From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Markus Armbruster <armbru@redhat.com>
Cc: peter.maydell@linaro.org, qemu-devel@nongnu.org,
peterx@redhat.com, dgilbert@redhat.com
Subject: Re: [PATCH v2] migration: Drop redundant query-migrate result @blocked
Date: Tue, 20 Apr 2021 09:35:23 +0100 [thread overview]
Message-ID: <YH6SS7gm3Ic6T49h@redhat.com> (raw)
In-Reply-To: <20210420051907.891470-2-armbru@redhat.com>
On Tue, Apr 20, 2021 at 07:19:07AM +0200, Markus Armbruster wrote:
> Result @blocked is true when and only when result @blocked-reasons is
> present. It's always non-empty when present. @blocked is redundant.
> It was introduced in commit 3af8554bd0 "migration: Add blocker
> information", and has not been released. This gives us a chance to
> fix the interface with minimal fuss: drop @blocked.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
> This is alternative to "[PATCH] migration: Deprecate redundant
> query-migrate result @blocked".
>
> qapi/migration.json | 7 +++----
> migration/migration.c | 29 +++++++++++++----------------
> monitor/hmp-cmds.c | 2 +-
> 3 files changed, 17 insertions(+), 21 deletions(-)
>
> diff --git a/qapi/migration.json b/qapi/migration.json
> index 9bf0bc4d25..7a5bdf9a0d 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -224,9 +224,9 @@
> # only returned if VFIO device is present, migration is supported by all
> # VFIO devices and status is 'active' or 'completed' (since 5.2)
> #
> -# @blocked: True if outgoing migration is blocked (since 6.0)
> -#
> -# @blocked-reasons: A list of reasons an outgoing migration is blocked (since 6.0)
> +# @blocked-reasons: A list of reasons an outgoing migration is blocked.
> +# Present and non-empty when migration is blocked.
> +# (since 6.0)
> #
> # Since: 0.14
> ##
> @@ -241,7 +241,6 @@
> '*setup-time': 'int',
> '*cpu-throttle-percentage': 'int',
> '*error-desc': 'str',
> - 'blocked': 'bool',
> '*blocked-reasons': ['str'],
> '*postcopy-blocktime' : 'uint32',
> '*postcopy-vcpu-blocktime': ['uint32'],
> diff --git a/migration/migration.c b/migration/migration.c
> index 8ca034136b..fdadee290e 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1073,27 +1073,24 @@ static void populate_vfio_info(MigrationInfo *info)
> static void fill_source_migration_info(MigrationInfo *info)
> {
> MigrationState *s = migrate_get_current();
> + GSList *cur_blocker = migration_blockers;
>
> - info->blocked = migration_is_blocked(NULL);
So migration_is_blocked() method returns true if either of the
following conditions is met
- qemu_savevm_state_blocked returns true - this happens
if a savevm state handler has 'unmigratable' flag set
- if any migration blockers are registered.
We're then calling qemu_savevm_non_migratable_list to populate
blocked_reasons based on "unmigratable" flag, and then further
populate blocked_reasons based on migration blockers.
So I agree it is functionally the same result old and new code.
> - info->has_blocked_reasons = info->blocked;
> info->blocked_reasons = NULL;
> - if (info->blocked) {
> - GSList *cur_blocker = migration_blockers;
>
> - /*
> - * There are two types of reasons a migration might be blocked;
> - * a) devices marked in VMState as non-migratable, and
> - * b) Explicit migration blockers
> - * We need to add both of them here.
> - */
> - qemu_savevm_non_migratable_list(&info->blocked_reasons);
> + /*
> + * There are two types of reasons a migration might be blocked;
> + * a) devices marked in VMState as non-migratable, and
> + * b) Explicit migration blockers
> + * We need to add both of them here.
> + */
> + qemu_savevm_non_migratable_list(&info->blocked_reasons);
>
> - while (cur_blocker) {
> - QAPI_LIST_PREPEND(info->blocked_reasons,
> - g_strdup(error_get_pretty(cur_blocker->data)));
> - cur_blocker = g_slist_next(cur_blocker);
> - }
> + while (cur_blocker) {
> + QAPI_LIST_PREPEND(info->blocked_reasons,
> + g_strdup(error_get_pretty(cur_blocker->data)));
> + cur_blocker = g_slist_next(cur_blocker);
> }
> + info->has_blocked_reasons = info->blocked_reasons != NULL;
>
> switch (s->state) {
> case MIGRATION_STATUS_NONE:
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Regards,
Daniel
--
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prev parent reply other threads:[~2021-04-20 8:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-20 5:19 [PATCH v2] migration: Drop redundant query-migrate result @blocked Markus Armbruster
2021-04-20 8:35 ` Daniel P. Berrangé [this message]
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