blkio_alloc_mem_region() requires that the requested buffer size is a multiple of the memory-alignment property. If it isn't, the allocation fails with a return value of -EINVAL.
Fix the call in blkio_resize_bounce_pool() to make sure the requested size is properly aligned. I observed this problem with vhost-vdpa, which requires page aligned memory. As the virtio-blk device behind it still had 512 byte blocks, we got bs->bl.request_alignment = 512, but actually any request that needed a bounce buffer and was not aligned to 4k would fail without this fix. Suggested-by: Stefano Garzarella <sgarz...@redhat.com> Signed-off-by: Kevin Wolf <kw...@redhat.com> --- block/blkio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blkio.c b/block/blkio.c index 0a0a6c0f5f..b989617608 100644 --- a/block/blkio.c +++ b/block/blkio.c @@ -89,6 +89,9 @@ static int blkio_resize_bounce_pool(BDRVBlkioState *s, int64_t bytes) /* Pad size to reduce frequency of resize calls */ bytes += 128 * 1024; + /* Align the pool size to avoid blkio_alloc_mem_region() failure */ + bytes = QEMU_ALIGN_UP(bytes, s->mem_region_alignment); + WITH_QEMU_LOCK_GUARD(&s->blkio_lock) { int ret; -- 2.43.0