linux-headers/linux/vhost.h

   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 /* Vhost have device IOTLB */
 176 #define VHOST_F_DEVICE_IOTLB 63
 177
 178 /* VHOST_SCSI specific definitions */
 179
 180 /*
 181  * Used by QEMU userspace to ensure a consistent vhost-scsi ABI.
 182  *
 183  * ABI Rev 0: July 2012 version starting point for v3.6-rc merge candidate +
 184  *            RFC-v2 vhost-scsi userspace.  Add GET_ABI_VERSION ioctl usage
 185  * ABI Rev 1: January 2013. Ignore vhost_tpgt filed in struct vhost_scsi_target.
 186  *            All the targets under vhost_wwpn can be seen and used by guset.
 187  */
 188
 189 #define VHOST_SCSI_ABI_VERSION  1
 190
 191 struct vhost_scsi_target {
 192         int abi_version;
 193         char vhost_wwpn[224]; /* TRANSPORT_IQN_LEN */
 194         unsigned short vhost_tpgt;
 195         unsigned short reserved;
 196 };
 197
 198 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
 199 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
 200 /* Changing this breaks userspace. */
 201 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
 202 /* Set and get the events missed flag */
 203 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
 204 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
 205
 206 /* VHOST_VSOCK specific defines */
 207
 208 #define VHOST_VSOCK_SET_GUEST_CID       _IOW(VHOST_VIRTIO, 0x60, __u64)
 209 #define VHOST_VSOCK_SET_RUNNING         _IOW(VHOST_VIRTIO, 0x61, int)
 210
 211 #endif