xref: /freebsd/sys/dev/virtio/virtio.h (revision b3512b30dbec579da28028e29d8b33ec7242af68)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2014, Bryan Venteicher <bryanv@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #ifndef _VIRTIO_H_
32 #define _VIRTIO_H_
33 
34 #include <dev/virtio/virtio_ids.h>
35 #include <dev/virtio/virtio_config.h>
36 
37 struct vq_alloc_info;
38 
39 /*
40  * Each virtqueue indirect descriptor list must be physically contiguous.
41  * To allow us to malloc(9) each list individually, limit the number
42  * supported to what will fit in one page. With 4KB pages, this is a limit
43  * of 256 descriptors. If there is ever a need for more, we can switch to
44  * contigmalloc(9) for the larger allocations, similar to what
45  * bus_dmamem_alloc(9) does.
46  *
47  * Note the sizeof(struct vring_desc) is 16 bytes.
48  */
49 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
50 
51 /*
52  * VirtIO instance variables indices.
53  */
54 #define VIRTIO_IVAR_DEVTYPE		1
55 #define VIRTIO_IVAR_FEATURE_DESC	2
56 #define VIRTIO_IVAR_VENDOR		3
57 #define VIRTIO_IVAR_DEVICE		4
58 #define VIRTIO_IVAR_SUBVENDOR		5
59 #define VIRTIO_IVAR_SUBDEVICE		6
60 
61 struct virtio_feature_desc {
62 	uint64_t	 vfd_val;
63 	const char	*vfd_str;
64 };
65 
66 struct virtio_pnp_match {
67 	uint32_t	 device_type;
68 	const char	*description;
69 };
70 #define VIRTIO_SIMPLE_PNPTABLE(driver, devtype, desc)			\
71 	static const struct virtio_pnp_match driver ## _match = {	\
72 		.device_type = devtype,					\
73 		.description = desc,					\
74 	}
75 #define VIRTIO_SIMPLE_PNPINFO(bus, driver)				\
76 	MODULE_PNP_INFO("U32:device_type;D:#", bus, driver,		\
77 	    &driver ## _match, 1)
78 #define VIRTIO_SIMPLE_PROBE(dev, driver)				\
79 	(virtio_simple_probe(dev, &driver ## _match))
80 
81 const char *virtio_device_name(uint16_t devid);
82 void	 virtio_describe(device_t dev, const char *msg,
83 	     uint64_t features, struct virtio_feature_desc *feature_desc);
84 
85 /*
86  * VirtIO Bus Methods.
87  */
88 void	 virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
89 void	 virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
90 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
91 int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
92 	     struct vq_alloc_info *info);
93 int	 virtio_setup_intr(device_t dev, enum intr_type type);
94 int	 virtio_with_feature(device_t dev, uint64_t feature);
95 void	 virtio_stop(device_t dev);
96 int	 virtio_config_generation(device_t dev);
97 int	 virtio_reinit(device_t dev, uint64_t features);
98 void	 virtio_reinit_complete(device_t dev);
99 int	 virtio_child_pnpinfo_str(device_t busdev, device_t child, char *buf,
100 	     size_t buflen);
101 
102 /*
103  * Read/write a variable amount from the device specific (ie, network)
104  * configuration region. This region is encoded in the same endian as
105  * the guest.
106  */
107 void	 virtio_read_device_config(device_t dev, bus_size_t offset,
108 	     void *dst, int length);
109 void	 virtio_write_device_config(device_t dev, bus_size_t offset,
110 	     void *src, int length);
111 
112 /* Inlined device specific read/write functions for common lengths. */
113 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
114 static inline type							\
115 __CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
116     bus_size_t offset)							\
117 {									\
118 	type val;							\
119 	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
120 	return (val);							\
121 }									\
122 									\
123 static inline void							\
124 __CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
125     bus_size_t offset, type val)					\
126 {									\
127 	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
128 }
129 
130 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
131 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
132 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
133 
134 #undef VIRTIO_RDWR_DEVICE_CONFIG
135 
136 #define VIRTIO_READ_IVAR(name, ivar)					\
137 static inline int							\
138 __CONCAT(virtio_get_,name)(device_t dev)				\
139 {									\
140 	uintptr_t val;							\
141 	virtio_read_ivar(dev, ivar, &val);				\
142 	return ((int) val);						\
143 }
144 
145 VIRTIO_READ_IVAR(device_type,	VIRTIO_IVAR_DEVTYPE);
146 VIRTIO_READ_IVAR(vendor,	VIRTIO_IVAR_VENDOR);
147 VIRTIO_READ_IVAR(device,	VIRTIO_IVAR_DEVICE);
148 VIRTIO_READ_IVAR(subvendor,	VIRTIO_IVAR_SUBVENDOR);
149 VIRTIO_READ_IVAR(subdevice,	VIRTIO_IVAR_SUBDEVICE);
150 
151 #undef VIRTIO_READ_IVAR
152 
153 #define VIRTIO_WRITE_IVAR(name, ivar)					\
154 static inline void							\
155 __CONCAT(virtio_set_,name)(device_t dev, void *val)			\
156 {									\
157 	virtio_write_ivar(dev, ivar, (uintptr_t) val);			\
158 }
159 
160 VIRTIO_WRITE_IVAR(feature_desc,	VIRTIO_IVAR_FEATURE_DESC);
161 
162 #undef VIRTIO_WRITE_IVAR
163 
164 static inline int
165 virtio_simple_probe(device_t dev, const struct virtio_pnp_match *match)
166 {
167 
168 	if (virtio_get_device_type(dev) != match->device_type)
169 		return (ENXIO);
170 	device_set_desc(dev, match->description);
171 	return (BUS_PROBE_DEFAULT);
172 }
173 
174 #endif /* _VIRTIO_H_ */
175