xref: /qemu/linux-headers/linux/virtio_config.h (revision 72ac97cd)
1 #ifndef _LINUX_VIRTIO_CONFIG_H
2 #define _LINUX_VIRTIO_CONFIG_H
3 /* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so
4  * anyone can use the definitions to implement compatible drivers/servers.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of IBM nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE. */
28 
29 /* Virtio devices use a standardized configuration space to define their
30  * features and pass configuration information, but each implementation can
31  * store and access that space differently. */
32 #include <linux/types.h>
33 
34 /* Status byte for guest to report progress, and synchronize features. */
35 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
36 #define VIRTIO_CONFIG_S_ACKNOWLEDGE	1
37 /* We have found a driver for the device. */
38 #define VIRTIO_CONFIG_S_DRIVER		2
39 /* Driver has used its parts of the config, and is happy */
40 #define VIRTIO_CONFIG_S_DRIVER_OK	4
41 /* We've given up on this device. */
42 #define VIRTIO_CONFIG_S_FAILED		0x80
43 
44 /* Some virtio feature bits (currently bits 28 through 31) are reserved for the
45  * transport being used (eg. virtio_ring), the rest are per-device feature
46  * bits. */
47 #define VIRTIO_TRANSPORT_F_START	28
48 #define VIRTIO_TRANSPORT_F_END		32
49 
50 /* Do we get callbacks when the ring is completely used, even if we've
51  * suppressed them? */
52 #define VIRTIO_F_NOTIFY_ON_EMPTY	24
53 
54 /* Can the device handle any descriptor layout? */
55 #define VIRTIO_F_ANY_LAYOUT		27
56 
57 #endif /* _LINUX_VIRTIO_CONFIG_H */
58