For legibility, wrap text paragraphs so every line is at most 70
characters long.
To check the generated documentation does not change, I compared the
generated HTML before and after this commit with "wdiff -3". Finds no
differences. Comparing with diff is not useful, as the refilled
paragraphs are visible there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240322140910.328840-11-armbru@redhat.com>
The doc comment documents an argument that doesn't exist. Would
fail compilation if it was marked up correctly. Delete.
The Returns: section fails to refer to the data type, leaving the user
to guess. Fix that.
The command name violates QAPI naming rules: it should be
query-migration-threads. Too late to fix.
Reported-by: John Snow <jsnow@redhat.com>
Fixes: 671326201d (migration: Introduce interface query-migrationthreads)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240322135117.195489-4-armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Enum MigrationParameter mirrors the members of struct
MigrateSetParameters. Differences to MigrateSetParameters's member
documentation are pointless. Clean them up:
* @compress-level, @compress-threads, @decompress-threads, and
x-checkpoint-delay are more thoroughly documented for
MigrationParameter, so use that version for both.
* @max-cpu-throttle is almost the same. Use MigrationParameter's
version for both.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240322135117.195489-3-armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
MigrateSetParameters is about setting parameters, and
MigrationParameters is about querying them. Their documentation of
@tls-creds and @tls-hostname has residual damage from a failed attempt
at de-duplicating them (see commit de63ab6124 "migrate: Share common
MigrationParameters struct" and commit 1bda8b3c69 "migration: Unshare
MigrationParameters struct for now").
MigrateSetParameters documentation issues:
* It claims plain text mode "was reported by omitting tls-creds"
before 2.9. MigrateSetParameters is not used for reporting, so this
is misleading. Delete.
* It similarly claims hostname defaulting to migration URI "was
reported by omitting tls-hostname" before 2.9. Delete as well.
Rephrase the remaining @tls-hostname contents for clarity.
Enum MigrationParameter mirrors the members of struct
MigrateSetParameters. Differences to MigrateSetParameters's member
documentation are pointless. Copy the new text to MigrationParameter.
MigrationParameters documentation issues:
* @tls-creds runs the two last sentences together without punctuation.
Fix that.
* Much of the contents on @tls-hostname only applies to setting
parameters, resulting in confusion. Replace by a suitable abridged
version of the new MigrateSetParameters text, and a note on
@tls-hostname omission in 2.8.
Additional damage is due to flawed doc fix commit
66fcb9d651 (qapi/migration: Add missing tls-authz documentation):
since it copied the missing MigrateSetParameters text from
MigrationParameters instead of MigrationParameter, the part on
recreating @tls-authz on the fly is missing. Copy that, too.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240322135117.195489-2-armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
[Some typos corrected]
1. Set default "zero-page-detection" option to "multifd". Now
zero page checking can be done in the multifd threads and this
becomes the default configuration.
2. Handle migration QEMU9.0 -> QEMU8.2 compatibility. We provide
backward compatibility where zero page checking is done from the
migration main thread.
Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240311180015.3359271-7-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
1. Add zero_pages field in MultiFDPacket_t.
2. Implements the zero page detection and handling on the multifd
threads for non-compression, zlib and zstd compression backends.
3. Added a new value 'multifd' in ZeroPageDetection enumeration.
4. Adds zero page counters and updates multifd send/receive tracing
format to track the newly added counters.
Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240311180015.3359271-5-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
Add a new migration capability 'mapped-ram'.
The core of the feature is to ensure that RAM pages are mapped
directly to offsets in the resulting migration file instead of being
streamed at arbitrary points.
The reasons why we'd want such behavior are:
- The resulting file will have a bounded size, since pages which are
dirtied multiple times will always go to a fixed location in the
file, rather than constantly being added to a sequential
stream. This eliminates cases where a VM with, say, 1G of RAM can
result in a migration file that's 10s of GBs, provided that the
workload constantly redirties memory.
- It paves the way to implement O_DIRECT-enabled save/restore of the
migration stream as the pages are ensured to be written at aligned
offsets.
- It allows the usage of multifd so we can write RAM pages to the
migration file in parallel.
For now, enabling the capability has no effect. The next couple of
patches implement the core functionality.
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-8-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
By convention, we indent the second and subsequent lines of
descriptions and tagged sections, except for examples.
Turn this into a hard rule, and apply it to examples, too.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240216145841.2099240-11-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[Straightforward conflicts in qapi/migration.json resolved]
docs/devel/qapi-code-gen demands that the "second and subsequent lines
of sections other than "Example"/"Examples" should be indented".
Commit a937b6aa739q (qapi: Reformat doc comments to conform to current
conventions) missed a few instances, and messed up a few others.
Clean that up.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240205074709.3613229-5-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
"Since X.Y" is not recognized as a tagged section, and therefore not
formatted as such in generated documentation. Fix by adding the
required colon.
Previously fixed in commit 433a4fdc42 (qapi: Fix malformed "Since:"
section tags)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240120095327.666239-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Markus Armbruster
Hao XiangandPeter Xu
Peter Maydell
Fabiano RosasandPeter Xu
Steve SistareandPeter Xu
Het GalaandMarkus Armbruster
Han HanandMichael Tokarev