Refactor the RamDiscardManager interface into two distinct components:
- RamDiscardSource: An interface that state providers (virtio-mem,
RamBlockAttributes) implement to provide discard state information
(granularity, populated/discarded ranges, replay callbacks).
- RamDiscardManager: A concrete QOM object that wraps a source, owns
the listener list, and handles listener registration/unregistration
and notifications.
This separation moves the listener management logic from individual
source implementations into the central RamDiscardManager, reducing
code duplication between virtio-mem and RamBlockAttributes.
The change prepares for future work where a RamDiscardManager could
aggregate multiple sources.
Note, the original virtio-mem code had conditions before discard:
if (vmem->size) {
rdl->notify_discard(rdl, rdl->section);
}
however, the new code calls discard unconditionally. This is considered
safe, since the populate/discard of sections are already asymmetrical
(unplug & unregister all listener section unconditionally).
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@kernel.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260604-rdm5-v5-1-5768e6a0943d@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
43d1320c6c