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  * Timeout for services such as KVP and fcopy.
  35  */
  36 #define HV_UTIL_TIMEOUT 30
  37
  38 /*
  39  * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
  40  * is set by CPUID(HVCPUID_VERSION_FEATURES).
  41  */
  42 enum hv_cpuid_function {
  43         HVCPUID_VERSION_FEATURES                = 0x00000001,
  44         HVCPUID_VENDOR_MAXFUNCTION              = 0x40000000,
  45         HVCPUID_INTERFACE                       = 0x40000001,
  46
  47         /*
  48          * The remaining functions depend on the value of
  49          * HVCPUID_INTERFACE
  50          */
  51         HVCPUID_VERSION                 = 0x40000002,
  52         HVCPUID_FEATURES                        = 0x40000003,
  53         HVCPUID_ENLIGHTENMENT_INFO      = 0x40000004,
  54         HVCPUID_IMPLEMENTATION_LIMITS           = 0x40000005,
  55 };
  56
  57 #define  HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE   0x400
  58
  59 #define HV_X64_MSR_CRASH_P0   0x40000100
  60 #define HV_X64_MSR_CRASH_P1   0x40000101
  61 #define HV_X64_MSR_CRASH_P2   0x40000102
  62 #define HV_X64_MSR_CRASH_P3   0x40000103
  63 #define HV_X64_MSR_CRASH_P4   0x40000104
  64 #define HV_X64_MSR_CRASH_CTL  0x40000105
  65
  66 #define HV_CRASH_CTL_CRASH_NOTIFY (1ULL << 63)
  67
  68 /* Define version of the synthetic interrupt controller. */
  69 #define HV_SYNIC_VERSION                (1)
  70
  71 #define HV_ANY_VP                       (0xFFFFFFFF)
  72
  73 /* Define synthetic interrupt controller flag constants. */
  74 #define HV_EVENT_FLAGS_COUNT            (256 * 8)
  75 #define HV_EVENT_FLAGS_BYTE_COUNT       (256)
  76 #define HV_EVENT_FLAGS_DWORD_COUNT      (256 / sizeof(u32))
  77
  78 /* Define invalid partition identifier. */
  79 #define HV_PARTITION_ID_INVALID         ((u64)0x0)
  80
  81 /* Define port type. */
  82 enum hv_port_type {
  83         HVPORT_MSG      = 1,
  84         HVPORT_EVENT            = 2,
  85         HVPORT_MONITOR  = 3
  86 };
  87
  88 /* Define port information structure. */
  89 struct hv_port_info {
  90         enum hv_port_type port_type;
  91         u32 padding;
  92         union {
  93                 struct {
  94                         u32 target_sint;
  95                         u32 target_vp;
  96                         u64 rsvdz;
  97                 } message_port_info;
  98                 struct {
  99                         u32 target_sint;
 100                         u32 target_vp;
 101                         u16 base_flag_number;
 102                         u16 flag_count;
 103                         u32 rsvdz;
 104                 } event_port_info;
 105                 struct {
 106                         u64 monitor_address;
 107                         u64 rsvdz;
 108                 } monitor_port_info;
 109         };
 110 };
 111
 112 struct hv_connection_info {
 113         enum hv_port_type port_type;
 114         u32 padding;
 115         union {
 116                 struct {
 117                         u64 rsvdz;
 118                 } message_connection_info;
 119                 struct {
 120                         u64 rsvdz;
 121                 } event_connection_info;
 122                 struct {
 123                         u64 monitor_address;
 124                 } monitor_connection_info;
 125         };
 126 };
 127
 128 /*
 129  * Timer configuration register.
 130  */
 131 union hv_timer_config {
 132         u64 as_uint64;
 133         struct {
 134                 u64 enable:1;
 135                 u64 periodic:1;
 136                 u64 lazy:1;
 137                 u64 auto_enable:1;
 138                 u64 reserved_z0:12;
 139                 u64 sintx:4;
 140                 u64 reserved_z1:44;
 141         };
 142 };
 143
 144 /* Define the number of message buffers associated with each port. */
 145 #define HV_PORT_MESSAGE_BUFFER_COUNT    (16)
 146
 147 /* Define the synthetic interrupt controller event flags format. */
 148 union hv_synic_event_flags {
 149         u8 flags8[HV_EVENT_FLAGS_BYTE_COUNT];
 150         u32 flags32[HV_EVENT_FLAGS_DWORD_COUNT];
 151 };
 152
 153 /* Define the synthetic interrupt flags page layout. */
 154 struct hv_synic_event_flags_page {
 155         union hv_synic_event_flags sintevent_flags[HV_SYNIC_SINT_COUNT];
 156 };
 157
 158 /* Define SynIC control register. */
 159 union hv_synic_scontrol {
 160         u64 as_uint64;
 161         struct {
 162                 u64 enable:1;
 163                 u64 reserved:63;
 164         };
 165 };
 166
 167 /* Define synthetic interrupt source. */
 168 union hv_synic_sint {
 169         u64 as_uint64;
 170         struct {
 171                 u64 vector:8;
 172                 u64 reserved1:8;
 173                 u64 masked:1;
 174                 u64 auto_eoi:1;
 175                 u64 reserved2:46;
 176         };
 177 };
 178
 179 /* Define the format of the SIMP register */
 180 union hv_synic_simp {
 181         u64 as_uint64;
 182         struct {
 183                 u64 simp_enabled:1;
 184                 u64 preserved:11;
 185                 u64 base_simp_gpa:52;
 186         };
 187 };
 188
 189 /* Define the format of the SIEFP register */
 190 union hv_synic_siefp {
 191         u64 as_uint64;
 192         struct {
 193                 u64 siefp_enabled:1;
 194                 u64 preserved:11;
 195                 u64 base_siefp_gpa:52;
 196         };
 197 };
 198
 199 /* Definitions for the monitored notification facility */
 200 union hv_monitor_trigger_group {
 201         u64 as_uint64;
 202         struct {
 203                 u32 pending;
 204                 u32 armed;
 205         };
 206 };
 207
 208 struct hv_monitor_parameter {
 209         union hv_connection_id connectionid;
 210         u16 flagnumber;
 211         u16 rsvdz;
 212 };
 213
 214 union hv_monitor_trigger_state {
 215         u32 asu32;
 216
 217         struct {
 218                 u32 group_enable:4;
 219                 u32 rsvdz:28;
 220         };
 221 };
 222
 223 /* struct hv_monitor_page Layout */
 224 /* ------------------------------------------------------ */
 225 /* | 0   | TriggerState (4 bytes) | Rsvd1 (4 bytes)     | */
 226 /* | 8   | TriggerGroup[0]                              | */
 227 /* | 10  | TriggerGroup[1]                              | */
 228 /* | 18  | TriggerGroup[2]                              | */
 229 /* | 20  | TriggerGroup[3]                              | */
 230 /* | 28  | Rsvd2[0]                                     | */
 231 /* | 30  | Rsvd2[1]                                     | */
 232 /* | 38  | Rsvd2[2]                                     | */
 233 /* | 40  | NextCheckTime[0][0]    | NextCheckTime[0][1] | */
 234 /* | ...                                                | */
 235 /* | 240 | Latency[0][0..3]                             | */
 236 /* | 340 | Rsvz3[0]                                     | */
 237 /* | 440 | Parameter[0][0]                              | */
 238 /* | 448 | Parameter[0][1]                              | */
 239 /* | ...                                                | */
 240 /* | 840 | Rsvd4[0]                                     | */
 241 /* ------------------------------------------------------ */
 242 struct hv_monitor_page {
 243         union hv_monitor_trigger_state trigger_state;
 244         u32 rsvdz1;
 245
 246         union hv_monitor_trigger_group trigger_group[4];
 247         u64 rsvdz2[3];
 248
 249         s32 next_checktime[4][32];
 250
 251         u16 latency[4][32];
 252         u64 rsvdz3[32];
 253
 254         struct hv_monitor_parameter parameter[4][32];
 255
 256         u8 rsvdz4[1984];
 257 };
 258
 259 /* Declare the various hypercall operations. */
 260 enum hv_call_code {
 261         HVCALL_POST_MESSAGE     = 0x005c,
 262         HVCALL_SIGNAL_EVENT     = 0x005d,
 263 };
 264
 265 /* Definition of the hv_post_message hypercall input structure. */
 266 struct hv_input_post_message {
 267         union hv_connection_id connectionid;
 268         u32 reserved;
 269         u32 message_type;
 270         u32 payload_size;
 271         u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 272 };
 273
 274 /*
 275  * Versioning definitions used for guests reporting themselves to the
 276  * hypervisor, and visa versa.
 277  */
 278
 279 /* Version info reported by guest OS's */
 280 enum hv_guest_os_vendor {
 281         HVGUESTOS_VENDOR_MICROSOFT      = 0x0001
 282 };
 283
 284 enum hv_guest_os_microsoft_ids {
 285         HVGUESTOS_MICROSOFT_UNDEFINED   = 0x00,
 286         HVGUESTOS_MICROSOFT_MSDOS               = 0x01,
 287         HVGUESTOS_MICROSOFT_WINDOWS3X   = 0x02,
 288         HVGUESTOS_MICROSOFT_WINDOWS9X   = 0x03,
 289         HVGUESTOS_MICROSOFT_WINDOWSNT   = 0x04,
 290         HVGUESTOS_MICROSOFT_WINDOWSCE   = 0x05
 291 };
 292
 293 /*
 294  * Declare the MSR used to identify the guest OS.
 295  */
 296 #define HV_X64_MSR_GUEST_OS_ID  0x40000000
 297
 298 union hv_x64_msr_guest_os_id_contents {
 299         u64 as_uint64;
 300         struct {
 301                 u64 build_number:16;
 302                 u64 service_version:8; /* Service Pack, etc. */
 303                 u64 minor_version:8;
 304                 u64 major_version:8;
 305                 u64 os_id:8; /* enum hv_guest_os_microsoft_ids (if Vendor=MS) */
 306                 u64 vendor_id:16; /* enum hv_guest_os_vendor */
 307         };
 308 };
 309
 310 /*
 311  * Declare the MSR used to setup pages used to communicate with the hypervisor.
 312  */
 313 #define HV_X64_MSR_HYPERCALL    0x40000001
 314
 315 union hv_x64_msr_hypercall_contents {
 316         u64 as_uint64;
 317         struct {
 318                 u64 enable:1;
 319                 u64 reserved:11;
 320                 u64 guest_physical_address:52;
 321         };
 322 };
 323
 324
 325 enum {
 326         VMBUS_MESSAGE_CONNECTION_ID     = 1,
 327         VMBUS_MESSAGE_PORT_ID           = 1,
 328         VMBUS_EVENT_CONNECTION_ID       = 2,
 329         VMBUS_EVENT_PORT_ID             = 2,
 330         VMBUS_MONITOR_CONNECTION_ID     = 3,
 331         VMBUS_MONITOR_PORT_ID           = 3,
 332         VMBUS_MESSAGE_SINT              = 2,
 333 };
 334
 335 /* #defines */
 336
 337 #define HV_PRESENT_BIT                  0x80000000
 338
 339 /*
 340  * The guest OS needs to register the guest ID with the hypervisor.
 341  * The guest ID is a 64 bit entity and the structure of this ID is
 342  * specified in the Hyper-V specification:
 343  *
 344  * http://msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 345  *
 346  * While the current guideline does not specify how Linux guest ID(s)
 347  * need to be generated, our plan is to publish the guidelines for
 348  * Linux and other guest operating systems that currently are hosted
 349  * on Hyper-V. The implementation here conforms to this yet
 350  * unpublished guidelines.
 351  *
 352  *
 353  * Bit(s)
 354  * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 355  * 62:56 - Os Type; Linux is 0x100
 356  * 55:48 - Distro specific identification
 357  * 47:16 - Linux kernel version number
 358  * 15:0  - Distro specific identification
 359  *
 360  *
 361  */
 362
 363 #define HV_LINUX_VENDOR_ID              0x8100
 364
 365 /*
 366  * Generate the guest ID based on the guideline described above.
 367  */
 368
 369 static inline  __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
 370                                         __u16 d_info2)
 371 {
 372         __u64 guest_id = 0;
 373
 374         guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
 375         guest_id |= (((__u64)(d_info1)) << 48);
 376         guest_id |= (((__u64)(kernel_version)) << 16);
 377         guest_id |= ((__u64)(d_info2));
 378
 379         return guest_id;
 380 }
 381
 382
 383 #define HV_CPU_POWER_MANAGEMENT         (1 << 0)
 384 #define HV_RECOMMENDATIONS_MAX          4
 385
 386 #define HV_X64_MAX                      5
 387 #define HV_CAPS_MAX                     8
 388
 389
 390 #define HV_HYPERCALL_PARAM_ALIGN        sizeof(u64)
 391
 392
 393 /* Service definitions */
 394
 395 #define HV_SERVICE_PARENT_PORT                          (0)
 396 #define HV_SERVICE_PARENT_CONNECTION                    (0)
 397
 398 #define HV_SERVICE_CONNECT_RESPONSE_SUCCESS             (0)
 399 #define HV_SERVICE_CONNECT_RESPONSE_INVALID_PARAMETER   (1)
 400 #define HV_SERVICE_CONNECT_RESPONSE_UNKNOWN_SERVICE     (2)
 401 #define HV_SERVICE_CONNECT_RESPONSE_CONNECTION_REJECTED (3)
 402
 403 #define HV_SERVICE_CONNECT_REQUEST_MESSAGE_ID           (1)
 404 #define HV_SERVICE_CONNECT_RESPONSE_MESSAGE_ID          (2)
 405 #define HV_SERVICE_DISCONNECT_REQUEST_MESSAGE_ID        (3)
 406 #define HV_SERVICE_DISCONNECT_RESPONSE_MESSAGE_ID       (4)
 407 #define HV_SERVICE_MAX_MESSAGE_ID                               (4)
 408
 409 #define HV_SERVICE_PROTOCOL_VERSION (0x0010)
 410 #define HV_CONNECT_PAYLOAD_BYTE_COUNT 64
 411
 412 /* #define VMBUS_REVISION_NUMBER        6 */
 413
 414 /* Our local vmbus's port and connection id. Anything >0 is fine */
 415 /* #define VMBUS_PORT_ID                11 */
 416
 417 /* 628180B8-308D-4c5e-B7DB-1BEB62E62EF4 */
 418 static const uuid_le VMBUS_SERVICE_ID = {
 419         .b = {
 420                 0xb8, 0x80, 0x81, 0x62, 0x8d, 0x30, 0x5e, 0x4c,
 421                 0xb7, 0xdb, 0x1b, 0xeb, 0x62, 0xe6, 0x2e, 0xf4
 422         },
 423 };
 424
 425
 426
 427 struct hv_context {
 428         /* We only support running on top of Hyper-V
 429         * So at this point this really can only contain the Hyper-V ID
 430         */
 431         u64 guestid;
 432
 433         void *hypercall_page;
 434         void *tsc_page;
 435
 436         bool synic_initialized;
 437
 438         void *synic_message_page[NR_CPUS];
 439         void *synic_event_page[NR_CPUS];
 440         /*
 441          * Hypervisor's notion of virtual processor ID is different from
 442          * Linux' notion of CPU ID. This information can only be retrieved
 443          * in the context of the calling CPU. Setup a map for easy access
 444          * to this information:
 445          *
 446          * vp_index[a] is the Hyper-V's processor ID corresponding to
 447          * Linux cpuid 'a'.
 448          */
 449         u32 vp_index[NR_CPUS];
 450         /*
 451          * Starting with win8, we can take channel interrupts on any CPU;
 452          * we will manage the tasklet that handles events on a per CPU
 453          * basis.
 454          */
 455         struct tasklet_struct *event_dpc[NR_CPUS];
 456         /*
 457          * To optimize the mapping of relid to channel, maintain
 458          * per-cpu list of the channels based on their CPU affinity.
 459          */
 460         struct list_head percpu_list[NR_CPUS];
 461         /*
 462          * buffer to post messages to the host.
 463          */
 464         void *post_msg_page[NR_CPUS];
 465         /*
 466          * Support PV clockevent device.
 467          */
 468         struct clock_event_device *clk_evt[NR_CPUS];
 469         /*
 470          * To manage allocations in a NUMA node.
 471          * Array indexed by numa node ID.
 472          */
 473         struct cpumask *hv_numa_map;
 474 };
 475
 476 extern struct hv_context hv_context;
 477
 478 struct ms_hyperv_tsc_page {
 479         volatile u32 tsc_sequence;
 480         u32 reserved1;
 481         volatile u64 tsc_scale;
 482         volatile s64 tsc_offset;
 483         u64 reserved2[509];
 484 };
 485
 486 struct hv_ring_buffer_debug_info {
 487         u32 current_interrupt_mask;
 488         u32 current_read_index;
 489         u32 current_write_index;
 490         u32 bytes_avail_toread;
 491         u32 bytes_avail_towrite;
 492 };
 493
 494 /* Hv Interface */
 495
 496 extern int hv_init(void);
 497
 498 extern void hv_cleanup(void);
 499
 500 extern int hv_post_message(union hv_connection_id connection_id,
 501                          enum hv_message_type message_type,
 502                          void *payload, size_t payload_size);
 503
 504 extern int hv_signal_event(void *con_id);
 505
 506 extern int hv_synic_alloc(void);
 507
 508 extern void hv_synic_free(void);
 509
 510 extern void hv_synic_init(void *irqarg);
 511
 512 extern void hv_synic_cleanup(void *arg);
 513
 514 extern void hv_synic_clockevents_cleanup(void);
 515
 516 /*
 517  * Host version information.
 518  */
 519 extern unsigned int host_info_eax;
 520 extern unsigned int host_info_ebx;
 521 extern unsigned int host_info_ecx;
 522 extern unsigned int host_info_edx;
 523
 524 /* Interface */
 525
 526
 527 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer,
 528                    u32 buflen);
 529
 530 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 531
 532 int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
 533                     struct kvec *kv_list,
 534                     u32 kv_count, bool *signal);
 535
 536 int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 537                        void *buffer, u32 buflen, u32 *buffer_actual_len,
 538                        u64 *requestid, bool *signal, bool raw);
 539
 540 void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 541                             struct hv_ring_buffer_debug_info *debug_info);
 542
 543 void hv_begin_read(struct hv_ring_buffer_info *rbi);
 544
 545 u32 hv_end_read(struct hv_ring_buffer_info *rbi);
 546
 547 /*
 548  * Maximum channels is determined by the size of the interrupt page
 549  * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
 550  * and the other is receive endpoint interrupt
 551  */
 552 #define MAX_NUM_CHANNELS        ((PAGE_SIZE >> 1) << 3) /* 16348 channels */
 553
 554 /* The value here must be in multiple of 32 */
 555 /* TODO: Need to make this configurable */
 556 #define MAX_NUM_CHANNELS_SUPPORTED      256
 557
 558
 559 enum vmbus_connect_state {
 560         DISCONNECTED,
 561         CONNECTING,
 562         CONNECTED,
 563         DISCONNECTING
 564 };
 565
 566 #define MAX_SIZE_CHANNEL_MESSAGE        HV_MESSAGE_PAYLOAD_BYTE_COUNT
 567
 568 struct vmbus_connection {
 569         enum vmbus_connect_state conn_state;
 570
 571         atomic_t next_gpadl_handle;
 572
 573         struct completion  unload_event;
 574         /*
 575          * Represents channel interrupts. Each bit position represents a
 576          * channel.  When a channel sends an interrupt via VMBUS, it finds its
 577          * bit in the sendInterruptPage, set it and calls Hv to generate a port
 578          * event. The other end receives the port event and parse the
 579          * recvInterruptPage to see which bit is set
 580          */
 581         void *int_page;
 582         void *send_int_page;
 583         void *recv_int_page;
 584
 585         /*
 586          * 2 pages - 1st page for parent->child notification and 2nd
 587          * is child->parent notification
 588          */
 589         struct hv_monitor_page *monitor_pages[2];
 590         struct list_head chn_msg_list;
 591         spinlock_t channelmsg_lock;
 592
 593         /* List of channels */
 594         struct list_head chn_list;
 595         struct mutex channel_mutex;
 596
 597         struct workqueue_struct *work_queue;
 598 };
 599
 600
 601 struct vmbus_msginfo {
 602         /* Bookkeeping stuff */
 603         struct list_head msglist_entry;
 604
 605         /* The message itself */
 606         unsigned char msg[0];
 607 };
 608
 609
 610 extern struct vmbus_connection vmbus_connection;
 611
 612 enum vmbus_message_handler_type {
 613         /* The related handler can sleep. */
 614         VMHT_BLOCKING = 0,
 615
 616         /* The related handler must NOT sleep. */
 617         VMHT_NON_BLOCKING = 1,
 618 };
 619
 620 struct vmbus_channel_message_table_entry {
 621         enum vmbus_channel_message_type message_type;
 622         enum vmbus_message_handler_type handler_type;
 623         void (*message_handler)(struct vmbus_channel_message_header *msg);
 624 };
 625
 626 extern struct vmbus_channel_message_table_entry
 627         channel_message_table[CHANNELMSG_COUNT];
 628
 629 /* General vmbus interface */
 630
 631 struct hv_device *vmbus_device_create(const uuid_le *type,
 632                                       const uuid_le *instance,
 633                                       struct vmbus_channel *channel);
 634
 635 int vmbus_device_register(struct hv_device *child_device_obj);
 636 void vmbus_device_unregister(struct hv_device *device_obj);
 637
 638 /* static void */
 639 /* VmbusChildDeviceDestroy( */
 640 /* struct hv_device *); */
 641
 642 struct vmbus_channel *relid2channel(u32 relid);
 643
 644 void vmbus_free_channels(void);
 645
 646 /* Connection interface */
 647
 648 int vmbus_connect(void);
 649 void vmbus_disconnect(void);
 650
 651 int vmbus_post_msg(void *buffer, size_t buflen);
 652
 653 int vmbus_set_event(struct vmbus_channel *channel);
 654
 655 void vmbus_on_event(unsigned long data);
 656
 657 int hv_kvp_init(struct hv_util_service *);
 658 void hv_kvp_deinit(void);
 659 void hv_kvp_onchannelcallback(void *);
 660
 661 int hv_vss_init(struct hv_util_service *);
 662 void hv_vss_deinit(void);
 663 void hv_vss_onchannelcallback(void *);
 664
 665 int hv_fcopy_init(struct hv_util_service *);
 666 void hv_fcopy_deinit(void);
 667 void hv_fcopy_onchannelcallback(void *);
 668 void vmbus_initiate_unload(void);
 669
 670 static inline void hv_poll_channel(struct vmbus_channel *channel,
 671                                    void (*cb)(void *))
 672 {
 673         if (!channel)
 674                 return;
 675
 676         smp_call_function_single(channel->target_cpu, cb, channel, true);
 677 }
 678
 679 enum hvutil_device_state {
 680         HVUTIL_DEVICE_INIT = 0,  /* driver is loaded, waiting for userspace */
 681         HVUTIL_READY,            /* userspace is registered */
 682         HVUTIL_HOSTMSG_RECEIVED, /* message from the host was received */
 683         HVUTIL_USERSPACE_REQ,    /* request to userspace was sent */
 684         HVUTIL_USERSPACE_RECV,   /* reply from userspace was received */
 685         HVUTIL_DEVICE_DYING,     /* driver unload is in progress */
 686 };
 687
 688 #endif /* _HYPERV_VMBUS_H */