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>
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c
index 5d10432..60cabaf 100644
--- a/tools/lguest/lguest.c
+++ b/tools/lguest/lguest.c
@@ -1037,6 +1037,12 @@
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 @@
/* 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 @@
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 */