xref: /freebsd/sys/dev/virtio/virtio.h (revision 864c53ead899f7838cd2e1cca3b485a4a82f5cdc)
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 
34 struct vq_alloc_info;
35 
36 /*
37  * Each virtqueue indirect descriptor list must be physically contiguous.
38  * To allow us to malloc(9) each list individually, limit the number
39  * supported to what will fit in one page. With 4KB pages, this is a limit
40  * of 256 descriptors. If there is ever a need for more, we can switch to
41  * contigmalloc(9) for the larger allocations, similar to what
42  * bus_dmamem_alloc(9) does.
43  *
44  * Note the sizeof(struct vring_desc) is 16 bytes.
45  */
46 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
47 
48 /*
49  * VirtIO instance variables indices.
50  */
51 #define VIRTIO_IVAR_DEVTYPE		1
52 #define VIRTIO_IVAR_FEATURE_DESC	2
53 #define VIRTIO_IVAR_VENDOR		3
54 #define VIRTIO_IVAR_DEVICE		4
55 #define VIRTIO_IVAR_SUBVENDOR		5
56 #define VIRTIO_IVAR_SUBDEVICE		6
57 
58 struct virtio_feature_desc {
59 	uint64_t	 vfd_val;
60 	const char	*vfd_str;
61 };
62 
63 const char *virtio_device_name(uint16_t devid);
64 void	 virtio_describe(device_t dev, const char *msg,
65 	     uint64_t features, struct virtio_feature_desc *feature_desc);
66 
67 /*
68  * VirtIO Bus Methods.
69  */
70 void	 virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
71 void	 virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
72 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
73 int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
74 	     struct vq_alloc_info *info);
75 int	 virtio_setup_intr(device_t dev, enum intr_type type);
76 int	 virtio_with_feature(device_t dev, uint64_t feature);
77 void	 virtio_stop(device_t dev);
78 int	 virtio_reinit(device_t dev, uint64_t features);
79 void	 virtio_reinit_complete(device_t dev);
80 
81 /*
82  * Read/write a variable amount from the device specific (ie, network)
83  * configuration region. This region is encoded in the same endian as
84  * the guest.
85  */
86 void	 virtio_read_device_config(device_t dev, bus_size_t offset,
87 	     void *dst, int length);
88 void	 virtio_write_device_config(device_t dev, bus_size_t offset,
89 	     void *src, int length);
90 
91 /* Inlined device specific read/write functions for common lengths. */
92 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
93 static inline type							\
94 __CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
95     bus_size_t offset)							\
96 {									\
97 	type val;							\
98 	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
99 	return (val);							\
100 }									\
101 									\
102 static inline void							\
103 __CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
104     bus_size_t offset, type val)					\
105 {									\
106 	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
107 }
108 
109 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
110 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
111 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
112 
113 #undef VIRTIO_RDWR_DEVICE_CONFIG
114 
115 #define VIRTIO_READ_IVAR(name, ivar)					\
116 static inline int							\
117 __CONCAT(virtio_get_,name)(device_t dev)				\
118 {									\
119 	uintptr_t val;							\
120 	virtio_read_ivar(dev, ivar, &val);				\
121 	return ((int) val);						\
122 }
123 
124 VIRTIO_READ_IVAR(device_type,	VIRTIO_IVAR_DEVTYPE);
125 VIRTIO_READ_IVAR(vendor,	VIRTIO_IVAR_VENDOR);
126 VIRTIO_READ_IVAR(device,	VIRTIO_IVAR_DEVICE);
127 VIRTIO_READ_IVAR(subvendor,	VIRTIO_IVAR_SUBVENDOR);
128 VIRTIO_READ_IVAR(subdevice,	VIRTIO_IVAR_SUBDEVICE);
129 
130 #undef VIRTIO_READ_IVAR
131 
132 #define VIRTIO_WRITE_IVAR(name, ivar)					\
133 static inline void							\
134 __CONCAT(virtio_set_,name)(device_t dev, void *val)			\
135 {									\
136 	virtio_write_ivar(dev, ivar, (uintptr_t) val);			\
137 }
138 
139 VIRTIO_WRITE_IVAR(feature_desc,	VIRTIO_IVAR_FEATURE_DESC);
140 
141 #undef VIRTIO_WRITE_IVAR
142 
143 #endif /* _VIRTIO_H_ */
144