Commit Graph

1145 Commits

Author SHA1 Message Date
Alexey Romko
8bba004cca Bug #1829242 correction.
Added type conversions to ram_addr_t before all left shifts of page
indexes to TARGET_PAGE_BITS, to correct overflows when the page
address was 4Gb and more.

Signed-off-by: Alexey Romko <nevilad@yahoo.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Jiahui Cen
9560a48ecc migration/multifd: fix destroyed mutex access in terminating multifd threads
One multifd will lock all the other multifds' IOChannel mutex to inform them
to quit by setting p->quit or shutting down p->c. In this senario, if some
multifds had already been terminated and multifd_load_cleanup/multifd_save_cleanup
had destroyed their mutex, it could cause destroyed mutex access when trying
lock their mutex.

Here is the coredump stack:
    #0  0x00007f81a2794437 in raise () from /usr/lib64/libc.so.6
    #1  0x00007f81a2795b28 in abort () from /usr/lib64/libc.so.6
    #2  0x00007f81a278d1b6 in __assert_fail_base () from /usr/lib64/libc.so.6
    #3  0x00007f81a278d262 in __assert_fail () from /usr/lib64/libc.so.6
    #4  0x000055eb1bfadbd3 in qemu_mutex_lock_impl (mutex=0x55eb1e2d1988, file=<optimized out>, line=<optimized out>) at util/qemu-thread-posix.c:64
    #5  0x000055eb1bb4564a in multifd_send_terminate_threads (err=<optimized out>) at migration/ram.c:1015
    #6  0x000055eb1bb4bb7f in multifd_send_thread (opaque=0x55eb1e2d19f8) at migration/ram.c:1171
    #7  0x000055eb1bfad628 in qemu_thread_start (args=0x55eb1e170450) at util/qemu-thread-posix.c:502
    #8  0x00007f81a2b36df5 in start_thread () from /usr/lib64/libpthread.so.0
    #9  0x00007f81a286048d in clone () from /usr/lib64/libc.so.6

To fix it up, let's destroy the mutex after all the other multifd threads had
been terminated.

Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
Signed-off-by: Ying Fang <fangying1@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Jiahui Cen
f76e32eb05 migration/multifd: fix nullptr access in terminating multifd threads
One multifd channel will shutdown all the other multifd's IOChannel when it
fails to receive an IOChannel. In this senario, if some multifds had not
received its IOChannel yet, it would try to shutdown its IOChannel which could
cause nullptr access at qio_channel_shutdown.

Here is the coredump stack:
    #0  object_get_class (obj=obj@entry=0x0) at qom/object.c:908
    #1  0x00005563fdbb8f4a in qio_channel_shutdown (ioc=0x0, how=QIO_CHANNEL_SHUTDOWN_BOTH, errp=0x0) at io/channel.c:355
    #2  0x00005563fd7b4c5f in multifd_recv_terminate_threads (err=<optimized out>) at migration/ram.c:1280
    #3  0x00005563fd7bc019 in multifd_recv_new_channel (ioc=ioc@entry=0x556400255610, errp=errp@entry=0x7ffec07dce00) at migration/ram.c:1478
    #4  0x00005563fda82177 in migration_ioc_process_incoming (ioc=ioc@entry=0x556400255610, errp=errp@entry=0x7ffec07dce30) at migration/migration.c:605
    #5  0x00005563fda8567d in migration_channel_process_incoming (ioc=0x556400255610) at migration/channel.c:44
    #6  0x00005563fda83ee0 in socket_accept_incoming_migration (listener=0x5563fff6b920, cioc=0x556400255610, opaque=<optimized out>) at migration/socket.c:166
    #7  0x00005563fdbc25cd in qio_net_listener_channel_func (ioc=<optimized out>, condition=<optimized out>, opaque=<optimized out>) at io/net-listener.c:54
    #8  0x00007f895b6fe9a9 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
    #9  0x00005563fdc18136 in glib_pollfds_poll () at util/main-loop.c:218
    #10 0x00005563fdc181b5 in os_host_main_loop_wait (timeout=1000000000) at util/main-loop.c:241
    #11 0x00005563fdc183a2 in main_loop_wait (nonblocking=nonblocking@entry=0) at util/main-loop.c:517
    #12 0x00005563fd8edb37 in main_loop () at vl.c:1791
    #13 0x00005563fd74fd45 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4473

To fix it up, let's check p->c before calling qio_channel_shutdown.

Signed-off-by: Jiahui Cen <cenjiahui@huawei.com>
Signed-off-by: Ying Fang <fangying1@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Wei Yang
c6b3a2e0c4 migration/multifd: not use multifd during postcopy
We don't support multifd during postcopy, but user still could enable
both multifd and postcopy. This leads to migration failure.

Skip multifd during postcopy.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Wei Yang
eab54aa78f migration/multifd: clean pages after filling packet
This is a preparation for the next patch:

    not use multifd during postcopy.

Without enabling postcopy, everything looks good. While after enabling
postcopy, migration may fail even not use multifd during postcopy. The
reason is the pages is not properly cleared and *old* target page will
continue to be transferred.

After clean pages, migration succeeds.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Wei Yang
644acf99b8 migration/postcopy: enable compress during postcopy
postcopy requires to place a whole host page, while migration thread
migrate memory in target page size. This makes postcopy need to collect
all target pages in one host page before placing via userfaultfd.

To enable compress during postcopy, there are two problems to solve:

    1. Random order for target page arrival
    2. Target pages in one host page arrives without interrupt by target
       page from other host page

The first one is handled by previous cleanup patch.

This patch handles the second one by:

    1. Flush compress thread for each host page
    2. Wait for decompress thread for before placing host page

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Wei Yang
91ba442f5c migration/postcopy: enable random order target page arrival
After using number of target page received to track one host page, we
could have the capability to handle random order target page arrival in
one host page.

This is a preparation for enabling compress during postcopy.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Wei Yang
e5e73b0f90 migration/postcopy: set all_zero to true on the first target page
For the first target page, all_zero is set to true for this round check.

After target_pages introduced, we could leverage this variable instead
of checking the address offset.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Wei Yang
4cbb3c63c1 migration/postcopy: count target page number to decide the place_needed
In postcopy, it requires to place whole host page instead of target
page.

Currently, it relies on the page offset to decide whether this is the
last target page. We also can count the target page number during the
iteration. When the number of target page equals
(host page size / target page size), this means it is the last target
page in the host page.

This is a preparation for non-ordered target page transmission.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Wei Yang
ca1a6b708b migration/postcopy: wait for decompress thread in precopy
Compress is not supported with postcopy, it is safe to wait for
decompress thread just in precopy.

This is a preparation for later patch.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Wei Yang
2e36bc1b88 migration/postcopy: reduce memset when it is zero page and matches_target_page_size
In this case, page_buffer content would not be used.

Skip this to save some time.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.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>
2020-01-20 09:10:23 +01:00
Yury Kotov
e65cec5e5d migration/ram: Yield periodically to the main loop
Usually, incoming migration coroutine yields to the main loop
while its IO-channel is waiting for data to receive. But there is a case
when RAM migration and data receive have the same speed: VM with huge
zeroed RAM. In this case, IO-channel won't read and thus the main loop
is stuck and for instance, it doesn't respond to QMP commands.

For this case, yield periodically, but not too often, so as not to
affect the speed of migration.

Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:22 +01:00
Scott Cheloha
174723ffe5 migration: savevm_state_handler_insert: constant-time element insertion
savevm_state's SaveStateEntry TAILQ is a priority queue.  Priority
sorting is maintained by searching from head to tail for a suitable
insertion spot.  Insertion is thus an O(n) operation.

If we instead keep track of the head of each priority's subqueue
within that larger queue we can reduce this operation to O(1) time.

savevm_state_handler_remove() becomes slightly more complex to
accomodate these gains: we need to replace the head of a priority's
subqueue when removing it.

With O(1) insertion, booting VMs with many SaveStateEntry objects is
more plausible.  For example, a ppc64 VM with maxmem=8T has 40000 such
objects to insert.

Signed-off-by: Scott Cheloha <cheloha@linux.vnet.ibm.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>
2020-01-20 09:10:22 +01:00
Scott Cheloha
bd5de61e7b migration: add savevm_state_handler_remove()
Create a function to abstract common logic needed when removing a
SaveStateEntry element from the savevm_state.handlers queue.

For now we just remove the element.  Soon it will involve additional
cleanup.

Signed-off-by: Scott Cheloha <cheloha@linux.vnet.ibm.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>
2020-01-20 09:10:22 +01:00
Yury Kotov
603d5a42d3 migration: Fix the re-run check of the migrate-incoming command
The current check sets an error but doesn't fail the command.
This may cause a problem if new connection attempt by the same URI
affects the first connection.

Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:22 +01:00
Fangrui Song
2667c98722 migration: Fix incorrect integer->float conversion caught by clang
Clang does not like qmp_migrate_set_downtime()'s code to clamp double
@value to 0..INT64_MAX:

    qemu/migration/migration.c:2038:24: error: implicit conversion from 'long' to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Werror,-Wimplicit-int-float-conversion]

The warning will be enabled by default in clang 10. It is not
available for clang <= 9.

The clamp is actually useless; @value is checked to be within
0..MAX_MIGRATE_DOWNTIME_SECONDS immediately before.  Delete it.

While there, make the conversion from double to int64_t explicit.

Signed-off-by: Fangrui Song <i@maskray.me>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Patch split, commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:22 +01:00
Dr. David Alan Gilbert
97e1e06780 migration: Rate limit inside host pages
When using hugepages, rate limiting is necessary within each huge
page, since a 1G huge page can take a significant time to send, so
you end up with bursty behaviour.

Fixes: 4c011c37ec ("postcopy: Send whole huge pages")
Reported-by: Lin Ma <LMa@suse.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:22 +01:00
Daniel Henrique Barboza
03acb4e94d ram.c: remove unneeded labels
ram_save_queue_pages() has an 'err' label that can be replaced by
'return -1' instead.

Same thing with ram_discard_range(), and in this case we can also
get rid of the 'ret' variable and return either '-1' on error
or the result of ram_block_discard_range().

CC: Juan Quintela <quintela@redhat.com>
CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.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>
2020-01-20 09:10:22 +01:00
Juan Quintela
4d65a6216b migration: Make sure that we don't call write() in case of error
If we are exiting due to an error/finish/.... Just don't try to even
touch the channel with one IO operation.

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>
2020-01-20 09:10:22 +01:00
Juan Quintela
d069bcca6c multifd: Initialize local variable
Fill everything with zero, so the padding fields are also initialized.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-20 09:08:53 +01:00
Marc-André Lureau
3cad405bab vmstate: replace DeviceState with VMStateIf
Replace DeviceState dependency with VMStateIf on vmstate API.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
2020-01-06 18:41:32 +04:00
Paolo Bonzini
44901b5aff colo: fix return without releasing RCU
Use WITH_RCU_READ_LOCK_GUARD to avoid exiting colo_init_ram_cache
without releasing RCU.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:33:52 +01:00
Marc-André Lureau
e4f1bea2a8 migration: fix maybe-uninitialized warning
../migration/ram.c: In function ‘multifd_recv_thread’:
/home/elmarco/src/qq/include/qapi/error.h:165:5: error: ‘block’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  165 |     error_setg_internal((errp), __FILE__, __LINE__, __func__,   \
      |     ^~~~~~~~~~~~~~~~~~~
../migration/ram.c:818:15: note: ‘block’ was declared here
  818 |     RAMBlock *block;
      |               ^~~~~

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:32:47 +01:00
Beata Michalska
bd108a44bc migration: ram: Switch to ram block writeback
Switch to ram block writeback for pmem migration.

Signed-off-by: Beata Michalska <beata.michalska@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20191121000843.24844-4-beata.michalska@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-16 10:46:35 +00:00
Jens Freimann
284f42a520 net/virtio: fix dev_unplug_pending
.dev_unplug_pending is set up by virtio-net code indepent of failover
support was set for the device or not. This gives a wrong result when
we check for existing primary devices in migration code.

Fix this by actually calling dev_unplug_pending() instead of just
checking if the function pointer was set. When the feature was not
negotiated dev_unplug_pending() will always return false. This prevents
us from going into the wait-unplug state when there's no primary device
present.

Fixes: 9711cd0dfc ("net/virtio: add failover support")
Signed-off-by: Jens Freimann <jfreimann@redhat.com>
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2019-11-25 23:30:28 +08:00
Jens Freimann
c7e0acd5a3 migration: add new migration state wait-unplug
This patch adds a new migration state called wait-unplug.  It is entered
after the SETUP state if failover devices are present. It will transition
into ACTIVE once all devices were succesfully unplugged from the guest.

So if a guest doesn't respond or takes long to honor the unplug request
the user will see the migration state 'wait-unplug'.

In the migration thread we query failover devices if they're are still
pending the guest unplug. When all are unplugged the migration
continues. If one device won't unplug migration will stay in wait_unplug
state.

Signed-off-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20191029114905.6856-9-jfreimann@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-29 18:55:26 -04:00
Wei Yang
038adc2f58 core: replace getpagesize() with qemu_real_host_page_size
There are three page size in qemu:

  real host page size
  host page size
  target page size

All of them have dedicate variable to represent. For the last two, we
use the same form in the whole qemu project, while for the first one we
use two forms: qemu_real_host_page_size and getpagesize().

qemu_real_host_page_size is defined to be a replacement of
getpagesize(), so let it serve the role.

[Note] Not fully tested for some arch or device.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191013021145.16011-3-richardw.yang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-26 15:38:06 +02:00
Vladimir Sementsov-Ogievskiy
ef9041a7b8 block/dirty-bitmap: refactor bdrv_dirty_bitmap_next
bdrv_dirty_bitmap_next is always used in same pattern. So, split it
into _next and _first, instead of combining two functions into one and
add FOR_EACH_DIRTY_BITMAP macro.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Vladimir Sementsov-Ogievskiy
5deb6cbd1f block/dirty-bitmap: add bs link
Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState
parameter from bitmap APIs where possible.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com
[Rebased on top of block-copy. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
2019-10-17 17:02:32 -04:00
Eric Auger
9a85e4b8f6 migration: Support gtree migration
Introduce support for GTree migration. A custom save/restore
is implemented. Each item is made of a key and a data.

If the key is a pointer to an object, 2 VMSDs are passed into
the GTree VMStateField.

When putting the items, the tree is traversed in sorted order by
g_tree_foreach.

On the get() path, gtrees must be allocated using the proper
key compare, key destroy and value destroy. This must be handled
beforehand, for example in a pre_load method.

Tests are added to test save/dump of structs containing gtrees
including the virtio-iommu domain/mappings scenario.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

Message-Id: <20191011121724.433-1-eric.auger@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  uintptr_t fixup for test on 32bit
2019-10-11 17:52:31 +01:00
Wei Yang
aff66d2ef0 migration/multifd: pages->used would be cleared when attach to multifd_send_state
When we found an available channel in multifd_send_pages(), its
pages->used is cleared and then attached to multifd_send_state.

It is not necessary to do this twice.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-5-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 15:02:06 +01:00
Wei Yang
9985e1f48d migration/multifd: initialize packet->magic/version once at setup stage
MultiFDPacket_t's magic and version field never changes during
migration, so move these two fields in setup stage.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-4-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 15:02:00 +01:00
Wei Yang
f2148c4c79 migration/multifd: use pages->allocated instead of the static max
multifd_send_fill_packet() prepares meta data for following pages to
transfer. It would be more proper to fill pages->allocated instead of
static max value, especially we want to support flexible packet size.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-3-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 15:01:54 +01:00
Wei Yang
d884e77bfe migration/multifd: fix a typo in comment of multifd_recv_unfill_packet()
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191011085050.17622-2-richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 15:01:44 +01:00
Wei Yang
0197d89025 migration/postcopy: check PostcopyState before setting to POSTCOPY_INCOMING_RUNNING
Currently, we set PostcopyState blindly to RUNNING, even we found the
previous state is not LISTENING. This will lead to a corner case.

First let's look at the code flow:

qemu_loadvm_state_main()
    ret = loadvm_process_command()
        loadvm_postcopy_handle_run()
            return -1;
    if (ret < 0) {
        if (postcopy_state_get() == POSTCOPY_INCOMING_RUNNING)
            ...
    }

>From above snippet, the corner case is loadvm_postcopy_handle_run()
always sets state to RUNNING. And then it checks the previous state. If
the previous state is not LISTENING, it will return -1. But at this
moment, PostcopyState is already been set to RUNNING.

Then ret is checked in qemu_loadvm_state_main(), when it is -1
PostcopyState is checked. Current logic would pause postcopy and retry
if PostcopyState is RUNNING. This is not what we expect, because
postcopy is not active yet.

This patch makes sure state is set to RUNNING only previous state is
LISTENING by checking the state first.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Suggested by: Peter Xu <peterx@redhat.com>
Message-Id: <20191010011316.31363-3-richardw.yang@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 15:00:16 +01:00
Wei Yang
2a7eb14844 migration/postcopy: rename postcopy_ram_enable_notify to postcopy_ram_incoming_setup
Function postcopy_ram_incoming_setup and postcopy_ram_incoming_cleanup
is a pair. Rename to make it clear for audience.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20191010011316.31363-2-richardw.yang@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:59:58 +01:00
Wei Yang
2d49bacda0 migration/postcopy: postpone setting PostcopyState to END
There are two places to call function postcopy_ram_incoming_cleanup()

    postcopy_ram_listen_thread on migration success
    loadvm_postcopy_handle_listen one setup failure

On success, the vm will never accept another migration. On failure,
PostcopyState is transited from LISTENING to END and would be checked in
qemu_loadvm_state_main(). If PostcopyState is RUNNING, migration would
be paused and retried.

Currently PostcopyState is set to END in function
postcopy_ram_incoming_cleanup(). With above analysis, we can take this
step out and postpone this till the end of listen thread to indicate the
listen thread is done.

This is a preparation patch for later cleanup.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191006000249.29926-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Fixed up in merge to the 1 parameter postcopy_state_set
2019-10-11 14:57:22 +01:00
Wei Yang
2a461c2467 migration/postcopy: mis->have_listen_thread check will never be touched
If mis->have_listen_thread is true, this means current PostcopyState
must be LISTENING or RUNNING. While the check at the beginning of the
function makes sure the state transaction happens when its previous
PostcopyState is ADVISE or DISCARD.

This means we would never touch this check.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191006000249.29926-2-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:53:30 +01:00
Wei Yang
4991f3091e migration: report SaveStateEntry id and name on failure
This provides helpful information on which entry failed.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-5-richardw.yang@linux.intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:31:39 +01:00
Wei Yang
17d9351bf2 migration: pass in_postcopy instead of check state again
Not necessary to do the check again.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-4-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:31:27 +01:00
Wei Yang
da1725d3f9 migration/postcopy: fix typo in mark_postcopy_blocktime_begin's comment
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005220517.24029-3-richardw.yang@linux.intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:31:08 +01:00
Wei Yang
6629890d55 migration/postcopy: map large zero page in postcopy_ram_incoming_setup()
postcopy_ram_incoming_setup() and postcopy_ram_incoming_cleanup() are
counterpart. It is reasonable to map/unmap large zero page in these two
functions respectively.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005135021.21721-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:28:49 +01:00
Wei Yang
3414322a83 migration/postcopy: allocate tmp_page in setup stage
During migration, a tmp page is allocated so that we could place a whole
host page during postcopy.

Currently the page is allocated during load stage, this is a little bit
late. And more important, if we failed to allocate it, the error is not
checked properly. Even it is NULL, we would still use it.

This patch moves the allocation to setup stage and if failed error
message would be printed and caller would notice it.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:28:19 +01:00
Dr. David Alan Gilbert
fb14a42ade migration: Don't try and recover return path in non-postcopy
In normal precopy we can't do reconnection recovery - but we also
don't need to, since you can just rerun migration.
At the moment if the 'return-path' capability is on, we use
the return path in precopy to give a positive 'OK' to the end
of migration; however if migration fails then we fall into
the postcopy recovery path and hang.  This fixes it by only
running the return path in the postcopy case.

Reported-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:25:26 +01:00
Dr. David Alan Gilbert
987ab2a549 migration: Use automatic rcu_read unlock in rdma.c
Use the automatic read unlocker in migration/rdma.c.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-5-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:20:01 +01:00
Dr. David Alan Gilbert
89ac5a1d2a migration: Use automatic rcu_read unlock in ram.c
Use the automatic read unlocker in migration/ram.c

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-4-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:20:00 +01:00
Dr. David Alan Gilbert
0e6ebd4877 migration: Fix missing rcu_read_unlock
Use the automatic rcu_read unlocker to fix a missing unlock.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20191007143642.301445-3-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:19:59 +01:00
Wei Yang
8f8d528e73 migration: use migration_is_active to represent active state
Wrap the check into a function to make it easy to read.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190717005341.14140-1-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:18:13 +01:00
Dr. David Alan Gilbert
3748fef9b9 migration/postcopy: Recognise the recovery states as 'in_postcopy'
Various parts of the migration code do different things when they're
in postcopy mode; prior to this patch this has been 'postcopy-active'.
This patch extends 'in_postcopy' to include 'postcopy-paused' and
'postcopy-recover'.

In particular, when you set the max-postcopy-bandwidth parameter, this
only affects the current migration fd if we're 'in_postcopy';
this leads to a race in the postcopy recovery test where it increases
the speed from 4k/sec to unlimited, but that increase can get ignored
if the change is made between the point at which the reconnection
happens and it transitions back to active.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190923174942.12182-1-dgilbert@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-25 15:51:19 +01:00
Dr. David Alan Gilbert
d46a4847ca migration/rdma.c: Swap synchronize_rcu for call_rcu
This fixes a deadlock that can occur on the migration source after
a failed RDMA migration;  as the source tries to cleanup it
clears a pair of pointers and uses synchronize_rcu to wait; this
is happening on the main thread.  With the CPUs running
a CPU thread can be an rcu reader and attempt to grab the main lock
(kvm_handle_io->address_space_write->flatview_write->flatview_write_continue->
prepare_mmio_access->qemu_mutex_lock_iothread_impl)

Replace the synchronize_rcu with a call_rcu to postpone the freeing.

Fixes: 74637e6f08 ("migration: implement bi-directional RDMA QIOChannel")

( https://bugzilla.redhat.com/show_bug.cgi?id=1746787 )

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190913163507.1403-3-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-25 15:51:19 +01:00