qemu/migration
Greg Kurz 875fcd013a migration: incoming postcopy advise sanity checks
If postcopy-ram was set on the source but not on the destination,
migration doesn't occur, the destination prints an error and boots
the guest:

qemu-system-ppc64: Expected vmdescription section, but got 0

We end up with two running instances.

This behaviour was introduced in 2.11 by commit 58110f0acb "migration:
split common postcopy out of ram postcopy" to prepare ground for the
upcoming dirty bitmap postcopy support. It adds a new case where the
source may send an empty postcopy advise because dirty bitmap doesn't
need to check page sizes like RAM postcopy does.

If the source has enabled postcopy-ram, then it sends an advise with
the page size values. If the destination hasn't enabled postcopy-ram,
then loadvm_postcopy_handle_advise() leaves the page size values on
the stream and returns. This confuses qemu_loadvm_state() later on
and causes the destination to start execution.

As discussed several times, postcopy-ram should be enabled both sides
to be functional. This patch changes the destination to perform some
extra checks on the advise length to ensure this is the case. Otherwise
an error is returned and migration is aborted.

Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <151791621042.19120.3103118434734245776.stgit@bahia>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-02-06 14:53:02 +00:00
..
block.c Replace all occurances of __FUNCTION__ with __func__ 2018-01-22 09:46:18 +01:00
block.h migration: disable auto-converge during bulk block migration 2017-09-27 11:27:14 +01:00
channel.c migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
channel.h migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
colo-comm.c migration: pre_save return int 2017-09-27 11:35:59 +01:00
colo-failover.c qapi: Mechanically convert FOO_lookup[...] to FOO_str(...) 2017-09-04 13:09:13 +02:00
colo.c qapi: Mechanically convert FOO_lookup[...] to FOO_str(...) 2017-09-04 13:09:13 +02:00
exec.c migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
exec.h migration: Export exec.c functions in its own file 2017-06-01 18:49:22 +02:00
fd.c migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
fd.h migration: Export fd.c functions in its own file 2017-06-01 18:49:22 +02:00
global_state.c migration: pre_save return int 2017-09-27 11:35:59 +01:00
Makefile.objs buildsys: Move rdma libs to per object 2017-09-22 10:20:34 +08:00
migration.c migration: Recover block devices if failure in device state 2018-02-06 14:53:02 +00:00
migration.h migration: Allow migrate_fd_connect to take an Error * 2018-02-06 10:55:12 +00:00
page_cache.c migration: Make sure that we pass the right cache size 2017-10-29 14:06:15 +01:00
page_cache.h migration: Make cache_init() take an error parameter 2017-10-23 18:03:25 +02:00
postcopy-ram.c migration: Revert postcopy-blocktime commit set 2018-01-23 10:08:05 +00:00
postcopy-ram.h migration: postcopy_place_page factoring out 2017-10-23 18:03:39 +02:00
qemu-file-channel.c migration: Split qemu-file.h 2017-06-01 18:49:22 +02:00
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 migration: Remove unneeded includes 2017-06-14 11:10:19 +02:00
qemu-file.h migration: ram_control_* are implemented in qemu_file 2017-06-13 11:00:45 +02:00
qjson.c migration: Move qjson.h to migration/ 2017-05-18 19:20:59 +02:00
qjson.h migration: Move qjson.h to migration/ 2017-05-18 19:20:59 +02:00
ram.c migration: Drop current address parameter from save_zero_page() 2018-02-06 10:55:13 +00:00
ram.h migration: No need to return the size of the cache 2017-10-29 14:06:15 +01:00
rdma.c migration: Allow migrate_fd_connect to take an Error * 2018-02-06 10:55:12 +00:00
rdma.h migration: Export rdma.c functions in its own file 2017-06-01 18:49:23 +02:00
savevm.c migration: incoming postcopy advise sanity checks 2018-02-06 14:53:02 +00:00
savevm.h migration: Create load_setup()/cleanup() methods 2017-07-10 17:52:21 +01:00
socket.c migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
socket.h migration: Export socket.c functions in its own file 2017-06-01 18:49:23 +02:00
tls.c migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
tls.h migration: Export tls.c functions in its own file 2017-06-01 18:49:23 +02:00
trace-events migration: Route errors down through migration_channel_connect 2018-02-06 10:55:12 +00:00
vmstate-types.c migration: Route more error paths 2017-09-27 11:44:18 +01:00
vmstate.c migration: wire vmstate_save_state errors up to vmstate_subsection_save 2017-09-27 11:38:21 +01:00
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