virtio.h revision 331722 
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: stable/11/sys/dev/virtio/virtio.h 331722 2018-03-29 02:50:57Z eadler $
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
35struct 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
59struct virtio_feature_desc {
60	uint64_t	 vfd_val;
61	const char	*vfd_str;
62};
63
64const char *virtio_device_name(uint16_t devid);
65void	 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 */
71void	 virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
72void	 virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
73uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
74int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
75	     struct vq_alloc_info *info);
76int	 virtio_setup_intr(device_t dev, enum intr_type type);
77int	 virtio_with_feature(device_t dev, uint64_t feature);
78void	 virtio_stop(device_t dev);
79int	 virtio_config_generation(device_t dev);
80int	 virtio_reinit(device_t dev, uint64_t features);
81void	 virtio_reinit_complete(device_t dev);
82
83/*
84 * Read/write a variable amount from the device specific (ie, network)
85 * configuration region. This region is encoded in the same endian as
86 * the guest.
87 */
88void	 virtio_read_device_config(device_t dev, bus_size_t offset,
89	     void *dst, int length);
90void	 virtio_write_device_config(device_t dev, bus_size_t offset,
91	     void *src, int length);
92
93/* Inlined device specific read/write functions for common lengths. */
94#define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
95static inline type							\
96__CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
97    bus_size_t offset)							\
98{									\
99	type val;							\
100	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
101	return (val);							\
102}									\
103									\
104static inline void							\
105__CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
106    bus_size_t offset, type val)					\
107{									\
108	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
109}
110
111VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
112VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
113VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
114
115#undef VIRTIO_RDWR_DEVICE_CONFIG
116
117#define VIRTIO_READ_IVAR(name, ivar)					\
118static inline int							\
119__CONCAT(virtio_get_,name)(device_t dev)				\
120{									\
121	uintptr_t val;							\
122	virtio_read_ivar(dev, ivar, &val);				\
123	return ((int) val);						\
124}
125
126VIRTIO_READ_IVAR(device_type,	VIRTIO_IVAR_DEVTYPE);
127VIRTIO_READ_IVAR(vendor,	VIRTIO_IVAR_VENDOR);
128VIRTIO_READ_IVAR(device,	VIRTIO_IVAR_DEVICE);
129VIRTIO_READ_IVAR(subvendor,	VIRTIO_IVAR_SUBVENDOR);
130VIRTIO_READ_IVAR(subdevice,	VIRTIO_IVAR_SUBDEVICE);
131
132#undef VIRTIO_READ_IVAR
133
134#define VIRTIO_WRITE_IVAR(name, ivar)					\
135static inline void							\
136__CONCAT(virtio_set_,name)(device_t dev, void *val)			\
137{									\
138	virtio_write_ivar(dev, ivar, (uintptr_t) val);			\
139}
140
141VIRTIO_WRITE_IVAR(feature_desc,	VIRTIO_IVAR_FEATURE_DESC);
142
143#undef VIRTIO_WRITE_IVAR
144
145#endif /* _VIRTIO_H_ */
146