Commit 2aece63c8a "hostmem: detect host backend memory is being used
properly" fixed "ivshmem-plain" to reject memory backends that are
already in use, and to block their deletion while in use. Two bugs
escaped review:
* New ivshmem_plain_exit() fails to call ivshmem_exit(). This breaks
unplug. Reproducer: migration after unplug still fails with
"Migration is disabled when using feature 'peer mode' in device
'ivshmem'".
* It failed to update legacy "ivshmem". Harmless, because it creates
the memory backend itself, and nothing else should use it.
Fix by moving the two host_memory_backend_set_mapped() calls into
ivshmem_common_realize() and ivshmem_exit(), guarded by s->hostmem.
Fixes: 2aece63c8a9d2c3a8ff41d2febc4cdeff2633331
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180926163709.22876-1-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
b266f1d112