* Device configurations
*
* The configuration information for a device consists of a series of fields.
- * The device will look for these fields during setup.
+ * We don't really care what they are: the Launcher set them up, and the driver
+ * will look at them during setup.
*
* For us these fields come immediately after that device's descriptor in the
* lguest_devices page.
* The other piece of infrastructure virtio needs is a "virtqueue": a way of
* the Guest device registering buffers for the other side to read from or
* write into (ie. send and receive buffers). Each device can have multiple
- * virtqueues: for example the console has one queue for sending and one for
- * receiving.
+ * virtqueues: for example the console driver uses one queue for sending and
+ * another for receiving.
*
* Fortunately for us, a very fast shared-memory-plus-descriptors virtqueue
* already exists in virtio_ring.c. We just need to connect it up.
*
* This is kind of an ugly duckling. It'd be nicer to have a standard
* representation of a virtqueue in the configuration space, but it seems that
- * everyone wants to do it differently. The KVM guys want the Guest to
+ * everyone wants to do it differently. The KVM coders want the Guest to
* allocate its own pages and tell the Host where they are, but for lguest it's
* simpler for the Host to simply tell us where the pages are.
*
/* Figure out how many pages the ring will take, and map that memory */
lvq->pages = lguest_map((unsigned long)lvq->config.pfn << PAGE_SHIFT,
- DIV_ROUND_UP(vring_size(lvq->config.num),
+ DIV_ROUND_UP(vring_size(lvq->config.num,
+ PAGE_SIZE),
PAGE_SIZE));
if (!lvq->pages) {
err = -ENOMEM;
{
struct lguest_vq_info *lvq = vq->priv;
+ /* Release the interrupt */
+ free_irq(lvq->config.irq, vq);
/* Tell virtio_ring.c to free the virtqueue. */
vring_del_virtqueue(vq);
/* Unmap the pages containing the ring. */
{
struct lguest_device *ldev;
+ /* Start with zeroed memory; Linux's device layer seems to count on
+ * it. */
ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
if (!ldev) {
printk(KERN_EMERG "Cannot allocate lguest dev %u\n",