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Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +00001#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
19struct vhost_vring_state {
20 unsigned int index;
21 unsigned int num;
22};
23
24struct vhost_vring_file {
25 unsigned int index;
26 int fd; /* Pass -1 to unbind from file. */
27
28};
29
30struct 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
50struct 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
60struct 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