xref: /linux-6.15/include/uapi/linux/vhost.h (revision c1ecd8e9)
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/vhost_types.h>
15 #include <linux/types.h>
16 #include <linux/ioctl.h>
17 
18 #define VHOST_FILE_UNBIND -1
19 
20 /* ioctls */
21 
22 #define VHOST_VIRTIO 0xAF
23 
24 /* Features bitmask for forward compatibility.  Transport bits are used for
25  * vhost specific features. */
26 #define VHOST_GET_FEATURES	_IOR(VHOST_VIRTIO, 0x00, __u64)
27 #define VHOST_SET_FEATURES	_IOW(VHOST_VIRTIO, 0x00, __u64)
28 
29 /* Set current process as the (exclusive) owner of this file descriptor.  This
30  * must be called before any other vhost command.  Further calls to
31  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
32 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
33 /* Give up ownership, and reset the device to default values.
34  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
35 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
36 
37 /* Set up/modify memory layout */
38 #define VHOST_SET_MEM_TABLE	_IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
39 
40 /* Write logging setup. */
41 /* Memory writes can optionally be logged by setting bit at an offset
42  * (calculated from the physical address) from specified log base.
43  * The bit is set using an atomic 32 bit operation. */
44 /* Set base address for logging. */
45 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
46 /* Specify an eventfd file descriptor to signal on log write. */
47 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
48 /* By default, a device gets one vhost_worker that its virtqueues share. This
49  * command allows the owner of the device to create an additional vhost_worker
50  * for the device. It can later be bound to 1 or more of its virtqueues using
51  * the VHOST_ATTACH_VRING_WORKER command.
52  *
53  * This must be called after VHOST_SET_OWNER and the caller must be the owner
54  * of the device. The new thread will inherit caller's cgroups and namespaces,
55  * and will share the caller's memory space. The new thread will also be
56  * counted against the caller's RLIMIT_NPROC value.
57  *
58  * The worker's ID used in other commands will be returned in
59  * vhost_worker_state.
60  */
61 #define VHOST_NEW_WORKER _IOR(VHOST_VIRTIO, 0x8, struct vhost_worker_state)
62 /* Free a worker created with VHOST_NEW_WORKER if it's not attached to any
63  * virtqueue. If userspace is not able to call this for workers its created,
64  * the kernel will free all the device's workers when the device is closed.
65  */
66 #define VHOST_FREE_WORKER _IOW(VHOST_VIRTIO, 0x9, struct vhost_worker_state)
67 
68 /* Ring setup. */
69 /* Set number of descriptors in ring. This parameter can not
70  * be modified while ring is running (bound to a device). */
71 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
72 /* Set addresses for the ring. */
73 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
74 /* Base value where queue looks for available descriptors */
75 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
76 /* Get accessor: reads index, writes value in num */
77 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
78 
79 /* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
80  * or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
81  * The byte order cannot be changed while the device is active: trying to do so
82  * returns -EBUSY.
83  * This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
84  * set.
85  * Not all kernel configurations support this ioctl, but all configurations that
86  * support SET also support GET.
87  */
88 #define VHOST_VRING_LITTLE_ENDIAN 0
89 #define VHOST_VRING_BIG_ENDIAN 1
90 #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
91 #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
92 /* Attach a vhost_worker created with VHOST_NEW_WORKER to one of the device's
93  * virtqueues. This must be done before VHOST_SET_VRING_KICK and the driver
94  * specific ioctl to activate the virtqueue (VHOST_SCSI_SET_ENDPOINT,
95  * VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING) has been run.
96  *
97  * This will replace the virtqueue's existing worker. If the replaced worker
98  * is no longer attached to any virtqueues, it can be freed with
99  * VHOST_FREE_WORKER.
100  */
101 #define VHOST_ATTACH_VRING_WORKER _IOW(VHOST_VIRTIO, 0x15,		\
102 				       struct vhost_vring_worker)
103 /* Return the vring worker's ID */
104 #define VHOST_GET_VRING_WORKER _IOWR(VHOST_VIRTIO, 0x16,		\
105 				     struct vhost_vring_worker)
106 
107 /* The following ioctls use eventfd file descriptors to signal and poll
108  * for events. */
109 
110 /* Set eventfd to poll for added buffers */
111 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
112 /* Set eventfd to signal when buffers have beed used */
113 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
114 /* Set eventfd to signal an error */
115 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
116 /* Set busy loop timeout (in us) */
117 #define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23,	\
118 					 struct vhost_vring_state)
119 /* Get busy loop timeout (in us) */
120 #define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24,	\
121 					 struct vhost_vring_state)
122 
123 /* Set or get vhost backend capability */
124 
125 #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
126 #define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
127 
128 /* VHOST_NET specific defines */
129 
130 /* Attach virtio net ring to a raw socket, or tap device.
131  * The socket must be already bound to an ethernet device, this device will be
132  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
133  * device.  This can be used to stop the ring (e.g. for migration). */
134 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
135 
136 /* VHOST_SCSI specific defines */
137 
138 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
139 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
140 /* Changing this breaks userspace. */
141 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
142 /* Set and get the events missed flag */
143 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
144 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
145 
146 /* VHOST_VSOCK specific defines */
147 
148 #define VHOST_VSOCK_SET_GUEST_CID	_IOW(VHOST_VIRTIO, 0x60, __u64)
149 #define VHOST_VSOCK_SET_RUNNING		_IOW(VHOST_VIRTIO, 0x61, int)
150 
151 /* VHOST_VDPA specific defines */
152 
153 /* Get the device id. The device ids follow the same definition of
154  * the device id defined in virtio-spec.
155  */
156 #define VHOST_VDPA_GET_DEVICE_ID	_IOR(VHOST_VIRTIO, 0x70, __u32)
157 /* Get and set the status. The status bits follow the same definition
158  * of the device status defined in virtio-spec.
159  */
160 #define VHOST_VDPA_GET_STATUS		_IOR(VHOST_VIRTIO, 0x71, __u8)
161 #define VHOST_VDPA_SET_STATUS		_IOW(VHOST_VIRTIO, 0x72, __u8)
162 /* Get and set the device config. The device config follows the same
163  * definition of the device config defined in virtio-spec.
164  */
165 #define VHOST_VDPA_GET_CONFIG		_IOR(VHOST_VIRTIO, 0x73, \
166 					     struct vhost_vdpa_config)
167 #define VHOST_VDPA_SET_CONFIG		_IOW(VHOST_VIRTIO, 0x74, \
168 					     struct vhost_vdpa_config)
169 /* Enable/disable the ring. */
170 #define VHOST_VDPA_SET_VRING_ENABLE	_IOW(VHOST_VIRTIO, 0x75, \
171 					     struct vhost_vring_state)
172 /* Get the max ring size. */
173 #define VHOST_VDPA_GET_VRING_NUM	_IOR(VHOST_VIRTIO, 0x76, __u16)
174 
175 /* Set event fd for config interrupt*/
176 #define VHOST_VDPA_SET_CONFIG_CALL	_IOW(VHOST_VIRTIO, 0x77, int)
177 
178 /* Get the valid iova range */
179 #define VHOST_VDPA_GET_IOVA_RANGE	_IOR(VHOST_VIRTIO, 0x78, \
180 					     struct vhost_vdpa_iova_range)
181 /* Get the config size */
182 #define VHOST_VDPA_GET_CONFIG_SIZE	_IOR(VHOST_VIRTIO, 0x79, __u32)
183 
184 /* Get the count of all virtqueues */
185 #define VHOST_VDPA_GET_VQS_COUNT	_IOR(VHOST_VIRTIO, 0x80, __u32)
186 
187 /* Get the number of virtqueue groups. */
188 #define VHOST_VDPA_GET_GROUP_NUM	_IOR(VHOST_VIRTIO, 0x81, __u32)
189 
190 /* Get the number of address spaces. */
191 #define VHOST_VDPA_GET_AS_NUM		_IOR(VHOST_VIRTIO, 0x7A, unsigned int)
192 
193 /* Get the group for a virtqueue: read index, write group in num,
194  * The virtqueue index is stored in the index field of
195  * vhost_vring_state. The group for this specific virtqueue is
196  * returned via num field of vhost_vring_state.
197  */
198 #define VHOST_VDPA_GET_VRING_GROUP	_IOWR(VHOST_VIRTIO, 0x7B,	\
199 					      struct vhost_vring_state)
200 /* Set the ASID for a virtqueue group. The group index is stored in
201  * the index field of vhost_vring_state, the ASID associated with this
202  * group is stored at num field of vhost_vring_state.
203  */
204 #define VHOST_VDPA_SET_GROUP_ASID	_IOW(VHOST_VIRTIO, 0x7C, \
205 					     struct vhost_vring_state)
206 
207 /* Suspend a device so it does not process virtqueue requests anymore
208  *
209  * After the return of ioctl the device must preserve all the necessary state
210  * (the virtqueue vring base plus the possible device specific states) that is
211  * required for restoring in the future. The device must not change its
212  * configuration after that point.
213  */
214 #define VHOST_VDPA_SUSPEND		_IO(VHOST_VIRTIO, 0x7D)
215 
216 /* Resume a device so it can resume processing virtqueue requests
217  *
218  * After the return of this ioctl the device will have restored all the
219  * necessary states and it is fully operational to continue processing the
220  * virtqueue descriptors.
221  */
222 #define VHOST_VDPA_RESUME		_IO(VHOST_VIRTIO, 0x7E)
223 
224 #endif
225