From 7abb568dbb32d055ec6a5633d26fb39fbcd525e3 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 11 Feb 2015 15:01:14 +1030 Subject: [PATCH] virtio_pci: use 16-bit accessor for queue_enable. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since PCI is little endian, 8-bit access might work, but the spec section is very clear on this: 4.1.3.1 Driver Requirements: PCI Device Layout The driver MUST access each field using the “natural” access method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit fields and 8-bit accesses for 8-bit fields. Signed-off-by: Rusty Russell Acked-by: Michael S. Tsirkin --- drivers/virtio/virtio_pci_modern.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index f16e462cb4ef..2aa38e59db2e 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -294,7 +294,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, /* Check if queue is either not available or already active. */ num = ioread16(&cfg->queue_size); - if (!num || ioread8(&cfg->queue_enable)) + if (!num || ioread16(&cfg->queue_enable)) return ERR_PTR(-ENOENT); if (num & (num - 1)) { @@ -394,7 +394,7 @@ static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs, */ list_for_each_entry(vq, &vdev->vqs, list) { iowrite16(vq->index, &vp_dev->common->queue_select); - iowrite8(1, &vp_dev->common->queue_enable); + iowrite16(1, &vp_dev->common->queue_enable); } return 0; -- 2.30.2