migrate: add migration blockers
This lets different subsystems register an Error that is thrown whenever
migration is attempted. This works nicely because it gracefully supports
things like hotplug.
Right now, if multiple errors are registered, only one of them is reported.
I expect that for 1.1, we'll extend query-migrate to return all of the reasons
why migration is disabled at any given point in time.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
projects / sdk / emulator / qemu.git / commit