hyperv.h

Go to the documentation of this file.

/*
 *
 * Copyright (c) 2011, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <[email protected]>
 *   Hank Janssen  <[email protected]>
 *   K. Y. Srinivasan <[email protected]>
 *
 */

#ifndef _HYPERV_H
#define _HYPERV_H

#include <linux/types.h>

/*
 * An implementation of HyperV key value pair (KVP) functionality for Linux.
 *
 *
 * Copyright (C) 2010, Novell, Inc.
 * Author : K. Y. Srinivasan <[email protected]>
 *
 */

/*
 * Maximum value size - used for both key names and value data, and includes
 * any applicable NULL terminators.
 *
 * Note:  This limit is somewhat arbitrary, but falls easily within what is
 * supported for all native guests (back to Win 2000) and what is reasonable
 * for the IC KVP exchange functionality.  Note that Windows Me/98/95 are
 * limited to 255 character key names.
 *
 * MSDN recommends not storing data values larger than 2048 bytes in the
 * registry.
 *
 * Note:  This value is used in defining the KVP exchange message - this value
 * cannot be modified without affecting the message size and compatibility.
 */

/*
 * bytes, including any null terminators
 */
#define HV_KVP_EXCHANGE_MAX_VALUE_SIZE          (2048)


/*
 * Maximum key size - the registry limit for the length of an entry name
 * is 256 characters, including the null terminator
 */

#define HV_KVP_EXCHANGE_MAX_KEY_SIZE            (512)

/*
 * In Linux, we implement the KVP functionality in two components:
 * 1) The kernel component which is packaged as part of the hv_utils driver
 * is responsible for communicating with the host and responsible for
 * implementing the host/guest protocol. 2) A user level daemon that is
 * responsible for data gathering.
 *
 * Host/Guest Protocol: The host iterates over an index and expects the guest
 * to assign a key name to the index and also return the value corresponding to
 * the key. The host will have atmost one KVP transaction outstanding at any
 * given point in time. The host side iteration stops when the guest returns
 * an error. Microsoft has specified the following mapping of key names to
 * host specified index:
 *
 *  Index       Key Name
 *  0       FullyQualifiedDomainName
 *  1       IntegrationServicesVersion
 *  2       NetworkAddressIPv4
 *  3       NetworkAddressIPv6
 *  4       OSBuildNumber
 *  5       OSName
 *  6       OSMajorVersion
 *  7       OSMinorVersion
 *  8       OSVersion
 *  9       ProcessorArchitecture
 *
 * The Windows host expects the Key Name and Key Value to be encoded in utf16.
 *
 * Guest Kernel/KVP Daemon Protocol: As noted earlier, we implement all of the
 * data gathering functionality in a user mode daemon. The user level daemon
 * is also responsible for binding the key name to the index as well. The
 * kernel and user-level daemon communicate using a connector channel.
 *
 * The user mode component first registers with the
 * the kernel component. Subsequently, the kernel component requests, data
 * for the specified keys. In response to this message the user mode component
 * fills in the value corresponding to the specified key. We overload the
 * sequence field in the cn_msg header to define our KVP message types.
 *
 *
 * The kernel component simply acts as a conduit for communication between the
 * Windows host and the user-level daemon. The kernel component passes up the
 * index received from the Host to the user-level daemon. If the index is
 * valid (supported), the corresponding key as well as its
 * value (both are strings) is returned. If the index is invalid
 * (not supported), a NULL key string is returned.
 */


/*
 * Registry value types.
 */

#define REG_SZ 1
#define REG_U32 4
#define REG_U64 8

/*
 * As we look at expanding the KVP functionality to include
 * IP injection functionality, we need to maintain binary
 * compatibility with older daemons.
 *
 * The KVP opcodes are defined by the host and it was unfortunate
 * that I chose to treat the registration operation as part of the
 * KVP operations defined by the host.
 * Here is the level of compatibility
 * (between the user level daemon and the kernel KVP driver) that we
 * will implement:
 *
 * An older daemon will always be supported on a newer driver.
 * A given user level daemon will require a minimal version of the
 * kernel driver.
 * If we cannot handle the version differences, we will fail gracefully
 * (this can happen when we have a user level daemon that is more
 * advanced than the KVP driver.
 *
 * We will use values used in this handshake for determining if we have
 * workable user level daemon and the kernel driver. We begin by taking the
 * registration opcode out of the KVP opcode namespace. We will however,
 * maintain compatibility with the existing user-level daemon code.
 */

/*
 * Daemon code not supporting IP injection (legacy daemon).
 */

#define KVP_OP_REGISTER 4

/*
 * Daemon code supporting IP injection.
 * The KVP opcode field is used to communicate the
 * registration information; so define a namespace that
 * will be distinct from the host defined KVP opcode.
 */

#define KVP_OP_REGISTER1 100

enum hv_kvp_exchg_op {
    KVP_OP_GET = 0,
    KVP_OP_SET,
    KVP_OP_DELETE,
    KVP_OP_ENUMERATE,
    KVP_OP_GET_IP_INFO,
    KVP_OP_SET_IP_INFO,
    KVP_OP_COUNT /* Number of operations, must be last. */
};

enum hv_kvp_exchg_pool {
    KVP_POOL_EXTERNAL = 0,
    KVP_POOL_GUEST,
    KVP_POOL_AUTO,
    KVP_POOL_AUTO_EXTERNAL,
    KVP_POOL_AUTO_INTERNAL,
    KVP_POOL_COUNT /* Number of pools, must be last. */
};

/*
 * Some Hyper-V status codes.
 */

#define HV_S_OK             0x00000000
#define HV_E_FAIL           0x80004005
#define HV_S_CONT           0x80070103
#define HV_ERROR_NOT_SUPPORTED      0x80070032
#define HV_ERROR_MACHINE_LOCKED     0x800704F7
#define HV_ERROR_DEVICE_NOT_CONNECTED   0x8007048F
#define HV_INVALIDARG           0x80070057
#define HV_GUID_NOTFOUND        0x80041002

#define ADDR_FAMILY_NONE    0x00
#define ADDR_FAMILY_IPV4    0x01
#define ADDR_FAMILY_IPV6    0x02

#define MAX_ADAPTER_ID_SIZE 128
#define MAX_IP_ADDR_SIZE    1024
#define MAX_GATEWAY_SIZE    512


struct hv_kvp_ipaddr_value {
    __u16   adapter_id[MAX_ADAPTER_ID_SIZE];
    __u8    addr_family;
    __u8    dhcp_enabled;
    __u16   ip_addr[MAX_IP_ADDR_SIZE];
    __u16   sub_net[MAX_IP_ADDR_SIZE];
    __u16   gate_way[MAX_GATEWAY_SIZE];
    __u16   dns_addr[MAX_IP_ADDR_SIZE];
} __attribute__((packed));


struct hv_kvp_hdr {
    __u8 operation;
    __u8 pool;
    __u16 pad;
} __attribute__((packed));

struct hv_kvp_exchg_msg_value {
    __u32 value_type;
    __u32 key_size;
    __u32 value_size;
    __u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
    union {
        __u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
        __u32 value_u32;
        __u64 value_u64;
    };
} __attribute__((packed));

struct hv_kvp_msg_enumerate {
    __u32 index;
    struct hv_kvp_exchg_msg_value data;
} __attribute__((packed));

struct hv_kvp_msg_get {
    struct hv_kvp_exchg_msg_value data;
};

struct hv_kvp_msg_set {
    struct hv_kvp_exchg_msg_value data;
};

struct hv_kvp_msg_delete {
    __u32 key_size;
    __u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
};

struct hv_kvp_register {
    __u8 version[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
};

struct hv_kvp_msg {
    union {
        struct hv_kvp_hdr   kvp_hdr;
        int error;
    };
    union {
        struct hv_kvp_msg_get       kvp_get;
        struct hv_kvp_msg_set       kvp_set;
        struct hv_kvp_msg_delete    kvp_delete;
        struct hv_kvp_msg_enumerate kvp_enum_data;
        struct hv_kvp_ipaddr_value      kvp_ip_val;
        struct hv_kvp_register      kvp_register;
    } body;
} __attribute__((packed));

struct hv_kvp_ip_msg {
    __u8 operation;
    __u8 pool;
    struct hv_kvp_ipaddr_value      kvp_ip_val;
} __attribute__((packed));

#ifdef __KERNEL__
#include <linux/scatterlist.h>
#include <linux/list.h>
#include <linux/uuid.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>


#define MAX_PAGE_BUFFER_COUNT               19
#define MAX_MULTIPAGE_BUFFER_COUNT          32 /* 128K */

#pragma pack(push, 1)

/* Single-page buffer */
struct hv_page_buffer {
    u32 len;
    u32 offset;
    u64 pfn;
};

/* Multiple-page buffer */
struct hv_multipage_buffer {
    /* Length and Offset determines the # of pfns in the array */
    u32 len;
    u32 offset;
    u64 pfn_array[MAX_MULTIPAGE_BUFFER_COUNT];
};

/* 0x18 includes the proprietary packet header */
#define MAX_PAGE_BUFFER_PACKET      (0x18 +         \
                    (sizeof(struct hv_page_buffer) * \
                     MAX_PAGE_BUFFER_COUNT))
#define MAX_MULTIPAGE_BUFFER_PACKET (0x18 +         \
                     sizeof(struct hv_multipage_buffer))


#pragma pack(pop)

struct hv_ring_buffer {
    /* Offset in bytes from the start of ring data below */
    u32 write_index;

    /* Offset in bytes from the start of ring data below */
    u32 read_index;

    u32 interrupt_mask;

    /* Pad it to PAGE_SIZE so that data starts on page boundary */
    u8  reserved[4084];

    /* NOTE:
     * The interrupt_mask field is used only for channels but since our
     * vmbus connection also uses this data structure and its data starts
     * here, we commented out this field.
     */

    /*
     * Ring data starts here + RingDataStartOffset
     * !!! DO NOT place any fields below this !!!
     */
    u8 buffer[0];
} __packed;

struct hv_ring_buffer_info {
    struct hv_ring_buffer *ring_buffer;
    u32 ring_size;          /* Include the shared header */
    spinlock_t ring_lock;

    u32 ring_datasize;      /* < ring_size */
    u32 ring_data_startoffset;
};

struct hv_ring_buffer_debug_info {
    u32 current_interrupt_mask;
    u32 current_read_index;
    u32 current_write_index;
    u32 bytes_avail_toread;
    u32 bytes_avail_towrite;
};


/*
 *
 * hv_get_ringbuffer_availbytes()
 *
 * Get number of bytes available to read and to write to
 * for the specified ring buffer
 */
static inline void
hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
              u32 *read, u32 *write)
{
    u32 read_loc, write_loc, dsize;

    smp_read_barrier_depends();

    /* Capture the read/write indices before they changed */
    read_loc = rbi->ring_buffer->read_index;
    write_loc = rbi->ring_buffer->write_index;
    dsize = rbi->ring_datasize;

    *write = write_loc >= read_loc ? dsize - (write_loc - read_loc) :
        read_loc - write_loc;
    *read = dsize - *write;
}


/*
 * We use the same version numbering for all Hyper-V modules.
 *
 * Definition of versioning is as follows;
 *
 *  Major Number    Changes for these scenarios;
 *          1.  When a new version of Windows Hyper-V
 *              is released.
 *          2.  A Major change has occurred in the
 *              Linux IC's.
 *          (For example the merge for the first time
 *          into the kernel) Every time the Major Number
 *          changes, the Revision number is reset to 0.
 *  Minor Number    Changes when new functionality is added
 *          to the Linux IC's that is not a bug fix.
 *
 * 3.1 - Added completed hv_utils driver. Shutdown/Heartbeat/Timesync
 */
#define HV_DRV_VERSION           "3.1"


/*
 * A revision number of vmbus that is used for ensuring both ends on a
 * partition are using compatible versions.
 */
#define VMBUS_REVISION_NUMBER       13

/* Make maximum size of pipe payload of 16K */
#define MAX_PIPE_DATA_PAYLOAD       (sizeof(u8) * 16384)

/* Define PipeMode values. */
#define VMBUS_PIPE_TYPE_BYTE        0x00000000
#define VMBUS_PIPE_TYPE_MESSAGE     0x00000004

/* The size of the user defined data buffer for non-pipe offers. */
#define MAX_USER_DEFINED_BYTES      120

/* The size of the user defined data buffer for pipe offers. */
#define MAX_PIPE_USER_DEFINED_BYTES 116

/*
 * At the center of the Channel Management library is the Channel Offer. This
 * struct contains the fundamental information about an offer.
 */
struct vmbus_channel_offer {
    uuid_le if_type;
    uuid_le if_instance;
    u64 int_latency; /* in 100ns units */
    u32 if_revision;
    u32 server_ctx_size;    /* in bytes */
    u16 chn_flags;
    u16 mmio_megabytes;     /* in bytes * 1024 * 1024 */

    union {
        /* Non-pipes: The user has MAX_USER_DEFINED_BYTES bytes. */
        struct {
            unsigned char user_def[MAX_USER_DEFINED_BYTES];
        } std;

        /*
         * Pipes:
         * The following sructure is an integrated pipe protocol, which
         * is implemented on top of standard user-defined data. Pipe
         * clients have MAX_PIPE_USER_DEFINED_BYTES left for their own
         * use.
         */
        struct {
            u32  pipe_mode;
            unsigned char user_def[MAX_PIPE_USER_DEFINED_BYTES];
        } pipe;
    } u;
    u32 padding;
} __packed;

/* Server Flags */
#define VMBUS_CHANNEL_ENUMERATE_DEVICE_INTERFACE    1
#define VMBUS_CHANNEL_SERVER_SUPPORTS_TRANSFER_PAGES    2
#define VMBUS_CHANNEL_SERVER_SUPPORTS_GPADLS        4
#define VMBUS_CHANNEL_NAMED_PIPE_MODE           0x10
#define VMBUS_CHANNEL_LOOPBACK_OFFER            0x100
#define VMBUS_CHANNEL_PARENT_OFFER          0x200
#define VMBUS_CHANNEL_REQUEST_MONITORED_NOTIFICATION    0x400

struct vmpacket_descriptor {
    u16 type;
    u16 offset8;
    u16 len8;
    u16 flags;
    u64 trans_id;
} __packed;

struct vmpacket_header {
    u32 prev_pkt_start_offset;
    struct vmpacket_descriptor descriptor;
} __packed;

struct vmtransfer_page_range {
    u32 byte_count;
    u32 byte_offset;
} __packed;

struct vmtransfer_page_packet_header {
    struct vmpacket_descriptor d;
    u16 xfer_pageset_id;
    u8  sender_owns_set;
    u8 reserved;
    u32 range_cnt;
    struct vmtransfer_page_range ranges[1];
} __packed;

struct vmgpadl_packet_header {
    struct vmpacket_descriptor d;
    u32 gpadl;
    u32 reserved;
} __packed;

struct vmadd_remove_transfer_page_set {
    struct vmpacket_descriptor d;
    u32 gpadl;
    u16 xfer_pageset_id;
    u16 reserved;
} __packed;

/*
 * This structure defines a range in guest physical space that can be made to
 * look virtually contiguous.
 */
struct gpa_range {
    u32 byte_count;
    u32 byte_offset;
    u64 pfn_array[0];
};

/*
 * This is the format for an Establish Gpadl packet, which contains a handle by
 * which this GPADL will be known and a set of GPA ranges associated with it.
 * This can be converted to a MDL by the guest OS.  If there are multiple GPA
 * ranges, then the resulting MDL will be "chained," representing multiple VA
 * ranges.
 */
struct vmestablish_gpadl {
    struct vmpacket_descriptor d;
    u32 gpadl;
    u32 range_cnt;
    struct gpa_range range[1];
} __packed;

/*
 * This is the format for a Teardown Gpadl packet, which indicates that the
 * GPADL handle in the Establish Gpadl packet will never be referenced again.
 */
struct vmteardown_gpadl {
    struct vmpacket_descriptor d;
    u32 gpadl;
    u32 reserved;   /* for alignment to a 8-byte boundary */
} __packed;

/*
 * This is the format for a GPA-Direct packet, which contains a set of GPA
 * ranges, in addition to commands and/or data.
 */
struct vmdata_gpa_direct {
    struct vmpacket_descriptor d;
    u32 reserved;
    u32 range_cnt;
    struct gpa_range range[1];
} __packed;

/* This is the format for a Additional Data Packet. */
struct vmadditional_data {
    struct vmpacket_descriptor d;
    u64 total_bytes;
    u32 offset;
    u32 byte_cnt;
    unsigned char data[1];
} __packed;

union vmpacket_largest_possible_header {
    struct vmpacket_descriptor simple_hdr;
    struct vmtransfer_page_packet_header xfer_page_hdr;
    struct vmgpadl_packet_header gpadl_hdr;
    struct vmadd_remove_transfer_page_set add_rm_xfer_page_hdr;
    struct vmestablish_gpadl establish_gpadl_hdr;
    struct vmteardown_gpadl teardown_gpadl_hdr;
    struct vmdata_gpa_direct data_gpa_direct_hdr;
};

#define VMPACKET_DATA_START_ADDRESS(__packet)   \
    (void *)(((unsigned char *)__packet) +  \
     ((struct vmpacket_descriptor)__packet)->offset8 * 8)

#define VMPACKET_DATA_LENGTH(__packet)      \
    ((((struct vmpacket_descriptor)__packet)->len8 -    \
      ((struct vmpacket_descriptor)__packet)->offset8) * 8)

#define VMPACKET_TRANSFER_MODE(__packet)    \
    (((struct IMPACT)__packet)->type)

enum vmbus_packet_type {
    VM_PKT_INVALID              = 0x0,
    VM_PKT_SYNCH                = 0x1,
    VM_PKT_ADD_XFER_PAGESET         = 0x2,
    VM_PKT_RM_XFER_PAGESET          = 0x3,
    VM_PKT_ESTABLISH_GPADL          = 0x4,
    VM_PKT_TEARDOWN_GPADL           = 0x5,
    VM_PKT_DATA_INBAND          = 0x6,
    VM_PKT_DATA_USING_XFER_PAGES        = 0x7,
    VM_PKT_DATA_USING_GPADL         = 0x8,
    VM_PKT_DATA_USING_GPA_DIRECT        = 0x9,
    VM_PKT_CANCEL_REQUEST           = 0xa,
    VM_PKT_COMP             = 0xb,
    VM_PKT_DATA_USING_ADDITIONAL_PKT    = 0xc,
    VM_PKT_ADDITIONAL_DATA          = 0xd
};

#define VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 1


/* Version 1 messages */
enum vmbus_channel_message_type {
    CHANNELMSG_INVALID          =  0,
    CHANNELMSG_OFFERCHANNEL     =  1,
    CHANNELMSG_RESCIND_CHANNELOFFER =  2,
    CHANNELMSG_REQUESTOFFERS        =  3,
    CHANNELMSG_ALLOFFERS_DELIVERED  =  4,
    CHANNELMSG_OPENCHANNEL      =  5,
    CHANNELMSG_OPENCHANNEL_RESULT       =  6,
    CHANNELMSG_CLOSECHANNEL     =  7,
    CHANNELMSG_GPADL_HEADER     =  8,
    CHANNELMSG_GPADL_BODY           =  9,
    CHANNELMSG_GPADL_CREATED        = 10,
    CHANNELMSG_GPADL_TEARDOWN       = 11,
    CHANNELMSG_GPADL_TORNDOWN       = 12,
    CHANNELMSG_RELID_RELEASED       = 13,
    CHANNELMSG_INITIATE_CONTACT     = 14,
    CHANNELMSG_VERSION_RESPONSE     = 15,
    CHANNELMSG_UNLOAD           = 16,
#ifdef VMBUS_FEATURE_PARENT_OR_PEER_MEMORY_MAPPED_INTO_A_CHILD
    CHANNELMSG_VIEWRANGE_ADD        = 17,
    CHANNELMSG_VIEWRANGE_REMOVE     = 18,
#endif
    CHANNELMSG_COUNT
};

struct vmbus_channel_message_header {
    enum vmbus_channel_message_type msgtype;
    u32 padding;
} __packed;

/* Query VMBus Version parameters */
struct vmbus_channel_query_vmbus_version {
    struct vmbus_channel_message_header header;
    u32 version;
} __packed;

/* VMBus Version Supported parameters */
struct vmbus_channel_version_supported {
    struct vmbus_channel_message_header header;
    u8 version_supported;
} __packed;

/* Offer Channel parameters */
struct vmbus_channel_offer_channel {
    struct vmbus_channel_message_header header;
    struct vmbus_channel_offer offer;
    u32 child_relid;
    u8 monitorid;
    u8 monitor_allocated;
} __packed;

/* Rescind Offer parameters */
struct vmbus_channel_rescind_offer {
    struct vmbus_channel_message_header header;
    u32 child_relid;
} __packed;

/*
 * Request Offer -- no parameters, SynIC message contains the partition ID
 * Set Snoop -- no parameters, SynIC message contains the partition ID
 * Clear Snoop -- no parameters, SynIC message contains the partition ID
 * All Offers Delivered -- no parameters, SynIC message contains the partition
 *                 ID
 * Flush Client -- no parameters, SynIC message contains the partition ID
 */

/* Open Channel parameters */
struct vmbus_channel_open_channel {
    struct vmbus_channel_message_header header;

    /* Identifies the specific VMBus channel that is being opened. */
    u32 child_relid;

    /* ID making a particular open request at a channel offer unique. */
    u32 openid;

    /* GPADL for the channel's ring buffer. */
    u32 ringbuffer_gpadlhandle;

    /* GPADL for the channel's server context save area. */
    u32 server_contextarea_gpadlhandle;

    /*
    * The upstream ring buffer begins at offset zero in the memory
    * described by RingBufferGpadlHandle. The downstream ring buffer
    * follows it at this offset (in pages).
    */
    u32 downstream_ringbuffer_pageoffset;

    /* User-specific data to be passed along to the server endpoint. */
    unsigned char userdata[MAX_USER_DEFINED_BYTES];
} __packed;

/* Open Channel Result parameters */
struct vmbus_channel_open_result {
    struct vmbus_channel_message_header header;
    u32 child_relid;
    u32 openid;
    u32 status;
} __packed;

/* Close channel parameters; */
struct vmbus_channel_close_channel {
    struct vmbus_channel_message_header header;
    u32 child_relid;
} __packed;

/* Channel Message GPADL */
#define GPADL_TYPE_RING_BUFFER      1
#define GPADL_TYPE_SERVER_SAVE_AREA 2
#define GPADL_TYPE_TRANSACTION      8

/*
 * The number of PFNs in a GPADL message is defined by the number of
 * pages that would be spanned by ByteCount and ByteOffset.  If the
 * implied number of PFNs won't fit in this packet, there will be a
 * follow-up packet that contains more.
 */
struct vmbus_channel_gpadl_header {
    struct vmbus_channel_message_header header;
    u32 child_relid;
    u32 gpadl;
    u16 range_buflen;
    u16 rangecount;
    struct gpa_range range[0];
} __packed;

/* This is the followup packet that contains more PFNs. */
struct vmbus_channel_gpadl_body {
    struct vmbus_channel_message_header header;
    u32 msgnumber;
    u32 gpadl;
    u64 pfn[0];
} __packed;

struct vmbus_channel_gpadl_created {
    struct vmbus_channel_message_header header;
    u32 child_relid;
    u32 gpadl;
    u32 creation_status;
} __packed;

struct vmbus_channel_gpadl_teardown {
    struct vmbus_channel_message_header header;
    u32 child_relid;
    u32 gpadl;
} __packed;

struct vmbus_channel_gpadl_torndown {
    struct vmbus_channel_message_header header;
    u32 gpadl;
} __packed;

#ifdef VMBUS_FEATURE_PARENT_OR_PEER_MEMORY_MAPPED_INTO_A_CHILD
struct vmbus_channel_view_range_add {
    struct vmbus_channel_message_header header;
    PHYSICAL_ADDRESS viewrange_base;
    u64 viewrange_length;
    u32 child_relid;
} __packed;

struct vmbus_channel_view_range_remove {
    struct vmbus_channel_message_header header;
    PHYSICAL_ADDRESS viewrange_base;
    u32 child_relid;
} __packed;
#endif

struct vmbus_channel_relid_released {
    struct vmbus_channel_message_header header;
    u32 child_relid;
} __packed;

struct vmbus_channel_initiate_contact {
    struct vmbus_channel_message_header header;
    u32 vmbus_version_requested;
    u32 padding2;
    u64 interrupt_page;
    u64 monitor_page1;
    u64 monitor_page2;
} __packed;

struct vmbus_channel_version_response {
    struct vmbus_channel_message_header header;
    u8 version_supported;
} __packed;

enum vmbus_channel_state {
    CHANNEL_OFFER_STATE,
    CHANNEL_OPENING_STATE,
    CHANNEL_OPEN_STATE,
};

struct vmbus_channel_debug_info {
    u32 relid;
    enum vmbus_channel_state state;
    uuid_le interfacetype;
    uuid_le interface_instance;
    u32 monitorid;
    u32 servermonitor_pending;
    u32 servermonitor_latency;
    u32 servermonitor_connectionid;
    u32 clientmonitor_pending;
    u32 clientmonitor_latency;
    u32 clientmonitor_connectionid;

    struct hv_ring_buffer_debug_info inbound;
    struct hv_ring_buffer_debug_info outbound;
};

/*
 * Represents each channel msg on the vmbus connection This is a
 * variable-size data structure depending on the msg type itself
 */
struct vmbus_channel_msginfo {
    /* Bookkeeping stuff */
    struct list_head msglistentry;

    /* So far, this is only used to handle gpadl body message */
    struct list_head submsglist;

    /* Synchronize the request/response if needed */
    struct completion  waitevent;
    union {
        struct vmbus_channel_version_supported version_supported;
        struct vmbus_channel_open_result open_result;
        struct vmbus_channel_gpadl_torndown gpadl_torndown;
        struct vmbus_channel_gpadl_created gpadl_created;
        struct vmbus_channel_version_response version_response;
    } response;

    u32 msgsize;
    /*
     * The channel message that goes out on the "wire".
     * It will contain at minimum the VMBUS_CHANNEL_MESSAGE_HEADER header
     */
    unsigned char msg[0];
};

struct vmbus_close_msg {
    struct vmbus_channel_msginfo info;
    struct vmbus_channel_close_channel msg;
};

struct vmbus_channel {
    struct list_head listentry;

    struct hv_device *device_obj;

    struct work_struct work;

    enum vmbus_channel_state state;

    struct vmbus_channel_offer_channel offermsg;
    /*
     * These are based on the OfferMsg.MonitorId.
     * Save it here for easy access.
     */
    u8 monitor_grp;
    u8 monitor_bit;

    u32 ringbuffer_gpadlhandle;

    /* Allocated memory for ring buffer */
    void *ringbuffer_pages;
    u32 ringbuffer_pagecount;
    struct hv_ring_buffer_info outbound;    /* send to parent */
    struct hv_ring_buffer_info inbound; /* receive from parent */
    spinlock_t inbound_lock;
    struct workqueue_struct *controlwq;

    struct vmbus_close_msg close_msg;

    /* Channel callback are invoked in this workqueue context */
    /* HANDLE dataWorkQueue; */

    void (*onchannel_callback)(void *context);
    void *channel_callback_context;
};

void vmbus_onmessage(void *context);

int vmbus_request_offers(void);

/* The format must be the same as struct vmdata_gpa_direct */
struct vmbus_channel_packet_page_buffer {
    u16 type;
    u16 dataoffset8;
    u16 length8;
    u16 flags;
    u64 transactionid;
    u32 reserved;
    u32 rangecount;
    struct hv_page_buffer range[MAX_PAGE_BUFFER_COUNT];
} __packed;

/* The format must be the same as struct vmdata_gpa_direct */
struct vmbus_channel_packet_multipage_buffer {
    u16 type;
    u16 dataoffset8;
    u16 length8;
    u16 flags;
    u64 transactionid;
    u32 reserved;
    u32 rangecount;     /* Always 1 in this case */
    struct hv_multipage_buffer range;
} __packed;


extern int vmbus_open(struct vmbus_channel *channel,
                u32 send_ringbuffersize,
                u32 recv_ringbuffersize,
                void *userdata,
                u32 userdatalen,
                void(*onchannel_callback)(void *context),
                void *context);

extern void vmbus_close(struct vmbus_channel *channel);

extern int vmbus_sendpacket(struct vmbus_channel *channel,
                  const void *buffer,
                  u32 bufferLen,
                  u64 requestid,
                  enum vmbus_packet_type type,
                  u32 flags);

extern int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
                        struct hv_page_buffer pagebuffers[],
                        u32 pagecount,
                        void *buffer,
                        u32 bufferlen,
                        u64 requestid);

extern int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
                    struct hv_multipage_buffer *mpb,
                    void *buffer,
                    u32 bufferlen,
                    u64 requestid);

extern int vmbus_establish_gpadl(struct vmbus_channel *channel,
                      void *kbuffer,
                      u32 size,
                      u32 *gpadl_handle);

extern int vmbus_teardown_gpadl(struct vmbus_channel *channel,
                     u32 gpadl_handle);

extern int vmbus_recvpacket(struct vmbus_channel *channel,
                  void *buffer,
                  u32 bufferlen,
                  u32 *buffer_actual_len,
                  u64 *requestid);

extern int vmbus_recvpacket_raw(struct vmbus_channel *channel,
                     void *buffer,
                     u32 bufferlen,
                     u32 *buffer_actual_len,
                     u64 *requestid);


extern void vmbus_get_debug_info(struct vmbus_channel *channel,
                     struct vmbus_channel_debug_info *debug);

extern void vmbus_ontimer(unsigned long data);

struct hv_dev_port_info {
    u32 int_mask;
    u32 read_idx;
    u32 write_idx;
    u32 bytes_avail_toread;
    u32 bytes_avail_towrite;
};

/* Base driver object */
struct hv_driver {
    const char *name;

    /* the device type supported by this driver */
    uuid_le dev_type;
    const struct hv_vmbus_device_id *id_table;

    struct device_driver driver;

    int (*probe)(struct hv_device *, const struct hv_vmbus_device_id *);
    int (*remove)(struct hv_device *);
    void (*shutdown)(struct hv_device *);

};

/* Base device object */
struct hv_device {
    /* the device type id of this device */
    uuid_le dev_type;

    /* the device instance id of this device */
    uuid_le dev_instance;

    struct device device;

    struct vmbus_channel *channel;
};


static inline struct hv_device *device_to_hv_device(struct device *d)
{
    return container_of(d, struct hv_device, device);
}

static inline struct hv_driver *drv_to_hv_drv(struct device_driver *d)
{
    return container_of(d, struct hv_driver, driver);
}

static inline void hv_set_drvdata(struct hv_device *dev, void *data)
{
    dev_set_drvdata(&dev->device, data);
}

static inline void *hv_get_drvdata(struct hv_device *dev)
{
    return dev_get_drvdata(&dev->device);
}

/* Vmbus interface */
#define vmbus_driver_register(driver)   \
    __vmbus_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
int __must_check __vmbus_driver_register(struct hv_driver *hv_driver,
                     struct module *owner,
                     const char *mod_name);
void vmbus_driver_unregister(struct hv_driver *hv_driver);

#define VMBUS_DEVICE(g0, g1, g2, g3, g4, g5, g6, g7,    \
             g8, g9, ga, gb, gc, gd, ge, gf)    \
    .guid = { g0, g1, g2, g3, g4, g5, g6, g7,   \
          g8, g9, ga, gb, gc, gd, ge, gf },

/*
 * Common header for Hyper-V ICs
 */

#define ICMSGTYPE_NEGOTIATE     0
#define ICMSGTYPE_HEARTBEAT     1
#define ICMSGTYPE_KVPEXCHANGE       2
#define ICMSGTYPE_SHUTDOWN      3
#define ICMSGTYPE_TIMESYNC      4
#define ICMSGTYPE_VSS           5

#define ICMSGHDRFLAG_TRANSACTION    1
#define ICMSGHDRFLAG_REQUEST        2
#define ICMSGHDRFLAG_RESPONSE       4


/*
 * While we want to handle util services as regular devices,
 * there is only one instance of each of these services; so
 * we statically allocate the service specific state.
 */

struct hv_util_service {
    u8 *recv_buffer;
    void (*util_cb)(void *);
    int (*util_init)(struct hv_util_service *);
    void (*util_deinit)(void);
};

struct vmbuspipe_hdr {
    u32 flags;
    u32 msgsize;
} __packed;

struct ic_version {
    u16 major;
    u16 minor;
} __packed;

struct icmsg_hdr {
    struct ic_version icverframe;
    u16 icmsgtype;
    struct ic_version icvermsg;
    u16 icmsgsize;
    u32 status;
    u8 ictransaction_id;
    u8 icflags;
    u8 reserved[2];
} __packed;

struct icmsg_negotiate {
    u16 icframe_vercnt;
    u16 icmsg_vercnt;
    u32 reserved;
    struct ic_version icversion_data[1]; /* any size array */
} __packed;

struct shutdown_msg_data {
    u32 reason_code;
    u32 timeout_seconds;
    u32 flags;
    u8  display_message[2048];
} __packed;

struct heartbeat_msg_data {
    u64 seq_num;
    u32 reserved[8];
} __packed;

/* Time Sync IC defs */
#define ICTIMESYNCFLAG_PROBE    0
#define ICTIMESYNCFLAG_SYNC 1
#define ICTIMESYNCFLAG_SAMPLE   2

#ifdef __x86_64__
#define WLTIMEDELTA 116444736000000000L /* in 100ns unit */
#else
#define WLTIMEDELTA 116444736000000000LL
#endif

struct ictimesync_data {
    u64 parenttime;
    u64 childtime;
    u64 roundtriptime;
    u8 flags;
} __packed;

struct hyperv_service_callback {
    u8 msg_type;
    char *log_msg;
    uuid_le data;
    struct vmbus_channel *channel;
    void (*callback) (void *context);
};

#define MAX_SRV_VER 0x7ffffff
extern void vmbus_prep_negotiate_resp(struct icmsg_hdr *,
                    struct icmsg_negotiate *, u8 *, int,
                    int);

int hv_kvp_init(struct hv_util_service *);
void hv_kvp_deinit(void);
void hv_kvp_onchannelcallback(void *);

#endif /* __KERNEL__ */
#endif /* _HYPERV_H */