@@ -2420,6 +2420,10 @@ static int virtio_mem_init(struct virtio_mem *vm)
dev_warn(&vm->vdev->dev,
"Some device memory is not addressable/pluggable. This can make some memory unusable.\n");
+ /* Prepare the offline threshold - make sure we can add two blocks. */
+ vm->offline_threshold = max_t(uint64_t, 2 * memory_block_size_bytes(),
+ VIRTIO_MEM_DEFAULT_OFFLINE_THRESHOLD);
+
/*
* We want subblocks to span at least MAX_ORDER_NR_PAGES and
* pageblock_nr_pages pages. This:
@@ -2466,14 +2470,11 @@ static int virtio_mem_init(struct virtio_mem *vm)
vm->bbm.bb_size - 1;
vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, addr);
vm->bbm.next_bb_id = vm->bbm.first_bb_id;
- }
- /* Prepare the offline threshold - make sure we can add two blocks. */
- vm->offline_threshold = max_t(uint64_t, 2 * memory_block_size_bytes(),
- VIRTIO_MEM_DEFAULT_OFFLINE_THRESHOLD);
- /* In BBM, we also want at least two big blocks. */
- vm->offline_threshold = max_t(uint64_t, 2 * vm->bbm.bb_size,
- vm->offline_threshold);
+ /* Make sure we can add two big blocks. */
+ vm->offline_threshold = max_t(uint64_t, 2 * vm->bbm.bb_size,
+ vm->offline_threshold);
+ }
dev_info(&vm->vdev->dev, "start address: 0x%llx", vm->addr);
dev_info(&vm->vdev->dev, "region size: 0x%llx", vm->region_size);
We are reading a Big Block Mode value while in Sub Block Mode when initializing. Fortunately, vm->bbm.bb_size maps to some counter in the vm->sbm.mb_count array, which is 0 at that point in time. No harm done; still, this was unintended and is not future-proof. Fixes: 4ba50cd3355d ("virtio-mem: Big Block Mode (BBM) memory hotplug") Signed-off-by: David Hildenbrand <david@redhat.com> --- drivers/virtio/virtio_mem.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)