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 struct vhost_memory_region { 51 __u64 guest_phys_addr; 52 __u64 memory_size; /* bytes */ 53 __u64 userspace_addr; 54 __u64 flags_padding; /* No flags are currently specified. */ 55 }; 56 57 /* All region addresses and sizes must be 4K aligned. */ 58 #define VHOST_PAGE_SIZE 0x1000 59 60 struct vhost_memory { 61 __u32 nregions; 62 __u32 padding; 63 struct vhost_memory_region regions[0]; 64 }; 65 66 /* ioctls */ 67 68 #define VHOST_VIRTIO 0xAF 69 70 /* Features bitmask for forward compatibility. Transport bits are used for 71 * vhost specific features. */ 72 #define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64) 73 #define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64) 74 75 /* Set current process as the (exclusive) owner of this file descriptor. This 76 * must be called before any other vhost command. Further calls to 77 * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */ 78 #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01) 79 /* Give up ownership, and reset the device to default values. 80 * Allows subsequent call to VHOST_OWNER_SET to succeed. */ 81 #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02) 82 83 /* Set up/modify memory layout */ 84 #define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory) 85 86 /* Write logging setup. */ 87 /* Memory writes can optionally be logged by setting bit at an offset 88 * (calculated from the physical address) from specified log base. 89 * The bit is set using an atomic 32 bit operation. */ 90 /* Set base address for logging. */ 91 #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64) 92 /* Specify an eventfd file descriptor to signal on log write. */ 93 #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int) 94 95 /* Ring setup. */ 96 /* Set number of descriptors in ring. This parameter can not 97 * be modified while ring is running (bound to a device). */ 98 #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state) 99 /* Set addresses for the ring. */ 100 #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr) 101 /* Base value where queue looks for available descriptors */ 102 #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state) 103 /* Get accessor: reads index, writes value in num */ 104 #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state) 105 106 /* The following ioctls use eventfd file descriptors to signal and poll 107 * for events. */ 108 109 /* Set eventfd to poll for added buffers */ 110 #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file) 111 /* Set eventfd to signal when buffers have beed used */ 112 #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file) 113 /* Set eventfd to signal an error */ 114 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file) 115 116 /* VHOST_NET specific defines */ 117 118 /* Attach virtio net ring to a raw socket, or tap device. 119 * The socket must be already bound to an ethernet device, this device will be 120 * used for transmit. Pass fd -1 to unbind from the socket and the transmit 121 * device. This can be used to stop the ring (e.g. for migration). */ 122 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file) 123 124 /* Feature bits */ 125 /* Log all write descriptors. Can be changed while device is active. */ 126 #define VHOST_F_LOG_ALL 26 127 /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */ 128 #define VHOST_NET_F_VIRTIO_NET_HDR 27 129 130 #endif 131
