xref: /dragonfly/sys/dev/virtual/virtio/virtio/virtio.h (revision 0ca59c34)
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  * $FreeBSD: src/sys/dev/virtio/virtio.h,v 1.2 2011/12/06 06:28:32 grehan Exp $
29  */
30 
31 #ifndef _VIRTIO_H_
32 #define _VIRTIO_H_
33 
34 #include <sys/types.h>
35 #include <sys/serialize.h>
36 
37 struct vq_alloc_info;
38 
39 /* VirtIO device IDs. */
40 #define VIRTIO_ID_NETWORK	0x01
41 #define VIRTIO_ID_BLOCK		0x02
42 #define VIRTIO_ID_CONSOLE	0x03
43 #define VIRTIO_ID_ENTROPY	0x04
44 #define VIRTIO_ID_BALLOON	0x05
45 #define VIRTIO_ID_IOMEMORY	0x06
46 #define VIRTIO_ID_9P		0x09
47 
48 /* Status byte for guest to report progress. */
49 #define VIRTIO_CONFIG_STATUS_RESET		0x00
50 #define VIRTIO_CONFIG_STATUS_ACK		0x01
51 #define VIRTIO_CONFIG_STATUS_DRIVER		0x02
52 #define VIRTIO_CONFIG_STATUS_DRIVER_OK		0x04
53 #define VIRTIO_CONFIG_STATUS_DEVICE_NEEDS_RESET	0x40
54 #define VIRTIO_CONFIG_STATUS_FAILED		0x80
55 
56 /*
57  * Generate interrupt when the virtqueue ring is
58  * completely used, even if we've suppressed them.
59  */
60 #define VIRTIO_F_NOTIFY_ON_EMPTY (1 << 24)
61 
62 /* The device accepts arbitrary descriptor layouts */
63 #define VIRTIO_F_ANY_LAYOUT (1 << 27)
64 
65 /*
66  * The guest should never negotiate this feature; it
67  * is used to detect faulty drivers.
68  */
69 #define VIRTIO_F_BAD_FEATURE (1 << 30)
70 
71 /*
72  * Some VirtIO feature bits (currently bits 28 through 31) are
73  * reserved for the transport being used (eg. virtio_ring), the
74  * rest are per-device feature bits.
75  */
76 #define VIRTIO_TRANSPORT_F_START	28
77 #define VIRTIO_TRANSPORT_F_END		32
78 
79 /*
80  * Maximum number of virtqueues per device.
81  */
82 #define VIRTIO_MAX_VIRTQUEUES 8
83 
84 /*
85  * XXX malloc(9) comment not correct on DragonFly
86  * Each virtqueue indirect descriptor list must be physically contiguous.
87  * To allow us to malloc(9) each list individually, limit the number
88  * supported to what will fit in one page. With 4KB pages, this is a limit
89  * of 256 descriptors. If there is ever a need for more, we can switch to
90  * contigmalloc(9) for the larger allocations, similar to what
91  * bus_dmamem_alloc(9) does.
92  *
93  * Note the sizeof(struct vring_desc) is 16 bytes.
94  */
95 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
96 
97 /*
98  * VirtIO instance variables indices.
99  */
100 #define VIRTIO_IVAR_DEVTYPE		1
101 #define VIRTIO_IVAR_FEATURE_DESC	2
102 
103 struct virtio_feature_desc {
104 	uint64_t	 vfd_val;
105 	const char	*vfd_str;
106 };
107 
108 const char *virtio_device_name(uint16_t devid);
109 int	 virtio_get_device_type(device_t dev);
110 void	 virtio_set_feature_desc(device_t dev,
111 	     struct virtio_feature_desc *feature_desc);
112 void	 virtio_describe(device_t dev, const char *msg,
113 	     uint64_t features, struct virtio_feature_desc *feature_desc);
114 
115 /*
116  * VirtIO Bus Methods.
117  */
118 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
119 int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
120 	     struct vq_alloc_info *info);
121 int	 virtio_setup_intr(device_t dev, lwkt_serialize_t);
122 int	 virtio_with_feature(device_t dev, uint64_t feature);
123 void	 virtio_stop(device_t dev);
124 int	 virtio_reinit(device_t dev, uint64_t features);
125 void	 virtio_reinit_complete(device_t dev);
126 
127 /*
128  * Read/write a variable amount from the device specific (ie, network)
129  * configuration region. This region is encoded in the same endian as
130  * the guest.
131  */
132 void	 virtio_read_device_config(device_t dev, bus_size_t offset,
133 	     void *dst, int length);
134 void	 virtio_write_device_config(device_t dev, bus_size_t offset,
135 	     void *src, int length);
136 
137 /* Inlined device specific read/write functions for common lengths. */
138 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
139 static inline type							\
140 __CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
141     bus_size_t offset)							\
142 {									\
143 	type val;							\
144 	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
145 	return (val);							\
146 }									\
147 									\
148 static inline void							\
149 __CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
150     bus_size_t offset, type val)					\
151 {									\
152 	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
153 }
154 
155 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
156 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
157 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
158 
159 #endif /* _VIRTIO_H_ */
160