From: Brian Foley <[email protected]> vm_setup_vq fails to allow VirtQueues needing only 2 pages of storage, as it should. Found with a kernel using 64kB pages, but can be provoked if a virtio device reports QueueNumMax where the descriptor table and available ring fit in one page, and the used ring on the second (<= 227 descriptors with 4kB pages and <= 3640 with 64kB pages.)
Signed-off-by: Brian Foley <[email protected]> --- drivers/virtio/virtio_mmio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 453db0c..58e2d78 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -335,8 +335,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, while (1) { size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN)); - /* Already smallest possible allocation? */ - if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) { + /* Did the last iter shrink the queue below minimum size? */ + if (size < VIRTIO_MMIO_VRING_ALIGN * 2) { err = -ENOMEM; goto error_alloc_pages; } -- 1.7.9.5 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
