Commit Graph

1715 Commits

Author SHA1 Message Date
Paolo Bonzini
4592eaf387 postcopy-ram: do not use qatomic_mb_read
It does not even pair with a qatomic_mb_set(), so it is clearer to use
load-acquire in this case; they are synonyms.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-04-20 11:17:35 +02:00
Paolo Bonzini
394b9407e4 migration: mark mixed functions that can suspend
There should be no paths from a coroutine_fn to aio_poll, however in
practice coroutine_mixed_fn will call aio_poll in the !qemu_in_coroutine()
path.  By marking mixed functions, we can track accurately the call paths
that execute entirely in coroutine context, and find more missing
coroutine_fn markers.  This results in more accurate checks that
coroutine code does not end up blocking.

If the marking were extended transitively to all functions that call
these ones, static analysis could be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-04-20 11:17:35 +02:00
Juan Quintela
28ef5339c3 migration: fix ram_state_pending_exact()
I removed that bit on commit:

commit c8df4a7aef
Author: Juan Quintela <quintela@redhat.com>
Date:   Mon Oct 3 02:00:03 2022 +0200

    migration: Split save_live_pending() into state_pending_*

Fixes: c8df4a7aef
Suggested-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-12 22:47:50 +02:00
Lukas Straub
37502df32c migration/ram.c: Fix migration with compress enabled
Since ec6f3ab9, migration with compress enabled was broken, because
the compress threads use a dummy QEMUFile which just acts as a
buffer and that commit accidentally changed it to use the outgoing
migration channel instead.

Fix this by using the dummy file again in the compress threads.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-12 21:51:34 +02:00
Peter Xu
06064a6715 migration: Recover behavior of preempt channel creation for pre-7.2
In 8.0 devel window we reworked preempt channel creation, so that there'll
be no race condition when the migration channel and preempt channel got
established in the wrong order in commit 5655aab079.

However no one noticed that the change will also be not compatible with
older qemus, majorly 7.1/7.2 versions where preempt mode started to be
supported.

Leverage the same pre-7.2 flag introduced in the previous patch to recover
the behavior hopefully before 8.0 releases, so we don't break migration
when we migrate from 8.0 to older qemu binaries.

Fixes: 5655aab079 ("migration: Postpone postcopy preempt channel to be after main")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-12 21:44:56 +02:00
Peter Xu
6621883f93 migration: Fix potential race on postcopy_qemufile_src
postcopy_qemufile_src object should be owned by one thread, either the main
thread (e.g. when at the beginning, or at the end of migration), or by the
return path thread (when during a preempt enabled postcopy migration).  If
that's not the case the access to the object might be racy.

postcopy_preempt_shutdown_file() can be potentially racy, because it's
called at the end phase of migration on the main thread, however during
which the return path thread hasn't yet been recycled; the recycle happens
in await_return_path_close_on_source() which is after this point.

It means, logically it's posslbe the main thread and the return path thread
are both operating on the same qemufile.  While I don't think qemufile is
thread safe at all.

postcopy_preempt_shutdown_file() used to be needed because that's where we
send EOS to dest so that dest can safely shutdown the preempt thread.

To avoid the possible race, remove this only place that a race can happen.
Instead we figure out another way to safely close the preempt thread on
dest.

The core idea during postcopy on deciding "when to stop" is that dest will
send a postcopy SHUT message to src, telling src that all data is there.
Hence to shut the dest preempt thread maybe better to do it directly on
dest node.

This patch proposed such a way that we change postcopy_prio_thread_created
into PreemptThreadStatus, so that we kick the preempt thread on dest qemu
by a sequence of:

  mis->preempt_thread_status = PREEMPT_THREAD_QUIT;
  qemu_file_shutdown(mis->postcopy_qemufile_dst);

While here shutdown() is probably so far the easiest way to kick preempt
thread from a blocked qemu_get_be64().  Then it reads preempt_thread_status
to make sure it's not a network failure but a willingness to quit the
thread.

We could have avoided that extra status but just rely on migration status.
The problem is postcopy_ram_incoming_cleanup() is just called early enough
so we're still during POSTCOPY_ACTIVE no matter what.. So just make it
simple to have the status introduced.

One flag x-preempt-pre-7-2 is added to keep old pre-7.2 behaviors of
postcopy preempt.

Fixes: 9358982744 ("migration: Send requested page directly in rp-return thread")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-12 21:44:38 +02:00
Paolo Bonzini
2c5451ca52 migration/block: replace uses of blk_nb_sectors that do not check result
Uses of blk_nb_sectors must check whether the result is negative.
Otherwise, underflow can happen.  Fortunately, alloc_aio_bitmap()
and bmds_aio_inflight() both have an alternative way to retrieve the
number of sectors in the file.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20230407153303.391121-6-pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-11 16:40:53 +02:00
Richard Henderson
cc37d98bfb *: Add missing includes of qemu/error-report.h
This had been pulled in via qemu/plugin.h from hw/core/cpu.h,
but that will be removed.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230310195252.210956-5-richard.henderson@linaro.org>
[AJB: add various additional cases shown by CI]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230315174331.2959-15-alex.bennee@linaro.org>
Reviewed-by: Emilio Cota <cota@braap.org>
2023-03-22 15:06:57 +00:00
Steve Sistare
fa76c854ae migration: fix populate_vfio_info
Include CONFIG_DEVICES so that populate_vfio_info is instantiated for
CONFIG_VFIO.  Without it, the 'info migrate' command never returns
info about vfio.

Fixes: 43bd0bf30f ("migration: Move populate_vfio_info() into a separate file")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Wei Wang
ff1585d1d8 migration/multifd: correct multifd_send_thread to trace the flags
The p->flags could be updated via the send_prepare callback, e.g. OR-ed
with MULTIFD_FLAG_ZLIB via zlib_send_prepare. Assign p->flags to the
local "flags" before the send_prepare callback could only get partial of
p->flags. Fix it by moving the assignment of p->flags to the local flags
after the callback, so that the correct flags can be traced.

Fixes: ab7cbb0b9a ("multifd: Make no compression operations into its own structure")
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Li Zhijian
bf0274192a migration/rdma: Remove deprecated variable rdma_return_path
It's no longer needed since commit
44bcfd45e9 ("migration/rdma: destination: create the return patch after the first accept")

Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Matheus Tavares Bernardino
1776b70f55 migration/xbzrle: fix out-of-bounds write with axv512
xbzrle_encode_buffer_avx512() checks for overflows too scarcely in its
outer loop, causing out-of-bounds writes:

$ ../configure --target-list=aarch64-softmmu --enable-sanitizers --enable-avx512bw
$ make tests/unit/test-xbzrle && ./tests/unit/test-xbzrle

==5518==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x62100000b100 at pc 0x561109a7714d bp 0x7ffed712a440 sp 0x7ffed712a430
WRITE of size 1 at 0x62100000b100 thread T0
    #0 0x561109a7714c in uleb128_encode_small ../util/cutils.c:831
    #1 0x561109b67f6a in xbzrle_encode_buffer_avx512 ../migration/xbzrle.c:275
    #2 0x5611099a7428 in test_encode_decode_overflow ../tests/unit/test-xbzrle.c:153
    #3 0x7fb2fb65a58d  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a58d)
    #4 0x7fb2fb65a333  (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7a333)
    #5 0x7fb2fb65aa79 in g_test_run_suite (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa79)
    #6 0x7fb2fb65aa94 in g_test_run (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x7aa94)
    #7 0x5611099a3a23 in main ../tests/unit/test-xbzrle.c:218
    #8 0x7fb2fa78c082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082)
    #9 0x5611099a608d in _start (/qemu/build/tests/unit/test-xbzrle+0x28408d)

0x62100000b100 is located 0 bytes to the right of 4096-byte region [0x62100000a100,0x62100000b100)
allocated by thread T0 here:
    #0 0x7fb2fb823a06 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cc:153
    #1 0x7fb2fb637ef0 in g_malloc0 (/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x57ef0)

Fix that by performing the overflow check in the inner loop, instead.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Matheus Tavares Bernardino
d84a78d15d migration/xbzrle: use ctz64 to avoid undefined result
__builtin_ctzll() produces undefined results when the argument is 0.
This can be seen through test-xbzrle, which produces the following
warning:

../migration/xbzrle.c:265: runtime error: passing zero to ctz(), which is not a valid argument

Replace __builtin_ctzll() with our ctz64() wrapper which properly
handles 0.

Signed-off-by: Matheus Tavares Bernardino <quic_mathbern@quicinc.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Dr. David Alan Gilbert
a5382214d8 migration/rdma: Fix return-path case
The RDMA code has return-path handling code, but it's only enabled
if postcopy is enabled; if the 'return-path' migration capability
is enabled, the return path is NOT setup but the core migration
code still tries to use it and breaks.

Enable the RDMA return path if either postcopy or the return-path
capability is enabled.

bz: https://bugzilla.redhat.com/show_bug.cgi?id=2063615

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
Peter Xu
a5d35dc7e0 migration: Wait on preempt channel in preempt thread
QEMU main thread will wait until dest preempt channel established during
processing the LISTEN command (within the whole postcopy PACKAGED data), by
waiting on the semaphore postcopy_qemufile_dst_done.

That's racy, because it's possible that the dest QEMU main thread hasn't
yet accept()ed the new connection when processing the LISTEN event.  The
sem_wait() will yield the main thread without being able to run anything
else including the accept() of the new socket, which can cause deadlock
within the main thread.

To avoid the race, move the "wait channel" from main thread to the preempt
thread right at the start.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: 5655aab079 ("migration: Postpone postcopy preempt channel to be after main")
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-16 16:07:07 +01:00
John Berberian, Jr
c31772ad68 Fix exec migration on Windows (w32+w64).
* Use cmd instead of /bin/sh on Windows.

* Try to auto-detect cmd.exe's path, but default to a hard-coded path.

Note that this will require that gspawn-win[32|64]-helper.exe and
gspawn-win[32|64]-helper-console.exe are included in the Windows binary
distributions (cc: Stefan Weil).

Signed-off-by: "John Berberian, Jr" <jeb.study@gmail.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-03-02 17:06:27 +01:00
Markus Armbruster
43aef7e632 migration/colo: Improve an x-colo-lost-heartbeat error message
The QERR_ macros are leftovers from the days of "rich" error objects.
We've been trying to reduce their remaining use.

Get rid of a use of QERR_FEATURE_DISABLED, and improve the somewhat
imprecise error message

    (qemu) x_colo_lost_heartbeat
    Error: The feature 'colo' is not enabled

to

    Error: VM is not in COLO mode

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-12-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2023-02-23 14:10:17 +01:00
Markus Armbruster
6f1e91f716 error: Drop superfluous #include "qapi/qmp/qerror.h"
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
2023-02-23 13:56:14 +01:00
Juan Quintela
24beea4efe migration: Rename res_{postcopy,precopy}_only
Once that res_compatible is removed, they don't make sense anymore.
We remove the _only preffix.  And to make things clearer we rename
them to must_precopy and can_postcopy.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 20:04:30 +01:00
Juan Quintela
24f254ed79 migration: Remove unused res_compatible
Nothing assigns to it after previous commit.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 20:04:30 +01:00
Juan Quintela
abbbd04da2 migration: In case of postcopy, the memory ends in res_postcopy_only
So remove last assignation of res_compatible.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 20:04:30 +01:00
Philippe Mathieu-Daudé
163b8663b8 migration/block: Convert remaining DPRINTF() debug macro to trace events
Finish the conversion from commit fe80c0241d
("migration: using trace_ to replace DPRINTF").

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 19:09:25 +01:00
Avihai Horon
c7a7db4b51 migration/qemu-file: Add qemu_file_get_to_fd()
Add new function qemu_file_get_to_fd() that allows reading data from
QEMUFile and writing it straight into a given fd.

This will be used later in VFIO migration code.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 19:09:25 +01:00
Juan Quintela
7b548761e5 ram: Document migration ram flags
0x80 is RAM_SAVE_FLAG_HOOK, it is in qemu-file now.
Bigger usable flag is 0x200, noticing that.
We can reuse RAM_SAVe_FLAG_FULL.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:45:47 +01:00
Leonardo Bras
cfc3bcf373 migration/multifd: Move load_cleanup inside incoming_state_destroy
Currently running migration_incoming_state_destroy() without first running
multifd_load_cleanup() will cause a yank error:

qemu-system-x86_64: ../util/yank.c:107: yank_unregister_instance:
Assertion `QLIST_EMPTY(&entry->yankfns)' failed.
(core dumped)

The above error happens in the target host, when multifd is being used
for precopy, and then postcopy is triggered and the migration finishes.
This will crash the VM in the target host.

To avoid that, move multifd_load_cleanup() inside
migration_incoming_state_destroy(), so that the load cleanup becomes part
of the incoming state destroying process.

Running multifd_load_cleanup() twice can become an issue, though, but the
only scenario it could be ran twice is on process_incoming_migration_bh().
So removing this extra call is necessary.

On the other hand, this multifd_load_cleanup() call happens way before the
migration_incoming_state_destroy() and having this happening before
dirty_bitmap_mig_before_vm_start() and vm_start() may be a need.

So introduce a new function multifd_load_shutdown() that will mainly stop
all multifd threads and close their QIOChannels. Then use this function
instead of multifd_load_cleanup() to make sure nothing else is received
before dirty_bitmap_mig_before_vm_start().

Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:45:40 +01:00
Leonardo Bras
10351fbad1 migration/multifd: Join all multifd threads in order to avoid leaks
Current approach will only join threads that are still running.

For the threads not joined, resources or private memory are always kept in
the process space and never reclaimed before process end, and this risks
serious memory leaks.

This should usually not represent a big problem, since multifd migration
is usually just ran at most a few times, and after it succeeds there is
not much to be done before exiting the process.

Yet still, it should not hurt performance to join all of them.

Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:45:34 +01:00
Leonardo Bras
d926f3bb2a migration/multifd: Remove unnecessary assignment on multifd_load_cleanup()
Before assigning "p->quit = true" for every multifd channel,
multifd_load_cleanup() will call multifd_recv_terminate_threads() which
already does the same assignment, while protected by a mutex.

So there is no point doing the same assignment again.

Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:45:28 +01:00
Leonardo Bras
e5bac1f525 migration/multifd: Change multifd_load_cleanup() signature and usage
Since it's introduction in commit f986c3d256 ("migration: Create multifd
migration threads"), multifd_load_cleanup() never returned any value
different than 0, neither set up any error on errp.

Even though, on process_incoming_migration_bh() an if clause uses it's
return value to decide on setting autostart = false, which will never
happen.

In order to simplify the codebase, change multifd_load_cleanup() signature
to 'void multifd_load_cleanup(void)', and for every usage remove error
handling or decision made based on return value != 0.

Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:44:44 +01:00
Peter Xu
5655aab079 migration: Postpone postcopy preempt channel to be after main
Postcopy with preempt-mode enabled needs two channels to communicate.  The
order of channel establishment is not guaranteed.  It can happen that the
dest QEMU got the preempt channel connection request before the main
channel is established, then the migration may make no progress even during
precopy due to the wrong order.

To fix it, create the preempt channel only if we know the main channel is
established.

For a general postcopy migration, we delay it until postcopy_start(),
that's where we already went through some part of precopy on the main
channel.  To make sure dest QEMU has already established the channel, we
wait until we got the first PONG received.  That's something we do at the
start of precopy when postcopy enabled so it's guaranteed to happen sooner
or later.

For a postcopy recovery, we delay it to qemu_savevm_state_resume_prepare()
where we'll have round trips of data on bitmap synchronizations, which
means the main channel must have been established.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Peter Xu
b28fb58227 migration: Add a semaphore to count PONGs
This is mostly useless, but useful for us to know whether the main channel
is correctly established without changing the migration protocol.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Peter Xu
fc063a7b8a migration: Cleanup postcopy_preempt_setup()
Since we just dropped the only case where postcopy_preempt_setup() can
return an error, it doesn't need a retval anymore because it never fails.
Move the preempt check to the caller, preparing it to be used elsewhere to
do nothing but as simple as kicking the async connection.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Peter Xu
d6f74fd12e migration: Rework multi-channel checks on URI
The whole idea of multi-channel checks was not properly done, IMHO.

Currently we check multi-channel in a lot of places, but actually that's
not needed because we only need to check it right after we get the URI and
that should be it.

If the URI check succeeded, we should never need to check it again because
we must have it.  If it check fails, we should fail immediately on either
the qmp_migrate or qmp_migrate_incoming, instead of failingg it later after
the connection established.

Neither should we fail any set capabiliities like what we used to do here:

5ad15e8614 ("migration: allow enabling mutilfd for specific protocol only", 2021-10-19)

Because logically the URI will only be set later after the capability is
set, so it doesn't make a lot of sense to check the URI type when setting
the capability, because we're checking the cap with an old URI passed in,
and that may not even be the URI we're going to use later.

This patch mostly reverted all such checks for before, dropping the
variable migrate_allow_multi_channels and helpers.  Instead, add a common
helper to check URI for multi-channels for either qmp_migrate and
qmp_migrate_incoming and that should do all the proper checks.  The failure
will only trigger with the "migrate" or "migrate_incoming" command, or when
user specified "-incoming xxx" where "xxx" is not "defer".

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
ling xu
04ffce137b AVX512 support for xbzrle_encode_buffer
This commit is the same with [PATCH v6 1/2], and provides avx512 support for xbzrle_encode_buffer
function to accelerate xbzrle encoding speed. Runtime check of avx512
support and benchmark for this feature are added. Compared with C
version of xbzrle_encode_buffer function, avx512 version can achieve
50%-70% performance improvement on benchmarking. In addition, if dirty
data is randomly located in 4K page, the avx512 version can achieve
almost 140% performance gain.

Signed-off-by: ling xu <ling1.xu@intel.com>
Co-authored-by: Zhou Zhao <zhou.zhao@intel.com>
Co-authored-by: Jun Jin <jun.i.jin@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
e264705012 migration: I messed state_pending_exact/estimate
I called the helper function from the wrong top level function.

This code was introduced in:

commit c8df4a7aef
Author: Juan Quintela <quintela@redhat.com>
Date:   Mon Oct 3 02:00:03 2022 +0200

    migration: Split save_live_pending() into state_pending_*

    We split the function into to:

    - state_pending_estimate: We estimate the remaining state size without
      stopping the machine.

    - state pending_exact: We calculate the exact amount of remaining
      state.

Thanks to Avihai Horon <avihaih@nvidia.com> for finding it.

Fixes:c8df4a7aeffcb46020f610526eea621fa5b0cd47

When we introduced that patch, we enden calling

state_pending_estimate() helper from qemu_savevm_statepending_exact()
and
state_pending_exact() helper from qemu_savevm_statepending_estimate()

This patch fixes it.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
4010ba388d migration: Make ram_save_target_page() a pointer
We are going to create a new function for multifd latest in the series.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
8d80e1951e migration: Calculate ram size once
We are recalculating ram size continously, when we know that it don't
change during migration.  Create a field in RAMState to track it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-02-11 16:51:09 +01:00
Juan Quintela
8008a272d6 migration: Split ram_bytes_total_common() in two functions
It is just a big if in the middle of the function, and we need two
functions anways.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>

---

Reindent to make Phillipe happy (and CODING_STYLE)
2023-02-11 16:51:09 +01:00
Juan Quintela
31e2ac742b migration: Make find_dirty_block() return a single parameter
We used to return two bools, just return a single int with the
following meaning:

old return / again / new return
false        false   PAGE_ALL_CLEAN
false        true    PAGE_TRY_AGAIN
true         true    PAGE_DIRTY_FOUND  /* We don't care about again at all */

Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
51efd36faf migration: Simplify ram_find_and_save_block()
We will need later that find_dirty_block() return errors, so
simplify the loop.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Li Zhang
bca762c2b9 multifd: Remove some redundant code
Clean up some unnecessary code

Signed-off-by: Li Zhang <lizhang@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Li Zhang
e3f37b2ce6 multifd: cleanup the function multifd_channel_connect
Cleanup multifd_channel_connect

Signed-off-by: Li Zhang <lizhang@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
b530ccde5d migration: Remove spurious files
I introduced spurious files on my tree during a rebase:

commit ebfc578715
Author: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date:   Mon Oct 17 15:53:51 2022 +0800

    multifd: Fix flush of zero copy page send request

    Make IO channel flush call after the inflight request has been drained
    in multifd thread, or else we may missed to flush the inflight request.

    Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
    Reviewed-by: Juan Quintela <quintela@redhat.com>
    Signed-off-by: Juan Quintela <quintela@redhat.com>

To make things worse, it appears like Zhenzhong is the one to blame.

for(int i=0; i < 1000000; i++) {
	printf("I will not do rebases when I am tired\n");
}

Sorry, Juan.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Markus Armbruster
a67dfa660b Drop duplicate #include
Tracked down with the help of scripts/clean-includes.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230202133830.2152150-21-armbru@redhat.com>
2023-02-08 07:28:05 +01:00
Jiang Jiacheng
1b1f4ab69c migration: save/delete migration thread info
To support query migration thread infomation, save and delete
thread(live_migration and multifdsend) information at thread
creation and finish.

Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
Jiang Jiacheng
671326201d migration: Introduce interface query-migrationthreads
Introduce interface query-migrationthreads. The interface is used
to query information about migration threads and returns with
migration thread's name and its id.
Introduce threadinfo.c to manage threads with migration.

Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
Zhenzhong Duan
ebfc578715 multifd: Fix flush of zero copy page send request
Make IO channel flush call after the inflight request has been drained
in multifd thread, or else we may missed to flush the inflight request.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
Zhenzhong Duan
ddbe628c97 multifd: Fix a race on reading MultiFDPages_t.block
In multifd_queue_page() MultiFDPages_t.block is checked twice.
Between the two checks, MultiFDPages_t.block may be reset to NULL
by multifd thread. This lead to the 2nd check always true then a
redundant page submitted to multifd thread again.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
manish.mishra
6720c2b327 migration: check magic value for deciding the mapping of channels
Current logic assumes that channel connections on the destination side are
always established in the same order as the source and the first one will
always be the main channel followed by the multifid or post-copy
preemption channel. This may not be always true, as even if a channel has a
connection established on the source side it can be in the pending state on
the destination side and a newer connection can be established first.
Basically causing out of order mapping of channels on the destination side.
Currently, all channels except post-copy preempt send a magic number, this
patch uses that magic number to decide the type of channel. This logic is
applicable only for precopy(multifd) live migration, as mentioned, the
post-copy preempt channel does not send any magic number. Also, tls live
migrations already does tls handshake before creating other channels, so
this issue is not possible with tls, hence this logic is avoided for tls
live migrations. This patch uses read peek to check the magic number of
channels so that current data/control stream management remains
un-effected.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
manish.mishra
84615a19dd io: Add support for MSG_PEEK for socket channel
MSG_PEEK peeks at the channel, The data is treated as unread and
the next read shall still return this data. This support is
currently added only for socket class. Extra parameter 'flags'
is added to io_readv calls to pass extra read flags like MSG_PEEK.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Zhenzhong Duan
bd9510d385 migration/dirtyrate: Show sample pages only in page-sampling mode
The value of "Sample Pages" is confusing in mode other than page-sampling.
See below:

(qemu) calc_dirty_rate -b 10 520
(qemu) info dirty_rate
Status: measuring
Start Time: 11646834 (ms)
Sample Pages: 520 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: (not ready)

(qemu) info dirty_rate
Status: measured
Start Time: 11646834 (ms)
Sample Pages: 0 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: 2 (MB/s)

While it's totally useless in dirty-ring and dirty-bitmap mode, fix to
show it only in page-sampling mode.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00