From 10b2393e5e7f4c1d633f1ac8578465681c333efb Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 31 Jan 2024 18:31:40 +0100 Subject: [PATCH] blkio: Respect memory-alignment for bounce buffer allocations 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 Signed-off-by: Kevin Wolf Message-ID: <20240131173140.42398-1-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Reviewed-by: Stefano Garzarella Signed-off-by: Kevin Wolf --- block/blkio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blkio.c b/block/blkio.c index bc2f21784c..882e1c297b 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;