qemu-e2k/migration
Leonardo Bras 5b1d9bab2d multifd: Implement zero copy write in multifd migration (multifd-zero-copy)
Implement zero copy send on nocomp_send_write(), by making use of QIOChannel
writev + flags & flush interface.

Change multifd_send_sync_main() so flush_zero_copy() can be called
after each iteration in order to make sure all dirty pages are sent before
a new iteration is started. It will also flush at the beginning and at the
end of migration.

Also make it return -1 if flush_zero_copy() fails, in order to cancel
the migration process, and avoid resuming the guest in the target host
without receiving all current RAM.

This will work fine on RAM migration because the RAM pages are not usually freed,
and there is no problem on changing the pages content between writev_zero_copy() and
the actual sending of the buffer, because this change will dirty the page and
cause it to be re-sent on a next iteration anyway.

A lot of locked memory may be needed in order to use multifd migration
with zero-copy enabled, so disabling the feature should be necessary for
low-privileged users trying to perform multifd migrations.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220513062836.965425-9-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
..
block-dirty-bitmap.c migration: block-dirty-bitmap: add missing qemu_mutex_lock_iothread 2021-10-05 13:10:29 +02:00
block.c block: rename bdrv_invalidate_cache_all, blk_invalidate_cache and test_sync_op_invalidate_cache 2022-03-04 18:14:40 +01:00
block.h migration: disable auto-converge during bulk block migration 2017-09-27 11:27:14 +01:00
channel.c migration: Add migrate_use_tls() helper 2022-05-16 13:56:24 +01:00
channel.h migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
colo-failover.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
colo.c COLO: Move some trace code behind qemu_mutex_unlock_iothread() 2021-12-15 10:31:42 +01:00
dirtyrate.c Use g_new() & friends where that makes obvious sense 2022-03-21 15:44:44 +01:00
dirtyrate.h migration/dirtyrate: introduce struct and adjust DirtyRateStat 2021-11-01 22:56:43 +01:00
exec.c migration: unify incoming processing 2018-07-10 12:48:53 +01:00
exec.h migration: Export exec.c functions in its own file 2017-06-01 18:49:22 +02:00
fd.c monitor: Use getter/setter functions for cur_mon 2020-10-09 07:08:19 +02:00
fd.h migration: Fix fd protocol for incoming defer 2019-06-05 12:43:55 +02:00
global_state.c migration: Silence compiler warning in global_state_store_running() 2020-10-02 12:28:48 +01:00
meson.build meson, configure: move RDMA options to meson 2022-04-28 08:52:20 +02:00
migration.c multifd: Implement zero copy write in multifd migration (multifd-zero-copy) 2022-05-16 13:56:24 +01:00
migration.h migration: Add migrate_use_tls() helper 2022-05-16 13:56:24 +01:00
multifd-zlib.c Use g_new() & friends where that makes obvious sense 2022-03-21 15:44:44 +01:00
multifd-zstd.c multifd: recv side only needs the RAMBlock host address 2022-01-28 15:38:23 +01:00
multifd.c multifd: Implement zero copy write in multifd migration (multifd-zero-copy) 2022-05-16 13:56:24 +01:00
multifd.h multifd: Implement zero copy write in multifd migration (multifd-zero-copy) 2022-05-16 13:56:24 +01:00
page_cache.c migration: Fix cache_init()'s "Failed to allocate" error messages 2021-02-08 11:19:51 +00:00
page_cache.h migration: Clean up signed vs. unsigned XBZRLE cache-size 2021-02-08 11:19:51 +00:00
postcopy-ram.c Replace qemu_real_host_page variables with inlined functions 2022-04-06 10:50:38 +02:00
postcopy-ram.h migration: Add postcopy_thread_create() 2022-03-02 18:20:45 +00:00
qemu-file-channel.c migration: Move the yank unregister of channel_close out 2021-07-26 12:45:03 +01:00
qemu-file-channel.h migration: Export qemu-file-channel.c functions in its own file 2017-05-18 19:20:50 +02:00
qemu-file.c include: Move qemu_madvise() and related #defines to new qemu/madvise.h 2022-02-21 13:30:20 +00:00
qemu-file.h migration: Teach QEMUFile to be QIOChannel-aware 2021-07-26 12:44:59 +01:00
ram.c multifd: multifd_send_sync_main now returns negative on error 2022-05-16 13:56:24 +01:00
ram.h migration: Export ram_load_postcopy() 2022-04-21 19:36:46 +01:00
rdma.c QIOChannel: Add flags on io_writev and introduce io_flush callback 2022-05-16 13:56:24 +01:00
rdma.h migration: Export rdma.c functions in its own file 2017-06-01 18:49:23 +02:00
savevm.c migration: Allow migrate-recover to run multiple times 2022-04-21 19:36:46 +01:00
savevm.h migration: Add blocker information 2021-02-08 11:19:51 +00:00
socket.c multifd: Implement zero copy write in multifd migration (multifd-zero-copy) 2022-05-16 13:56:24 +01:00
socket.h migration: unify the framework of socket-type channel 2020-08-28 13:34:52 +01:00
target.c migration: Move populate_vfio_info() into a separate file 2021-05-14 12:31:51 +02:00
tls.c migration: fix use of TLS PSK credentials with a UNIX socket 2022-04-21 19:36:46 +01:00
tls.h migration: Fix Lesser GPL version number 2020-11-15 16:43:28 +01:00
trace-events migration: Tracepoint change in postcopy-run bottom half 2022-03-02 18:17:56 +00:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
vmstate-types.c Move CPU softfloat unions to cpu-float.h 2022-04-06 14:31:43 +02:00
vmstate.c migration: Remove load_state_old and minimum_version_id_old 2022-03-02 18:20:45 +00:00
xbzrle.c migration: Create migration/xbzrle.h 2017-05-18 18:04:54 +02:00
xbzrle.h migration: Create migration/xbzrle.h 2017-05-18 18:04:54 +02:00
yank_functions.c migration: Move the yank unregister of channel_close out 2021-07-26 12:45:03 +01:00
yank_functions.h migration: Move the yank unregister of channel_close out 2021-07-26 12:45:03 +01:00