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-rw-r--r--Documentation/virtual/lguest/lguest.c25
-rw-r--r--drivers/lguest/lguest_device.c37
2 files changed, 28 insertions, 34 deletions
diff --git a/Documentation/virtual/lguest/lguest.c b/Documentation/virtual/lguest/lguest.c
index e3b9bb7a644a..80261d34da3d 100644
--- a/Documentation/virtual/lguest/lguest.c
+++ b/Documentation/virtual/lguest/lguest.c
@@ -1095,9 +1095,10 @@ static void update_device_status(struct device *dev)
warnx("Device %s configuration FAILED", dev->name);
if (dev->running)
reset_device(dev);
- } else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) {
- if (!dev->running)
- start_device(dev);
+ } else {
+ if (dev->running)
+ err(1, "Device %s features finalized twice", dev->name);
+ start_device(dev);
}
}
@@ -1122,25 +1123,11 @@ static void handle_output(unsigned long addr)
return;
}
- /*
- * Devices *can* be used before status is set to DRIVER_OK.
- * The original plan was that they would never do this: they
- * would always finish setting up their status bits before
- * actually touching the virtqueues. In practice, we allowed
- * them to, and they do (eg. the disk probes for partition
- * tables as part of initialization).
- *
- * If we see this, we start the device: once it's running, we
- * expect the device to catch all the notifications.
- */
+ /* Devices should not be used before features are finalized. */
for (vq = i->vq; vq; vq = vq->next) {
if (addr != vq->config.pfn*getpagesize())
continue;
- if (i->running)
- errx(1, "Notification on running %s", i->name);
- /* This just calls create_thread() for each virtqueue */
- start_device(i);
- return;
+ errx(1, "Notification on %s before setup!", i->name);
}
}
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index 69c84a1d88ea..5289ffa2e500 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -109,6 +109,17 @@ static u32 lg_get_features(struct virtio_device *vdev)
}
/*
+ * To notify on reset or feature finalization, we (ab)use the NOTIFY
+ * hypercall, with the descriptor address of the device.
+ */
+static void status_notify(struct virtio_device *vdev)
+{
+ unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices;
+
+ hcall(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset, 0, 0, 0);
+}
+
+/*
* The virtio core takes the features the Host offers, and copies the ones
* supported by the driver into the vdev->features array. Once that's all
* sorted out, this routine is called so we can tell the Host which features we
@@ -135,6 +146,9 @@ static void lg_finalize_features(struct virtio_device *vdev)
if (test_bit(i, vdev->features))
out_features[i / 8] |= (1 << (i % 8));
}
+
+ /* Tell Host we've finished with this device's feature negotiation */
+ status_notify(vdev);
}
/* Once they've found a field, getting a copy of it is easy. */
@@ -168,28 +182,21 @@ static u8 lg_get_status(struct virtio_device *vdev)
return to_lgdev(vdev)->desc->status;
}
-/*
- * To notify on status updates, we (ab)use the NOTIFY hypercall, with the
- * descriptor address of the device. A zero status means "reset".
- */
-static void set_status(struct virtio_device *vdev, u8 status)
-{
- unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices;
-
- /* We set the status. */
- to_lgdev(vdev)->desc->status = status;
- hcall(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset, 0, 0, 0);
-}
-
static void lg_set_status(struct virtio_device *vdev, u8 status)
{
BUG_ON(!status);
- set_status(vdev, status);
+ to_lgdev(vdev)->desc->status = status;
+
+ /* Tell Host immediately if we failed. */
+ if (status & VIRTIO_CONFIG_S_FAILED)
+ status_notify(vdev);
}
static void lg_reset(struct virtio_device *vdev)
{
- set_status(vdev, 0);
+ /* 0 status means "reset" */
+ to_lgdev(vdev)->desc->status = 0;
+ status_notify(vdev);
}
/*