Listeners now hold a reference to the RamDiscardManager, ensuring it
stays alive while listeners are registered. The RDM is eagerly freed
when the last source and listener are removed, and also unreffed during
MemoryRegion finalization as a safety net.
This completes the TODO left in the previous commit and prevents both
use-after-free and memory leaks of the RamDiscardManager.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20260604-rdm5-v5-9-5768e6a0943d@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Refactor RamDiscardManager to aggregate multiple RamDiscardSource
instances. This enables scenarios where multiple components (e.g.,
virtio-mem and RamBlockAttributes) can coordinate memory discard
state for the same memory region.
The aggregation uses:
- Populated: ALL sources populated
- Discarded: ANY source discarded
When a source is added with existing listeners, they are notified
about regions that become discarded. When a source is removed,
listeners are notified about regions that become populated.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20260604-rdm5-v5-7-5768e6a0943d@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Replace the source-level replay wrappers with a new
replay_by_populated_state() helper that iterates the section at
min-granularity, calls is_populated() for each chunk, and aggregates
consecutive chunks of the same state before invoking the callback.
This moves the iteration logic from individual sources into the manager,
preparing for multi-source aggregation where the manager must combine
state from multiple sources anyway.
The replay_populated/replay_discarded vtable entries in
RamDiscardSourceClass are no longer called but remain in the interface
for now; they will be removed in follow-up commits along with the
now-dead source implementations.
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: David Hildenbrand <david@kernel.org>
Link: https://lore.kernel.org/r/20260604-rdm5-v5-4-5768e6a0943d@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Extract RamDiscardManager and RamDiscardSource from system/memory.c into
dedicated a unit.
This reduces coupling and allows code that only needs the
RamDiscardManager interface to avoid pulling in all of memory.h
dependencies.
rust-sys bindings are no longer generated for RamDiscardSourceClass at
this point, thus we drop the unneeded InterfaceClass use.
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-v5-2-5768e6a0943d@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
