tree 753ad52ec84d825b4d5e4c878ac99f62e032226b
parent b0cc3f839751bd83bdfcc480097c981c7aa1f3ec
author Michael S. Tsirkin <mst@redhat.com> 1416176676 +0200
committer Michael S. Tsirkin <mst@redhat.com> 1420715875 +0200

memory: API to allocate resizeable RAM MR

Add API to allocate resizeable RAM MR.

This looks just like regular RAM generally, but
has a special property that only a portion of it
(used_length) is actually used, and migrated.

This used_length size can change across reboots.

Follow up patches will change used_length for such blocks at migration,
making it easier to extend devices using such RAM (notably ACPI,
but in the future thinkably other ROMs) without breaking migration
compatibility or wasting ROM (guest) memory.

Device is notified on resize, so it can adjust if necessary.

Note: nothing prevents making all RAM resizeable in this way.
However, reviewers felt that only enabling this selectively will
make some class of errors easier to detect.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>