virtio_pci: use 16-bit accessor for queue_enable.

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 <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Rusty Russell 2015-02-11 15:01:14 +10:30
parent 6d96ee98b1
commit 7abb568dbb

View File

@ -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;