hvm: infrastructure for backwards-compatible loading

The hvm_save code is used to save and restore hypervisor-related hvm
state, either for classic save/restore, or for migration (including
remus).  This is meant to be backwards-compatible across some
hypervisor versions; but if it does change, there is no way to handle
the old format as well as the new.

This patch introduces the infrastructure to allow a single older
version ("compat") of any given "save type" to be defined, along with
a function to turn the "old" version into the "new" version.  If the
size check fails for the "normal" version, it will check the "compat"
version, and if it matches, will read the old entry and call the
conversion function.

This patch involves some preprocessor hackery, but I'm only extending
the hackery that's already there.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Tim Deegan <Tim.Deegan@citrix.com>
Committed-by: Tim Deegan <Tim.Deegan@citrix.com>
xen-unstable changeset:   23171:6a5830de7b54
xen-unstable date:        Wed Apr 06 11:40:51 2011 +0100

0 files changed, 0 insertions, 0 deletions