1 /* Copyright 2012 Red Hat, Inc. and/or its affiliates
2 * Copyright IBM, Corp. 2012
4 * Based on Linux 2.6.39 vhost code:
5 * Copyright (C) 2009 Red Hat, Inc.
6 * Copyright (C) 2006 Rusty Russell IBM Corporation
8 * Author: Michael S. Tsirkin <mst@redhat.com>
9 * Stefan Hajnoczi <stefanha@redhat.com>
11 * Inspiration, some code, and most witty comments come from
12 * Documentation/virtual/lguest/lguest.c, by Rusty Russell
14 * This work is licensed under the terms of the GNU GPL, version 2.
20 #include "qemu-common.h"
21 #include "standard-headers/linux/virtio_ring.h"
22 #include "hw/virtio/virtio.h"
25 MemoryRegion *mr; /* memory region containing the vring */
26 struct vring vr; /* virtqueue vring mapped to host memory */
27 uint16_t last_avail_idx; /* last processed avail ring index */
28 uint16_t last_used_idx; /* last processed used ring index */
29 uint16_t signalled_used; /* EVENT_IDX state */
30 bool signalled_used_valid;
31 bool broken; /* was there a fatal error? */
34 /* Fail future vring_pop() and vring_push() calls until reset */
35 static inline void vring_set_broken(Vring *vring)
40 bool vring_setup(Vring *vring, VirtIODevice *vdev, int n);
41 void vring_teardown(Vring *vring, VirtIODevice *vdev, int n);
42 void vring_disable_notification(VirtIODevice *vdev, Vring *vring);
43 bool vring_enable_notification(VirtIODevice *vdev, Vring *vring);
44 bool vring_should_notify(VirtIODevice *vdev, Vring *vring);
45 int vring_pop(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem);
46 void vring_push(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem,