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      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 #include <linux/compiler.h>
     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