xref: /dragonfly/sys/dev/virtual/virtio/virtio/virtio.h (revision 1fe7e945)
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_SCSI		0x08
47 #define VIRTIO_ID_9P		0x09
48 
49 /* Status byte for guest to report progress. */
50 #define VIRTIO_CONFIG_STATUS_RESET		0x00
51 #define VIRTIO_CONFIG_STATUS_ACK		0x01
52 #define VIRTIO_CONFIG_STATUS_DRIVER		0x02
53 #define VIRTIO_CONFIG_STATUS_DRIVER_OK		0x04
54 #define VIRTIO_CONFIG_STATUS_DEVICE_NEEDS_RESET	0x40
55 #define VIRTIO_CONFIG_STATUS_FAILED		0x80
56 
57 /*
58  * Generate interrupt when the virtqueue ring is
59  * completely used, even if we've suppressed them.
60  */
61 #define VIRTIO_F_NOTIFY_ON_EMPTY (1 << 24)
62 
63 /* The device accepts arbitrary descriptor layouts */
64 #define VIRTIO_F_ANY_LAYOUT (1 << 27)
65 
66 /*
67  * The guest should never negotiate this feature; it
68  * is used to detect faulty drivers.
69  */
70 #define VIRTIO_F_BAD_FEATURE (1 << 30)
71 
72 /*
73  * Some VirtIO feature bits (currently bits 28 through 31) are
74  * reserved for the transport being used (eg. virtio_ring), the
75  * rest are per-device feature bits.
76  */
77 #define VIRTIO_TRANSPORT_F_START	28
78 #define VIRTIO_TRANSPORT_F_END		32
79 
80 /*
81  * Maximum number of virtqueues per device.
82  */
83 #define VIRTIO_MAX_VIRTQUEUES 8
84 
85 /*
86  * XXX malloc(9) comment not correct on DragonFly
87  * Each virtqueue indirect descriptor list must be physically contiguous.
88  * To allow us to malloc(9) each list individually, limit the number
89  * supported to what will fit in one page. With 4KB pages, this is a limit
90  * of 256 descriptors. If there is ever a need for more, we can switch to
91  * contigmalloc(9) for the larger allocations, similar to what
92  * bus_dmamem_alloc(9) does.
93  *
94  * Note the sizeof(struct vring_desc) is 16 bytes.
95  */
96 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
97 
98 /*
99  * VirtIO instance variables indices.
100  */
101 #define VIRTIO_IVAR_DEVTYPE		1
102 #define VIRTIO_IVAR_FEATURE_DESC	2
103 
104 struct virtio_feature_desc {
105 	uint64_t	 vfd_val;
106 	const char	*vfd_str;
107 };
108 
109 const char *virtio_device_name(uint16_t devid);
110 int	 virtio_get_device_type(device_t dev);
111 void	 virtio_set_feature_desc(device_t dev,
112 	     struct virtio_feature_desc *feature_desc);
113 void	 virtio_describe(device_t dev, const char *msg,
114 	     uint64_t features, struct virtio_feature_desc *feature_desc);
115 
116 /*
117  * VirtIO Bus Methods.
118  */
119 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
120 int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
121 	     struct vq_alloc_info *info);
122 int	 virtio_setup_intr(device_t dev, lwkt_serialize_t);
123 int	 virtio_with_feature(device_t dev, uint64_t feature);
124 void	 virtio_stop(device_t dev);
125 int	 virtio_reinit(device_t dev, uint64_t features);
126 void	 virtio_reinit_complete(device_t dev);
127 
128 /*
129  * Read/write a variable amount from the device specific (ie, network)
130  * configuration region. This region is encoded in the same endian as
131  * the guest.
132  */
133 void	 virtio_read_device_config(device_t dev, bus_size_t offset,
134 	     void *dst, int length);
135 void	 virtio_write_device_config(device_t dev, bus_size_t offset,
136 	     void *src, int length);
137 
138 /* Inlined device specific read/write functions for common lengths. */
139 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
140 static inline type							\
141 __CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
142     bus_size_t offset)							\
143 {									\
144 	type val;							\
145 	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
146 	return (val);							\
147 }									\
148 									\
149 static inline void							\
150 __CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
151     bus_size_t offset, type val)					\
152 {									\
153 	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
154 }
155 
156 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
157 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
158 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
159 
160 #endif /* _VIRTIO_H_ */
161