_sectors(bs); > dbms->sectors_per_chunk = CHUNK_SIZE * 8 * > @@ -337,43 +534,52 @@ static int init_dirty_bitmap_migration(void) > DirtyBitmapMigBitmapState *dbms; > GHashTable *handled_by_blk = g_hash_table_new(NULL, NULL); > BlockBackend *blk; > + const MigrationParameters *mig_params = &migrate_get_current()->parameters; > + GHashTable *alias_map = NULL; > + > + if (mig_params->has_block_bitmap_mapping) { > + alias_map = construct_alias_map(mig_params->block_bitmap_mapping, true, > + &error_abort); > + } > > dirty_bitmap_mig_state.bulk_completed = false; > dirty_bitmap_mig_state.prev_bs = NULL; > dirty_bitmap_mig_state.prev_bitmap = NULL; > dirty_bitmap_mig_state.no_bitmaps = false; > > - /* > - * Use blockdevice name for direct (or filtered) children of named block > - * backends. > - */ > - for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { > - const char *name = blk_name(blk); > - > - if (!name || strcmp(name, "") == 0) { > - continue; > - } > + if (!alias_map) { > + /* > + * Use blockdevice name for direct (or filtered) children of named block > + * backends. > + */ > + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { > + const char *name = blk_name(blk); > > - bs = blk_bs(blk); > + if (!name || strcmp(name, "") == 0) { > + continue; > + } > > - /* Skip filters without bitmaps */ > - while (bs && bs->drv && bs->drv->is_filter && > - !bdrv_has_named_bitmaps(bs)) > - { > - if (bs->backing) { > - bs = bs->backing->bs; > - } else if (bs->file) { > - bs = bs->file->bs; > - } else { > - bs = NULL; > + bs = blk_bs(blk); > + > + /* Skip filters without bitmaps */ > + while (bs && bs->drv && bs->drv->is_filter && > + !bdrv_has_named_bitmaps(bs)) > + { > + if (bs->backing) { > + bs = bs->backing->bs; > + } else if (bs->file) { > + bs = bs->file->bs; > + } else { > + bs = NULL; > + } > } > - } > > - if (bs && bs->drv && !bs->drv->is_filter) { > - if (add_bitmaps_to_list(bs, name)) { > - goto fail; > + if (bs && bs->drv && !bs->drv->is_filter) { > + if (add_bitmaps_to_list(bs, name, NULL)) { > + goto fail; > + } > + g_hash_table_add(handled_by_blk, bs); > } > - g_hash_table_add(handled_by_blk, bs); > } > } > > @@ -382,7 +588,7 @@ static int init_dirty_bitmap_migration(void) > continue; > } > > - if (add_bitmaps_to_list(bs, bdrv_get_node_name(bs))) { > + if (add_bitmaps_to_list(bs, bdrv_get_node_name(bs), alias_map)) { > goto fail; > } > } > @@ -397,11 +603,17 @@ static int init_dirty_bitmap_migration(void) > } > > g_hash_table_destroy(handled_by_blk); > + if (alias_map) { > + g_hash_table_destroy(alias_map); > + } > > return 0; > > fail: > g_hash_table_destroy(handled_by_blk); > + if (alias_map) { > + g_hash_table_destroy(alias_map); > + } > dirty_bitmap_mig_cleanup(); > > return -1; > @@ -666,8 +878,10 @@ static int dirty_bitmap_load_bits(QEMUFile *f, DirtyBitmapLoadState *s) > return 0; > } > > -static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) > +static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s, > + GHashTable *alias_map) > { > + GHashTable *bitmap_alias_map = NULL; > Error *local_err = NULL; > bool nothing; > s->flags = qemu_get_bitmap_flags(f); > @@ -676,25 +890,68 @@ static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) > nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS); > > if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { > - if (!qemu_get_counted_string(f, s->node_name)) { > - error_report("Unable to read node name string"); > + if (!qemu_get_counted_string(f, s->node_alias)) { > + error_report("Unable to read node alias string"); > return -EINVAL; > } > - s->bs = bdrv_lookup_bs(s->node_name, s->node_name, &local_err); > + > + if (alias_map) { > + const AliasMapInnerNode *amin; > + > + amin = g_hash_table_lookup(alias_map, s->node_alias); > + if (!amin) { > + error_report("Error: Unknown node alias '%s'", s->node_alias); > + return -EINVAL; > + } > + > + bitmap_alias_map = amin->subtree; > + s->bs = bdrv_lookup_bs(NULL, amin->string, &local_err); > + } else { > + s->bs = bdrv_lookup_bs(s->node_alias, s->node_alias, &local_err); > + } > if (!s->bs) { > error_report_err(local_err); > return -EINVAL; > } > - } else if (!s->bs && !nothing) { > + } else if (s->bs) { > + if (alias_map) { > + const AliasMapInnerNode *amin; > + > + /* Must be present in the map, or s->bs would not be set */ > + amin = g_hash_table_lookup(alias_map, s->node_alias); > + assert(amin != NULL); > + > + bitmap_alias_map = amin->subtree; > + } > + } else if (!nothing) { > error_report("Error: block device name is not set"); > return -EINVAL; > } > > + assert(!!alias_map == !!bitmap_alias_map); > + > if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { > - if (!qemu_get_counted_string(f, s->bitmap_name)) { > + const char *bitmap_name; > + > + if (!qemu_get_counted_string(f, s->bitmap_alias)) { > error_report("Unable to read bitmap name string"); > return -EINVAL; > } > + > + if (bitmap_alias_map) { > + bitmap_name = g_hash_table_lookup(bitmap_alias_map, > + s->bitmap_alias); > + if (!bitmap_name) { > + error_report("Error: Unknown bitmap alias '%s' on node '%s' " > + "(alias '%s')", s->bitmap_alias, s->bs->node_name, > + s->node_alias); > + return -EINVAL; > + } > + } else { > + bitmap_name = s->bitmap_alias; > + } > + > + g_strlcpy(s->bitmap_name, bitmap_name, sizeof(s->bitmap_name)); > s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name); > > /* bitmap may be NULL here, it wouldn't be an error if it is the > @@ -702,7 +959,7 @@ static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) > if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) { > error_report("Error: unknown dirty bitmap " > "'%s' for block device '%s'", > - s->bitmap_name, s->node_name); > + s->bitmap_name, s->bs->node_name); > return -EINVAL; > } > } else if (!s->bitmap && !nothing) { > @@ -715,6 +972,8 @@ static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) > > static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) > { > + GHashTable *alias_map = NULL; > + const MigrationParameters *mig_params = &migrate_get_current()->parameters; > static DirtyBitmapLoadState s; > int ret = 0; > > @@ -724,10 +983,15 @@ static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) > return -EINVAL; > } > > + if (mig_params->has_block_bitmap_mapping) { > + alias_map = construct_alias_map(mig_params->block_bitmap_mapping, > + false, &error_abort); > + } > + > do { > - ret = dirty_bitmap_load_header(f, &s); > + ret = dirty_bitmap_load_header(f, &s, alias_map); > if (ret < 0) { > - return ret; > + goto fail; > } > > if (s.flags & DIRTY_BITMAP_MIG_FLAG_START) { > @@ -743,12 +1007,17 @@ static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) > } > > if (ret) { > - return ret; > + goto fail; > } > } while (!(s.flags & DIRTY_BITMAP_MIG_FLAG_EOS)); > > trace_dirty_bitmap_load_success(); > - return 0; > + ret = 0; > +fail: > + if (alias_map) { > + g_hash_table_destroy(alias_map); > + } > + return ret; > } > > static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque) > diff --git a/migration/migration.c b/migration/migration.c > index 2ed9923227..bcf7c3bf76 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -36,6 +36,7 @@ > #include "block/block.h" > #include "qapi/error.h" > #include "qapi/clone-visitor.h" > +#include "qapi/qapi-visit-migration.h" > #include "qapi/qapi-visit-sockets.h" > #include "qapi/qapi-commands-migration.h" > #include "qapi/qapi-events-migration.h" > @@ -832,6 +833,13 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) > params->has_announce_step = true; > params->announce_step = s->parameters.announce_step; > > + if (s->parameters.has_block_bitmap_mapping) { > + params->has_block_bitmap_mapping = true; > + params->block_bitmap_mapping = > + QAPI_CLONE(BitmapMigrationNodeAliasList, > + s->parameters.block_bitmap_mapping); > + } > + > return params; > } > > @@ -1297,6 +1305,13 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp) > "is invalid, it must be in the range of 1 to 10000 ms"); > return false; > } > + > + if (params->has_block_bitmap_mapping && > + !check_dirty_bitmap_mig_alias_map(params->block_bitmap_mapping, errp)) { > + error_prepend(errp, "Invalid mapping given for block-bitmap-mapping: "); > + return false; > + } > + > return true; > } > > @@ -1391,6 +1406,11 @@ static void migrate_params_test_apply(MigrateSetParameters *params, > if (params->has_announce_step) { > dest->announce_step = params->announce_step; > } > + > + if (params->has_block_bitmap_mapping) { > + dest->has_block_bitmap_mapping = true; > + dest->block_bitmap_mapping = params->block_bitmap_mapping; > + } > } > > static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > @@ -1503,6 +1523,16 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) > if (params->has_announce_step) { > s->parameters.announce_step = params->announce_step; > } > + > + if (params->has_block_bitmap_mapping) { > + qapi_free_BitmapMigrationNodeAliasList( > + s->parameters.block_bitmap_mapping); > + > + s->parameters.has_block_bitmap_mapping = true; > + s->parameters.block_bitmap_mapping = > + QAPI_CLONE(BitmapMigrationNodeAliasList, > + params->block_bitmap_mapping); > + } > } > > void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c > index ae4b6a4246..7711726fd2 100644 > --- a/monitor/hmp-cmds.c > +++ b/monitor/hmp-cmds.c > @@ -469,6 +469,32 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) > monitor_printf(mon, "%s: '%s'\n", > MigrationParameter_str(MIGRATION_PARAMETER_TLS_AUTHZ), > params->tls_authz); > + > + if (params->has_block_bitmap_mapping) { > + const BitmapMigrationNodeAliasList *bmnal; > + > + monitor_printf(mon, "%s:\n", > + MigrationParameter_str( > + MIGRATION_PARAMETER_BLOCK_BITMAP_MAPPING)); > + > + for (bmnal = params->block_bitmap_mapping; > + bmnal; > + bmnal = bmnal->next) > + { > + const BitmapMigrationNodeAlias *bmna = bmnal->value; > + const BitmapMigrationBitmapAliasList *bmbal; > + > + monitor_printf(mon, " '%s' -> '%s'\n", > + bmna->node_name, bmna->alias); > + > + for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) { > + const BitmapMigrationBitmapAlias *bmba = bmbal->value; > + > + monitor_printf(mon, " '%s' -> '%s'\n", > + bmba->name, bmba->alias); > + } > + } > + } > } > > qapi_free_MigrationParameters(params); > @@ -1384,6 +1410,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > p->has_announce_step = true; > visit_type_size(v, param, &p->announce_step, &err); > break; > + case MIGRATION_PARAMETER_BLOCK_BITMAP_MAPPING: > + error_setg(&err, "The block-bitmap-mapping parameter can only be set " > + "through QMP"); > + break; > default: > assert(0); > } > -- > 2.26.2 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK