tools/lguest: handle device reset correctly in example launcher.

The example launcher doesn't reset the queue_enable like the spec says
we have to.  Plus, we should reset the size in case they negotiated
a different (smaller) one.

This is easy to test by unloading and reloading a virtio module.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell 2015-02-13 17:13:40 +10:30
parent a2e1999157
commit d2dbdac336
1 changed files with 18 additions and 2 deletions

View File

@ -1037,6 +1037,12 @@ static void kill_launcher(int signal)
kill(0, SIGTERM);
}
static void reset_vq_pci_config(struct virtqueue *vq)
{
vq->pci_config.queue_size = VIRTQUEUE_NUM;
vq->pci_config.queue_enable = 0;
}
static void reset_device(struct device *dev)
{
struct virtqueue *vq;
@ -1049,8 +1055,19 @@ static void reset_device(struct device *dev)
/* We're going to be explicitly killing threads, so ignore them. */
signal(SIGCHLD, SIG_IGN);
/*
* 4.1.4.3.1:
*
* The device MUST present a 0 in queue_enable on reset.
*
* This means we set it here, and reset the saved ones in every vq.
*/
dev->mmio->cfg.queue_enable = 0;
/* Get rid of the virtqueue threads */
for (vq = dev->vq; vq; vq = vq->next) {
vq->last_avail_idx = 0;
reset_vq_pci_config(vq);
if (vq->thread != (pid_t)-1) {
kill(vq->thread, SIGTERM);
waitpid(vq->thread, NULL, 0);
@ -1952,8 +1969,7 @@ static void add_pci_virtqueue(struct device *dev,
vq->thread = (pid_t)-1;
/* Initialize the configuration. */
vq->pci_config.queue_size = VIRTQUEUE_NUM;
vq->pci_config.queue_enable = 0;
reset_vq_pci_config(vq);
vq->pci_config.queue_notify_off = 0;
/* Add one to the number of queues */