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
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block.c
block.h
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
colo-failover.c
colo.c
exec.c	migration: Route errors down through migration_channel_connect	2018-02-06 10:55:12 +00:00
exec.h
fd.c	migration: Route errors down through migration_channel_connect	2018-02-06 10:55:12 +00:00
fd.h
global_state.c
Makefile.objs
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
page_cache.h
postcopy-ram.c	migration: Revert postcopy-blocktime commit set	2018-01-23 10:08:05 +00:00
postcopy-ram.h
qemu-file-channel.c
qemu-file-channel.h
qemu-file.c
qemu-file.h
qjson.c
qjson.h
ram.c	migration: Drop current address parameter from save_zero_page()	2018-02-06 10:55:13 +00:00
ram.h
rdma.c	migration: Allow migrate_fd_connect to take an Error *	2018-02-06 10:55:12 +00:00
rdma.h
savevm.c	migration: incoming postcopy advise sanity checks	2018-02-06 14:53:02 +00:00
savevm.h
socket.c	migration: Route errors down through migration_channel_connect	2018-02-06 10:55:12 +00:00
socket.h
tls.c	migration: Route errors down through migration_channel_connect	2018-02-06 10:55:12 +00:00
tls.h
trace-events	migration: Route errors down through migration_channel_connect	2018-02-06 10:55:12 +00:00
vmstate-types.c
vmstate.c
xbzrle.c
xbzrle.h