diff mbox series

[v3,1/7] migration/multifd: Add new migration option zero-page-detection.

Message ID 20240226195654.934709-2-hao.xiang@bytedance.com (mailing list archive)
State New, archived
Headers show
Series Introduce multifd zero page checking. | expand

Commit Message

Hao Xiang Feb. 26, 2024, 7:56 p.m. UTC
This new parameter controls where the zero page checking is running.
1. If this parameter is set to 'legacy', zero page checking is
done in the migration main thread.
2. If this parameter is set to 'none', zero page checking is disabled.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
---
 hw/core/qdev-properties-system.c    | 10 ++++++++++
 include/hw/qdev-properties-system.h |  4 ++++
 migration/migration-hmp-cmds.c      |  9 +++++++++
 migration/options.c                 | 21 ++++++++++++++++++++
 migration/options.h                 |  1 +
 migration/ram.c                     |  4 ++++
 qapi/migration.json                 | 30 ++++++++++++++++++++++++++---
 7 files changed, 76 insertions(+), 3 deletions(-)

Comments

Markus Armbruster Feb. 28, 2024, 9:43 a.m. UTC | #1
Hao Xiang <hao.xiang@bytedance.com> writes:

> This new parameter controls where the zero page checking is running.
> 1. If this parameter is set to 'legacy', zero page checking is
> done in the migration main thread.
> 2. If this parameter is set to 'none', zero page checking is disabled.
>
> Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>

[...]

> diff --git a/qapi/migration.json b/qapi/migration.json
> index 5a565d9b8d..1e66272f8f 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -653,6 +653,18 @@
>  { 'enum': 'MigMode',
>    'data': [ 'normal', 'cpr-reboot' ] }
>  
> +##
> +# @ZeroPageDetection:
> +#
> +# @none: Do not perform zero page checking.
> +#
> +# @legacy: Perform zero page checking from main migration thread.
> +#
> +# Since: 9.0
> +##
> +{ 'enum': 'ZeroPageDetection',
> +  'data': [ 'none', 'legacy' ] }
> +
>  ##
>  # @BitmapMigrationBitmapAliasTransform:
>  #
> @@ -874,6 +886,9 @@
>  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
>  #        (Since 8.2)
>  #
> +# @zero-page-detection: Whether and how to detect zero pages. More details
> +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> +#

I'm not sure we need to point to the member's type.  If we want to, we
better fix the prose: "For additional information, see
@ZeroPageDetection" or similar.

Two spaces between sentences for consistency, please.  Also, limit line
length 70 characters.

Together:

   # @zero-page-detection: Whether and how to detect zero pages.  For
   #     additional information, see @ZeroPageDetection.  Default is
   #     'multifd'.  (since 9.0)

Same for the other two copies.

>  # Features:
>  #
>  # @deprecated: Member @block-incremental is deprecated.  Use
> @@ -907,7 +922,8 @@
>             'block-bitmap-mapping',
>             { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
>             'vcpu-dirty-limit',
> -           'mode'] }
> +           'mode',
> +           'zero-page-detection'] }
>  
>  ##
>  # @MigrateSetParameters:
> @@ -1066,6 +1082,9 @@
>  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
>  #        (Since 8.2)
>  #
> +# @zero-page-detection: Whether and how to detect zero pages. More details
> +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> +#
>  # Features:
>  #
>  # @deprecated: Member @block-incremental is deprecated.  Use
> @@ -1119,7 +1138,8 @@
>              '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
>                                              'features': [ 'unstable' ] },
>              '*vcpu-dirty-limit': 'uint64',
> -            '*mode': 'MigMode'} }
> +            '*mode': 'MigMode',
> +            '*zero-page-detection': 'ZeroPageDetection'} }
>  
>  ##
>  # @migrate-set-parameters:
> @@ -1294,6 +1314,9 @@
>  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
>  #        (Since 8.2)
>  #
> +# @zero-page-detection: Whether and how to detect zero pages. More details
> +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> +#
>  # Features:
>  #
>  # @deprecated: Member @block-incremental is deprecated.  Use
> @@ -1344,7 +1367,8 @@
>              '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
>                                              'features': [ 'unstable' ] },
>              '*vcpu-dirty-limit': 'uint64',
> -            '*mode': 'MigMode'} }
> +            '*mode': 'MigMode',
> +            '*zero-page-detection': 'ZeroPageDetection'} }
>  
>  ##
>  # @query-migrate-parameters:
Hao Xiang Feb. 28, 2024, 6:30 p.m. UTC | #2
On Wed, Feb 28, 2024 at 1:43 AM Markus Armbruster <armbru@redhat.com> wrote:
>
> Hao Xiang <hao.xiang@bytedance.com> writes:
>
> > This new parameter controls where the zero page checking is running.
> > 1. If this parameter is set to 'legacy', zero page checking is
> > done in the migration main thread.
> > 2. If this parameter is set to 'none', zero page checking is disabled.
> >
> > Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
>
> [...]
>
> > diff --git a/qapi/migration.json b/qapi/migration.json
> > index 5a565d9b8d..1e66272f8f 100644
> > --- a/qapi/migration.json
> > +++ b/qapi/migration.json
> > @@ -653,6 +653,18 @@
> >  { 'enum': 'MigMode',
> >    'data': [ 'normal', 'cpr-reboot' ] }
> >
> > +##
> > +# @ZeroPageDetection:
> > +#
> > +# @none: Do not perform zero page checking.
> > +#
> > +# @legacy: Perform zero page checking from main migration thread.
> > +#
> > +# Since: 9.0
> > +##
> > +{ 'enum': 'ZeroPageDetection',
> > +  'data': [ 'none', 'legacy' ] }
> > +
> >  ##
> >  # @BitmapMigrationBitmapAliasTransform:
> >  #
> > @@ -874,6 +886,9 @@
> >  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
> >  #        (Since 8.2)
> >  #
> > +# @zero-page-detection: Whether and how to detect zero pages. More details
> > +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> > +#
>
> I'm not sure we need to point to the member's type.  If we want to, we
> better fix the prose: "For additional information, see
> @ZeroPageDetection" or similar.

This is mimicking what was done for the "mode" migration option. There
aren't many enumeration types on the interface I can learn from.

Existing code

#
# @mode: Migration mode. See description in @MigMode. Default is 'normal'.
# (Since 8.2)

>
> Two spaces between sentences for consistency, please.  Also, limit line
> length 70 characters.
>
> Together:
>
>    # @zero-page-detection: Whether and how to detect zero pages.  For
>    #     additional information, see @ZeroPageDetection.  Default is
>    #     'multifd'.  (since 9.0)
>
> Same for the other two copies.

Will change that.

>
> >  # Features:
> >  #
> >  # @deprecated: Member @block-incremental is deprecated.  Use
> > @@ -907,7 +922,8 @@
> >             'block-bitmap-mapping',
> >             { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
> >             'vcpu-dirty-limit',
> > -           'mode'] }
> > +           'mode',
> > +           'zero-page-detection'] }
> >
> >  ##
> >  # @MigrateSetParameters:
> > @@ -1066,6 +1082,9 @@
> >  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
> >  #        (Since 8.2)
> >  #
> > +# @zero-page-detection: Whether and how to detect zero pages. More details
> > +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> > +#
> >  # Features:
> >  #
> >  # @deprecated: Member @block-incremental is deprecated.  Use
> > @@ -1119,7 +1138,8 @@
> >              '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
> >                                              'features': [ 'unstable' ] },
> >              '*vcpu-dirty-limit': 'uint64',
> > -            '*mode': 'MigMode'} }
> > +            '*mode': 'MigMode',
> > +            '*zero-page-detection': 'ZeroPageDetection'} }
> >
> >  ##
> >  # @migrate-set-parameters:
> > @@ -1294,6 +1314,9 @@
> >  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
> >  #        (Since 8.2)
> >  #
> > +# @zero-page-detection: Whether and how to detect zero pages. More details
> > +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
> > +#
> >  # Features:
> >  #
> >  # @deprecated: Member @block-incremental is deprecated.  Use
> > @@ -1344,7 +1367,8 @@
> >              '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
> >                                              'features': [ 'unstable' ] },
> >              '*vcpu-dirty-limit': 'uint64',
> > -            '*mode': 'MigMode'} }
> > +            '*mode': 'MigMode',
> > +            '*zero-page-detection': 'ZeroPageDetection'} }
> >
> >  ##
> >  # @query-migrate-parameters:
>
Markus Armbruster Feb. 29, 2024, 5:34 a.m. UTC | #3
Hao Xiang <hao.xiang@bytedance.com> writes:

> On Wed, Feb 28, 2024 at 1:43 AM Markus Armbruster <armbru@redhat.com> wrote:
>>
>> Hao Xiang <hao.xiang@bytedance.com> writes:
>>
>> > This new parameter controls where the zero page checking is running.
>> > 1. If this parameter is set to 'legacy', zero page checking is
>> > done in the migration main thread.
>> > 2. If this parameter is set to 'none', zero page checking is disabled.
>> >
>> > Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
>>
>> [...]
>>
>> > diff --git a/qapi/migration.json b/qapi/migration.json
>> > index 5a565d9b8d..1e66272f8f 100644
>> > --- a/qapi/migration.json
>> > +++ b/qapi/migration.json
>> > @@ -653,6 +653,18 @@
>> >  { 'enum': 'MigMode',
>> >    'data': [ 'normal', 'cpr-reboot' ] }
>> >
>> > +##
>> > +# @ZeroPageDetection:
>> > +#
>> > +# @none: Do not perform zero page checking.
>> > +#
>> > +# @legacy: Perform zero page checking from main migration thread.
>> > +#
>> > +# Since: 9.0
>> > +##
>> > +{ 'enum': 'ZeroPageDetection',
>> > +  'data': [ 'none', 'legacy' ] }
>> > +
>> >  ##
>> >  # @BitmapMigrationBitmapAliasTransform:
>> >  #
>> > @@ -874,6 +886,9 @@
>> >  # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
>> >  #        (Since 8.2)
>> >  #
>> > +# @zero-page-detection: Whether and how to detect zero pages. More details
>> > +#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
>> > +#
>>
>> I'm not sure we need to point to the member's type.  If we want to, we
>> better fix the prose: "For additional information, see
>> @ZeroPageDetection" or similar.
>
> This is mimicking what was done for the "mode" migration option. There
> aren't many enumeration types on the interface I can learn from.
>
> Existing code
>
> #
> # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
> # (Since 8.2)

"More details see description in @TYPE" feels off, "See description in
@TYPE" is better.  Feel free to use it instead of my suggested phrasing.

[...]
diff mbox series

Patch

diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index 1a396521d5..228e685f52 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -679,6 +679,16 @@  const PropertyInfo qdev_prop_mig_mode = {
     .set_default_value = qdev_propinfo_set_default_value_enum,
 };
 
+const PropertyInfo qdev_prop_zero_page_detection = {
+    .name = "ZeroPageDetection",
+    .description = "zero_page_detection values, "
+                   "none,legacy",
+    .enum_table = &ZeroPageDetection_lookup,
+    .get = qdev_propinfo_get_enum,
+    .set = qdev_propinfo_set_enum,
+    .set_default_value = qdev_propinfo_set_default_value_enum,
+};
+
 /* --- Reserved Region --- */
 
 /*
diff --git a/include/hw/qdev-properties-system.h b/include/hw/qdev-properties-system.h
index 06c359c190..839b170235 100644
--- a/include/hw/qdev-properties-system.h
+++ b/include/hw/qdev-properties-system.h
@@ -8,6 +8,7 @@  extern const PropertyInfo qdev_prop_macaddr;
 extern const PropertyInfo qdev_prop_reserved_region;
 extern const PropertyInfo qdev_prop_multifd_compression;
 extern const PropertyInfo qdev_prop_mig_mode;
+extern const PropertyInfo qdev_prop_zero_page_detection;
 extern const PropertyInfo qdev_prop_losttickpolicy;
 extern const PropertyInfo qdev_prop_blockdev_on_error;
 extern const PropertyInfo qdev_prop_bios_chs_trans;
@@ -47,6 +48,9 @@  extern const PropertyInfo qdev_prop_iothread_vq_mapping_list;
 #define DEFINE_PROP_MIG_MODE(_n, _s, _f, _d) \
     DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_mig_mode, \
                        MigMode)
+#define DEFINE_PROP_ZERO_PAGE_DETECTION(_n, _s, _f, _d) \
+    DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_zero_page_detection, \
+                       ZeroPageDetection)
 #define DEFINE_PROP_LOSTTICKPOLICY(_n, _s, _f, _d) \
     DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_losttickpolicy, \
                         LostTickPolicy)
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 99b49df5dd..7e96ae6ffd 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -344,6 +344,11 @@  void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "%s: %s\n",
             MigrationParameter_str(MIGRATION_PARAMETER_MULTIFD_COMPRESSION),
             MultiFDCompression_str(params->multifd_compression));
+        assert(params->has_zero_page_detection);
+        monitor_printf(mon, "%s: %s\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_ZERO_PAGE_DETECTION),
+            qapi_enum_lookup(&ZeroPageDetection_lookup,
+                params->zero_page_detection));
         monitor_printf(mon, "%s: %" PRIu64 " bytes\n",
             MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
             params->xbzrle_cache_size);
@@ -634,6 +639,10 @@  void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         p->has_multifd_zstd_level = true;
         visit_type_uint8(v, param, &p->multifd_zstd_level, &err);
         break;
+    case MIGRATION_PARAMETER_ZERO_PAGE_DETECTION:
+        p->has_zero_page_detection = true;
+        visit_type_ZeroPageDetection(v, param, &p->zero_page_detection, &err);
+        break;
     case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
         p->has_xbzrle_cache_size = true;
         if (!visit_type_size(v, param, &cache_size, &err)) {
diff --git a/migration/options.c b/migration/options.c
index 3e3e0b93b4..3c603391b0 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -179,6 +179,9 @@  Property migration_properties[] = {
     DEFINE_PROP_MIG_MODE("mode", MigrationState,
                       parameters.mode,
                       MIG_MODE_NORMAL),
+    DEFINE_PROP_ZERO_PAGE_DETECTION("zero-page-detection", MigrationState,
+                       parameters.zero_page_detection,
+                       ZERO_PAGE_DETECTION_LEGACY),
 
     /* Migration capabilities */
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -903,6 +906,13 @@  uint64_t migrate_xbzrle_cache_size(void)
     return s->parameters.xbzrle_cache_size;
 }
 
+ZeroPageDetection migrate_zero_page_detection(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return s->parameters.zero_page_detection;
+}
+
 /* parameter setters */
 
 void migrate_set_block_incremental(bool value)
@@ -1013,6 +1023,8 @@  MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->vcpu_dirty_limit = s->parameters.vcpu_dirty_limit;
     params->has_mode = true;
     params->mode = s->parameters.mode;
+    params->has_zero_page_detection = true;
+    params->zero_page_detection = s->parameters.zero_page_detection;
 
     return params;
 }
@@ -1049,6 +1061,7 @@  void migrate_params_init(MigrationParameters *params)
     params->has_x_vcpu_dirty_limit_period = true;
     params->has_vcpu_dirty_limit = true;
     params->has_mode = true;
+    params->has_zero_page_detection = true;
 }
 
 /*
@@ -1350,6 +1363,10 @@  static void migrate_params_test_apply(MigrateSetParameters *params,
     if (params->has_mode) {
         dest->mode = params->mode;
     }
+
+    if (params->has_zero_page_detection) {
+        dest->zero_page_detection = params->zero_page_detection;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1494,6 +1511,10 @@  static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
     if (params->has_mode) {
         s->parameters.mode = params->mode;
     }
+
+    if (params->has_zero_page_detection) {
+        s->parameters.zero_page_detection = params->zero_page_detection;
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
diff --git a/migration/options.h b/migration/options.h
index 246c160aee..b7c4fb3861 100644
--- a/migration/options.h
+++ b/migration/options.h
@@ -93,6 +93,7 @@  const char *migrate_tls_authz(void);
 const char *migrate_tls_creds(void);
 const char *migrate_tls_hostname(void);
 uint64_t migrate_xbzrle_cache_size(void);
+ZeroPageDetection migrate_zero_page_detection(void);
 
 /* parameters setters */
 
diff --git a/migration/ram.c b/migration/ram.c
index 4649a81204..67035fb4b1 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1123,6 +1123,10 @@  static int save_zero_page(RAMState *rs, PageSearchStatus *pss,
     QEMUFile *file = pss->pss_channel;
     int len = 0;
 
+    if (migrate_zero_page_detection() == ZERO_PAGE_DETECTION_NONE) {
+        return 0;
+    }
+
     if (!buffer_is_zero(p, TARGET_PAGE_SIZE)) {
         return 0;
     }
diff --git a/qapi/migration.json b/qapi/migration.json
index 5a565d9b8d..1e66272f8f 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -653,6 +653,18 @@ 
 { 'enum': 'MigMode',
   'data': [ 'normal', 'cpr-reboot' ] }
 
+##
+# @ZeroPageDetection:
+#
+# @none: Do not perform zero page checking.
+#
+# @legacy: Perform zero page checking from main migration thread.
+#
+# Since: 9.0
+##
+{ 'enum': 'ZeroPageDetection',
+  'data': [ 'none', 'legacy' ] }
+
 ##
 # @BitmapMigrationBitmapAliasTransform:
 #
@@ -874,6 +886,9 @@ 
 # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
 #        (Since 8.2)
 #
+# @zero-page-detection: Whether and how to detect zero pages. More details
+#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
+#
 # Features:
 #
 # @deprecated: Member @block-incremental is deprecated.  Use
@@ -907,7 +922,8 @@ 
            'block-bitmap-mapping',
            { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
            'vcpu-dirty-limit',
-           'mode'] }
+           'mode',
+           'zero-page-detection'] }
 
 ##
 # @MigrateSetParameters:
@@ -1066,6 +1082,9 @@ 
 # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
 #        (Since 8.2)
 #
+# @zero-page-detection: Whether and how to detect zero pages. More details
+#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
+#
 # Features:
 #
 # @deprecated: Member @block-incremental is deprecated.  Use
@@ -1119,7 +1138,8 @@ 
             '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
                                             'features': [ 'unstable' ] },
             '*vcpu-dirty-limit': 'uint64',
-            '*mode': 'MigMode'} }
+            '*mode': 'MigMode',
+            '*zero-page-detection': 'ZeroPageDetection'} }
 
 ##
 # @migrate-set-parameters:
@@ -1294,6 +1314,9 @@ 
 # @mode: Migration mode. See description in @MigMode. Default is 'normal'.
 #        (Since 8.2)
 #
+# @zero-page-detection: Whether and how to detect zero pages. More details
+#     see description in @ZeroPageDetection. Default is 'legacy'.  (since 9.0)
+#
 # Features:
 #
 # @deprecated: Member @block-incremental is deprecated.  Use
@@ -1344,7 +1367,8 @@ 
             '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
                                             'features': [ 'unstable' ] },
             '*vcpu-dirty-limit': 'uint64',
-            '*mode': 'MigMode'} }
+            '*mode': 'MigMode',
+            '*zero-page-detection': 'ZeroPageDetection'} }
 
 ##
 # @query-migrate-parameters: