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Diffstat (limited to 'drivers/lguest/lguest_device.c')
-rw-r--r--drivers/lguest/lguest_device.c38
1 files changed, 23 insertions, 15 deletions
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index 69c84a1..0dc30ff 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -15,6 +15,7 @@
#include <linux/interrupt.h>
#include <linux/virtio_ring.h>
#include <linux/err.h>
+#include <linux/export.h>
#include <linux/slab.h>
#include <asm/io.h>
#include <asm/paravirt.h>
@@ -109,6 +110,17 @@ 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 +147,9 @@ 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 +183,21 @@ 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);
}
/*