Make 'uri' optional for migrate QAPI

'uri' argument should be optional, as 'uri' and 'channels'
arguments are mutally exclusive in nature.

Fixes: 074dbce5fcce (migration: New migrate and migrate-in

Make 'uri' optional for migrate QAPI

'uri' argument should be optional, as 'uri' and 'channels'
arguments are mutally exclusive in nature.

Fixes: 074dbce5fcce (migration: New migrate and migrate-incoming argument 'channels')
Signed-off-by: Het Gala <het.gala@nutanix.com>
Link: https://lore.kernel.org/r/20240123064219.40514-1-het.gala@nutanix.com
Signed-off-by: Peter Xu <peterx@redhat.com>
(cherry picked from commit 57fd4b4e10756448acd6c90ce041ba8dc9313efc)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

show more ...

qapi/migration.json: spelling: transfering

Fixes: 074dbce5fcce "migration: New migrate and migrate-incoming argument 'channels'"
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

migration: New migrate and migrate-incoming argument 'channels'

MigrateChannelList allows to connect accross multiple interfaces.
Add MigrateChannelList struct as argument to migration QAPIs.

We pl

migration: New migrate and migrate-incoming argument 'channels'

MigrateChannelList allows to connect accross multiple interfaces.
Add MigrateChannelList struct as argument to migration QAPIs.

We plan to include multiple channels in future, to connnect
multiple interfaces. Hence, we choose 'MigrateChannelList'
as the new argument over 'MigrateChannel' to make migration
QAPIs future proof.

Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
Signed-off-by: Het Gala <het.gala@nutanix.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231023182053.8711-10-farosas@suse.de>

show more ...

migration: New QAPI type 'MigrateAddress'

This patch introduces well defined MigrateAddress struct
and its related child objects.

The existing argument of 'migrate' and 'migrate-incoming' QAPI
- 'u

migration: New QAPI type 'MigrateAddress'

This patch introduces well defined MigrateAddress struct
and its related child objects.

The existing argument of 'migrate' and 'migrate-incoming' QAPI
- 'uri' is of type string. The current implementation follows
double encoding scheme for fetching migration parameters like
'uri' and this is not an ideal design.

Motive for intoducing struct level design is to prevent double
encoding of QAPI arguments, as Qemu should be able to directly
use the QAPI arguments without any level of encoding.

Note: this commit only adds the type, and actual uses comes
in later commits.

Fabiano fixed for "file" transport.

Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
Signed-off-by: Het Gala <het.gala@nutanix.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231023182053.8711-2-farosas@suse.de>
Message-Id: <20231023182053.8711-3-farosas@suse.de>

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cpr: reboot mode

Add the cpr-reboot migration mode. Usage:

$ qemu-system-$arch -monitor stdio ...
QEMU 8.1.50 monitor - type 'help' for more information
(qemu) migrate_set_capability x-ignore-shar

cpr: reboot mode

Add the cpr-reboot migration mode. Usage:

$ qemu-system-$arch -monitor stdio ...
QEMU 8.1.50 monitor - type 'help' for more information
(qemu) migrate_set_capability x-ignore-shared on
(qemu) migrate_set_parameter mode cpr-reboot
(qemu) migrate -d file:vm.state
(qemu) info status
VM status: paused (postmigrate)
(qemu) quit

$ qemu-system-$arch -monitor stdio -incoming defer ...
QEMU 8.1.50 monitor - type 'help' for more information
(qemu) migrate_set_capability x-ignore-shared on
(qemu) migrate_set_parameter mode cpr-reboot
(qemu) migrate_incoming file:vm.state
(qemu) info status
VM status: running

In this mode, the migrate command saves state to a file, allowing one
to quit qemu, reboot to an updated kernel, and restart an updated version
of qemu. The caller must specify a migration URI that writes to and reads
from a file. Unlike normal mode, the use of certain local storage options
does not block the migration, but the caller must not modify guest block
devices between the quit and restart. To avoid saving guest RAM to the
file, the memory backend must be shared, and the @x-ignore-shared migration
capability must be set. Guest RAM must be non-volatile across reboot, such
as by backing it with a dax device, but this is not enforced. The restarted
qemu arguments must match those used to initially start qemu, plus the
-incoming option.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-6-git-send-email-steven.sistare@oracle.com>

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migration: mode parameter

Create a mode migration parameter that can be used to select alternate
migration algorithms. The default mode is normal, representing the
current migration algorithm, and

migration: mode parameter

Create a mode migration parameter that can be used to select alternate
migration algorithms. The default mode is normal, representing the
current migration algorithm, and does not need to be explicitly set.

No functional change until a new mode is added, except that the mode is
shown by the 'info migrate' command.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-2-git-send-email-steven.sistare@oracle.com>

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migration: Deprecate old compression method

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: J

migration: Deprecate old compression method

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018115513.2163-6-quintela@redhat.com>

show more ...

migration: Deprecate block migration

It is obsolete. It is better to use driver-mirror with NBD instead.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Stefan Hajnoczi <s

migration: Deprecate block migration

It is obsolete. It is better to use driver-mirror with NBD instead.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Hanna Czenczek <hreitz@redhat.com>

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018115513.2163-5-quintela@redhat.com>

show more ...

migration: migrate 'blk' command option is deprecated.

Use blocked-mirror with NBD instead.

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by:

migration: migrate 'blk' command option is deprecated.

Use blocked-mirror with NBD instead.

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018115513.2163-4-quintela@redhat.com>

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migration: migrate 'inc' command option is deprecated.

Use blockdev-mirror with NBD instead.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by:

migration: migrate 'inc' command option is deprecated.

Use blockdev-mirror with NBD instead.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231018115513.2163-3-quintela@redhat.com>

show more ...

migration: Improve json and formatting

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231013104736.31722-2-quintela@redhat.com>

migration: Allow user to specify available switchover bandwidth

Migration bandwidth is a very important value to live migration. It's
because it's one of the major factors that we'll make decision

migration: Allow user to specify available switchover bandwidth

Migration bandwidth is a very important value to live migration. It's
because it's one of the major factors that we'll make decision on when to
switchover to destination in a precopy process.

This value is currently estimated by QEMU during the whole live migration
process by monitoring how fast we were sending the data. This can be the
most accurate bandwidth if in the ideal world, where we're always feeding
unlimited data to the migration channel, and then it'll be limited to the
bandwidth that is available.

However in reality it may be very different, e.g., over a 10Gbps network we
can see query-migrate showing migration bandwidth of only a few tens of
MB/s just because there are plenty of other things the migration thread
might be doing. For example, the migration thread can be busy scanning
zero pages, or it can be fetching dirty bitmap from other external dirty
sources (like vhost or KVM). It means we may not be pushing data as much
as possible to migration channel, so the bandwidth estimated from "how many
data we sent in the channel" can be dramatically inaccurate sometimes.

With that, the decision to switchover will be affected, by assuming that we
may not be able to switchover at all with such a low bandwidth, but in
reality we can.

The migration may not even converge at all with the downtime specified,
with that wrong estimation of bandwidth, keeping iterations forever with a
low estimation of bandwidth.

The issue is QEMU itself may not be able to avoid those uncertainties on
measuing the real "available migration bandwidth". At least not something
I can think of so far.

One way to fix this is when the user is fully aware of the available
bandwidth, then we can allow the user to help providing an accurate value.

For example, if the user has a dedicated channel of 10Gbps for migration
for this specific VM, the user can specify this bandwidth so QEMU can
always do the calculation based on this fact, trusting the user as long as
specified. It may not be the exact bandwidth when switching over (in which
case qemu will push migration data as fast as possible), but much better
than QEMU trying to wildly guess, especially when very wrong.

A new parameter "avail-switchover-bandwidth" is introduced just for this.
So when the user specified this parameter, instead of trusting the
estimated value from QEMU itself (based on the QEMUFile send speed), it
trusts the user more by using this value to decide when to switchover,
assuming that we'll have such bandwidth available then.

Note that specifying this value will not throttle the bandwidth for
switchover yet, so QEMU will always use the full bandwidth possible for
sending switchover data, assuming that should always be the most important
way to use the network at that time.

This can resolve issues like "unconvergence migration" which is caused by
hilarious low "migration bandwidth" detected for whatever reason.

Reported-by: Zhiyi Guo <zhguo@redhat.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231010221922.40638-1-peterx@redhat.com>

show more ...

migration: Display error in query-migrate irrelevant of status

Display it as long as being set, irrelevant of FAILED status. E.g., it may
also be applicable to PAUSED stage of postcopy, to provide

migration: Display error in query-migrate irrelevant of status

Display it as long as being set, irrelevant of FAILED status. E.g., it may
also be applicable to PAUSED stage of postcopy, to provide hint on what has
gone wrong.

The error_mutex seems to be overlooked when referencing the error, add it
to be very safe.

This will change QAPI behavior by showing up error message outside !FAILED
status, but it's intended and doesn't expect to break anyone.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2018404
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231004220240.167175-2-peterx@redhat.com>

show more ...

migration/dirtyrate: use QEMU_CLOCK_HOST to report start-time

Currently query-dirty-rate uses QEMU_CLOCK_REALTIME as
the source for start-time field. This translates to
clock_gettime(CLOCK_MONOTONIC

migration/dirtyrate: use QEMU_CLOCK_HOST to report start-time

Currently query-dirty-rate uses QEMU_CLOCK_REALTIME as
the source for start-time field. This translates to
clock_gettime(CLOCK_MONOTONIC), i.e. number of seconds
since host boot. This is not very useful. The only
reasonable use case of start-time I can imagine is to
check whether previously completed measurements are
too old or not. But this makes sense only if start-time
is reported as host wall-clock time.

This patch replaces source of start-time from
QEMU_CLOCK_REALTIME to QEMU_CLOCK_HOST.

Signed-off-by: Andrei Gudkov <gudkov.andrei@huawei.com>
Reviewed-by: Hyman Huang <yong.huang@smartx.com>
Message-Id: <399861531e3b24a1ecea2ba453fb2c3d129fb03a.1693905328.git.gudkov.andrei@huawei.com>
Signed-off-by: Hyman Huang <yong.huang@smartx.com>

show more ...

migration/calc-dirty-rate: millisecond-granularity period

This patch allows to measure dirty page rate for
sub-second intervals of time. An optional argument is
introduced -- calc-time-unit. For exa

migration/calc-dirty-rate: millisecond-granularity period

This patch allows to measure dirty page rate for
sub-second intervals of time. An optional argument is
introduced -- calc-time-unit. For example:
{"execute": "calc-dirty-rate", "arguments":
{"calc-time": 500, "calc-time-unit": "millisecond"} }

Millisecond granularity allows to make predictions whether
migration will succeed or not. To do this, calculate dirty
rate with calc-time set to max allowed downtime (e.g. 300ms),
convert measured rate into volume of dirtied memory,
and divide by network throughput. If the value is lower
than max allowed downtime, then migration will converge.

Measurement results for single thread randomly writing to
a 1/4/24GiB memory region:

+----------------+-----------------------------------------------+
| calc-time | dirty rate MiB/s |
| (milliseconds) +----------------+---------------+--------------+
| | theoretical | page-sampling | dirty-bitmap |
| | (at 3M wr/sec) | | |
+----------------+----------------+---------------+--------------+
| 1GiB |
+----------------+----------------+---------------+--------------+
| 100 | 6996 | 7100 | 3192 |
| 200 | 4606 | 4660 | 2655 |
| 300 | 3305 | 3280 | 2371 |
| 400 | 2534 | 2525 | 2154 |
| 500 | 2041 | 2044 | 1871 |
| 750 | 1365 | 1341 | 1358 |
| 1000 | 1024 | 1052 | 1025 |
| 1500 | 683 | 678 | 684 |
| 2000 | 512 | 507 | 513 |
+----------------+----------------+---------------+--------------+
| 4GiB |
+----------------+----------------+---------------+--------------+
| 100 | 10232 | 8880 | 4070 |
| 200 | 8954 | 8049 | 3195 |
| 300 | 7889 | 7193 | 2881 |
| 400 | 6996 | 6530 | 2700 |
| 500 | 6245 | 5772 | 2312 |
| 750 | 4829 | 4586 | 2465 |
| 1000 | 3865 | 3780 | 2178 |
| 1500 | 2694 | 2633 | 2004 |
| 2000 | 2041 | 2031 | 1789 |
+----------------+----------------+---------------+--------------+
| 24GiB |
+----------------+----------------+---------------+--------------+
| 100 | 11495 | 8640 | 5597 |
| 200 | 11226 | 8616 | 3527 |
| 300 | 10965 | 8386 | 2355 |
| 400 | 10713 | 8370 | 2179 |
| 500 | 10469 | 8196 | 2098 |
| 750 | 9890 | 7885 | 2556 |
| 1000 | 9354 | 7506 | 2084 |
| 1500 | 8397 | 6944 | 2075 |
| 2000 | 7574 | 6402 | 2062 |
+----------------+----------------+---------------+--------------+

Theoretical values are computed according to the following formula:
size * (1 - (1-(4096/size))^(time*wps)) / (time * 2^20),
where size is in bytes, time is in seconds, and wps is number of
writes per second.

Signed-off-by: Andrei Gudkov <gudkov.andrei@huawei.com>
Reviewed-by: Hyman Huang <yong.huang@smartx.com>
Message-Id: <d802e6b8053eb60fbec1a784cf86f67d9528e0a8.1693895970.git.gudkov.andrei@huawei.com>
Signed-off-by: Hyman Huang <yong.huang@smartx.com>

show more ...

qapi: Craft the dirty-limit capability comment

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Message-ID: <169073570563.19893.2928364761104733482-2@git.sr.ht>
Reviewed-by: Markus Armbruster

qapi: Craft the dirty-limit capability comment

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Message-ID: <169073570563.19893.2928364761104733482-2@git.sr.ht>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Reformat the dirty-limit migration doc comments

Reformat the dirty-limit migration doc comments to conform
to current conventions as commit a937b6aa739 (qapi: Reformat
doc comments to conform

qapi: Reformat the dirty-limit migration doc comments

Reformat the dirty-limit migration doc comments to conform
to current conventions as commit a937b6aa739 (qapi: Reformat
doc comments to conform to current conventions).

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Message-ID: <169073570563.19893.2928364761104733482-1@git.sr.ht>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Whitespace tidied up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Reformat recent doc comments to conform to current conventions

Since commit a937b6aa739 (qapi: Reformat doc comments to conform to
current conventions), a number of comments not conforming to

qapi: Reformat recent doc comments to conform to current conventions

Since commit a937b6aa739 (qapi: Reformat doc comments to conform to
current conventions), a number of comments not conforming to the
current formatting conventions were added. No problem, just sweep
the entire documentation once more.

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 reflown
paragraphs are visible there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20230720071610.1096458-7-armbru@redhat.com>

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migration: skipped field is really obsolete.

Has return zero for more than 10 years.

Specifically we introduced the field in 1.5.0

commit f1c72795af573b24a7da5eb52375c9aba8a37972
Author: Peter Lie

migration: skipped field is really obsolete.

Has return zero for more than 10 years.

Specifically we introduced the field in 1.5.0

commit f1c72795af573b24a7da5eb52375c9aba8a37972
Author: Peter Lieven <pl@kamp.de>
Date: Tue Mar 26 10:58:37 2013 +0100

migration: do not sent zero pages in bulk stage

during bulk stage of ram migration if a page is a
zero page do not send it at all.
the memory at the destination reads as zero anyway.

even if there is an madvise with QEMU_MADV_DONTNEED
at the target upon receipt of a zero page I have observed
that the target starts swapping if the memory is overcommitted.
it seems that the pages are dropped asynchronously.

this patch also updates QMP to return the number of
skipped pages in MigrationStats.

but removed its usage in 1.5.3

commit 9ef051e5536b6368a1076046ec6c4ec4ac12b5c6
Author: Peter Lieven <pl@kamp.de>
Date: Mon Jun 10 12:14:19 2013 +0200

Revert "migration: do not sent zero pages in bulk stage"

Not sending zero pages breaks migration if a page is zero
at the source but not at the destination. This can e.g. happen
if different BIOS versions are used at source and destination.
It has also been reported that migration on pseries is completely
broken with this patch.

This effectively reverts commit f1c72795af573b24a7da5eb52375c9aba8a37972.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20230612193344.3796-2-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

migration: Extend query-migrate to provide dirty page limit info

Extend query-migrate to provide throttle time and estimated
ring full time with dirty-limit capability enabled, through which
we can

migration: Extend query-migrate to provide dirty page limit info

Extend query-migrate to provide throttle time and estimated
ring full time with dirty-limit capability enabled, through which
we can observe if dirty limit take effect during live migration.

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-ID: <168733225273.5845.15871826788879741674-8@git.sr.ht>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

migration: Introduce dirty-limit capability

Introduce migration dirty-limit capability, which can
be turned on before live migration and limit dirty
page rate durty live migration.

Introduce migrat

migration: Introduce dirty-limit capability

Introduce migration dirty-limit capability, which can
be turned on before live migration and limit dirty
page rate durty live migration.

Introduce migrate_dirty_limit function to help check
if dirty-limit capability enabled during live migration.

Meanwhile, refactor vcpu_dirty_rate_stat_collect
so that period can be configured instead of hardcoded.

dirty-limit capability is kind of like auto-converge
but using dirty limit instead of traditional cpu-throttle
to throttle guest down. To enable this feature, turn on
the dirty-limit capability before live migration using
migrate-set-capabilities, and set the parameters
"x-vcpu-dirty-limit-period", "vcpu-dirty-limit" suitably
to speed up convergence.

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <168618975839.6361.17407633874747688653-4@git.sr.ht>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

qapi/migration: Introduce vcpu-dirty-limit parameters

Introduce "vcpu-dirty-limit" migration parameter used
to limit dirty page rate during live migration.

"vcpu-dirty-limit" and "x-vcpu-dirty-limi

qapi/migration: Introduce vcpu-dirty-limit parameters

Introduce "vcpu-dirty-limit" migration parameter used
to limit dirty page rate during live migration.

"vcpu-dirty-limit" and "x-vcpu-dirty-limit-period" are
two dirty-limit-related migration parameters, which can
be set before and during live migration by qmp
migrate-set-parameters.

This two parameters are used to help implement the dirty
page rate limit algo of migration.

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <168618975839.6361.17407633874747688653-3@git.sr.ht>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

qapi/migration: Introduce x-vcpu-dirty-limit-period parameter

Introduce "x-vcpu-dirty-limit-period" migration experimental
parameter, which is in the range of 1 to 1000ms and used to
make dirtyrate

qapi/migration: Introduce x-vcpu-dirty-limit-period parameter

Introduce "x-vcpu-dirty-limit-period" migration experimental
parameter, which is in the range of 1 to 1000ms and used to
make dirtyrate calculation period configurable.

Currently with the "x-vcpu-dirty-limit-period" varies, the
total time of live migration changes, test results show the
optimal value of "x-vcpu-dirty-limit-period" ranges from
500ms to 1000 ms. "x-vcpu-dirty-limit-period" should be made
stable once it proves best value can not be determined with
developer's experiments.

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <168618975839.6361.17407633874747688653-2@git.sr.ht>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

migration.json: Don't use space before colon

So all the file is consistent.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230612191604.2219-1-quintela@redhat.com>
Reviewed-by: M

migration.json: Don't use space before colon

So all the file is consistent.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230612191604.2219-1-quintela@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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qapi: better docs for calc-dirty-rate and friends

Rewrote calc-dirty-rate documentation. Briefly described
different modes of dirty page rate measurement. Added some
examples. Fixed obvious grammar

qapi: better docs for calc-dirty-rate and friends

Rewrote calc-dirty-rate documentation. Briefly described
different modes of dirty page rate measurement. Added some
examples. Fixed obvious grammar errors.

Signed-off-by: Andrei Gudkov <gudkov.andrei@huawei.com>
Message-Id: <fe7d32a621ebd69ef6974beb2499c0b5dccb9e19.1684854849.git.gudkov.andrei@huawei.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
[Prose tweaked and spacing corrected, as per review]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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