linux-headers/linux/vhost.h

   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 _IOW(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