@@ -966,16 +966,26 @@
# @announce-step: Increase in delay (in milliseconds) between
# subsequent packets in the announcement (Since 4.0)
#
-# @compress-level: compression level
+# @compress-level: Set the compression level to be used in live
+# migration, the compression level is an integer between 0 and 9,
+# where 0 means no compression, 1 means the best compression
+# speed, and 9 means best compression ratio which will consume
+# more CPU.
#
-# @compress-threads: compression thread count
+# @compress-threads: Set compression thread count to be used in live
+# migration, the compression thread count is an integer between 1
+# and 255.
#
# @compress-wait-thread: Controls behavior when all compression
# threads are currently busy. If true (default), wait for a free
# compression thread to become available; otherwise, send the page
# uncompressed. (Since 3.1)
#
-# @decompress-threads: decompression thread count
+# @decompress-threads: Set decompression thread count to be used in
+# live migration, the decompression thread count is an integer
+# between 1 and 255. Usually, decompression is at least 4 times as
+# fast as compression, so set the decompress-threads to the number
+# about 1/4 of compress-threads is adequate.
#
# @throttle-trigger-threshold: The ratio of bytes_dirty_period and
# bytes_xfer_period to trigger throttling. It is expressed as
@@ -1042,8 +1052,8 @@
# @downtime-limit: set maximum tolerated downtime for migration.
# maximum downtime in milliseconds (Since 2.8)
#
-# @x-checkpoint-delay: the delay time between two COLO checkpoints.
-# (Since 2.8)
+# @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
@@ -1064,8 +1074,8 @@
# postcopy. Defaults to 0 (unlimited). In bytes per second.
# (Since 3.0)
#
-# @max-cpu-throttle: maximum cpu throttle percentage. The default
-# value is 99. (Since 3.1)
+# @max-cpu-throttle: maximum cpu throttle percentage. Defaults to 99.
+# (Since 3.1)
#
# @multifd-compression: Which compression method to use. Defaults to
# none. (Since 5.0)
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> --- qapi/migration.json | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)