qemu/migration
Peter Xu f37bc03623 migration: allow to prioritize save state entries
During migration, save state entries are saved/loaded without a specific
order - we just traverse the savevm_state.handlers list and do it one by
one. This might not be enough.

There are requirements that we need to load specific device's vmstate
first before others. For example, VT-d IOMMU contains DMA address
remapping information, which is required by all the PCI devices to do
address translations. We need to make sure IOMMU's device state is
loaded before the rest of the PCI devices, so that DMA address
translation can work properly.

This patch provide a VMStateDescription.priority value to allow specify
the priority of the saved states. The loadvm operation will be done with
those devices with higher vmsd priority.

Before this patch, we are possibly achieving the ordering requirement by
an assumption that the ordering will be the same with the ordering that
objects are created. A better way is to mark it out explicitly in the
VMStateDescription table, like what this patch does.

Current ordering logic is still naive and slow, but after all that's not
a critical path so IMO it's a workable solution for now.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-01-10 05:56:57 +02:00
..
block.c migration/block: Convert saving to BlockBackend 2016-06-08 10:21:08 +02:00
colo-comm.c COLO: Add 'x-colo-lost-heartbeat' command to trigger failover 2016-10-30 15:17:39 +05:30
colo-failover.c COLO: Implement the process of failover for primary VM 2016-10-30 15:17:39 +05:30
colo.c migration: fix compiler warning on uninitialized variable 2016-11-01 09:31:53 +00:00
exec.c migration: set name for all I/O channels created 2016-10-27 09:13:10 +02:00
fd.c migration: set name for all I/O channels created 2016-10-27 09:13:10 +02:00
Makefile.objs COLO: Add 'x-colo-lost-heartbeat' command to trigger failover 2016-10-30 15:17:39 +05:30
migration.c migration: fix missing assignment for has_x_checkpoint_delay 2016-11-14 14:50:56 +01:00
postcopy-ram.c migration/postcopy: Explicitly disallow huge pages 2016-10-13 17:23:53 +02:00
qemu-file-channel.c migration: introduce a new QEMUFile impl based on QIOChannel 2016-05-26 11:31:24 +05:30
qemu-file.c migration: fix live migration failure with compression 2016-08-11 16:59:53 +05:30
qjson.c qjson: free str 2016-08-08 00:00:24 +04:00
ram.c migration: Fix return code of ram_save_iterate() 2016-11-14 19:35:41 +01:00
rdma.c migration/rdma: Don't flag an error when we've been told about one 2016-10-13 17:22:38 +02:00
savevm.c migration: allow to prioritize save state entries 2017-01-10 05:56:57 +02:00
socket.c migration: set name for all I/O channels created 2016-10-27 09:13:10 +02:00
tls.c migration: set name for all I/O channels created 2016-10-27 09:13:10 +02:00
trace-events COLO: Introduce state to record failover process 2016-10-30 15:17:39 +05:30
vmstate.c migration: Report values for comparisons 2016-10-13 17:22:38 +02:00
xbzrle.c util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00