xref: /freebsd/sys/dev/virtio/pci/virtio_pci.h (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*-
2  * Copyright IBM Corp. 2007
3  *
4  * Authors:
5  *  Anthony Liguori  <aliguori@us.ibm.com>
6  *
7  * This header is BSD licensed so anyone can use the definitions to implement
8  * compatible drivers/servers.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of IBM nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD$
34  */
35 
36 #ifndef _VIRTIO_PCI_H
37 #define _VIRTIO_PCI_H
38 
39 /* VirtIO PCI vendor/device ID. */
40 #define VIRTIO_PCI_VENDORID	0x1AF4
41 #define VIRTIO_PCI_DEVICEID_MIN	0x1000
42 #define VIRTIO_PCI_DEVICEID_MAX	0x103F
43 
44 /* VirtIO ABI version, this must match exactly. */
45 #define VIRTIO_PCI_ABI_VERSION	0
46 
47 /*
48  * VirtIO Header, located in BAR 0.
49  */
50 #define VIRTIO_PCI_HOST_FEATURES  0  /* host's supported features (32bit, RO)*/
51 #define VIRTIO_PCI_GUEST_FEATURES 4  /* guest's supported features (32, RW) */
52 #define VIRTIO_PCI_QUEUE_PFN      8  /* physical address of VQ (32, RW) */
53 #define VIRTIO_PCI_QUEUE_NUM      12 /* number of ring entries (16, RO) */
54 #define VIRTIO_PCI_QUEUE_SEL      14 /* current VQ selection (16, RW) */
55 #define VIRTIO_PCI_QUEUE_NOTIFY	  16 /* notify host regarding VQ (16, RW) */
56 #define VIRTIO_PCI_STATUS         18 /* device status register (8, RW) */
57 #define VIRTIO_PCI_ISR            19 /* interrupt status register, reading
58 				      * also clears the register (8, RO) */
59 /* Only if MSIX is enabled: */
60 #define VIRTIO_MSI_CONFIG_VECTOR  20 /* configuration change vector (16, RW) */
61 #define VIRTIO_MSI_QUEUE_VECTOR   22 /* vector for selected VQ notifications
62 					(16, RW) */
63 
64 /* The bit of the ISR which indicates a device has an interrupt. */
65 #define VIRTIO_PCI_ISR_INTR	0x1
66 /* The bit of the ISR which indicates a device configuration change. */
67 #define VIRTIO_PCI_ISR_CONFIG	0x2
68 /* Vector value used to disable MSI for queue. */
69 #define VIRTIO_MSI_NO_VECTOR	0xFFFF
70 
71 /*
72  * The remaining space is defined by each driver as the per-driver
73  * configuration space.
74  */
75 #define VIRTIO_PCI_CONFIG_OFF(msix_enabled)     ((msix_enabled) ? 24 : 20)
76 
77 /*
78  * How many bits to shift physical queue address written to QUEUE_PFN.
79  * 12 is historical, and due to x86 page size.
80  */
81 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12
82 
83 /* The alignment to use between consumer and producer parts of vring. */
84 #define VIRTIO_PCI_VRING_ALIGN	4096
85 
86 #endif /* _VIRTIO_PCI_H */
87