xref: /freebsd/sys/dev/virtio/virtio_config.h (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*-
2  * This header is BSD licensed so anyone can use the definitions to implement
3  * compatible drivers/servers.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of IBM nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef _VIRTIO_CONFIG_H_
30 #define _VIRTIO_CONFIG_H_
31 
32 /* Status byte for guest to report progress. */
33 #define VIRTIO_CONFIG_STATUS_RESET	0x00
34 /* We have seen device and processed generic fields. */
35 #define VIRTIO_CONFIG_STATUS_ACK	0x01
36 /* We have found a driver for the device. */
37 #define VIRTIO_CONFIG_STATUS_DRIVER	0x02
38 /* Driver has used its parts of the config, and is happy. */
39 #define VIRTIO_CONFIG_STATUS_DRIVER_OK	0x04
40 /* Driver has finished configuring features (modern only). */
41 #define VIRTIO_CONFIG_S_FEATURES_OK	0x08
42 /* Device entered invalid state, driver must reset it. */
43 #define VIRTIO_CONFIG_S_NEEDS_RESET	0x40
44 /* We've given up on this device. */
45 #define VIRTIO_CONFIG_STATUS_FAILED	0x80
46 
47 /*
48  * Generate interrupt when the virtqueue ring is
49  * completely used, even if we've suppressed them.
50  */
51 #define VIRTIO_F_NOTIFY_ON_EMPTY	(1UL << 24)
52 
53 /* Can the device handle any descriptor layout? */
54 #define VIRTIO_F_ANY_LAYOUT		(1UL << 27)
55 
56 /* Support for indirect buffer descriptors. */
57 #define VIRTIO_RING_F_INDIRECT_DESC	(1UL << 28)
58 
59 /* Support to suppress interrupt until specific index is reached. */
60 #define VIRTIO_RING_F_EVENT_IDX		(1UL << 29)
61 
62 /*
63  * The guest should never negotiate this feature; it
64  * is used to detect faulty drivers.
65  */
66 #define VIRTIO_F_BAD_FEATURE	(1UL << 30)
67 
68 /* v1.0 compliant. */
69 #define VIRTIO_F_VERSION_1	(1ULL << 32)
70 
71 /*
72  * If clear - device has the IOMMU bypass quirk feature.
73  * If set - use platform tools to detect the IOMMU.
74  *
75  * Note the reverse polarity (compared to most other features),
76  * this is for compatibility with legacy systems.
77  */
78 #define VIRTIO_F_IOMMU_PLATFORM		(1ULL << 33)
79 
80 /*
81  * Some VirtIO feature bits (currently bits 28 through 34) are
82  * reserved for the transport being used (eg. virtio_ring), the
83  * rest are per-device feature bits.
84  */
85 #define VIRTIO_TRANSPORT_F_START	28
86 #define VIRTIO_TRANSPORT_F_END		34
87 
88 #endif /* _VIRTIO_CONFIG_H_ */
89