xref: /qemu/linux-headers/linux/vhost.h (revision 6402cbbb)
1 #ifndef _LINUX_VHOST_H
2 #define _LINUX_VHOST_H
3 /* Userspace interface for in-kernel virtio accelerators. */
4 
5 /* vhost is used to reduce the number of system calls involved in virtio.
6  *
7  * Existing virtio net code is used in the guest without modification.
8  *
9  * This header includes interface used by userspace hypervisor for
10  * device configuration.
11  */
12 
13 #include <linux/types.h>
14 
15 #include <linux/ioctl.h>
16 #include <linux/virtio_config.h>
17 #include <linux/virtio_ring.h>
18 
19 struct vhost_vring_state {
20 	unsigned int index;
21 	unsigned int num;
22 };
23 
24 struct vhost_vring_file {
25 	unsigned int index;
26 	int fd; /* Pass -1 to unbind from file. */
27 
28 };
29 
30 struct vhost_vring_addr {
31 	unsigned int index;
32 	/* Option flags. */
33 	unsigned int flags;
34 	/* Flag values: */
35 	/* Whether log address is valid. If set enables logging. */
36 #define VHOST_VRING_F_LOG 0
37 
38 	/* Start of array of descriptors (virtually contiguous) */
39 	__u64 desc_user_addr;
40 	/* Used structure address. Must be 32 bit aligned */
41 	__u64 used_user_addr;
42 	/* Available structure address. Must be 16 bit aligned */
43 	__u64 avail_user_addr;
44 	/* Logging support. */
45 	/* Log writes to used structure, at offset calculated from specified
46 	 * address. Address must be 32 bit aligned. */
47 	__u64 log_guest_addr;
48 };
49 
50 /* no alignment requirement */
51 struct vhost_iotlb_msg {
52 	__u64 iova;
53 	__u64 size;
54 	__u64 uaddr;
55 #define VHOST_ACCESS_RO      0x1
56 #define VHOST_ACCESS_WO      0x2
57 #define VHOST_ACCESS_RW      0x3
58 	__u8 perm;
59 #define VHOST_IOTLB_MISS           1
60 #define VHOST_IOTLB_UPDATE         2
61 #define VHOST_IOTLB_INVALIDATE     3
62 #define VHOST_IOTLB_ACCESS_FAIL    4
63 	__u8 type;
64 };
65 
66 #define VHOST_IOTLB_MSG 0x1
67 
68 struct vhost_msg {
69 	int type;
70 	union {
71 		struct vhost_iotlb_msg iotlb;
72 		__u8 padding[64];
73 	};
74 };
75 
76 struct vhost_memory_region {
77 	__u64 guest_phys_addr;
78 	__u64 memory_size; /* bytes */
79 	__u64 userspace_addr;
80 	__u64 flags_padding; /* No flags are currently specified. */
81 };
82 
83 /* All region addresses and sizes must be 4K aligned. */
84 #define VHOST_PAGE_SIZE 0x1000
85 
86 struct vhost_memory {
87 	__u32 nregions;
88 	__u32 padding;
89 	struct vhost_memory_region regions[0];
90 };
91 
92 /* ioctls */
93 
94 #define VHOST_VIRTIO 0xAF
95 
96 /* Features bitmask for forward compatibility.  Transport bits are used for
97  * vhost specific features. */
98 #define VHOST_GET_FEATURES	_IOR(VHOST_VIRTIO, 0x00, __u64)
99 #define VHOST_SET_FEATURES	_IOW(VHOST_VIRTIO, 0x00, __u64)
100 
101 /* Set current process as the (exclusive) owner of this file descriptor.  This
102  * must be called before any other vhost command.  Further calls to
103  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
104 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
105 /* Give up ownership, and reset the device to default values.
106  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
107 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
108 
109 /* Set up/modify memory layout */
110 #define VHOST_SET_MEM_TABLE	_IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
111 
112 /* Write logging setup. */
113 /* Memory writes can optionally be logged by setting bit at an offset
114  * (calculated from the physical address) from specified log base.
115  * The bit is set using an atomic 32 bit operation. */
116 /* Set base address for logging. */
117 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
118 /* Specify an eventfd file descriptor to signal on log write. */
119 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
120 
121 /* Ring setup. */
122 /* Set number of descriptors in ring. This parameter can not
123  * be modified while ring is running (bound to a device). */
124 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
125 /* Set addresses for the ring. */
126 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
127 /* Base value where queue looks for available descriptors */
128 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
129 /* Get accessor: reads index, writes value in num */
130 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
131 
132 /* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
133  * or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
134  * The byte order cannot be changed while the device is active: trying to do so
135  * returns -EBUSY.
136  * This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
137  * set.
138  * Not all kernel configurations support this ioctl, but all configurations that
139  * support SET also support GET.
140  */
141 #define VHOST_VRING_LITTLE_ENDIAN 0
142 #define VHOST_VRING_BIG_ENDIAN 1
143 #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
144 #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
145 
146 /* The following ioctls use eventfd file descriptors to signal and poll
147  * for events. */
148 
149 /* Set eventfd to poll for added buffers */
150 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
151 /* Set eventfd to signal when buffers have beed used */
152 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
153 /* Set eventfd to signal an error */
154 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
155 /* Set busy loop timeout (in us) */
156 #define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23,	\
157 					 struct vhost_vring_state)
158 /* Get busy loop timeout (in us) */
159 #define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24,	\
160 					 struct vhost_vring_state)
161 
162 /* VHOST_NET specific defines */
163 
164 /* Attach virtio net ring to a raw socket, or tap device.
165  * The socket must be already bound to an ethernet device, this device will be
166  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
167  * device.  This can be used to stop the ring (e.g. for migration). */
168 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
169 
170 /* Feature bits */
171 /* Log all write descriptors. Can be changed while device is active. */
172 #define VHOST_F_LOG_ALL 26
173 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
174 #define VHOST_NET_F_VIRTIO_NET_HDR 27
175 
176 /* VHOST_SCSI specific definitions */
177 
178 /*
179  * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
180  *
181  * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
182  *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
183  * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
184  *            All the targets under vhost_wwpn can be seen and used by guset.
185  */
186 
187 #define VHOST_SCSI_ABI_VERSION	1
188 
189 struct vhost_scsi_target {
190 	int abi_version;
191 	char vhost_wwpn[224]; /* TRANSPORT_IQN_LEN */
192 	unsigned short vhost_tpgt;
193 	unsigned short reserved;
194 };
195 
196 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
197 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
198 /* Changing this breaks userspace. */
199 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
200 /* Set and get the events missed flag */
201 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
202 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
203 
204 /* VHOST_VSOCK specific defines */
205 
206 #define VHOST_VSOCK_SET_GUEST_CID	_IOW(VHOST_VIRTIO, 0x60, __u64)
207 #define VHOST_VSOCK_SET_RUNNING		_IOW(VHOST_VIRTIO, 0x61, int)
208 
209 #endif
210