drivers/hv/hyperv_vmbus.h

   1 /*
   2  *
   3  * Copyright (c) 2011, Microsoft Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  *
  18  * Authors:
  19  *   Haiyang Zhang <haiyangz@microsoft.com>
  20  *   Hank Janssen  <hjanssen@microsoft.com>
  21  *   K. Y. Srinivasan <kys@microsoft.com>
  22  *
  23  */
  24
  25 #ifndef _HYPERV_VMBUS_H
  26 #define _HYPERV_VMBUS_H
  27
  28 #include <linux/list.h>
  29 #include <asm/sync_bitops.h>
  30 #include <linux/atomic.h>
  31 #include <linux/hyperv.h>
  32
  33 /*
  34  * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
  35  * is set by CPUID(HVCPUID_VERSION_FEATURES).
  36  */
  37 enum hv_cpuid_function {
  38         HVCPUID_VERSION_FEATURES                = 0x00000001,
  39         HVCPUID_VENDOR_MAXFUNCTION              = 0x40000000,
  40         HVCPUID_INTERFACE                       = 0x40000001,
  41
  42         /*
  43          * The remaining functions depend on the value of
  44          * HVCPUID_INTERFACE
  45          */
  46         HVCPUID_VERSION                 = 0x40000002,
  47         HVCPUID_FEATURES                        = 0x40000003,
  48         HVCPUID_ENLIGHTENMENT_INFO      = 0x40000004,
  49         HVCPUID_IMPLEMENTATION_LIMITS           = 0x40000005,
  50 };
  51
  52 /* Define version of the synthetic interrupt controller. */
  53 #define HV_SYNIC_VERSION                (1)
  54
  55 /* Define the expected SynIC version. */
  56 #define HV_SYNIC_VERSION_1              (0x1)
  57
  58 /* Define synthetic interrupt controller message constants. */
  59 #define HV_MESSAGE_SIZE                 (256)
  60 #define HV_MESSAGE_PAYLOAD_BYTE_COUNT   (240)
  61 #define HV_MESSAGE_PAYLOAD_QWORD_COUNT  (30)
  62 #define HV_ANY_VP                       (0xFFFFFFFF)
  63
  64 /* Define synthetic interrupt controller flag constants. */
  65 #define HV_EVENT_FLAGS_COUNT            (256 * 8)
  66 #define HV_EVENT_FLAGS_BYTE_COUNT       (256)
  67 #define HV_EVENT_FLAGS_DWORD_COUNT      (256 / sizeof(u32))
  68
  69 /* Define hypervisor message types. */
  70 enum hv_message_type {
  71         HVMSG_NONE                      = 0x00000000,
  72
  73         /* Memory access messages. */
  74         HVMSG_UNMAPPED_GPA              = 0x80000000,
  75         HVMSG_GPA_INTERCEPT             = 0x80000001,
  76
  77         /* Timer notification messages. */
  78         HVMSG_TIMER_EXPIRED                     = 0x80000010,
  79
  80         /* Error messages. */
  81         HVMSG_INVALID_VP_REGISTER_VALUE = 0x80000020,
  82         HVMSG_UNRECOVERABLE_EXCEPTION   = 0x80000021,
  83         HVMSG_UNSUPPORTED_FEATURE               = 0x80000022,
  84
  85         /* Trace buffer complete messages. */
  86         HVMSG_EVENTLOG_BUFFERCOMPLETE   = 0x80000040,
  87
  88         /* Platform-specific processor intercept messages. */
  89         HVMSG_X64_IOPORT_INTERCEPT              = 0x80010000,
  90         HVMSG_X64_MSR_INTERCEPT         = 0x80010001,
  91         HVMSG_X64_CPUID_INTERCEPT               = 0x80010002,
  92         HVMSG_X64_EXCEPTION_INTERCEPT   = 0x80010003,
  93         HVMSG_X64_APIC_EOI                      = 0x80010004,
  94         HVMSG_X64_LEGACY_FP_ERROR               = 0x80010005
  95 };
  96
  97 /* Define the number of synthetic interrupt sources. */
  98 #define HV_SYNIC_SINT_COUNT             (16)
  99 #define HV_SYNIC_STIMER_COUNT           (4)
 100
 101 /* Define invalid partition identifier. */
 102 #define HV_PARTITION_ID_INVALID         ((u64)0x0)
 103
 104 /* Define port identifier type. */
 105 union hv_port_id {
 106         u32 asu32;
 107         struct {
 108                 u32 id:24;
 109                 u32 reserved:8;
 110         } u ;
 111 };
 112
 113 /* Define port type. */
 114 enum hv_port_type {
 115         HVPORT_MSG      = 1,
 116         HVPORT_EVENT            = 2,
 117         HVPORT_MONITOR  = 3
 118 };
 119
 120 /* Define port information structure. */
 121 struct hv_port_info {
 122         enum hv_port_type port_type;
 123         u32 padding;
 124         union {
 125                 struct {
 126                         u32 target_sint;
 127                         u32 target_vp;
 128                         u64 rsvdz;
 129                 } message_port_info;
 130                 struct {
 131                         u32 target_sint;
 132                         u32 target_vp;
 133                         u16 base_flag_bumber;
 134                         u16 flag_count;
 135                         u32 rsvdz;
 136                 } event_port_info;
 137                 struct {
 138                         u64 monitor_address;
 139                         u64 rsvdz;
 140                 } monitor_port_info;
 141         };
 142 };
 143
 144 struct hv_connection_info {
 145         enum hv_port_type port_type;
 146         u32 padding;
 147         union {
 148                 struct {
 149                         u64 rsvdz;
 150                 } message_connection_info;
 151                 struct {
 152                         u64 rsvdz;
 153                 } event_connection_info;
 154                 struct {
 155                         u64 monitor_address;
 156                 } monitor_connection_info;
 157         };
 158 };
 159
 160 /* Define synthetic interrupt controller message flags. */
 161 union hv_message_flags {
 162         u8 asu8;
 163         struct {
 164                 u8 msg_pending:1;
 165                 u8 reserved:7;
 166         };
 167 };
 168
 169 /* Define synthetic interrupt controller message header. */
 170 struct hv_message_header {
 171         enum hv_message_type message_type;
 172         u8 payload_size;
 173         union hv_message_flags message_flags;
 174         u8 reserved[2];
 175         union {
 176                 u64 sender;
 177                 union hv_port_id port;
 178         };
 179 };
 180
 181 /* Define timer message payload structure. */
 182 struct hv_timer_message_payload {
 183         u32 timer_index;
 184         u32 reserved;
 185         u64 expiration_time;    /* When the timer expired */
 186         u64 delivery_time;      /* When the message was delivered */
 187 };
 188
 189 /* Define synthetic interrupt controller message format. */
 190 struct hv_message {
 191         struct hv_message_header header;
 192         union {
 193                 u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 194         } u ;
 195 };
 196
 197 /* Define the number of message buffers associated with each port. */
 198 #define HV_PORT_MESSAGE_BUFFER_COUNT    (16)
 199
 200 /* Define the synthetic interrupt message page layout. */
 201 struct hv_message_page {
 202         struct hv_message sint_message[HV_SYNIC_SINT_COUNT];
 203 };
 204
 205 /* Define the synthetic interrupt controller event flags format. */
 206 union hv_synic_event_flags {
 207         u8 flags8[HV_EVENT_FLAGS_BYTE_COUNT];
 208         u32 flags32[HV_EVENT_FLAGS_DWORD_COUNT];
 209 };
 210
 211 /* Define the synthetic interrupt flags page layout. */
 212 struct hv_synic_event_flags_page {
 213         union hv_synic_event_flags sintevent_flags[HV_SYNIC_SINT_COUNT];
 214 };
 215
 216 /* Define SynIC control register. */
 217 union hv_synic_scontrol {
 218         u64 as_uint64;
 219         struct {
 220                 u64 enable:1;
 221                 u64 reserved:63;
 222         };
 223 };
 224
 225 /* Define synthetic interrupt source. */
 226 union hv_synic_sint {
 227         u64 as_uint64;
 228         struct {
 229                 u64 vector:8;
 230                 u64 reserved1:8;
 231                 u64 masked:1;
 232                 u64 auto_eoi:1;
 233                 u64 reserved2:46;
 234         };
 235 };
 236
 237 /* Define the format of the SIMP register */
 238 union hv_synic_simp {
 239         u64 as_uint64;
 240         struct {
 241                 u64 simp_enabled:1;
 242                 u64 preserved:11;
 243                 u64 base_simp_gpa:52;
 244         };
 245 };
 246
 247 /* Define the format of the SIEFP register */
 248 union hv_synic_siefp {
 249         u64 as_uint64;
 250         struct {
 251                 u64 siefp_enabled:1;
 252                 u64 preserved:11;
 253                 u64 base_siefp_gpa:52;
 254         };
 255 };
 256
 257 /* Definitions for the monitored notification facility */
 258 union hv_monitor_trigger_group {
 259         u64 as_uint64;
 260         struct {
 261                 u32 pending;
 262                 u32 armed;
 263         };
 264 };
 265
 266 struct hv_monitor_parameter {
 267         union hv_connection_id connectionid;
 268         u16 flagnumber;
 269         u16 rsvdz;
 270 };
 271
 272 union hv_monitor_trigger_state {
 273         u32 asu32;
 274
 275         struct {
 276                 u32 group_enable:4;
 277                 u32 rsvdz:28;
 278         };
 279 };
 280
 281 /* struct hv_monitor_page Layout */
 282 /* ------------------------------------------------------ */
 283 /* | 0   | TriggerState (4 bytes) | Rsvd1 (4 bytes)     | */
 284 /* | 8   | TriggerGroup[0]                              | */
 285 /* | 10  | TriggerGroup[1]                              | */
 286 /* | 18  | TriggerGroup[2]                              | */
 287 /* | 20  | TriggerGroup[3]                              | */
 288 /* | 28  | Rsvd2[0]                                     | */
 289 /* | 30  | Rsvd2[1]                                     | */
 290 /* | 38  | Rsvd2[2]                                     | */
 291 /* | 40  | NextCheckTime[0][0]    | NextCheckTime[0][1] | */
 292 /* | ...                                                | */
 293 /* | 240 | Latency[0][0..3]                             | */
 294 /* | 340 | Rsvz3[0]                                     | */
 295 /* | 440 | Parameter[0][0]                              | */
 296 /* | 448 | Parameter[0][1]                              | */
 297 /* | ...                                                | */
 298 /* | 840 | Rsvd4[0]                                     | */
 299 /* ------------------------------------------------------ */
 300 struct hv_monitor_page {
 301         union hv_monitor_trigger_state trigger_state;
 302         u32 rsvdz1;
 303
 304         union hv_monitor_trigger_group trigger_group[4];
 305         u64 rsvdz2[3];
 306
 307         s32 next_checktime[4][32];
 308
 309         u16 latency[4][32];
 310         u64 rsvdz3[32];
 311
 312         struct hv_monitor_parameter parameter[4][32];
 313
 314         u8 rsvdz4[1984];
 315 };
 316
 317 /* Declare the various hypercall operations. */
 318 enum hv_call_code {
 319         HVCALL_POST_MESSAGE     = 0x005c,
 320         HVCALL_SIGNAL_EVENT     = 0x005d,
 321 };
 322
 323 /* Definition of the hv_post_message hypercall input structure. */
 324 struct hv_input_post_message {
 325         union hv_connection_id connectionid;
 326         u32 reserved;
 327         enum hv_message_type message_type;
 328         u32 payload_size;
 329         u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 330 };
 331
 332 /*
 333  * Versioning definitions used for guests reporting themselves to the
 334  * hypervisor, and visa versa.
 335  */
 336
 337 /* Version info reported by guest OS's */
 338 enum hv_guest_os_vendor {
 339         HVGUESTOS_VENDOR_MICROSOFT      = 0x0001
 340 };
 341
 342 enum hv_guest_os_microsoft_ids {
 343         HVGUESTOS_MICROSOFT_UNDEFINED   = 0x00,
 344         HVGUESTOS_MICROSOFT_MSDOS               = 0x01,
 345         HVGUESTOS_MICROSOFT_WINDOWS3X   = 0x02,
 346         HVGUESTOS_MICROSOFT_WINDOWS9X   = 0x03,
 347         HVGUESTOS_MICROSOFT_WINDOWSNT   = 0x04,
 348         HVGUESTOS_MICROSOFT_WINDOWSCE   = 0x05
 349 };
 350
 351 /*
 352  * Declare the MSR used to identify the guest OS.
 353  */
 354 #define HV_X64_MSR_GUEST_OS_ID  0x40000000
 355
 356 union hv_x64_msr_guest_os_id_contents {
 357         u64 as_uint64;
 358         struct {
 359                 u64 build_number:16;
 360                 u64 service_version:8; /* Service Pack, etc. */
 361                 u64 minor_version:8;
 362                 u64 major_version:8;
 363                 u64 os_id:8; /* enum hv_guest_os_microsoft_ids (if Vendor=MS) */
 364                 u64 vendor_id:16; /* enum hv_guest_os_vendor */
 365         };
 366 };
 367
 368 /*
 369  * Declare the MSR used to setup pages used to communicate with the hypervisor.
 370  */
 371 #define HV_X64_MSR_HYPERCALL    0x40000001
 372
 373 union hv_x64_msr_hypercall_contents {
 374         u64 as_uint64;
 375         struct {
 376                 u64 enable:1;
 377                 u64 reserved:11;
 378                 u64 guest_physical_address:52;
 379         };
 380 };
 381
 382
 383 enum {
 384         VMBUS_MESSAGE_CONNECTION_ID     = 1,
 385         VMBUS_MESSAGE_PORT_ID           = 1,
 386         VMBUS_EVENT_CONNECTION_ID       = 2,
 387         VMBUS_EVENT_PORT_ID             = 2,
 388         VMBUS_MONITOR_CONNECTION_ID     = 3,
 389         VMBUS_MONITOR_PORT_ID           = 3,
 390         VMBUS_MESSAGE_SINT              = 2,
 391 };
 392
 393 /* #defines */
 394
 395 #define HV_PRESENT_BIT                  0x80000000
 396
 397 /*
 398  * The guest OS needs to register the guest ID with the hypervisor.
 399  * The guest ID is a 64 bit entity and the structure of this ID is
 400  * specified in the Hyper-V specification:
 401  *
 402  * http://msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 403  *
 404  * While the current guideline does not specify how Linux guest ID(s)
 405  * need to be generated, our plan is to publish the guidelines for
 406  * Linux and other guest operating systems that currently are hosted
 407  * on Hyper-V. The implementation here conforms to this yet
 408  * unpublished guidelines.
 409  *
 410  *
 411  * Bit(s)
 412  * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 413  * 62:56 - Os Type; Linux is 0x100
 414  * 55:48 - Distro specific identification
 415  * 47:16 - Linux kernel version number
 416  * 15:0  - Distro specific identification
 417  *
 418  *
 419  */
 420
 421 #define HV_LINUX_VENDOR_ID              0x8100
 422
 423 /*
 424  * Generate the guest ID based on the guideline described above.
 425  */
 426
 427 static inline  __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
 428                                         __u16 d_info2)
 429 {
 430         __u64 guest_id = 0;
 431
 432         guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
 433         guest_id |= (((__u64)(d_info1)) << 48);
 434         guest_id |= (((__u64)(kernel_version)) << 16);
 435         guest_id |= ((__u64)(d_info2));
 436
 437         return guest_id;
 438 }
 439
 440
 441 #define HV_CPU_POWER_MANAGEMENT         (1 << 0)
 442 #define HV_RECOMMENDATIONS_MAX          4
 443
 444 #define HV_X64_MAX                      5
 445 #define HV_CAPS_MAX                     8
 446
 447
 448 #define HV_HYPERCALL_PARAM_ALIGN        sizeof(u64)
 449
 450
 451 /* Service definitions */
 452
 453 #define HV_SERVICE_PARENT_PORT                          (0)
 454 #define HV_SERVICE_PARENT_CONNECTION                    (0)
 455
 456 #define HV_SERVICE_CONNECT_RESPONSE_SUCCESS             (0)
 457 #define HV_SERVICE_CONNECT_RESPONSE_INVALID_PARAMETER   (1)
 458 #define HV_SERVICE_CONNECT_RESPONSE_UNKNOWN_SERVICE     (2)
 459 #define HV_SERVICE_CONNECT_RESPONSE_CONNECTION_REJECTED (3)
 460
 461 #define HV_SERVICE_CONNECT_REQUEST_MESSAGE_ID           (1)
 462 #define HV_SERVICE_CONNECT_RESPONSE_MESSAGE_ID          (2)
 463 #define HV_SERVICE_DISCONNECT_REQUEST_MESSAGE_ID        (3)
 464 #define HV_SERVICE_DISCONNECT_RESPONSE_MESSAGE_ID       (4)
 465 #define HV_SERVICE_MAX_MESSAGE_ID                               (4)
 466
 467 #define HV_SERVICE_PROTOCOL_VERSION (0x0010)
 468 #define HV_CONNECT_PAYLOAD_BYTE_COUNT 64
 469
 470 /* #define VMBUS_REVISION_NUMBER        6 */
 471
 472 /* Our local vmbus's port and connection id. Anything >0 is fine */
 473 /* #define VMBUS_PORT_ID                11 */
 474
 475 /* 628180B8-308D-4c5e-B7DB-1BEB62E62EF4 */
 476 static const uuid_le VMBUS_SERVICE_ID = {
 477         .b = {
 478                 0xb8, 0x80, 0x81, 0x62, 0x8d, 0x30, 0x5e, 0x4c,
 479                 0xb7, 0xdb, 0x1b, 0xeb, 0x62, 0xe6, 0x2e, 0xf4
 480         },
 481 };
 482
 483
 484
 485 struct hv_context {
 486         /* We only support running on top of Hyper-V
 487         * So at this point this really can only contain the Hyper-V ID
 488         */
 489         u64 guestid;
 490
 491         void *hypercall_page;
 492
 493         bool synic_initialized;
 494
 495         void *synic_message_page[NR_CPUS];
 496         void *synic_event_page[NR_CPUS];
 497         /*
 498          * Hypervisor's notion of virtual processor ID is different from
 499          * Linux' notion of CPU ID. This information can only be retrieved
 500          * in the context of the calling CPU. Setup a map for easy access
 501          * to this information:
 502          *
 503          * vp_index[a] is the Hyper-V's processor ID corresponding to
 504          * Linux cpuid 'a'.
 505          */
 506         u32 vp_index[NR_CPUS];
 507         /*
 508          * Starting with win8, we can take channel interrupts on any CPU;
 509          * we will manage the tasklet that handles events on a per CPU
 510          * basis.
 511          */
 512         struct tasklet_struct *event_dpc[NR_CPUS];
 513 };
 514
 515 extern struct hv_context hv_context;
 516
 517 struct hv_ring_buffer_debug_info {
 518         u32 current_interrupt_mask;
 519         u32 current_read_index;
 520         u32 current_write_index;
 521         u32 bytes_avail_toread;
 522         u32 bytes_avail_towrite;
 523 };
 524
 525 /* Hv Interface */
 526
 527 extern int hv_init(void);
 528
 529 extern void hv_cleanup(void);
 530
 531 extern int hv_post_message(union hv_connection_id connection_id,
 532                          enum hv_message_type message_type,
 533                          void *payload, size_t payload_size);
 534
 535 extern u16 hv_signal_event(void *con_id);
 536
 537 extern int hv_synic_alloc(void);
 538
 539 extern void hv_synic_free(void);
 540
 541 extern void hv_synic_init(void *irqarg);
 542
 543 extern void hv_synic_cleanup(void *arg);
 544
 545 /*
 546  * Host version information.
 547  */
 548 extern unsigned int host_info_eax;
 549 extern unsigned int host_info_ebx;
 550 extern unsigned int host_info_ecx;
 551 extern unsigned int host_info_edx;
 552
 553 /* Interface */
 554
 555
 556 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer,
 557                    u32 buflen);
 558
 559 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 560
 561 int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
 562                     struct scatterlist *sglist,
 563                     u32 sgcount, bool *signal);
 564
 565 int hv_ringbuffer_peek(struct hv_ring_buffer_info *ring_info, void *buffer,
 566                    u32 buflen);
 567
 568 int hv_ringbuffer_read(struct hv_ring_buffer_info *ring_info,
 569                    void *buffer,
 570                    u32 buflen,
 571                    u32 offset, bool *signal);
 572
 573
 574 void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 575                             struct hv_ring_buffer_debug_info *debug_info);
 576
 577 void hv_begin_read(struct hv_ring_buffer_info *rbi);
 578
 579 u32 hv_end_read(struct hv_ring_buffer_info *rbi);
 580
 581 /*
 582  * Maximum channels is determined by the size of the interrupt page
 583  * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
 584  * and the other is receive endpoint interrupt
 585  */
 586 #define MAX_NUM_CHANNELS        ((PAGE_SIZE >> 1) << 3) /* 16348 channels */
 587
 588 /* The value here must be in multiple of 32 */
 589 /* TODO: Need to make this configurable */
 590 #define MAX_NUM_CHANNELS_SUPPORTED      256
 591
 592
 593 enum vmbus_connect_state {
 594         DISCONNECTED,
 595         CONNECTING,
 596         CONNECTED,
 597         DISCONNECTING
 598 };
 599
 600 #define MAX_SIZE_CHANNEL_MESSAGE        HV_MESSAGE_PAYLOAD_BYTE_COUNT
 601
 602 struct vmbus_connection {
 603         enum vmbus_connect_state conn_state;
 604
 605         atomic_t next_gpadl_handle;
 606
 607         /*
 608          * Represents channel interrupts. Each bit position represents a
 609          * channel.  When a channel sends an interrupt via VMBUS, it finds its
 610          * bit in the sendInterruptPage, set it and calls Hv to generate a port
 611          * event. The other end receives the port event and parse the
 612          * recvInterruptPage to see which bit is set
 613          */
 614         void *int_page;
 615         void *send_int_page;
 616         void *recv_int_page;
 617
 618         /*
 619          * 2 pages - 1st page for parent->child notification and 2nd
 620          * is child->parent notification
 621          */
 622         struct hv_monitor_page *monitor_pages[2];
 623         struct list_head chn_msg_list;
 624         spinlock_t channelmsg_lock;
 625
 626         /* List of channels */
 627         struct list_head chn_list;
 628         spinlock_t channel_lock;
 629
 630         struct workqueue_struct *work_queue;
 631 };
 632
 633
 634 struct vmbus_msginfo {
 635         /* Bookkeeping stuff */
 636         struct list_head msglist_entry;
 637
 638         /* The message itself */
 639         unsigned char msg[0];
 640 };
 641
 642
 643 extern struct vmbus_connection vmbus_connection;
 644
 645 /* General vmbus interface */
 646
 647 struct hv_device *vmbus_device_create(uuid_le *type,
 648                                          uuid_le *instance,
 649                                          struct vmbus_channel *channel);
 650
 651 int vmbus_device_register(struct hv_device *child_device_obj);
 652 void vmbus_device_unregister(struct hv_device *device_obj);
 653
 654 /* static void */
 655 /* VmbusChildDeviceDestroy( */
 656 /* struct hv_device *); */
 657
 658 struct vmbus_channel *relid2channel(u32 relid);
 659
 660 void vmbus_free_channels(void);
 661
 662 /* Connection interface */
 663
 664 int vmbus_connect(void);
 665
 666 int vmbus_post_msg(void *buffer, size_t buflen);
 667
 668 int vmbus_set_event(struct vmbus_channel *channel);
 669
 670 void vmbus_on_event(unsigned long data);
 671
 672
 673 #endif /* _HYPERV_VMBUS_H */