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
  69 struct vhost_msg {
  70         int type;
  71         union {
  72                 struct vhost_iotlb_msg iotlb;
  73                 __u8 padding[64];
  74         };
  75 };
  76
  77 struct vhost_memory_region {
  78         __u64 guest_phys_addr;
  79         __u64 memory_size; /* bytes */
  80         __u64 userspace_addr;
  81         __u64 flags_padding; /* No flags are currently specified. */
  82 };
  83
  84 /* All region addresses and sizes must be 4K aligned. */
  85 #define VHOST_PAGE_SIZE 0x1000
  86
  87 struct vhost_memory {
  88         __u32 nregions;
  89         __u32 padding;
  90         struct vhost_memory_region regions[0];
  91 };
  92
  93 /* ioctls */
  94
  95 #define VHOST_VIRTIO 0xAF
  96
  97 /* Features bitmask for forward compatibility.  Transport bits are used for
  98  * vhost specific features. */
  99 #define VHOST_GET_FEATURES      _IOR(VHOST_VIRTIO, 0x00, __u64)
 100 #define VHOST_SET_FEATURES      _IOW(VHOST_VIRTIO, 0x00, __u64)
 101
 102 /* Set current process as the (exclusive) owner of this file descriptor.  This
 103  * must be called before any other vhost command.  Further calls to
 104  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
 105 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
 106 /* Give up ownership, and reset the device to default values.
 107  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
 108 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
 109
 110 /* Set up/modify memory layout */
 111 #define VHOST_SET_MEM_TABLE     _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
 112
 113 /* Write logging setup. */
 114 /* Memory writes can optionally be logged by setting bit at an offset
 115  * (calculated from the physical address) from specified log base.
 116  * The bit is set using an atomic 32 bit operation. */
 117 /* Set base address for logging. */
 118 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
 119 /* Specify an eventfd file descriptor to signal on log write. */
 120 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
 121
 122 /* Ring setup. */
 123 /* Set number of descriptors in ring. This parameter can not
 124  * be modified while ring is running (bound to a device). */
 125 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
 126 /* Set addresses for the ring. */
 127 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
 128 /* Base value where queue looks for available descriptors */
 129 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
 130 /* Get accessor: reads index, writes value in num */
 131 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
 132
 133 /* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
 134  * or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
 135  * The byte order cannot be changed while the device is active: trying to do so
 136  * returns -EBUSY.
 137  * This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
 138  * set.
 139  * Not all kernel configurations support this ioctl, but all configurations that
 140  * support SET also support GET.
 141  */
 142 #define VHOST_VRING_LITTLE_ENDIAN 0
 143 #define VHOST_VRING_BIG_ENDIAN 1
 144 #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
 145 #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
 146
 147 /* The following ioctls use eventfd file descriptors to signal and poll
 148  * for events. */
 149
 150 /* Set eventfd to poll for added buffers */
 151 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
 152 /* Set eventfd to signal when buffers have beed used */
 153 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
 154 /* Set eventfd to signal an error */
 155 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
 156 /* Set busy loop timeout (in us) */
 157 #define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23,       \
 158                                          struct vhost_vring_state)
 159 /* Get busy loop timeout (in us) */
 160 #define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24,       \
 161                                          struct vhost_vring_state)
 162
 163 /* VHOST_NET specific defines */
 164
 165 /* Attach virtio net ring to a raw socket, or tap device.
 166  * The socket must be already bound to an ethernet device, this device will be
 167  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
 168  * device.  This can be used to stop the ring (e.g. for migration). */
 169 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
 170
 171 /* Feature bits */
 172 /* Log all write descriptors. Can be changed while device is active. */
 173 #define VHOST_F_LOG_ALL 26
 174 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
 175 #define VHOST_NET_F_VIRTIO_NET_HDR 27
 176
 177 /* VHOST_SCSI specific definitions */
 178
 179 /*
 180  * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
 181  *
 182  * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
 183  *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
 184  * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
 185  *            All the targets under vhost_wwpn can be seen and used by guset.
 186  */
 187
 188 #define VHOST_SCSI_ABI_VERSION  1
 189
 190 struct vhost_scsi_target {
 191         int abi_version;
 192         char vhost_wwpn[224]; /* TRANSPORT_IQN_LEN */
 193         unsigned short vhost_tpgt;
 194         unsigned short reserved;
 195 };
 196
 197 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
 198 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
 199 /* Changing this breaks userspace. */
 200 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
 201 /* Set and get the events missed flag */
 202 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
 203 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
 204
 205 /* VHOST_VSOCK specific defines */
 206
 207 #define VHOST_VSOCK_SET_GUEST_CID       _IOW(VHOST_VIRTIO, 0x60, __u64)
 208 #define VHOST_VSOCK_SET_RUNNING         _IOW(VHOST_VIRTIO, 0x61, int)
 209
 210 #endif