xref: /openbmc/qemu/linux-headers/linux/vhost.h (revision 073d9f2c)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _LINUX_VHOST_H
3 #define _LINUX_VHOST_H
4 /* Userspace interface for in-kernel virtio accelerators. */
5 
6 /* vhost is used to reduce the number of system calls involved in virtio.
7  *
8  * Existing virtio net code is used in the guest without modification.
9  *
10  * This header includes interface used by userspace hypervisor for
11  * device configuration.
12  */
13 
14 #include <linux/types.h>
15 
16 #include <linux/ioctl.h>
17 #include <linux/virtio_config.h>
18 #include <linux/virtio_ring.h>
19 
20 struct vhost_vring_state {
21 	unsigned int index;
22 	unsigned int num;
23 };
24 
25 struct vhost_vring_file {
26 	unsigned int index;
27 	int fd; /* Pass -1 to unbind from file. */
28 
29 };
30 
31 struct vhost_vring_addr {
32 	unsigned int index;
33 	/* Option flags. */
34 	unsigned int flags;
35 	/* Flag values: */
36 	/* Whether log address is valid. If set enables logging. */
37 #define VHOST_VRING_F_LOG 0
38 
39 	/* Start of array of descriptors (virtually contiguous) */
40 	__u64 desc_user_addr;
41 	/* Used structure address. Must be 32 bit aligned */
42 	__u64 used_user_addr;
43 	/* Available structure address. Must be 16 bit aligned */
44 	__u64 avail_user_addr;
45 	/* Logging support. */
46 	/* Log writes to used structure, at offset calculated from specified
47 	 * address. Address must be 32 bit aligned. */
48 	__u64 log_guest_addr;
49 };
50 
51 /* no alignment requirement */
52 struct vhost_iotlb_msg {
53 	__u64 iova;
54 	__u64 size;
55 	__u64 uaddr;
56 #define VHOST_ACCESS_RO      0x1
57 #define VHOST_ACCESS_WO      0x2
58 #define VHOST_ACCESS_RW      0x3
59 	__u8 perm;
60 #define VHOST_IOTLB_MISS           1
61 #define VHOST_IOTLB_UPDATE         2
62 #define VHOST_IOTLB_INVALIDATE     3
63 #define VHOST_IOTLB_ACCESS_FAIL    4
64 	__u8 type;
65 };
66 
67 #define VHOST_IOTLB_MSG 0x1
68 #define VHOST_IOTLB_MSG_V2 0x2
69 
70 struct vhost_msg {
71 	int type;
72 	union {
73 		struct vhost_iotlb_msg iotlb;
74 		__u8 padding[64];
75 	};
76 };
77 
78 struct vhost_msg_v2 {
79 	__u32 type;
80 	__u32 reserved;
81 	union {
82 		struct vhost_iotlb_msg iotlb;
83 		__u8 padding[64];
84 	};
85 };
86 
87 struct vhost_memory_region {
88 	__u64 guest_phys_addr;
89 	__u64 memory_size; /* bytes */
90 	__u64 userspace_addr;
91 	__u64 flags_padding; /* No flags are currently specified. */
92 };
93 
94 /* All region addresses and sizes must be 4K aligned. */
95 #define VHOST_PAGE_SIZE 0x1000
96 
97 struct vhost_memory {
98 	__u32 nregions;
99 	__u32 padding;
100 	struct vhost_memory_region regions[0];
101 };
102 
103 /* ioctls */
104 
105 #define VHOST_VIRTIO 0xAF
106 
107 /* Features bitmask for forward compatibility.  Transport bits are used for
108  * vhost specific features. */
109 #define VHOST_GET_FEATURES	_IOR(VHOST_VIRTIO, 0x00, __u64)
110 #define VHOST_SET_FEATURES	_IOW(VHOST_VIRTIO, 0x00, __u64)
111 
112 /* Set current process as the (exclusive) owner of this file descriptor.  This
113  * must be called before any other vhost command.  Further calls to
114  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
115 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
116 /* Give up ownership, and reset the device to default values.
117  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
118 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
119 
120 /* Set up/modify memory layout */
121 #define VHOST_SET_MEM_TABLE	_IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
122 
123 /* Write logging setup. */
124 /* Memory writes can optionally be logged by setting bit at an offset
125  * (calculated from the physical address) from specified log base.
126  * The bit is set using an atomic 32 bit operation. */
127 /* Set base address for logging. */
128 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
129 /* Specify an eventfd file descriptor to signal on log write. */
130 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
131 
132 /* Ring setup. */
133 /* Set number of descriptors in ring. This parameter can not
134  * be modified while ring is running (bound to a device). */
135 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
136 /* Set addresses for the ring. */
137 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
138 /* Base value where queue looks for available descriptors */
139 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
140 /* Get accessor: reads index, writes value in num */
141 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
142 
143 /* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
144  * or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
145  * The byte order cannot be changed while the device is active: trying to do so
146  * returns -EBUSY.
147  * This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
148  * set.
149  * Not all kernel configurations support this ioctl, but all configurations that
150  * support SET also support GET.
151  */
152 #define VHOST_VRING_LITTLE_ENDIAN 0
153 #define VHOST_VRING_BIG_ENDIAN 1
154 #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
155 #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
156 
157 /* The following ioctls use eventfd file descriptors to signal and poll
158  * for events. */
159 
160 /* Set eventfd to poll for added buffers */
161 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
162 /* Set eventfd to signal when buffers have beed used */
163 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
164 /* Set eventfd to signal an error */
165 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
166 /* Set busy loop timeout (in us) */
167 #define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23,	\
168 					 struct vhost_vring_state)
169 /* Get busy loop timeout (in us) */
170 #define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24,	\
171 					 struct vhost_vring_state)
172 
173 /* Set or get vhost backend capability */
174 
175 /* Use message type V2 */
176 #define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
177 
178 #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
179 #define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
180 
181 /* VHOST_NET specific defines */
182 
183 /* Attach virtio net ring to a raw socket, or tap device.
184  * The socket must be already bound to an ethernet device, this device will be
185  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
186  * device.  This can be used to stop the ring (e.g. for migration). */
187 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
188 
189 /* Feature bits */
190 /* Log all write descriptors. Can be changed while device is active. */
191 #define VHOST_F_LOG_ALL 26
192 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
193 #define VHOST_NET_F_VIRTIO_NET_HDR 27
194 
195 /* VHOST_SCSI specific definitions */
196 
197 /*
198  * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
199  *
200  * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
201  *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
202  * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
203  *            All the targets under vhost_wwpn can be seen and used by guset.
204  */
205 
206 #define VHOST_SCSI_ABI_VERSION	1
207 
208 struct vhost_scsi_target {
209 	int abi_version;
210 	char vhost_wwpn[224]; /* TRANSPORT_IQN_LEN */
211 	unsigned short vhost_tpgt;
212 	unsigned short reserved;
213 };
214 
215 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
216 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
217 /* Changing this breaks userspace. */
218 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
219 /* Set and get the events missed flag */
220 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
221 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
222 
223 /* VHOST_VSOCK specific defines */
224 
225 #define VHOST_VSOCK_SET_GUEST_CID	_IOW(VHOST_VIRTIO, 0x60, __u64)
226 #define VHOST_VSOCK_SET_RUNNING		_IOW(VHOST_VIRTIO, 0x61, int)
227 
228 #endif
229