We will need to split it later in zero_num (number of zero pages) and
normal_num (number of normal pages). This name is better.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
To: <quintela@redhat.com>, <dgilbert@redhat.com>, <qemu-devel@nongnu.org>
CC: Li Zhijian <lizhijian@cn.fujitsu.com>
Date: Sat, 31 Jul 2021 22:05:52 +0800 (5 weeks, 4 days, 17 hours ago)
And change the default to true so that in '-incoming defer' case, user is able
to change multifd capability.
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
To: <quintela@redhat.com>, <dgilbert@redhat.com>, <qemu-devel@nongnu.org>
CC: Li Zhijian <lizhijian@cn.fujitsu.com>
Date: Sat, 31 Jul 2021 22:05:51 +0800 (5 weeks, 4 days, 17 hours ago)
multifd with unsupported protocol will cause a segment fault.
(gdb) bt
#0 0x0000563b4a93faf8 in socket_connect (addr=0x0, errp=0x7f7f02675410) at ../util/qemu-sockets.c:1190
#1 0x0000563b4a797a03 in qio_channel_socket_connect_sync
(ioc=0x563b4d16e8c0, addr=0x0, errp=0x7f7f02675410) at
../io/channel-socket.c:145
#2 0x0000563b4a797abf in qio_channel_socket_connect_worker (task=0x563b4cd86c30, opaque=0x0) at ../io/channel-socket.c:168
#3 0x0000563b4a792631 in qio_task_thread_worker (opaque=0x563b4cd86c30) at ../io/task.c:124
#4 0x0000563b4a91da69 in qemu_thread_start (args=0x563b4c44bb80) at ../util/qemu-thread-posix.c:541
#5 0x00007f7fe9b5b3f9 in ?? ()
#6 0x0000000000000000 in ?? ()
It's enough to check migrate_multifd_is_allowed() in multifd cleanup() and
multifd setup() though there are so many other places using migrate_use_multifd().
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
To: qemu-devel <qemu-devel@nongnu.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Juan Quintela
<quintela@redhat.com>, Peter Xu <peterx@redhat.com>, Leonardo Bras Soares
Passos <lsoaresp@redhat.com>
Date: Wed, 4 Aug 2021 21:26:32 +0200 (5 weeks, 11 hours, 52 minutes ago)
[[PGP Signed Part:No public key for 35AB0B289C5DB258 created at 2021-08-04T21:26:32+0200 using RSA]]
Unconditionally unregister yank function in multifd_load_cleanup().
If it is not unregistered here, it will leak and cause a crash
in yank_unregister_instance(). Now if the ioc is still in use
afterwards, it will only lead to qemu not being able to recover
from a hang related to that ioc.
After checking the code, i am pretty sure that ref is always 1
when arriving here. So all this currently does is remove the
unneeded check.
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
To: qemu-devel <qemu-devel@nongnu.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Juan Quintela
<quintela@redhat.com>, Peter Xu <peterx@redhat.com>, Leonardo Bras Soares
Passos <lsoaresp@redhat.com>
Date: Wed, 1 Sep 2021 17:58:57 +0200 (1 week, 15 hours, 17 minutes ago)
[[PGP Signed Part:No public key for 35AB0B289C5DB258 created at 2021-09-01T17:58:57+0200 using RSA]]
When introducing yank functionality in the migration code I forgot
to cover the multifd send side.
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
There're plenty of places in migration/* that checks against either socket or
tls typed ioc for yank operations. Provide two helpers to hide all these
information.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-4-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Delay closing the listener until the cleanup hook at the end; mptcp
needs the listener to stay open while the other paths come in.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210421112834.107651-5-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
After yank feature was introduced in migration, whenever migration
is started using TLS, the following error happens in both source and
destination hosts:
(qemu) qemu-kvm: ../util/yank.c:107: yank_unregister_instance:
Assertion `QLIST_EMPTY(&entry->yankfns)' failed.
This happens because of a missing yank_unregister_function() when using
qio-channel-tls.
Fix this by also allowing TYPE_QIO_CHANNEL_TLS object type to perform
yank_unregister_function() in channel_close() and multifd_load_cleanup().
Also, inside migration_channel_connect() and
migration_channel_process_incoming() move yank_register_function() so
it only runs once on a TLS migration.
Fixes: b5eea99ec2 ("migration: Add yank feature", 2021-01-13)
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1964326
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Changes since v2:
- Dropped all references to ioc->master
- yank_register_function() and yank_unregister_function() now only run
once in a TLS migration.
Changes since v1:
- Cast p->c to QIOChannelTLS into multifd_load_cleanup()
Message-Id: <20210601054030.1153249-1-leobras.c@gmail.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We actually want to print the used_length, against which we check.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210429112708.12291-10-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Remove dependency on qiochannel by removing yank_generic_iochannel and
letting migration and chardev use their own yank function for
iochannel.
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20ff143fc2db23e27cd41d38043e481376c9cec1.1616521341.git.lukasstraub2@web.de>
If any error happens during multifd send thread creating (e.g. channel broke
because new domain is destroyed by the dst), multifd_tls_handshake_thread
may exit silently, leaving main migration thread hanging (ram_save_setup ->
multifd_send_sync_main -> qemu_sem_wait(&p->sem_sync)).
Fix that by adding error handling in multifd_tls_handshake_thread.
Signed-off-by: Hao Wang <wanghao232@huawei.com>
Message-Id: <20210209104237.2250941-3-wanghao232@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Function multifd_channel_connect() return "true" to indicate failure,
which is rather confusing. Fix that.
Signed-off-by: Hao Wang <wanghao232@huawei.com>
Message-Id: <20210209104237.2250941-2-wanghao232@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Register yank functions on sockets to shut them down.
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <484c6a14cc2506bebedd5a237259b91363ff8f88.1609167865.git.lukasstraub2@web.de>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
When creating new tls client, the tioc->master will be referenced which results in socket
leaking after multifd_save_cleanup if we cancel migration.
Fix it by do object_unref() after tls client creation.
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Message-Id: <1605104763-118687-1-git-send-email-zhengchuan@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The qemu main loop could hang up forever when we enable TLS+Multifd.
The Src multifd_send_0 invokes tls handshake, it sends hello to sever
and wait response.
However, the Dst main qemu loop has been waiting recvmsg() for multifd_recv_1.
Both of Src and Dst main qemu loop are blocking and waiting for reponse which
results in hanging up forever.
Src: (multifd_send_0) Dst: (multifd_recv_1)
multifd_channel_connect migration_channel_process_incoming
multifd_tls_channel_connect migration_tls_channel_process_incoming
multifd_tls_channel_connect qio_channel_tls_handshake_task
qio_channel_tls_handshake gnutls_handshake
qio_channel_tls_handshake_task ...
qcrypto_tls_session_handshake ...
gnutls_handshake ...
... ...
recvmsg (Blocking I/O waiting for response) recvmsg (Blocking I/O waiting for response)
Fix this by offloadinig handshake work to a background thread.
Reported-by: Yan Jin <jinyan12@huawei.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Message-Id: <1604643893-8223-1-git-send-email-zhengchuan@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
add trace points for multifd-tls for debug.
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Yan Jin <jinyan12@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <1600139042-104593-7-git-send-email-zhengchuan@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Similar like migration main thread, we need to do handshake
for each multifd thread.
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Yan Jin <jinyan12@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <1600139042-104593-6-git-send-email-zhengchuan@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
multifd channel cleanup is need if multifd handshake failed,
let's extract it.
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Yan Jin <jinyan12@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <1600139042-104593-5-git-send-email-zhengchuan@huawei.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Since multifd creation is async with migration_channel_connect, we should
pass the hostname from MigrationState to MultiFDSendParams.
Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: Yan Jin <jinyan12@huawei.com>
Message-Id: <1600139042-104593-4-git-send-email-zhengchuan@huawei.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:
$ CC=clang CXX=clang++ ./configure ... && make
../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.
This patch was generated using:
$ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
sort -u >/tmp/changed_identifiers
$ for identifier in $(</tmp/changed_identifiers); do
sed -i "s%\<$identifier\>%q$identifier%g" \
$(git grep -I -l "\<$identifier\>")
done
I manually fixed line-wrap issues and misaligned rST tables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
I found that there are many spelling errors in the comments of qemu,
so I used the spellcheck tool to check the spelling errors
and finally found some spelling errors in the migration folder.
Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200917075029.313-3-zhaolichang@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
multifd_send_pages() loops around the available channels,
the next channel to use between two calls to multifd_send_pages() is stored
inside a local static variable, next_channel.
It works well, except if the number of channels decreases between two calls
to multifd_send_pages(). In this case, the loop can try to access the
data of a channel that doesn't exist anymore.
The problem can be triggered if we start a migration with a given number of
channels and then we cancel the migration to restart it with a lower number.
This ends generally with an error like:
qemu-system-ppc64: .../util/qemu-thread-posix.c:77: qemu_mutex_lock_impl: Assertion `mutex->initialized' failed.
This patch fixes the error by capping next_channel with the current number
of channels before using it.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20200617113154.593233-1-lvivier@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
When error happen in multifd_send_thread, it use error_copy to set migrate error in
multifd_send_terminate_threads(). We should call error_free after it.
Similarly, fix another two places in multifd_recv_thread/multifd_save_cleanup.
The leak stack:
Direct leak of 48 byte(s) in 1 object(s) allocated from:
#0 0x7f781af07cf0 in calloc (/lib64/libasan.so.5+0xefcf0)
#1 0x7f781a2ce22d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5322d)
#2 0x55ee1d075c17 in error_setv /mnt/sdb/backup/qemu/util/error.c:61
#3 0x55ee1d076464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
#4 0x55ee1cef066e in qio_channel_socket_writev /mnt/sdb/backup/qemu/io/channel-socket.c:569
#5 0x55ee1cee806b in qio_channel_writev /mnt/sdb/backup/qemu/io/channel.c:207
#6 0x55ee1cee806b in qio_channel_writev_all /mnt/sdb/backup/qemu/io/channel.c:171
#7 0x55ee1cee8248 in qio_channel_write_all /mnt/sdb/backup/qemu/io/channel.c:257
#8 0x55ee1ca12c9a in multifd_send_thread /mnt/sdb/backup/qemu/migration/multifd.c:657
#9 0x55ee1d0607fc in qemu_thread_start /mnt/sdb/backup/qemu/util/qemu-thread-posix.c:519
#10 0x7f78159ae2dd in start_thread (/lib64/libpthread.so.0+0x82dd)
#11 0x7f78156df4b2 in __GI___clone (/lib64/libc.so.6+0xfc4b2)
Indirect leak of 52 byte(s) in 1 object(s) allocated from:
#0 0x7f781af07f28 in __interceptor_realloc (/lib64/libasan.so.5+0xeff28)
#1 0x7f78156f07d9 in __GI___vasprintf_chk (/lib64/libc.so.6+0x10d7d9)
#2 0x7f781a30ea6c in g_vasprintf (/lib64/libglib-2.0.so.0+0x93a6c)
#3 0x7f781a2e7cd0 in g_strdup_vprintf (/lib64/libglib-2.0.so.0+0x6ccd0)
#4 0x7f781a2e7d8c in g_strdup_printf (/lib64/libglib-2.0.so.0+0x6cd8c)
#5 0x55ee1d075c86 in error_setv /mnt/sdb/backup/qemu/util/error.c:65
#6 0x55ee1d076464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
#7 0x55ee1cef066e in qio_channel_socket_writev /mnt/sdb/backup/qemu/io/channel-socket.c:569
#8 0x55ee1cee806b in qio_channel_writev /mnt/sdb/backup/qemu/io/channel.c:207
#9 0x55ee1cee806b in qio_channel_writev_all /mnt/sdb/backup/qemu/io/channel.c:171
#10 0x55ee1cee8248 in qio_channel_write_all /mnt/sdb/backup/qemu/io/channel.c:257
#11 0x55ee1ca12c9a in multifd_send_thread /mnt/sdb/backup/qemu/migration/multifd.c:657
#12 0x55ee1d0607fc in qemu_thread_start /mnt/sdb/backup/qemu/util/qemu-thread-posix.c:519
#13 0x7f78159ae2dd in start_thread (/lib64/libpthread.so.0+0x82dd)
#14 0x7f78156df4b2 in __GI___clone (/lib64/libc.so.6+0xfc4b2)
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Message-Id: <20200506095416.26099-3-pannengyuan@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
When error happen in multifd_new_send_channel_async, 'sioc' will not be used
to create the multifd_send_thread. Let's free it to avoid a memleak. And also
do error_free after migrate_set_error() to avoid another leak in the same place.
The leak stack:
Direct leak of 2880 byte(s) in 8 object(s) allocated from:
#0 0x7f20b5118ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8)
#1 0x7f20b44df1d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5)
#2 0x564133bce18b in object_new_with_type /mnt/sdb/backup/qemu/qom/object.c:683
#3 0x564133eea950 in qio_channel_socket_new /mnt/sdb/backup/qemu/io/channel-socket.c:56
#4 0x5641339cfe4f in socket_send_channel_create /mnt/sdb/backup/qemu/migration/socket.c:37
#5 0x564133a10328 in multifd_save_setup /mnt/sdb/backup/qemu/migration/multifd.c:772
#6 0x5641339cebed in migrate_fd_connect /mnt/sdb/backup/qemu/migration/migration.c:3530
#7 0x5641339d15e4 in migration_channel_connect /mnt/sdb/backup/qemu/migration/channel.c:92
#8 0x5641339cf5b7 in socket_outgoing_migration /mnt/sdb/backup/qemu/migration/socket.c:108
Direct leak of 384 byte(s) in 8 object(s) allocated from:
#0 0x7f20b5118cf0 in calloc (/lib64/libasan.so.5+0xefcf0)
#1 0x7f20b44df22d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5322d)
#2 0x56413406fc17 in error_setv /mnt/sdb/backup/qemu/util/error.c:61
#3 0x564134070464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
#4 0x5641340851be in inet_connect_addr /mnt/sdb/backup/qemu/util/qemu-sockets.c:379
#5 0x5641340851be in inet_connect_saddr /mnt/sdb/backup/qemu/util/qemu-sockets.c:458
#6 0x5641340870ab in socket_connect /mnt/sdb/backup/qemu/util/qemu-sockets.c:1105
#7 0x564133eeaabf in qio_channel_socket_connect_sync /mnt/sdb/backup/qemu/io/channel-socket.c:145
#8 0x564133eeabf5 in qio_channel_socket_connect_worker /mnt/sdb/backup/qemu/io/channel-socket.c:168
Indirect leak of 360 byte(s) in 8 object(s) allocated from:
#0 0x7f20b5118ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8)
#1 0x7f20af901817 in __GI___vasprintf_chk (/lib64/libc.so.6+0x10d817)
#2 0x7f20b451fa6c in g_vasprintf (/lib64/libglib-2.0.so.0+0x93a6c)
#3 0x7f20b44f8cd0 in g_strdup_vprintf (/lib64/libglib-2.0.so.0+0x6ccd0)
#4 0x7f20b44f8d8c in g_strdup_printf (/lib64/libglib-2.0.so.0+0x6cd8c)
#5 0x56413406fc86 in error_setv /mnt/sdb/backup/qemu/util/error.c:65
#6 0x564134070464 in error_setg_errno_internal /mnt/sdb/backup/qemu/util/error.c:109
#7 0x5641340851be in inet_connect_addr /mnt/sdb/backup/qemu/util/qemu-sockets.c:379
#8 0x5641340851be in inet_connect_saddr /mnt/sdb/backup/qemu/util/qemu-sockets.c:458
#9 0x5641340870ab in socket_connect /mnt/sdb/backup/qemu/util/qemu-sockets.c:1105
#10 0x564133eeaabf in qio_channel_socket_connect_sync /mnt/sdb/backup/qemu/io/channel-socket.c:145
#11 0x564133eeabf5 in qio_channel_socket_connect_worker /mnt/sdb/backup/qemu/io/channel-socket.c:168
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Message-Id: <20200506095416.26099-2-pannengyuan@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
- ran regexp "qemu_mutex_lock\(.*\).*\n.*if" to find targets
- replaced result with QEMU_LOCK_GUARD if all unlocks at function end
- replaced result with WITH_QEMU_LOCK_GUARD if unlock not at end
Signed-off-by: Daniel Brodsky <dnbrdsky@gmail.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-id: 20200404042108.389635-3-dnbrdsky@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
It will be used later.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
No comp value needs to be zero.
Juan Quintela
Li Zhijian
Lukas Straub
Peter Xu
Dr. David Alan Gilbert
Leonardo Bras
David Hildenbrand
Hao Wang
Chuan Zheng
Peter Maydell
Philippe Mathieu-Daudé
Stefan Hajnoczi
zhaolichang
Laurent Vivier
Pan Nengyuan
Daniel Brodsky