From: David Hildenbrand david@redhat.com
[ Upstream commit 500817bf5e110ad9b7138bc582971bb7ee77d6f7 ]
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 Link: https://lore.kernel.org/r/20210602185720.31821-2-david@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/virtio/virtio_mem.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 10ec60d81e84..3bf08b5bb359 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -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);