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 <linux/virtio_ring.h>
21 #include "qemu-common.h"
23 #include "hw/virtio.h"
26 HostMem hostmem
; /* guest memory mapper */
27 struct vring vr
; /* virtqueue vring mapped to host memory */
28 uint16_t last_avail_idx
; /* last processed avail ring index */
29 uint16_t last_used_idx
; /* last processed used ring index */
30 uint16_t signalled_used
; /* EVENT_IDX state */
31 bool signalled_used_valid
;
32 bool broken
; /* was there a fatal error? */
35 static inline unsigned int vring_get_num(Vring
*vring
)
40 /* Are there more descriptors available? */
41 static inline bool vring_more_avail(Vring
*vring
)
43 return vring
->vr
.avail
->idx
!= vring
->last_avail_idx
;
46 /* Fail future vring_pop() and vring_push() calls until reset */
47 static inline void vring_set_broken(Vring
*vring
)
52 bool vring_setup(Vring
*vring
, VirtIODevice
*vdev
, int n
);
53 void vring_teardown(Vring
*vring
);
54 void vring_disable_notification(VirtIODevice
*vdev
, Vring
*vring
);
55 bool vring_enable_notification(VirtIODevice
*vdev
, Vring
*vring
);
56 bool vring_should_notify(VirtIODevice
*vdev
, Vring
*vring
);
57 int vring_pop(VirtIODevice
*vdev
, Vring
*vring
,
58 struct iovec iov
[], struct iovec
*iov_end
,
59 unsigned int *out_num
, unsigned int *in_num
);
60 void vring_push(Vring
*vring
, unsigned int head
, int len
);