[Qemu-devel] [PATCH 0/5] Remove old MigrationParams

[Qemu-devel] [PATCH 0/5] Remove old MigrationParams

[Juan Quintela]

Hi

Changes from v4:
- make suggested logic change by eric
- remove extra space in error message
- allow migrate_set_capability block off when block migration is complied off
  (eric request)

Please review

[v4]

- Address Markus review
  * better documentation messages (thanks)
  * reorganize error checking to have small data
  * Use g_new0
  * Improve commints messages

[v4]

- patch 1 included again. We have a 'block' capability and a
  'block_incremental' parameter
  Make Dave happy: rename shared into incremental
  Make Eric and Markus happy:

    block: off -> no block migration, we don't care about
                  block_incremental value
    block: on block_incremental: off -> no incremental block migration
    block: on block_incremental: on  -> incremental block migration

- Use visitors.
  You ask if there is not a better way than hand coding a boolean parser.
  QAPI people (a.k.a. Markus) answer to use a visitor.
  Once there, I used it also for integers, not only booleans.

- Use -b/-i parameters.  OK, I bit the bullet: You can't use
  capabilities/parameters and -b/-i: it gives you one error If you use
  -b/-i, capability parameter is cleanup after the migration ends (Who
  would have guessed that there are cases where we call
  migration_fd_error(), but not migration_fd_cleanup()
  I think this should make Peter and Markus and Dave happy.

- Integrate migrate block compile time disabling
  Well, it conflicted left and right, so I fixed it
  Once there, I disable setting/getting block capability if it is disabled.

[v3]

- Patch 1 included in pull request
- disable block_shared when we disable block_enable
- enable block_enabled when we enable block_shared

[v2]

- make migrate_block_set_* take a boolean
- disable block migration in colo to maintain semantics.

[v1]
Upon a time there were MigrationParms (only used for block migration)
and then MigrationParams used for everything else.  This series:

- create migration capabilities for block parameters
- make the migrate command line parameters to use capabilities
- remove MigrationParams completely


Dr. David Alan Gilbert (1):
  block migration: Allow compile time disable

Juan Quintela (4):
  hmp: Use visitor api for hmp_migrate_set_parameter()
  migration: Create block capability
  migration: Remove use of old MigrationParams
  migration: Remove old MigrationParams

 configure                     | 11 +++++
 hmp.c                         | 23 +++++++++--
 include/migration/block.h     | 24 +++++++++++
 include/migration/migration.h | 17 ++++----
 include/migration/vmstate.h   |  1 -
 include/qemu/typedefs.h       |  1 -
 include/sysemu/sysemu.h       |  3 +-
 migration/Makefile.objs       |  2 +-
 migration/block.c             | 17 +-------
 migration/colo.c              |  6 +--
 migration/migration.c         | 96 +++++++++++++++++++++++++++++++++++++++----
 migration/savevm.c            | 24 ++++-------
 qapi-schema.json              | 28 +++++++++++--
 13 files changed, 191 insertions(+), 62 deletions(-)

-- 
2.9.3

[Qemu-devel] [PATCH 1/5] hmp: Use visitor api for hmp_migrate_set_parameter()

[Juan Quintela]

We only use it for int64 at this point, I am not able to find a way to
parse an int with MiB units.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
---
 hmp.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/hmp.c b/hmp.c
index b9dd933..acbbc5c 100644
--- a/hmp.c
+++ b/hmp.c
@@ -29,6 +29,7 @@
 #include "monitor/qdev.h"
 #include "qapi/opts-visitor.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/string-input-visitor.h"
 #include "qapi/string-output-visitor.h"
 #include "qapi/util.h"
 #include "qapi-visit.h"
@@ -1523,8 +1524,9 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
 {
     const char *param = qdict_get_str(qdict, "parameter");
     const char *valuestr = qdict_get_str(qdict, "value");
+    Visitor *v = string_input_visitor_new(valuestr);
     uint64_t valuebw = 0;
-    long valueint = 0;
+    int64_t valueint = 0;
     Error *err = NULL;
     bool use_int_value = false;
     int i, ret;
@@ -1582,9 +1584,8 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
             }
 
             if (use_int_value) {
-                if (qemu_strtol(valuestr, NULL, 10, &valueint) < 0) {
-                    error_setg(&err, "Unable to parse '%s' as an int",
-                               valuestr);
+                visit_type_int(v, param, &valueint, &err);
+                if (err) {
                     goto cleanup;
                 }
                 /* Set all integers; only one has_FOO will be set, and
@@ -1608,6 +1609,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
     }
 
  cleanup:
+    visit_free(v);
     if (err) {
         error_report_err(err);
     }
-- 
2.9.3

[Qemu-devel] [PATCH 2/5] migration: Create block capability

[Juan Quintela]

Create one capability for block migration and one parameter for
incremental block migration.

Signed-off-by: Juan Quintela <quintela@redhat.com>

---

- address all Markus comments
- use Markus and Eric text descriptions
- change logic another time
- improve text messages
---
 hmp.c                         | 13 ++++++++
 include/migration/block.h     |  2 ++
 include/migration/migration.h |  6 ++++
 migration/migration.c         | 71 +++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json              | 28 +++++++++++++++--
 5 files changed, 117 insertions(+), 3 deletions(-)

diff --git a/hmp.c b/hmp.c
index acbbc5c..208154c 100644
--- a/hmp.c
+++ b/hmp.c
@@ -326,6 +326,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: %" PRId64 "\n",
             MigrationParameter_lookup[MIGRATION_PARAMETER_X_CHECKPOINT_DELAY],
             params->x_checkpoint_delay);
+        assert(params->has_block_incremental);
+        monitor_printf(mon, "%s: %s\n",
+            MigrationParameter_lookup[MIGRATION_PARAMETER_BLOCK_INCREMENTAL],
+                       params->block_incremental ? "on" : "off");
     }
 
     qapi_free_MigrationParameters(params);
@@ -1527,6 +1531,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
     Visitor *v = string_input_visitor_new(valuestr);
     uint64_t valuebw = 0;
     int64_t valueint = 0;
+    bool valuebool = false;
     Error *err = NULL;
     bool use_int_value = false;
     int i, ret;
@@ -1581,6 +1586,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
                 p.has_x_checkpoint_delay = true;
                 use_int_value = true;
                 break;
+            case MIGRATION_PARAMETER_BLOCK_INCREMENTAL:
+                p.has_block_incremental = true;
+                visit_type_bool(v, param, &valuebool, &err);
+                if (err) {
+                    goto cleanup;
+                }
+                p.block_incremental = valuebool;
+                break;
             }
 
             if (use_int_value) {
diff --git a/include/migration/block.h b/include/migration/block.h
index 41a1ac8..5225af9 100644
--- a/include/migration/block.h
+++ b/include/migration/block.h
@@ -20,4 +20,6 @@ uint64_t blk_mig_bytes_transferred(void);
 uint64_t blk_mig_bytes_remaining(void);
 uint64_t blk_mig_bytes_total(void);
 
+void migrate_set_block_enabled(bool value, Error **errp);
+
 #endif /* MIGRATION_BLOCK_H */
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 49ec501..024a048 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -153,6 +153,9 @@ struct MigrationState
 
     /* The last error that occurred */
     Error *error;
+    /* Do we have to clean up -b/-i from old migrate parameters */
+    /* This feature is deprecated and will be removed */
+    bool must_remove_block_options;
 };
 
 void migrate_set_state(int *state, int old_state, int new_state);
@@ -265,6 +268,9 @@ bool migrate_colo_enabled(void);
 
 int64_t xbzrle_cache_resize(int64_t new_size);
 
+bool migrate_use_block(void);
+bool migrate_use_block_incremental(void);
+
 bool migrate_use_compression(void);
 int migrate_compress_level(void);
 int migrate_compress_threads(void);
diff --git a/migration/migration.c b/migration/migration.c
index 0304c01..c13c0a2 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -592,6 +592,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->downtime_limit = s->parameters.downtime_limit;
     params->has_x_checkpoint_delay = true;
     params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
+    params->has_block_incremental = true;
+    params->block_incremental = s->parameters.block_incremental;
 
     return params;
 }
@@ -900,6 +902,9 @@ void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp)
             colo_checkpoint_notify(s);
         }
     }
+    if (params->has_block_incremental) {
+        s->parameters.block_incremental = params->block_incremental;
+    }
 }
 
 
@@ -935,6 +940,33 @@ void migrate_set_state(int *state, int old_state, int new_state)
     }
 }
 
+void migrate_set_block_enabled(bool value, Error **errp)
+{
+    MigrationCapabilityStatusList *cap;
+
+    cap = g_new0(MigrationCapabilityStatusList, 1);
+    cap->value = g_new0(MigrationCapabilityStatus, 1);
+    cap->value->capability = MIGRATION_CAPABILITY_BLOCK;
+    cap->value->state = value;
+    qmp_migrate_set_capabilities(cap, errp);
+    qapi_free_MigrationCapabilityStatusList(cap);
+}
+
+static void migrate_set_block_incremental(MigrationState *s, bool value)
+{
+    s->parameters.block_incremental = value;
+}
+
+static void block_cleanup_parameters(MigrationState *s)
+{
+    if (s->must_remove_block_options) {
+        /* setting to false can never fail */
+        migrate_set_block_enabled(false, &error_abort);
+        migrate_set_block_incremental(s, false);
+        s->must_remove_block_options = false;
+    }
+}
+
 static void migrate_fd_cleanup(void *opaque)
 {
     MigrationState *s = opaque;
@@ -967,6 +999,7 @@ static void migrate_fd_cleanup(void *opaque)
     }
 
     notifier_list_notify(&migration_state_notifiers, s);
+    block_cleanup_parameters(s);
 }
 
 void migrate_fd_error(MigrationState *s, const Error *error)
@@ -979,6 +1012,7 @@ void migrate_fd_error(MigrationState *s, const Error *error)
         s->error = error_copy(error);
     }
     notifier_list_notify(&migration_state_notifiers, s);
+    block_cleanup_parameters(s);
 }
 
 static void migrate_fd_cancel(MigrationState *s)
@@ -1020,6 +1054,7 @@ static void migrate_fd_cancel(MigrationState *s)
             s->block_inactive = false;
         }
     }
+    block_cleanup_parameters(s);
 }
 
 void add_migration_state_change_notifier(Notifier *notify)
@@ -1207,6 +1242,24 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
         return;
     }
 
+    if ((has_blk && blk) || (has_inc && inc)) {
+        if (migrate_use_block() || migrate_use_block_incremental()) {
+            error_setg(errp, "Command options are incompatible with "
+                       "current migration capabilities");
+            return;
+        }
+        migrate_set_block_enabled(true, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+        s->must_remove_block_options = true;
+    }
+
+    if (has_inc && inc) {
+        migrate_set_block_incremental(s, true);
+    }
+
     s = migrate_init(&params);
 
     if (strstart(uri, "tcp:", &p)) {
@@ -1404,6 +1457,24 @@ int64_t migrate_xbzrle_cache_size(void)
     return s->xbzrle_cache_size;
 }
 
+bool migrate_use_block(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK];
+}
+
+bool migrate_use_block_incremental(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters.block_incremental;
+}
+
 /* migration thread support */
 /*
  * Something bad happened to the RP stream, mark an error
diff --git a/qapi-schema.json b/qapi-schema.json
index 80603cf..e38c5f0 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -894,11 +894,18 @@
 # @release-ram: if enabled, qemu will free the migrated ram pages on the source
 #        during postcopy-ram migration. (since 2.9)
 #
+# @block: If enabled, QEMU will also migrate the contents of all block
+#          devices.  Default is disabled.  A possible alternative uses
+#          mirror jobs to a builtin NBD server on the destination, which
+#          offers more flexibility.
+#          (Since 2.10)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
-           'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram'] }
+           'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
+           'block' ] }
 
 ##
 # @MigrationCapabilityStatus:
@@ -1009,13 +1016,20 @@
 # @x-checkpoint-delay: The delay time (in ms) between two COLO checkpoints in
 #          periodic mode. (Since 2.8)
 #
+# @block-incremental: Affects how much storage is migrated when the
+# 	block migration capability is enabled.  When false, the entire
+# 	storage backing chain is migrated into a flattened image at
+# 	the destination; when true, only the active qcow2 layer is
+# 	migrated and the destination must already have access to the
+# 	same backing chain as was used on the source.  (since 2.10)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
   'data': ['compress-level', 'compress-threads', 'decompress-threads',
            'cpu-throttle-initial', 'cpu-throttle-increment',
            'tls-creds', 'tls-hostname', 'max-bandwidth',
-           'downtime-limit', 'x-checkpoint-delay' ] }
+           'downtime-limit', 'x-checkpoint-delay', 'block-incremental' ] }
 
 ##
 # @migrate-set-parameters:
@@ -1082,6 +1096,13 @@
 #
 # @x-checkpoint-delay: the delay time between two COLO checkpoints. (Since 2.8)
 #
+# @block-incremental: Affects how much storage is migrated when the
+# 	block migration capability is enabled.  When false, the entire
+# 	storage backing chain is migrated into a flattened image at
+# 	the destination; when true, only the active qcow2 layer is
+# 	migrated and the destination must already have access to the
+# 	same backing chain as was used on the source.  (since 2.10)
+#
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -1094,7 +1115,8 @@
             '*tls-hostname': 'str',
             '*max-bandwidth': 'int',
             '*downtime-limit': 'int',
-            '*x-checkpoint-delay': 'int'} }
+            '*x-checkpoint-delay': 'int',
+            '*block-incremental': 'bool' } }
 
 ##
 # @query-migrate-parameters:
-- 
2.9.3

Re: [Qemu-devel] [PATCH 2/5] migration: Create block capability

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 397 bytes --]

On 05/18/2017 06:18 AM, Juan Quintela wrote:
> Create one capability for block migration and one parameter for
> incremental block migration.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> ---
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]

Re: [Qemu-devel] [PATCH 2/5] migration: Create block capability

[Markus Armbruster]

Juan Quintela <quintela@redhat.com> writes:

> Create one capability for block migration and one parameter for
> incremental block migration.
>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
[...]
> diff --git a/include/migration/block.h b/include/migration/block.h
> index 41a1ac8..5225af9 100644
> --- a/include/migration/block.h
> +++ b/include/migration/block.h
> @@ -20,4 +20,6 @@ uint64_t blk_mig_bytes_transferred(void);
>  uint64_t blk_mig_bytes_remaining(void);
>  uint64_t blk_mig_bytes_total(void);
>  
> +void migrate_set_block_enabled(bool value, Error **errp);
> +
>  #endif /* MIGRATION_BLOCK_H */
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index 49ec501..024a048 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -153,6 +153,9 @@ struct MigrationState
>  
>      /* The last error that occurred */
>      Error *error;
> +    /* Do we have to clean up -b/-i from old migrate parameters */

The sentence is a question, so it should end with a '?'.

> +    /* This feature is deprecated and will be removed */
> +    bool must_remove_block_options;
>  };
>  
>  void migrate_set_state(int *state, int old_state, int new_state);
> @@ -265,6 +268,9 @@ bool migrate_colo_enabled(void);
>  
>  int64_t xbzrle_cache_resize(int64_t new_size);
>  
> +bool migrate_use_block(void);
> +bool migrate_use_block_incremental(void);
> +
>  bool migrate_use_compression(void);
>  int migrate_compress_level(void);
>  int migrate_compress_threads(void);
> diff --git a/migration/migration.c b/migration/migration.c
> index 0304c01..c13c0a2 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
[...]
> @@ -1207,6 +1242,24 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>          return;
>      }
>  
> +    if ((has_blk && blk) || (has_inc && inc)) {
> +        if (migrate_use_block() || migrate_use_block_incremental()) {
> +            error_setg(errp, "Command options are incompatible with "
> +                       "current migration capabilities");
> +            return;
> +        }
> +        migrate_set_block_enabled(true, &local_err);
> +        if (local_err) {
> +            error_propagate(errp, local_err);
> +            return;
> +        }
> +        s->must_remove_block_options = true;
> +    }
> +
> +    if (has_inc && inc) {
> +        migrate_set_block_incremental(s, true);
> +    }
> +

Putting this within the previous conditional might be clearer.  Your
choice.

>      s = migrate_init(&params);
>  
>      if (strstart(uri, "tcp:", &p)) {
[...]

Only nitpicks, so
Reviewed-by: Markus Armbruster <armbru@redhat.com>

[Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Juan Quintela]

We have change in the previous patch to use migration capabilities for
it.  Notice that we continue using the old command line flags from
migrate command from the time being.  Remove the set_params method as
now it is empty.

For savevm, one can't do a:

savevm -b/-i foo

but now one can do:

migrate_set_capability block on
savevm foo

And we can't use block migration. We could disable block capability
unconditionally, but it would not be much better.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

---
- Maintain shared/enabled dependency (Xu suggestion)
- Now we maintain the dependency on the setter functions
- improve error messages
---
 include/migration/migration.h |  3 +--
 migration/block.c             | 17 ++---------------
 migration/colo.c              |  4 ++--
 migration/migration.c         |  3 ---
 migration/savevm.c            |  8 ++++++--
 5 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 024a048..4dedc66 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -39,8 +39,7 @@
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
 struct MigrationParams {
-    bool blk;
-    bool shared;
+    bool unused; /* C doesn't allow empty structs */
 };
 
 /* Messages sent on the return path from destination to source */
diff --git a/migration/block.c b/migration/block.c
index 060087f..5d22926 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -94,9 +94,6 @@ typedef struct BlkMigBlock {
 } BlkMigBlock;
 
 typedef struct BlkMigState {
-    /* Written during setup phase.  Can be read without a lock.  */
-    int blk_enable;
-    int shared_base;
     QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
     int64_t total_sector_sum;
     bool zero_blocks;
@@ -425,7 +422,7 @@ static int init_blk_migration(QEMUFile *f)
         bmds->bulk_completed = 0;
         bmds->total_sectors = sectors;
         bmds->completed_sectors = 0;
-        bmds->shared_base = block_mig_state.shared_base;
+        bmds->shared_base = migrate_use_block_incremental();
 
         assert(i < num_bs);
         bmds_bs[i].bmds = bmds;
@@ -994,22 +991,12 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static void block_set_params(const MigrationParams *params, void *opaque)
-{
-    block_mig_state.blk_enable = params->blk;
-    block_mig_state.shared_base = params->shared;
-
-    /* shared base means that blk_enable = 1 */
-    block_mig_state.blk_enable |= params->shared;
-}
-
 static bool block_is_active(void *opaque)
 {
-    return block_mig_state.blk_enable == 1;
+    return migrate_use_block();
 }
 
 static SaveVMHandlers savevm_block_handlers = {
-    .set_params = block_set_params,
     .save_live_setup = block_save_setup,
     .save_live_iterate = block_save_iterate,
     .save_live_complete_precopy = block_save_complete,
diff --git a/migration/colo.c b/migration/colo.c
index 963c802..8c86892 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -14,6 +14,7 @@
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "migration/block.h"
 #include "io/channel-buffer.h"
 #include "trace.h"
 #include "qemu/error-report.h"
@@ -345,8 +346,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     }
 
     /* Disable block migration */
-    s->params.blk = 0;
-    s->params.shared = 0;
+    migrate_set_block_enabled(false, &local_err);
     qemu_savevm_state_header(fb);
     qemu_savevm_state_begin(fb, &s->params);
     qemu_mutex_lock_iothread();
diff --git a/migration/migration.c b/migration/migration.c
index c13c0a2..b3d300d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1224,9 +1224,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     MigrationParams params;
     const char *p;
 
-    params.blk = has_blk && blk;
-    params.shared = has_inc && inc;
-
     if (migration_is_setup_or_active(s->state) ||
         s->state == MIGRATION_STATUS_CANCELLING ||
         s->state == MIGRATION_STATUS_COLO) {
diff --git a/migration/savevm.c b/migration/savevm.c
index f5e8194..2f1f4eb 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
 {
     int ret;
     MigrationParams params = {
-        .blk = 0,
-        .shared = 0
     };
     MigrationState *ms = migrate_init(&params);
     MigrationStatus status;
@@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
         goto done;
     }
 
+    if (migrate_use_block()) {
+        error_setg(errp, "Block migration and snapshots are incompatible");
+        ret = -EINVAL;
+        goto done;
+    }
+
     qemu_mutex_unlock_iothread();
     qemu_savevm_state_header(f);
     qemu_savevm_state_begin(f, &params);
-- 
2.9.3

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

Juan Quintela <quintela@redhat.com> writes:

> We have change in the previous patch to use migration capabilities for
> it.  Notice that we continue using the old command line flags from
> migrate command from the time being.  Remove the set_params method as
> now it is empty.
>
> For savevm, one can't do a:
>
> savevm -b/-i foo

Yes (savem has no such options).

> but now one can do:
>
> migrate_set_capability block on
> savevm foo
>
> And we can't use block migration. We could disable block capability
> unconditionally, but it would not be much better.

This leaves me confused: what does the example do?  Reading ahead...
looks like it fails with "Block migration and snapshots are
incompatible".  What are you trying to say here?

> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Patch looks good to me.

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

Markus Armbruster <armbru@redhat.com> writes:

> Juan Quintela <quintela@redhat.com> writes:
>
>> We have change in the previous patch to use migration capabilities for
>> it.  Notice that we continue using the old command line flags from
>> migrate command from the time being.  Remove the set_params method as
>> now it is empty.
>>
>> For savevm, one can't do a:
>>
>> savevm -b/-i foo
>
> Yes (savem has no such options).
>
>> but now one can do:
>>
>> migrate_set_capability block on
>> savevm foo
>>
>> And we can't use block migration. We could disable block capability
>> unconditionally, but it would not be much better.
>
> This leaves me confused: what does the example do?  Reading ahead...
> looks like it fails with "Block migration and snapshots are
> incompatible".  What are you trying to say here?

I think I now get what you're trying to say, but only because I've
picked up enough context.  Let me try to rephrase:

  migration: Use new configuration instead of old MigrationParams

  The previous commit introduced a MigrationCapability and a
  MigrationParameter for block migration.  Use them instead of the old
  MigrationParams.

  Take care to reject attempts to combine block migration with
  snapshots, e.g. like this:

      migrate_set_capability block on
      savevm foo

>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>
> Patch looks good to me.

Preferably with a commit message I can still understand three weeks from
now:
Reviewed-by: Markus Armbruster <armbru@redhat.com>

[Qemu-devel] [PATCH 4/5] migration: Remove old MigrationParams

[Juan Quintela]

Not used anymore after moving block migration to use capabilities.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
 include/migration/migration.h | 10 ++--------
 include/migration/vmstate.h   |  1 -
 include/qemu/typedefs.h       |  1 -
 include/sysemu/sysemu.h       |  3 +--
 migration/colo.c              |  2 +-
 migration/migration.c         |  8 +++-----
 migration/savevm.c            | 16 +++-------------
 7 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 4dedc66..b80a6ed 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -38,10 +38,6 @@
 #define QEMU_VM_COMMAND              0x08
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
-struct MigrationParams {
-    bool unused; /* C doesn't allow empty structs */
-};
-
 /* Messages sent on the return path from destination to source */
 enum mig_rp_message_type {
     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
@@ -109,12 +105,10 @@ struct MigrationState
     QEMUBH *cleanup_bh;
     QEMUFile *to_dst_file;
 
-    /* New style params from 'migrate-set-parameters' */
+    /* params from 'migrate-set-parameters' */
     MigrationParameters parameters;
 
     int state;
-    /* Old style params from 'migrate' command */
-    MigrationParams params;
 
     /* State related to return path */
     struct {
@@ -207,7 +201,7 @@ void migrate_fd_connect(MigrationState *s);
 
 void add_migration_state_change_notifier(Notifier *notify);
 void remove_migration_state_change_notifier(Notifier *notify);
-MigrationState *migrate_init(const MigrationParams *params);
+MigrationState *migrate_init(void);
 bool migration_is_blocked(Error **errp);
 bool migration_in_setup(MigrationState *);
 bool migration_is_idle(void);
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 8489659..dacb052 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -37,7 +37,6 @@ typedef int LoadStateHandler(QEMUFile *f, void *opaque, int version_id);
 
 typedef struct SaveVMHandlers {
     /* This runs inside the iothread lock.  */
-    void (*set_params)(const MigrationParams *params, void * opaque);
     SaveStateHandler *save_state;
 
     void (*cleanup)(void *opaque);
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index 7d85057..33a6aa1 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -49,7 +49,6 @@ typedef struct MemoryRegion MemoryRegion;
 typedef struct MemoryRegionCache MemoryRegionCache;
 typedef struct MemoryRegionSection MemoryRegionSection;
 typedef struct MigrationIncomingState MigrationIncomingState;
-typedef struct MigrationParams MigrationParams;
 typedef struct MigrationState MigrationState;
 typedef struct Monitor Monitor;
 typedef struct MonitorDef MonitorDef;
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 83c1ceb..765358e 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -102,8 +102,7 @@ enum qemu_vm_cmd {
 #define MAX_VM_CMD_PACKAGED_SIZE (1ul << 24)
 
 bool qemu_savevm_state_blocked(Error **errp);
-void qemu_savevm_state_begin(QEMUFile *f,
-                             const MigrationParams *params);
+void qemu_savevm_state_begin(QEMUFile *f);
 void qemu_savevm_state_header(QEMUFile *f);
 int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy);
 void qemu_savevm_state_cleanup(void);
diff --git a/migration/colo.c b/migration/colo.c
index 8c86892..dd38fed 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -348,7 +348,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     /* Disable block migration */
     migrate_set_block_enabled(false, &local_err);
     qemu_savevm_state_header(fb);
-    qemu_savevm_state_begin(fb, &s->params);
+    qemu_savevm_state_begin(fb);
     qemu_mutex_lock_iothread();
     qemu_savevm_state_complete_precopy(fb, false);
     qemu_mutex_unlock_iothread();
diff --git a/migration/migration.c b/migration/migration.c
index b3d300d..ed66158 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1118,7 +1118,7 @@ bool migration_is_idle(void)
     return false;
 }
 
-MigrationState *migrate_init(const MigrationParams *params)
+MigrationState *migrate_init(void)
 {
     MigrationState *s = migrate_get_current();
 
@@ -1132,7 +1132,6 @@ MigrationState *migrate_init(const MigrationParams *params)
     s->cleanup_bh = 0;
     s->to_dst_file = NULL;
     s->state = MIGRATION_STATUS_NONE;
-    s->params = *params;
     s->rp_state.from_dst_file = NULL;
     s->rp_state.error = false;
     s->mbps = 0.0;
@@ -1221,7 +1220,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
 {
     Error *local_err = NULL;
     MigrationState *s = migrate_get_current();
-    MigrationParams params;
     const char *p;
 
     if (migration_is_setup_or_active(s->state) ||
@@ -1257,7 +1255,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
         migrate_set_block_incremental(s, true);
     }
 
-    s = migrate_init(&params);
+    s = migrate_init();
 
     if (strstart(uri, "tcp:", &p)) {
         tcp_start_outgoing_migration(s, p, &local_err);
@@ -1981,7 +1979,7 @@ static void *migration_thread(void *opaque)
         qemu_savevm_send_postcopy_advise(s->to_dst_file);
     }
 
-    qemu_savevm_state_begin(s->to_dst_file, &s->params);
+    qemu_savevm_state_begin(s->to_dst_file);
 
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
     migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
diff --git a/migration/savevm.c b/migration/savevm.c
index 2f1f4eb..a728414 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -966,21 +966,13 @@ void qemu_savevm_state_header(QEMUFile *f)
 
 }
 
-void qemu_savevm_state_begin(QEMUFile *f,
-                             const MigrationParams *params)
+void qemu_savevm_state_begin(QEMUFile *f)
 {
     SaveStateEntry *se;
     int ret;
 
     trace_savevm_state_begin();
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
-        if (!se->ops || !se->ops->set_params) {
-            continue;
-        }
-        se->ops->set_params(params, se->opaque);
-    }
-
-    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_setup) {
             continue;
         }
@@ -1232,9 +1224,7 @@ void qemu_savevm_state_cleanup(void)
 static int qemu_savevm_state(QEMUFile *f, Error **errp)
 {
     int ret;
-    MigrationParams params = {
-    };
-    MigrationState *ms = migrate_init(&params);
+    MigrationState *ms = migrate_init();
     MigrationStatus status;
     ms->to_dst_file = f;
 
@@ -1251,7 +1241,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
 
     qemu_mutex_unlock_iothread();
     qemu_savevm_state_header(f);
-    qemu_savevm_state_begin(f, &params);
+    qemu_savevm_state_begin(f);
     qemu_mutex_lock_iothread();
 
     while (qemu_file_get_error(f) == 0) {
-- 
2.9.3

[Qemu-devel] [PATCH 5/5] block migration: Allow compile time disable

[Juan Quintela]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Many users now prefer to use drive_mirror over NBD as an
alternative to the older migrate -b option; drive_mirror is
more complex to setup but gives you more options (e.g. only
migrating some of the disks if some of them are shared).

Allow the large chunk of block migration code to be compiled
out for those who don't use it.

Based on a downstream-patch we've had for a while by Jeff Cody.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

--

- When compiled out, allow seting block only with false value (eric)
---
 configure                 | 11 +++++++++++
 include/migration/block.h | 24 +++++++++++++++++++++++-
 migration/Makefile.objs   |  2 +-
 migration/migration.c     | 14 ++++++++++++++
 4 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 57b5ae6..ace1a52 100755
--- a/configure
+++ b/configure
@@ -316,6 +316,7 @@ vte=""
 virglrenderer=""
 tpm="yes"
 libssh2=""
+live_block_migration="yes"
 numa=""
 tcmalloc="no"
 jemalloc="no"
@@ -1169,6 +1170,10 @@ for opt do
   ;;
   --enable-libssh2) libssh2="yes"
   ;;
+  --disable-live-block-migration) live_block_migration="no"
+  ;;
+  --enable-live-block-migration) live_block_migration="yes"
+  ;;
   --disable-numa) numa="no"
   ;;
   --enable-numa) numa="yes"
@@ -1401,6 +1406,7 @@ disabled with --disable-FEATURE, default is enabled if available:
   libnfs          nfs support
   smartcard       smartcard support (libcacard)
   libusb          libusb (for usb passthrough)
+  live-block-migration   Block migration in the main migration stream
   usb-redir       usb network redirection support
   lzo             support of lzo compression library
   snappy          support of snappy compression library
@@ -5216,6 +5222,7 @@ echo "TPM support       $tpm"
 echo "libssh2 support   $libssh2"
 echo "TPM passthrough   $tpm_passthrough"
 echo "QOM debugging     $qom_cast_debug"
+echo "Live block migration $live_block_migration"
 echo "lzo support       $lzo"
 echo "snappy support    $snappy"
 echo "bzip2 support     $bzip2"
@@ -5782,6 +5789,10 @@ if test "$libssh2" = "yes" ; then
   echo "LIBSSH2_LIBS=$libssh2_libs" >> $config_host_mak
 fi
 
+if test "$live_block_migration" = "yes" ; then
+  echo "CONFIG_LIVE_BLOCK_MIGRATION=y" >> $config_host_mak
+fi
+
 # USB host support
 if test "$libusb" = "yes"; then
   echo "HOST_USB=libusb legacy" >> $config_host_mak
diff --git a/include/migration/block.h b/include/migration/block.h
index 5225af9..28cff53 100644
--- a/include/migration/block.h
+++ b/include/migration/block.h
@@ -14,12 +14,34 @@
 #ifndef MIGRATION_BLOCK_H
 #define MIGRATION_BLOCK_H
 
+#ifdef CONFIG_LIVE_BLOCK_MIGRATION
 void blk_mig_init(void);
 int blk_mig_active(void);
 uint64_t blk_mig_bytes_transferred(void);
 uint64_t blk_mig_bytes_remaining(void);
 uint64_t blk_mig_bytes_total(void);
 
+#else
+static inline void blk_mig_init(void) { }
+static inline int blk_mig_active(void)
+{
+    return false;
+}
+static inline uint64_t blk_mig_bytes_transferred(void)
+{
+    return 0;
+}
+
+static inline uint64_t blk_mig_bytes_remaining(void)
+{
+    return 0;
+}
+
+static inline uint64_t blk_mig_bytes_total(void)
+{
+    return 0;
+}
+#endif /* CONFIG_LIVE_BLOCK_MIGRATION */
+
 void migrate_set_block_enabled(bool value, Error **errp);
-
 #endif /* MIGRATION_BLOCK_H */
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index c1920b6..00a3f4a 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -9,5 +9,5 @@ common-obj-y += qjson.o
 
 common-obj-$(CONFIG_RDMA) += rdma.o
 
-common-obj-y += block.o
+common-obj-$(CONFIG_LIVE_BLOCK_MIGRATION) += block.o
 
diff --git a/migration/migration.c b/migration/migration.c
index ed66158..2feeee8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -547,6 +547,11 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
 
     caps = NULL; /* silence compiler warning */
     for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+#ifndef CONFIG_LIVE_BLOCK_MIGRATION
+        if (i == MIGRATION_CAPABILITY_BLOCK) {
+            continue;
+        }
+#endif
         if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) {
             continue;
         }
@@ -763,6 +768,15 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
     }
 
     for (cap = params; cap; cap = cap->next) {
+#ifndef CONFIG_LIVE_BLOCK_MIGRATION
+        if (cap->value->capability == MIGRATION_CAPABILITY_BLOCK
+            && cap->value->state) {
+            error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
+                       "block migration");
+            error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
+            continue;
+        }
+#endif
         if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) {
             if (!colo_supported()) {
                 error_setg(errp, "COLO is not currently supported, please"
-- 
2.9.3

Re: [Qemu-devel] [PATCH 5/5] block migration: Allow compile time disable

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Many users now prefer to use drive_mirror over NBD as an
> alternative to the older migrate -b option; drive_mirror is
> more complex to setup but gives you more options (e.g. only
> migrating some of the disks if some of them are shared).
> 
> Allow the large chunk of block migration code to be compiled
> out for those who don't use it.
> 
> Based on a downstream-patch we've had for a while by Jeff Cody.
> 
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
> --
> 
> - When compiled out, allow seting block only with false value (eric)
> ---
>  configure                 | 11 +++++++++++
>  include/migration/block.h | 24 +++++++++++++++++++++++-
>  migration/Makefile.objs   |  2 +-
>  migration/migration.c     | 14 ++++++++++++++
>  4 files changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/configure b/configure
> index 57b5ae6..ace1a52 100755
> --- a/configure
> +++ b/configure
> @@ -316,6 +316,7 @@ vte=""
>  virglrenderer=""
>  tpm="yes"
>  libssh2=""
> +live_block_migration="yes"
>  numa=""
>  tcmalloc="no"
>  jemalloc="no"
> @@ -1169,6 +1170,10 @@ for opt do
>    ;;
>    --enable-libssh2) libssh2="yes"
>    ;;
> +  --disable-live-block-migration) live_block_migration="no"
> +  ;;
> +  --enable-live-block-migration) live_block_migration="yes"
> +  ;;
>    --disable-numa) numa="no"
>    ;;
>    --enable-numa) numa="yes"
> @@ -1401,6 +1406,7 @@ disabled with --disable-FEATURE, default is enabled if available:
>    libnfs          nfs support
>    smartcard       smartcard support (libcacard)
>    libusb          libusb (for usb passthrough)
> +  live-block-migration   Block migration in the main migration stream
>    usb-redir       usb network redirection support
>    lzo             support of lzo compression library
>    snappy          support of snappy compression library
> @@ -5216,6 +5222,7 @@ echo "TPM support       $tpm"
>  echo "libssh2 support   $libssh2"
>  echo "TPM passthrough   $tpm_passthrough"
>  echo "QOM debugging     $qom_cast_debug"
> +echo "Live block migration $live_block_migration"
>  echo "lzo support       $lzo"
>  echo "snappy support    $snappy"
>  echo "bzip2 support     $bzip2"
> @@ -5782,6 +5789,10 @@ if test "$libssh2" = "yes" ; then
>    echo "LIBSSH2_LIBS=$libssh2_libs" >> $config_host_mak
>  fi
>  
> +if test "$live_block_migration" = "yes" ; then
> +  echo "CONFIG_LIVE_BLOCK_MIGRATION=y" >> $config_host_mak
> +fi
> +
>  # USB host support
>  if test "$libusb" = "yes"; then
>    echo "HOST_USB=libusb legacy" >> $config_host_mak
> diff --git a/include/migration/block.h b/include/migration/block.h
> index 5225af9..28cff53 100644
> --- a/include/migration/block.h
> +++ b/include/migration/block.h
> @@ -14,12 +14,34 @@
>  #ifndef MIGRATION_BLOCK_H
>  #define MIGRATION_BLOCK_H
>  
> +#ifdef CONFIG_LIVE_BLOCK_MIGRATION
>  void blk_mig_init(void);
>  int blk_mig_active(void);
>  uint64_t blk_mig_bytes_transferred(void);
>  uint64_t blk_mig_bytes_remaining(void);
>  uint64_t blk_mig_bytes_total(void);
>  
> +#else
> +static inline void blk_mig_init(void) { }
> +static inline int blk_mig_active(void)
> +{
> +    return false;
> +}
> +static inline uint64_t blk_mig_bytes_transferred(void)
> +{
> +    return 0;
> +}
> +
> +static inline uint64_t blk_mig_bytes_remaining(void)
> +{
> +    return 0;
> +}
> +
> +static inline uint64_t blk_mig_bytes_total(void)
> +{
> +    return 0;
> +}
> +#endif /* CONFIG_LIVE_BLOCK_MIGRATION */
> +
>  void migrate_set_block_enabled(bool value, Error **errp);
> -
>  #endif /* MIGRATION_BLOCK_H */
> diff --git a/migration/Makefile.objs b/migration/Makefile.objs
> index c1920b6..00a3f4a 100644
> --- a/migration/Makefile.objs
> +++ b/migration/Makefile.objs
> @@ -9,5 +9,5 @@ common-obj-y += qjson.o
>  
>  common-obj-$(CONFIG_RDMA) += rdma.o
>  
> -common-obj-y += block.o
> +common-obj-$(CONFIG_LIVE_BLOCK_MIGRATION) += block.o
>  
> diff --git a/migration/migration.c b/migration/migration.c
> index ed66158..2feeee8 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -547,6 +547,11 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
>  
>      caps = NULL; /* silence compiler warning */
>      for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
> +#ifndef CONFIG_LIVE_BLOCK_MIGRATION
> +        if (i == MIGRATION_CAPABILITY_BLOCK) {
> +            continue;
> +        }
> +#endif
>          if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) {
>              continue;
>          }
> @@ -763,6 +768,15 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
>      }
>  
>      for (cap = params; cap; cap = cap->next) {
> +#ifndef CONFIG_LIVE_BLOCK_MIGRATION
> +        if (cap->value->capability == MIGRATION_CAPABILITY_BLOCK
> +            && cap->value->state) {
> +            error_setg(errp, "QEMU compiled without old-style (blk/-b, inc/-i) "
> +                       "block migration");
> +            error_append_hint(errp, "Use drive_mirror+NBD instead.\n");
> +            continue;
> +        }
> +#endif

Yes, I think that looks OK, but you lost your S-o-b for your changes.

Dave

>          if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) {
>              if (!colo_supported()) {
>                  error_setg(errp, "COLO is not currently supported, please"
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH 5/5] block migration: Allow compile time disable

[Juan Quintela]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> 
>> Many users now prefer to use drive_mirror over NBD as an
>> alternative to the older migrate -b option; drive_mirror is
>> more complex to setup but gives you more options (e.g. only
>> migrating some of the disks if some of them are shared).
>> 
>> Allow the large chunk of block migration code to be compiled
>> out for those who don't use it.
>> 
>> Based on a downstream-patch we've had for a while by Jeff Cody.
>> 
>> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

>
> Yes, I think that looks OK, but you lost your S-o-b for your changes.

git decided that the patch is still yours.

Will add my S-o-b.  Thanks.

Later, Juan.

Re: [Qemu-devel] [PATCH 5/5] block migration: Allow compile time disable

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 810 bytes --]

On 05/18/2017 06:18 AM, Juan Quintela wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> 
> Many users now prefer to use drive_mirror over NBD as an
> alternative to the older migrate -b option; drive_mirror is
> more complex to setup but gives you more options (e.g. only
> migrating some of the disks if some of them are shared).
> 
> Allow the large chunk of block migration code to be compiled
> out for those who don't use it.
> 
> Based on a downstream-patch we've had for a while by Jeff Cody.
> 
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
> --
> 

With your S-o-b added,
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH 0/5] Remove old MigrationParams

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> Hi
> 
> Changes from v4:
> - make suggested logic change by eric
> - remove extra space in error message
> - allow migrate_set_capability block off when block migration is complied off
>   (eric request)

Hang on, is this v6? I think you've missed the '-v'

Dave

> 
> Please review
> 
> [v4]
> 
> - Address Markus review
>   * better documentation messages (thanks)
>   * reorganize error checking to have small data
>   * Use g_new0
>   * Improve commints messages
> 
> [v4]
> 
> - patch 1 included again. We have a 'block' capability and a
>   'block_incremental' parameter
>   Make Dave happy: rename shared into incremental
>   Make Eric and Markus happy:
> 
>     block: off -> no block migration, we don't care about
>                   block_incremental value
>     block: on block_incremental: off -> no incremental block migration
>     block: on block_incremental: on  -> incremental block migration
> 
> - Use visitors.
>   You ask if there is not a better way than hand coding a boolean parser.
>   QAPI people (a.k.a. Markus) answer to use a visitor.
>   Once there, I used it also for integers, not only booleans.
> 
> - Use -b/-i parameters.  OK, I bit the bullet: You can't use
>   capabilities/parameters and -b/-i: it gives you one error If you use
>   -b/-i, capability parameter is cleanup after the migration ends (Who
>   would have guessed that there are cases where we call
>   migration_fd_error(), but not migration_fd_cleanup()
>   I think this should make Peter and Markus and Dave happy.
> 
> - Integrate migrate block compile time disabling
>   Well, it conflicted left and right, so I fixed it
>   Once there, I disable setting/getting block capability if it is disabled.
> 
> [v3]
> 
> - Patch 1 included in pull request
> - disable block_shared when we disable block_enable
> - enable block_enabled when we enable block_shared
> 
> [v2]
> 
> - make migrate_block_set_* take a boolean
> - disable block migration in colo to maintain semantics.
> 
> [v1]
> Upon a time there were MigrationParms (only used for block migration)
> and then MigrationParams used for everything else.  This series:
> 
> - create migration capabilities for block parameters
> - make the migrate command line parameters to use capabilities
> - remove MigrationParams completely
> 
> 
> Dr. David Alan Gilbert (1):
>   block migration: Allow compile time disable
> 
> Juan Quintela (4):
>   hmp: Use visitor api for hmp_migrate_set_parameter()
>   migration: Create block capability
>   migration: Remove use of old MigrationParams
>   migration: Remove old MigrationParams
> 
>  configure                     | 11 +++++
>  hmp.c                         | 23 +++++++++--
>  include/migration/block.h     | 24 +++++++++++
>  include/migration/migration.h | 17 ++++----
>  include/migration/vmstate.h   |  1 -
>  include/qemu/typedefs.h       |  1 -
>  include/sysemu/sysemu.h       |  3 +-
>  migration/Makefile.objs       |  2 +-
>  migration/block.c             | 17 +-------
>  migration/colo.c              |  6 +--
>  migration/migration.c         | 96 +++++++++++++++++++++++++++++++++++++++----
>  migration/savevm.c            | 24 ++++-------
>  qapi-schema.json              | 28 +++++++++++--
>  13 files changed, 191 insertions(+), 62 deletions(-)
> 
> -- 
> 2.9.3
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH 0/5] Remove old MigrationParams

[Juan Quintela]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> Hi
>> 
>> Changes from v4:
>> - make suggested logic change by eric
>> - remove extra space in error message
>> - allow migrate_set_capability block off when block migration is complied off
>>   (eric request)
>
> Hang on, is this v6? I think you've missed the '-v'

Yeap, sorry.

The '-v': Old dog learning new tricks.

Later, Juan.

[Qemu-devel] [PATCH v5 0/5] Remove old MigrationParams

[Juan Quintela]

Hi

changes from v4:

- Address Markus review
  * better documentation messages (thanks)
  * reorganize error checking to have small data
  * Use g_new0
  * Improve commints messages

Please review.

[v4]

- patch 1 included again. We have a 'block' capability and a
  'block_incremental' parameter
  Make Dave happy: rename shared into incremental
  Make Eric and Markus happy:

    block: off -> no block migration, we don't care about
                  block_incremental value
    block: on block_incremental: off -> no incremental block migration
    block: on block_incremental: on  -> incremental block migration

- Use visitors.
  You ask if there is not a better way than hand coding a boolean parser.
  QAPI people (a.k.a. Markus) answer to use a visitor.
  Once there, I used it also for integers, not only booleans.

- Use -b/-i parameters.  OK, I bit the bullet: You can't use
  capabilities/parameters and -b/-i: it gives you one error If you use
  -b/-i, capability parameter is cleanup after the migration ends (Who
  would have guessed that there are cases where we call
  migration_fd_error(), but not migration_fd_cleanup()
  I think this should make Peter and Markus and Dave happy.

- Integrate migrate block compile time disabling
  Well, it conflicted left and right, so I fixed it
  Once there, I disable setting/getting block capability if it is disabled.

[v3]

- Patch 1 included in pull request
- disable block_shared when we disable block_enable
- enable block_enabled when we enable block_shared

[v2]

- make migrate_block_set_* take a boolean
- disable block migration in colo to maintain semantics.

[v1]
Upon a time there were MigrationParms (only used for block migration)
and then MigrationParams used for everything else.  This series:

- create migration capabilities for block parameters
- make the migrate command line parameters to use capabilities
- remove MigrationParams completely


Dr. David Alan Gilbert (1):
  block migration: Allow compile time disable

Juan Quintela (4):
  hmp: Use visitor api for hmp_migrate_set_parameter()
  migration: Create block capability
  migration: Remove use of old MigrationParams
  migration: Remove old MigrationParams

 configure                     | 11 +++++
 hmp.c                         | 23 ++++++++--
 include/migration/block.h     | 24 +++++++++++
 include/migration/migration.h | 17 ++++----
 include/migration/vmstate.h   |  1 -
 include/qemu/typedefs.h       |  1 -
 include/sysemu/sysemu.h       |  3 +-
 migration/Makefile.objs       |  2 +-
 migration/block.c             | 17 +-------
 migration/colo.c              |  6 +--
 migration/migration.c         | 97 +++++++++++++++++++++++++++++++++++++++----
 migration/savevm.c            | 24 ++++-------
 qapi-schema.json              | 28 +++++++++++--
 13 files changed, 192 insertions(+), 62 deletions(-)

-- 
2.9.3

[Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Juan Quintela]

We have change in the previous patch to use migration capabilities for
it.  Notice that we continue using the old command line flags from
migrate command from the time being.  Remove the set_params method as
now it is empty.

For savevm, one can't do a:

savevm -b/-i foo

but now one can do:

migrate_set_capability block on
savevm foo

And we can't use block migration. We could disable block capability
unconditionally, but it would not be much better.

Signed-off-by: Juan Quintela <quintela@redhat.com>

---
- Maintain shared/enabled dependency (Xu suggestion)
- Now we maintain the dependency on the setter functions
- improve error messages

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 include/migration/migration.h |  3 +--
 migration/block.c             | 17 ++---------------
 migration/colo.c              |  4 ++--
 migration/migration.c         |  3 ---
 migration/savevm.c            |  8 ++++++--
 5 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 024a048..4dedc66 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -39,8 +39,7 @@
 #define QEMU_VM_SECTION_FOOTER       0x7e
 
 struct MigrationParams {
-    bool blk;
-    bool shared;
+    bool unused; /* C doesn't allow empty structs */
 };
 
 /* Messages sent on the return path from destination to source */
diff --git a/migration/block.c b/migration/block.c
index 060087f..5d22926 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -94,9 +94,6 @@ typedef struct BlkMigBlock {
 } BlkMigBlock;
 
 typedef struct BlkMigState {
-    /* Written during setup phase.  Can be read without a lock.  */
-    int blk_enable;
-    int shared_base;
     QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
     int64_t total_sector_sum;
     bool zero_blocks;
@@ -425,7 +422,7 @@ static int init_blk_migration(QEMUFile *f)
         bmds->bulk_completed = 0;
         bmds->total_sectors = sectors;
         bmds->completed_sectors = 0;
-        bmds->shared_base = block_mig_state.shared_base;
+        bmds->shared_base = migrate_use_block_incremental();
 
         assert(i < num_bs);
         bmds_bs[i].bmds = bmds;
@@ -994,22 +991,12 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static void block_set_params(const MigrationParams *params, void *opaque)
-{
-    block_mig_state.blk_enable = params->blk;
-    block_mig_state.shared_base = params->shared;
-
-    /* shared base means that blk_enable = 1 */
-    block_mig_state.blk_enable |= params->shared;
-}
-
 static bool block_is_active(void *opaque)
 {
-    return block_mig_state.blk_enable == 1;
+    return migrate_use_block();
 }
 
 static SaveVMHandlers savevm_block_handlers = {
-    .set_params = block_set_params,
     .save_live_setup = block_save_setup,
     .save_live_iterate = block_save_iterate,
     .save_live_complete_precopy = block_save_complete,
diff --git a/migration/colo.c b/migration/colo.c
index 963c802..8c86892 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -14,6 +14,7 @@
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "migration/block.h"
 #include "io/channel-buffer.h"
 #include "trace.h"
 #include "qemu/error-report.h"
@@ -345,8 +346,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     }
 
     /* Disable block migration */
-    s->params.blk = 0;
-    s->params.shared = 0;
+    migrate_set_block_enabled(false, &local_err);
     qemu_savevm_state_header(fb);
     qemu_savevm_state_begin(fb, &s->params);
     qemu_mutex_lock_iothread();
diff --git a/migration/migration.c b/migration/migration.c
index f2bb448..f4cbfe6 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1224,9 +1224,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     MigrationParams params;
     const char *p;
 
-    params.blk = has_blk && blk;
-    params.shared = has_inc && inc;
-
     if (migration_is_setup_or_active(s->state) ||
         s->state == MIGRATION_STATUS_CANCELLING ||
         s->state == MIGRATION_STATUS_COLO) {
diff --git a/migration/savevm.c b/migration/savevm.c
index f5e8194..2f1f4eb 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
 {
     int ret;
     MigrationParams params = {
-        .blk = 0,
-        .shared = 0
     };
     MigrationState *ms = migrate_init(&params);
     MigrationStatus status;
@@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
         goto done;
     }
 
+    if (migrate_use_block()) {
+        error_setg(errp, "Block migration and snapshots are incompatible");
+        ret = -EINVAL;
+        goto done;
+    }
+
     qemu_mutex_unlock_iothread();
     qemu_savevm_state_header(f);
     qemu_savevm_state_begin(f, &params);
-- 
2.9.3

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Eric Blake]

[-- Attachment #1: Type: text/plain, Size: 1199 bytes --]

On 05/17/2017 10:38 AM, Juan Quintela wrote:
> We have change in the previous patch to use migration capabilities for
> it.  Notice that we continue using the old command line flags from
> migrate command from the time being.  Remove the set_params method as
> now it is empty.
> 
> For savevm, one can't do a:
> 
> savevm -b/-i foo
> 
> but now one can do:
> 
> migrate_set_capability block on
> savevm foo
> 
> And we can't use block migration. We could disable block capability
> unconditionally, but it would not be much better.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> ---
> - Maintain shared/enabled dependency (Xu suggestion)
> - Now we maintain the dependency on the setter functions
> - improve error messages
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>

This second S-o-b gets stripped, but the one that counts is in place
(I've made the same mistake before, as well - doing 'git commit --amend
-s' on a commit where I already had a --- separator)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Juan Quintela]

Eric Blake <eblake@redhat.com> wrote:
> On 05/17/2017 10:38 AM, Juan Quintela wrote:
>> We have change in the previous patch to use migration capabilities for
>> it.  Notice that we continue using the old command line flags from
>> migrate command from the time being.  Remove the set_params method as
>> now it is empty.
>> 
>> For savevm, one can't do a:
>> 
>> savevm -b/-i foo
>> 
>> but now one can do:
>> 
>> migrate_set_capability block on
>> savevm foo
>> 
>> And we can't use block migration. We could disable block capability
>> unconditionally, but it would not be much better.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> 
>> ---
>> - Maintain shared/enabled dependency (Xu suggestion)
>> - Now we maintain the dependency on the setter functions
>> - improve error messages
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>
> This second S-o-b gets stripped, but the one that counts is in place
> (I've made the same mistake before, as well - doing 'git commit --amend
> -s' on a commit where I already had a --- separator)

And this time I *really* remove the -s from my git-format-patch alias.
I dropped that last week on the terminal, rebooted the machine and
..... magic ... got the old alias O:-)

> Reviewed-by: Eric Blake <eblake@redhat.com>

Thanks

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

Juan Quintela <quintela@redhat.com> writes:

> We have change in the previous patch to use migration capabilities for
> it.  Notice that we continue using the old command line flags from
> migrate command from the time being.  Remove the set_params method as

for the time being

> now it is empty.
>
> For savevm, one can't do a:
>
> savevm -b/-i foo
>
> but now one can do:
>
> migrate_set_capability block on
> savevm foo
>
> And we can't use block migration. We could disable block capability
> unconditionally, but it would not be much better.

I think I get what you're trying to say, but only because I have plenty
of context right now.  Let me try to rephrase:

  migration: Use new configuration instead of old MigrationParams

  The previous commit introduced a MigrationCapability and a
  MigrationParameter for block migration.  Use them instead of the old
  MigrationParams.

  Take care to reject attempts to combine block migration with
  snapshots, e.g. like this:

      migrate_set_capability block on
      savevm foo

> Signed-off-by: Juan Quintela <quintela@redhat.com>

Preferably with a commit message I can still understand three weeks from
now:
Reviewed-by: Markus Armbruster <armbru@redhat.com>

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

I got confused and replied to an old version.  Please ignore.

Markus Armbruster <armbru@redhat.com> writes:

> Juan Quintela <quintela@redhat.com> writes:
>
>> We have change in the previous patch to use migration capabilities for
>> it.  Notice that we continue using the old command line flags from
>> migrate command from the time being.  Remove the set_params method as
>
> for the time being
>
>> now it is empty.
>>
>> For savevm, one can't do a:
>>
>> savevm -b/-i foo
>>
>> but now one can do:
>>
>> migrate_set_capability block on
>> savevm foo
>>
>> And we can't use block migration. We could disable block capability
>> unconditionally, but it would not be much better.
>
> I think I get what you're trying to say, but only because I have plenty
> of context right now.  Let me try to rephrase:
>
>   migration: Use new configuration instead of old MigrationParams
>
>   The previous commit introduced a MigrationCapability and a
>   MigrationParameter for block migration.  Use them instead of the old
>   MigrationParams.
>
>   Take care to reject attempts to combine block migration with
>   snapshots, e.g. like this:
>
>       migrate_set_capability block on
>       savevm foo
>
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>
> Preferably with a commit message I can still understand three weeks from
> now:
> Reviewed-by: Markus Armbruster <armbru@redhat.com>

[Qemu-devel] [PATCH v4 0/5] Remove old MigrationParams

[Juan Quintela]

changes from v3

- patch 1 included again. We have a 'block' capability and a
  'block_incremental' parameter
  Make Dave happy: rename shared into incremental
  Make Eric and Markus happy:

    block: off -> no block migration, we don't care about
                  block_incremental value
    block: on block_incremental: off -> no incremental block migration
    block: on block_incremental: on  -> incremental block migration

- Use visitors.
  You ask if there is not a better way than hand coding a boolean parser.
  QAPI people (a.k.a. Markus) answer to use a visitor.
  Once there, I used it also for integers, not only booleans.

- Use -b/-i parameters.  OK, I bit the bullet: You can't use
  capabilities/parameters and -b/-i: it gives you one error If you use
  -b/-i, capability parameter is cleanup after the migration ends (Who
  would have guessed that there are cases where we call
  migration_fd_error(), but not migration_fd_cleanup()
  I think this should make Peter and Markus and Dave happy.

- Integrate migrate block compile time disabling
  Well, it conflicted left and right, so I fixed it
  Once there, I disable setting/getting block capability if it is disabled.

Please review.

[v3]

- Patch 1 included in pull request
- disable block_shared when we disable block_enable
- enable block_enabled when we enable block_shared

Please, review.

[v2]

- make migrate_block_set_* take a boolean
- disable block migration in colo to maintain semantics.

[v1]
Upon a time there were MigrationParms (only used for block migration)
and then MigrationParams used for everything else.  This series:

- create migration capabilities for block parameters
- make the migrate command line parameters to use capabilities
- remove MigrationParams completely


Dr. David Alan Gilbert (1):
  block migration: Allow compile time disable

Juan Quintela (4):
  hmp: Use visitor api for hmp_migrate_set_parameter()
  migration: Create block capability
  migration: Remove use of old MigrationParams
  migration: Remove old MigrationParams

 configure                     |  11 +++++
 hmp.c                         |  23 +++++++--
 include/migration/block.h     |  24 +++++++++
 include/migration/migration.h |  18 +++----
 include/migration/vmstate.h   |   1 -
 include/qemu/typedefs.h       |   1 -
 include/sysemu/sysemu.h       |   3 +-
 migration/Makefile.objs       |   2 +-
 migration/block.c             |  17 +------
 migration/colo.c              |   6 +--
 migration/migration.c         | 112 +++++++++++++++++++++++++++++++++++++++---
 migration/savevm.c            |  24 ++++-----
 qapi-schema.json              |  14 ++++--
 13 files changed, 194 insertions(+), 62 deletions(-)

-- 
2.9.3

[Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Juan Quintela]

We have change in the previous patch to use migration capabilities for
it.  Notice that we continue using the old command line flags from
migrate command from the time being.  Remove the set_params method as
now it is empty.

Signed-off-by: Juan Quintela <quintela@redhat.com>

---
- Maintain shared/enabled dependency (Xu suggestion)
- Now we maintain the dependency on the setter functions
---
 include/migration/migration.h |  3 +--
 migration/block.c             | 17 ++---------------
 migration/colo.c              |  4 ++--
 migration/migration.c         |  3 ---
 migration/savevm.c            |  8 ++++++--
 5 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index adcb8f6..1277226 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -43,8 +43,7 @@
 extern int only_migratable;
 
 struct MigrationParams {
-    bool blk;
-    bool shared;
+    bool unused; /* C doesn't allow empty structs */
 };
 
 /* Messages sent on the return path from destination to source */
diff --git a/migration/block.c b/migration/block.c
index 060087f..5d22926 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -94,9 +94,6 @@ typedef struct BlkMigBlock {
 } BlkMigBlock;
 
 typedef struct BlkMigState {
-    /* Written during setup phase.  Can be read without a lock.  */
-    int blk_enable;
-    int shared_base;
     QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
     int64_t total_sector_sum;
     bool zero_blocks;
@@ -425,7 +422,7 @@ static int init_blk_migration(QEMUFile *f)
         bmds->bulk_completed = 0;
         bmds->total_sectors = sectors;
         bmds->completed_sectors = 0;
-        bmds->shared_base = block_mig_state.shared_base;
+        bmds->shared_base = migrate_use_block_incremental();
 
         assert(i < num_bs);
         bmds_bs[i].bmds = bmds;
@@ -994,22 +991,12 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
     return 0;
 }
 
-static void block_set_params(const MigrationParams *params, void *opaque)
-{
-    block_mig_state.blk_enable = params->blk;
-    block_mig_state.shared_base = params->shared;
-
-    /* shared base means that blk_enable = 1 */
-    block_mig_state.blk_enable |= params->shared;
-}
-
 static bool block_is_active(void *opaque)
 {
-    return block_mig_state.blk_enable == 1;
+    return migrate_use_block();
 }
 
 static SaveVMHandlers savevm_block_handlers = {
-    .set_params = block_set_params,
     .save_live_setup = block_save_setup,
     .save_live_iterate = block_save_iterate,
     .save_live_complete_precopy = block_save_complete,
diff --git a/migration/colo.c b/migration/colo.c
index 963c802..8c86892 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -14,6 +14,7 @@
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "migration/block.h"
 #include "io/channel-buffer.h"
 #include "trace.h"
 #include "qemu/error-report.h"
@@ -345,8 +346,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     }
 
     /* Disable block migration */
-    s->params.blk = 0;
-    s->params.shared = 0;
+    migrate_set_block_enabled(false, &local_err);
     qemu_savevm_state_header(fb);
     qemu_savevm_state_begin(fb, &s->params);
     qemu_mutex_lock_iothread();
diff --git a/migration/migration.c b/migration/migration.c
index 03f96df..c03f34e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1249,9 +1249,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     bool block_enabled = false;
     const char *p;
 
-    params.blk = has_blk && blk;
-    params.shared = has_inc && inc;
-
     if (migration_is_setup_or_active(s->state) ||
         s->state == MIGRATION_STATUS_CANCELLING ||
         s->state == MIGRATION_STATUS_COLO) {
diff --git a/migration/savevm.c b/migration/savevm.c
index b4f736f..5fc10ab 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
 {
     int ret;
     MigrationParams params = {
-        .blk = 0,
-        .shared = 0
     };
     MigrationState *ms = migrate_init(&params);
     MigrationStatus status;
@@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
         goto done;
     }
 
+    if (migrate_use_block()) {
+        error_setg(errp, "Block migration and snapshots are incompatible");
+        ret = -EINVAL;
+        goto done;
+    }
+
     qemu_mutex_unlock_iothread();
     qemu_savevm_state_header(f);
     qemu_savevm_state_begin(f, &params);
-- 
2.9.3

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

Juan Quintela <quintela@redhat.com> writes:

> We have change in the previous patch to use migration capabilities for
> it.  Notice that we continue using the old command line flags from
> migrate command from the time being.  Remove the set_params method as
> now it is empty.
>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
>
> ---
> - Maintain shared/enabled dependency (Xu suggestion)
> - Now we maintain the dependency on the setter functions
> ---
>  include/migration/migration.h |  3 +--
>  migration/block.c             | 17 ++---------------
>  migration/colo.c              |  4 ++--
>  migration/migration.c         |  3 ---
>  migration/savevm.c            |  8 ++++++--
>  5 files changed, 11 insertions(+), 24 deletions(-)
>
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index adcb8f6..1277226 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -43,8 +43,7 @@
>  extern int only_migratable;
>  
>  struct MigrationParams {
> -    bool blk;
> -    bool shared;
> +    bool unused; /* C doesn't allow empty structs */
>  };
>  
>  /* Messages sent on the return path from destination to source */
> diff --git a/migration/block.c b/migration/block.c
> index 060087f..5d22926 100644
> --- a/migration/block.c
> +++ b/migration/block.c
> @@ -94,9 +94,6 @@ typedef struct BlkMigBlock {
>  } BlkMigBlock;
>  
>  typedef struct BlkMigState {
> -    /* Written during setup phase.  Can be read without a lock.  */
> -    int blk_enable;
> -    int shared_base;
>      QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
>      int64_t total_sector_sum;
>      bool zero_blocks;
> @@ -425,7 +422,7 @@ static int init_blk_migration(QEMUFile *f)
>          bmds->bulk_completed = 0;
>          bmds->total_sectors = sectors;
>          bmds->completed_sectors = 0;
> -        bmds->shared_base = block_mig_state.shared_base;
> +        bmds->shared_base = migrate_use_block_incremental();
>  
>          assert(i < num_bs);
>          bmds_bs[i].bmds = bmds;
> @@ -994,22 +991,12 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
>      return 0;
>  }
>  
> -static void block_set_params(const MigrationParams *params, void *opaque)
> -{
> -    block_mig_state.blk_enable = params->blk;
> -    block_mig_state.shared_base = params->shared;
> -
> -    /* shared base means that blk_enable = 1 */
> -    block_mig_state.blk_enable |= params->shared;
> -}
> -
>  static bool block_is_active(void *opaque)
>  {
> -    return block_mig_state.blk_enable == 1;
> +    return migrate_use_block();
>  }
>  
>  static SaveVMHandlers savevm_block_handlers = {
> -    .set_params = block_set_params,
>      .save_live_setup = block_save_setup,
>      .save_live_iterate = block_save_iterate,
>      .save_live_complete_precopy = block_save_complete,
> diff --git a/migration/colo.c b/migration/colo.c
> index 963c802..8c86892 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -14,6 +14,7 @@
>  #include "qemu/timer.h"
>  #include "sysemu/sysemu.h"
>  #include "migration/colo.h"
> +#include "migration/block.h"
>  #include "io/channel-buffer.h"
>  #include "trace.h"
>  #include "qemu/error-report.h"
> @@ -345,8 +346,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
>      }
>  
>      /* Disable block migration */
> -    s->params.blk = 0;
> -    s->params.shared = 0;
> +    migrate_set_block_enabled(false, &local_err);
>      qemu_savevm_state_header(fb);
>      qemu_savevm_state_begin(fb, &s->params);
>      qemu_mutex_lock_iothread();
> diff --git a/migration/migration.c b/migration/migration.c
> index 03f96df..c03f34e 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1249,9 +1249,6 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>      bool block_enabled = false;
>      const char *p;
>  
> -    params.blk = has_blk && blk;
> -    params.shared = has_inc && inc;
> -
>      if (migration_is_setup_or_active(s->state) ||
>          s->state == MIGRATION_STATUS_CANCELLING ||
>          s->state == MIGRATION_STATUS_COLO) {
> diff --git a/migration/savevm.c b/migration/savevm.c
> index b4f736f..5fc10ab 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>  {
>      int ret;
>      MigrationParams params = {
> -        .blk = 0,
> -        .shared = 0
>      };
>      MigrationState *ms = migrate_init(&params);
>      MigrationStatus status;
> @@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>          goto done;
>      }
>  
> +    if (migrate_use_block()) {
> +        error_setg(errp, "Block migration and snapshots are incompatible");
> +        ret = -EINVAL;
> +        goto done;
> +    }
> +
>      qemu_mutex_unlock_iothread();
>      qemu_savevm_state_header(f);
>      qemu_savevm_state_begin(f, &params);

New error that isn't mentioned in the commit message.  Does it belong
here?

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Juan Quintela]

Markus Armbruster <armbru@redhat.com> wrote:
> Juan Quintela <quintela@redhat.com> writes:
>
>> We have change in the previous patch to use migration capabilities for
>> it.  Notice that we continue using the old command line flags from
>> migrate command from the time being.  Remove the set_params method as
>> now it is empty.
>>
>> Signed-off-by: Juan Quintela <quintela@redhat.com>

>> diff --git a/migration/savevm.c b/migration/savevm.c
>> index b4f736f..5fc10ab 100644
>> --- a/migration/savevm.c
>> +++ b/migration/savevm.c
>> @@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>>  {
>>      int ret;
>>      MigrationParams params = {
>> -        .blk = 0,
>> -        .shared = 0
>>      };
>>      MigrationState *ms = migrate_init(&params);
>>      MigrationStatus status;
>> @@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>>          goto done;
>>      }
>>  
>> +    if (migrate_use_block()) {
>> +        error_setg(errp, "Block migration and snapshots are incompatible");
>> +        ret = -EINVAL;
>> +        goto done;
>> +    }
>> +
>>      qemu_mutex_unlock_iothread();
>>      qemu_savevm_state_header(f);
>>      qemu_savevm_state_begin(f, &params);
>
> New error that isn't mentioned in the commit message.  Does it belong
> here?

It is the equivalent of the previous chunk.

If you do a savevm, you can't do a:

savevm -b/-i foo

but now you can do:

migrate_set_capability block on
savevm foo

And we can't use block migration.  If you preffer, I can disable the
feature unconditionally, but I am not sure that it is much better.

Later, Juan.

Re: [Qemu-devel] [PATCH 3/5] migration: Remove use of old MigrationParams

[Markus Armbruster]

Juan Quintela <quintela@redhat.com> writes:

> Markus Armbruster <armbru@redhat.com> wrote:
>> Juan Quintela <quintela@redhat.com> writes:
>>
>>> We have change in the previous patch to use migration capabilities for
>>> it.  Notice that we continue using the old command line flags from
>>> migrate command from the time being.  Remove the set_params method as
>>> now it is empty.
>>>
>>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>
>>> diff --git a/migration/savevm.c b/migration/savevm.c
>>> index b4f736f..5fc10ab 100644
>>> --- a/migration/savevm.c
>>> +++ b/migration/savevm.c
>>> @@ -1233,8 +1233,6 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>>>  {
>>>      int ret;
>>>      MigrationParams params = {
>>> -        .blk = 0,
>>> -        .shared = 0
>>>      };
>>>      MigrationState *ms = migrate_init(&params);
>>>      MigrationStatus status;
>>> @@ -1245,6 +1243,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>>>          goto done;
>>>      }
>>>  
>>> +    if (migrate_use_block()) {
>>> +        error_setg(errp, "Block migration and snapshots are incompatible");
>>> +        ret = -EINVAL;
>>> +        goto done;
>>> +    }
>>> +
>>>      qemu_mutex_unlock_iothread();
>>>      qemu_savevm_state_header(f);
>>>      qemu_savevm_state_begin(f, &params);
>>
>> New error that isn't mentioned in the commit message.  Does it belong
>> here?
>
> It is the equivalent of the previous chunk.
>
> If you do a savevm, you can't do a:
>
> savevm -b/-i foo
>
> but now you can do:
>
> migrate_set_capability block on
> savevm foo
>
> And we can't use block migration.  If you preffer, I can disable the
> feature unconditionally, but I am not sure that it is much better.

I see.

Add your explanation to the commit message, and I'm happy.