xref: /freebsd/sys/dev/virtio/virtio.h (revision b1f9167f94059fd55c630891d359bcff987bd7eb)
1 /*-
2  * Copyright (c) 2014, Bryan Venteicher <bryanv@FreeBSD.org>
3  * All rights reserved.
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 unmodified, this list of conditions, and the following
10  *    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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _VIRTIO_H_
30 #define _VIRTIO_H_
31 
32 #include <dev/virtio/virtio_ids.h>
33 #include <dev/virtio/virtio_config.h>
34 
35 struct vq_alloc_info;
36 
37 /*
38  * Each virtqueue indirect descriptor list must be physically contiguous.
39  * To allow us to malloc(9) each list individually, limit the number
40  * supported to what will fit in one page. With 4KB pages, this is a limit
41  * of 256 descriptors. If there is ever a need for more, we can switch to
42  * contigmalloc(9) for the larger allocations, similar to what
43  * bus_dmamem_alloc(9) does.
44  *
45  * Note the sizeof(struct vring_desc) is 16 bytes.
46  */
47 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
48 
49 /*
50  * VirtIO instance variables indices.
51  */
52 #define VIRTIO_IVAR_DEVTYPE		1
53 #define VIRTIO_IVAR_FEATURE_DESC	2
54 #define VIRTIO_IVAR_VENDOR		3
55 #define VIRTIO_IVAR_DEVICE		4
56 #define VIRTIO_IVAR_SUBVENDOR		5
57 #define VIRTIO_IVAR_SUBDEVICE		6
58 
59 struct virtio_feature_desc {
60 	uint64_t	 vfd_val;
61 	const char	*vfd_str;
62 };
63 
64 const char *virtio_device_name(uint16_t devid);
65 void	 virtio_describe(device_t dev, const char *msg,
66 	     uint64_t features, struct virtio_feature_desc *feature_desc);
67 
68 /*
69  * VirtIO Bus Methods.
70  */
71 void	 virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
72 void	 virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
73 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
74 int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
75 	     struct vq_alloc_info *info);
76 int	 virtio_setup_intr(device_t dev, enum intr_type type);
77 int	 virtio_with_feature(device_t dev, uint64_t feature);
78 void	 virtio_stop(device_t dev);
79 int	 virtio_reinit(device_t dev, uint64_t features);
80 void	 virtio_reinit_complete(device_t dev);
81 
82 /*
83  * Read/write a variable amount from the device specific (ie, network)
84  * configuration region. This region is encoded in the same endian as
85  * the guest.
86  */
87 void	 virtio_read_device_config(device_t dev, bus_size_t offset,
88 	     void *dst, int length);
89 void	 virtio_write_device_config(device_t dev, bus_size_t offset,
90 	     void *src, int length);
91 
92 /* Inlined device specific read/write functions for common lengths. */
93 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
94 static inline type							\
95 __CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
96     bus_size_t offset)							\
97 {									\
98 	type val;							\
99 	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
100 	return (val);							\
101 }									\
102 									\
103 static inline void							\
104 __CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
105     bus_size_t offset, type val)					\
106 {									\
107 	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
108 }
109 
110 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
111 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
112 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
113 
114 #undef VIRTIO_RDWR_DEVICE_CONFIG
115 
116 #define VIRTIO_READ_IVAR(name, ivar)					\
117 static inline int							\
118 __CONCAT(virtio_get_,name)(device_t dev)				\
119 {									\
120 	uintptr_t val;							\
121 	virtio_read_ivar(dev, ivar, &val);				\
122 	return ((int) val);						\
123 }
124 
125 VIRTIO_READ_IVAR(device_type,	VIRTIO_IVAR_DEVTYPE);
126 VIRTIO_READ_IVAR(vendor,	VIRTIO_IVAR_VENDOR);
127 VIRTIO_READ_IVAR(device,	VIRTIO_IVAR_DEVICE);
128 VIRTIO_READ_IVAR(subvendor,	VIRTIO_IVAR_SUBVENDOR);
129 VIRTIO_READ_IVAR(subdevice,	VIRTIO_IVAR_SUBDEVICE);
130 
131 #undef VIRTIO_READ_IVAR
132 
133 #define VIRTIO_WRITE_IVAR(name, ivar)					\
134 static inline void							\
135 __CONCAT(virtio_set_,name)(device_t dev, void *val)			\
136 {									\
137 	virtio_write_ivar(dev, ivar, (uintptr_t) val);			\
138 }
139 
140 VIRTIO_WRITE_IVAR(feature_desc,	VIRTIO_IVAR_FEATURE_DESC);
141 
142 #undef VIRTIO_WRITE_IVAR
143 
144 #endif /* _VIRTIO_H_ */
145