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/vhost_types.h>
  15 #include <linux/types.h>
  16 #include <linux/ioctl.h>
  17
  18 /* ioctls */
  19
  20 #define VHOST_VIRTIO 0xAF
  21
  22 /* Features bitmask for forward compatibility.  Transport bits are used for
  23  * vhost specific features. */
  24 #define VHOST_GET_FEATURES      _IOR(VHOST_VIRTIO, 0x00, __u64)
  25 #define VHOST_SET_FEATURES      _IOW(VHOST_VIRTIO, 0x00, __u64)
  26
  27 /* Set current process as the (exclusive) owner of this file descriptor.  This
  28  * must be called before any other vhost command.  Further calls to
  29  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
  30 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
  31 /* Give up ownership, and reset the device to default values.
  32  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
  33 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
  34
  35 /* Set up/modify memory layout */
  36 #define VHOST_SET_MEM_TABLE     _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
  37
  38 /* Write logging setup. */
  39 /* Memory writes can optionally be logged by setting bit at an offset
  40  * (calculated from the physical address) from specified log base.
  41  * The bit is set using an atomic 32 bit operation. */
  42 /* Set base address for logging. */
  43 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
  44 /* Specify an eventfd file descriptor to signal on log write. */
  45 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
  46
  47 /* Ring setup. */
  48 /* Set number of descriptors in ring. This parameter can not
  49  * be modified while ring is running (bound to a device). */
  50 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
  51 /* Set addresses for the ring. */
  52 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
  53 /* Base value where queue looks for available descriptors */
  54 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
  55 /* Get accessor: reads index, writes value in num */
  56 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
  57
  58 /* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
  59  * or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
  60  * The byte order cannot be changed while the device is active: trying to do so
  61  * returns -EBUSY.
  62  * This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
  63  * set.
  64  * Not all kernel configurations support this ioctl, but all configurations that
  65  * support SET also support GET.
  66  */
  67 #define VHOST_VRING_LITTLE_ENDIAN 0
  68 #define VHOST_VRING_BIG_ENDIAN 1
  69 #define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
  70 #define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
  71
  72 /* The following ioctls use eventfd file descriptors to signal and poll
  73  * for events. */
  74
  75 /* Set eventfd to poll for added buffers */
  76 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
  77 /* Set eventfd to signal when buffers have beed used */
  78 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
  79 /* Set eventfd to signal an error */
  80 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
  81 /* Set busy loop timeout (in us) */
  82 #define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23,       \
  83                                          struct vhost_vring_state)
  84 /* Get busy loop timeout (in us) */
  85 #define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24,       \
  86                                          struct vhost_vring_state)
  87
  88 /* Set or get vhost backend capability */
  89
  90 /* Use message type V2 */
  91 #define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
  92
  93 #define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
  94 #define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
  95
  96 /* VHOST_NET specific defines */
  97
  98 /* Attach virtio net ring to a raw socket, or tap device.
  99  * The socket must be already bound to an ethernet device, this device will be
 100  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
 101  * device.  This can be used to stop the ring (e.g. for migration). */
 102 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
 103
 104 /* VHOST_SCSI specific defines */
 105
 106 #define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
 107 #define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
 108 /* Changing this breaks userspace. */
 109 #define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
 110 /* Set and get the events missed flag */
 111 #define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
 112 #define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
 113
 114 /* VHOST_VSOCK specific defines */
 115
 116 #define VHOST_VSOCK_SET_GUEST_CID       _IOW(VHOST_VIRTIO, 0x60, __u64)
 117 #define VHOST_VSOCK_SET_RUNNING         _IOW(VHOST_VIRTIO, 0x61, int)
 118
 119 #endif