1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2013 Chris Torek <torek @ torek net>
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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR 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
29 #ifndef _BHYVE_COMPAT_VIRTIO_H_
30 #define _BHYVE_COMPAT_VIRTIO_H_
31
32 #define VRING_DESC_F_NEXT (1 << 0)
33 #define VRING_DESC_F_WRITE (1 << 1)
34 #define VRING_DESC_F_INDIRECT (1 << 2)
35
36 struct vring_desc {
37 uint64_t addr; /* guest physical address */
38 uint32_t len; /* length of scatter/gather seg */
39 uint16_t flags; /* VRING_F_DESC_* */
40 uint16_t next; /* next desc if F_NEXT */
41 } __packed;
42
43 struct vring_used_elem {
44 uint32_t id; /* head of used descriptor chain */
45 uint32_t len; /* length written-to */
46 } __packed;
47
48 #define VRING_AVAIL_F_NO_INTERRUPT 1
49
50 struct vring_avail {
51 uint16_t flags; /* VRING_AVAIL_F_* */
52 uint16_t idx; /* counts to 65535, then cycles */
53 uint16_t ring[]; /* size N, reported in QNUM value */
54 /* uint16_t used_event; -- after N ring entries */
55 } __packed;
56
57 #define VRING_USED_F_NO_NOTIFY 1
58 struct vring_used {
59 uint16_t flags; /* VRING_USED_F_* */
60 uint16_t idx; /* counts to 65535, then cycles */
61 struct vring_used_elem ring[]; /* size N */
62 /* uint16_t avail_event; -- after N ring entries */
63 } __packed;
64
65 /*
66 * Virtio device types
67 */
68 #define VIRTIO_ID_NETWORK 1
69 #define VIRTIO_ID_BLOCK 2
70 #define VIRTIO_ID_CONSOLE 3
71 #define VIRTIO_ID_ENTROPY 4
72 #define VIRTIO_ID_BALLOON 5
73 #define VIRTIO_ID_IOMEMORY 6
74 #define VIRTIO_ID_RPMSG 7
75 #define VIRTIO_ID_SCSI 8
76 #define VIRTIO_ID_9P 9
77
78 /* experimental IDs start at 65535 and work down */
79
80 /*
81 * PCI config space constants.
82 *
83 * If MSI-X is enabled, the ISR register is generally not used,
84 * and the configuration vector and queue vector appear at offsets
85 * 20 and 22 with the remaining configuration registers at 24.
86 * If MSI-X is not enabled, those two registers disappear and
87 * the remaining configuration registers start at offset 20.
88 */
89 #define VIRTIO_PCI_HOST_FEATURES 0
90 #define VIRTIO_PCI_GUEST_FEATURES 4
91 #define VIRTIO_PCI_QUEUE_PFN 8
92 #define VIRTIO_PCI_QUEUE_NUM 12
93 #define VIRTIO_PCI_QUEUE_SEL 14
94 #define VIRTIO_PCI_QUEUE_NOTIFY 16
95 #define VIRTIO_PCI_STATUS 18
96 #define VIRTIO_PCI_ISR 19
97 #define VIRTIO_MSI_CONFIG_VECTOR 20
98 #define VIRTIO_MSI_QUEUE_VECTOR 22
99 #define VIRTIO_PCI_CONFIG_OFF(msix_enabled) ((msix_enabled) ? 24 : 20)
100
101 /*
102 * Bits in VTCFG_R_STATUS. Guests need not actually set any of these,
103 * but a guest writing 0 to this register means "please reset".
104 */
105 #define VTCFG_STATUS_ACK 0x01 /* guest OS has acknowledged dev */
106 #define VTCFG_STATUS_DRIVER 0x02 /* guest OS driver is loaded */
107 #define VTCFG_STATUS_DRIVER_OK 0x04 /* guest OS driver ready */
108 #define VTCFG_STATUS_FAILED 0x80 /* guest has given up on this dev */
109
110 /*
111 * Bits in VTCFG_R_ISR. These apply only if not using MSI-X.
112 */
113 /* The bit of the ISR which indicates a device has an interrupt. */
114 #define VIRTIO_PCI_ISR_INTR 0x01
115 /* The bit of the ISR which indicates a device configuration change. */
116 #define VIRTIO_PCI_ISR_CONFIG 0x02
117
118 #define VIRTIO_MSI_NO_VECTOR 0xFFFF
119
120 /*
121 * Feature flags.
122 * Note: bits 0 through 23 are reserved to each device type.
123 */
124 #define VIRTIO_F_NOTIFY_ON_EMPTY (1 << 24)
125 #define VIRTIO_RING_F_INDIRECT_DESC (1 << 28)
126 #define VIRTIO_RING_F_EVENT_IDX (1 << 29)
127
128 static inline int
vring_size(unsigned int num,unsigned long align)129 vring_size(unsigned int num, unsigned long align)
130 {
131 int size;
132
133 size = num * sizeof(struct vring_desc);
134 size += sizeof(struct vring_avail) + (num * sizeof(uint16_t)) +
135 sizeof(uint16_t);
136 size = (size + align - 1) & ~(align - 1);
137 size += sizeof(struct vring_used) +
138 (num * sizeof(struct vring_used_elem)) + sizeof(uint16_t);
139 return (size);
140 }
141
142 #endif /* _BHYVE_COMPAT_VIRTIO_H_ */
143