Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- include/exec/memory.h | 34 ++++++++++++++++++++++++++++++++++ memory.c | 14 ++++++++++++++ 2 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h index 5c20bac..ebac085 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -253,6 +253,40 @@ struct MemoryListener { void memory_region_init(MemoryRegion *mr, const char *name, uint64_t size); + +/** + * memory_region_ref: Add 1 to a memory region's reference count + * + * Whenever memory regions are accessed outside the BQL, they need to be + * preserved against hot-unplug. MemoryRegions actually do not have their + * own reference count; they piggyback on a QOM object, their "owner". + * This function adds a reference to the owner. + * + * All MemoryRegions must have an owner if they can disappear, even if the + * device they belong to operates exclusively under the BQL. This is because + * the region could be returned at any time by memory_region_find, and this + * is usually under guest control. + * + * @mr: the #MemoryRegion to be initialized + * @name: used for debugging; not visible to the user or ABI + * @size: size of the region; any subregions beyond this size will be clipped + */ +void memory_region_ref(MemoryRegion *mr); + +/** + * memory_region_ref: Remove 1 to a memory region's reference count + * + * Whenever memory regions are accessed outside the BQL, they need to be + * preserved against hot-unplug. MemoryRegions actually do not have their + * own reference count; they piggyback on a QOM object, their "owner". + * This function removes a reference to the owner and possibly destroys it. + * + * @mr: the #MemoryRegion to be initialized + * @name: used for debugging; not visible to the user or ABI + * @size: size of the region; any subregions beyond this size will be clipped + */ +void memory_region_unref(MemoryRegion *mr); + /** * memory_region_init_io: Initialize an I/O memory region. * diff --git a/memory.c b/memory.c index f7fddb1..c7ab19c 100644 --- a/memory.c +++ b/memory.c @@ -1061,6 +1061,20 @@ void memory_region_set_owner(MemoryRegion *mr, } } +void memory_region_ref(MemoryRegion *mr) +{ + if (mr && mr->owner) { + object_ref(mr->owner); + } +} + +void memory_region_unref(MemoryRegion *mr) +{ + if (mr && mr->owner) { + object_unref(mr->owner); + } +} + uint64_t memory_region_size(MemoryRegion *mr) { if (int128_eq(mr->size, int128_2_64())) { -- 1.7.1