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 /* Definition of the hv_post_message hypercall input structure. */
 260 struct hv_input_post_message {
 261         union hv_connection_id connectionid;
 262         u32 reserved;
 263         u32 message_type;
 264         u32 payload_size;
 265         u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 266 };
 267
 268 /*
 269  * Versioning definitions used for guests reporting themselves to the
 270  * hypervisor, and visa versa.
 271  */
 272
 273 /* Version info reported by guest OS's */
 274 enum hv_guest_os_vendor {
 275         HVGUESTOS_VENDOR_MICROSOFT      = 0x0001
 276 };
 277
 278 enum hv_guest_os_microsoft_ids {
 279         HVGUESTOS_MICROSOFT_UNDEFINED   = 0x00,
 280         HVGUESTOS_MICROSOFT_MSDOS               = 0x01,
 281         HVGUESTOS_MICROSOFT_WINDOWS3X   = 0x02,
 282         HVGUESTOS_MICROSOFT_WINDOWS9X   = 0x03,
 283         HVGUESTOS_MICROSOFT_WINDOWSNT   = 0x04,
 284         HVGUESTOS_MICROSOFT_WINDOWSCE   = 0x05
 285 };
 286
 287 /*
 288  * Declare the MSR used to identify the guest OS.
 289  */
 290 #define HV_X64_MSR_GUEST_OS_ID  0x40000000
 291
 292 union hv_x64_msr_guest_os_id_contents {
 293         u64 as_uint64;
 294         struct {
 295                 u64 build_number:16;
 296                 u64 service_version:8; /* Service Pack, etc. */
 297                 u64 minor_version:8;
 298                 u64 major_version:8;
 299                 u64 os_id:8; /* enum hv_guest_os_microsoft_ids (if Vendor=MS) */
 300                 u64 vendor_id:16; /* enum hv_guest_os_vendor */
 301         };
 302 };
 303
 304 /*
 305  * Declare the MSR used to setup pages used to communicate with the hypervisor.
 306  */
 307 #define HV_X64_MSR_HYPERCALL    0x40000001
 308
 309 union hv_x64_msr_hypercall_contents {
 310         u64 as_uint64;
 311         struct {
 312                 u64 enable:1;
 313                 u64 reserved:11;
 314                 u64 guest_physical_address:52;
 315         };
 316 };
 317
 318
 319 enum {
 320         VMBUS_MESSAGE_CONNECTION_ID     = 1,
 321         VMBUS_MESSAGE_PORT_ID           = 1,
 322         VMBUS_EVENT_CONNECTION_ID       = 2,
 323         VMBUS_EVENT_PORT_ID             = 2,
 324         VMBUS_MONITOR_CONNECTION_ID     = 3,
 325         VMBUS_MONITOR_PORT_ID           = 3,
 326         VMBUS_MESSAGE_SINT              = 2,
 327 };
 328
 329 /* #defines */
 330
 331 #define HV_PRESENT_BIT                  0x80000000
 332
 333 /*
 334  * The guest OS needs to register the guest ID with the hypervisor.
 335  * The guest ID is a 64 bit entity and the structure of this ID is
 336  * specified in the Hyper-V specification:
 337  *
 338  * http://msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 339  *
 340  * While the current guideline does not specify how Linux guest ID(s)
 341  * need to be generated, our plan is to publish the guidelines for
 342  * Linux and other guest operating systems that currently are hosted
 343  * on Hyper-V. The implementation here conforms to this yet
 344  * unpublished guidelines.
 345  *
 346  *
 347  * Bit(s)
 348  * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 349  * 62:56 - Os Type; Linux is 0x100
 350  * 55:48 - Distro specific identification
 351  * 47:16 - Linux kernel version number
 352  * 15:0  - Distro specific identification
 353  *
 354  *
 355  */
 356
 357 #define HV_LINUX_VENDOR_ID              0x8100
 358
 359 /*
 360  * Generate the guest ID based on the guideline described above.
 361  */
 362
 363 static inline  __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
 364                                         __u16 d_info2)
 365 {
 366         __u64 guest_id = 0;
 367
 368         guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
 369         guest_id |= (((__u64)(d_info1)) << 48);
 370         guest_id |= (((__u64)(kernel_version)) << 16);
 371         guest_id |= ((__u64)(d_info2));
 372
 373         return guest_id;
 374 }
 375
 376
 377 #define HV_CPU_POWER_MANAGEMENT         (1 << 0)
 378 #define HV_RECOMMENDATIONS_MAX          4
 379
 380 #define HV_X64_MAX                      5
 381 #define HV_CAPS_MAX                     8
 382
 383
 384 #define HV_HYPERCALL_PARAM_ALIGN        sizeof(u64)
 385
 386
 387 /* Service definitions */
 388
 389 #define HV_SERVICE_PARENT_PORT                          (0)
 390 #define HV_SERVICE_PARENT_CONNECTION                    (0)
 391
 392 #define HV_SERVICE_CONNECT_RESPONSE_SUCCESS             (0)
 393 #define HV_SERVICE_CONNECT_RESPONSE_INVALID_PARAMETER   (1)
 394 #define HV_SERVICE_CONNECT_RESPONSE_UNKNOWN_SERVICE     (2)
 395 #define HV_SERVICE_CONNECT_RESPONSE_CONNECTION_REJECTED (3)
 396
 397 #define HV_SERVICE_CONNECT_REQUEST_MESSAGE_ID           (1)
 398 #define HV_SERVICE_CONNECT_RESPONSE_MESSAGE_ID          (2)
 399 #define HV_SERVICE_DISCONNECT_REQUEST_MESSAGE_ID        (3)
 400 #define HV_SERVICE_DISCONNECT_RESPONSE_MESSAGE_ID       (4)
 401 #define HV_SERVICE_MAX_MESSAGE_ID                               (4)
 402
 403 #define HV_SERVICE_PROTOCOL_VERSION (0x0010)
 404 #define HV_CONNECT_PAYLOAD_BYTE_COUNT 64
 405
 406 /* #define VMBUS_REVISION_NUMBER        6 */
 407
 408 /* Our local vmbus's port and connection id. Anything >0 is fine */
 409 /* #define VMBUS_PORT_ID                11 */
 410
 411 /* 628180B8-308D-4c5e-B7DB-1BEB62E62EF4 */
 412 static const uuid_le VMBUS_SERVICE_ID = {
 413         .b = {
 414                 0xb8, 0x80, 0x81, 0x62, 0x8d, 0x30, 0x5e, 0x4c,
 415                 0xb7, 0xdb, 0x1b, 0xeb, 0x62, 0xe6, 0x2e, 0xf4
 416         },
 417 };
 418
 419
 420
 421 struct hv_context {
 422         /* We only support running on top of Hyper-V
 423         * So at this point this really can only contain the Hyper-V ID
 424         */
 425         u64 guestid;
 426
 427         void *hypercall_page;
 428         void *tsc_page;
 429
 430         bool synic_initialized;
 431
 432         void *synic_message_page[NR_CPUS];
 433         void *synic_event_page[NR_CPUS];
 434         /*
 435          * Hypervisor's notion of virtual processor ID is different from
 436          * Linux' notion of CPU ID. This information can only be retrieved
 437          * in the context of the calling CPU. Setup a map for easy access
 438          * to this information:
 439          *
 440          * vp_index[a] is the Hyper-V's processor ID corresponding to
 441          * Linux cpuid 'a'.
 442          */
 443         u32 vp_index[NR_CPUS];
 444         /*
 445          * Starting with win8, we can take channel interrupts on any CPU;
 446          * we will manage the tasklet that handles events on a per CPU
 447          * basis.
 448          */
 449         struct tasklet_struct *event_dpc[NR_CPUS];
 450         /*
 451          * To optimize the mapping of relid to channel, maintain
 452          * per-cpu list of the channels based on their CPU affinity.
 453          */
 454         struct list_head percpu_list[NR_CPUS];
 455         /*
 456          * buffer to post messages to the host.
 457          */
 458         void *post_msg_page[NR_CPUS];
 459         /*
 460          * Support PV clockevent device.
 461          */
 462         struct clock_event_device *clk_evt[NR_CPUS];
 463         /*
 464          * To manage allocations in a NUMA node.
 465          * Array indexed by numa node ID.
 466          */
 467         struct cpumask *hv_numa_map;
 468 };
 469
 470 extern struct hv_context hv_context;
 471
 472 struct ms_hyperv_tsc_page {
 473         volatile u32 tsc_sequence;
 474         u32 reserved1;
 475         volatile u64 tsc_scale;
 476         volatile s64 tsc_offset;
 477         u64 reserved2[509];
 478 };
 479
 480 struct hv_ring_buffer_debug_info {
 481         u32 current_interrupt_mask;
 482         u32 current_read_index;
 483         u32 current_write_index;
 484         u32 bytes_avail_toread;
 485         u32 bytes_avail_towrite;
 486 };
 487
 488 /* Hv Interface */
 489
 490 extern int hv_init(void);
 491
 492 extern void hv_cleanup(void);
 493
 494 extern int hv_post_message(union hv_connection_id connection_id,
 495                          enum hv_message_type message_type,
 496                          void *payload, size_t payload_size);
 497
 498 extern int hv_signal_event(void *con_id);
 499
 500 extern int hv_synic_alloc(void);
 501
 502 extern void hv_synic_free(void);
 503
 504 extern void hv_synic_init(void *irqarg);
 505
 506 extern void hv_synic_cleanup(void *arg);
 507
 508 extern void hv_synic_clockevents_cleanup(void);
 509
 510 /*
 511  * Host version information.
 512  */
 513 extern unsigned int host_info_eax;
 514 extern unsigned int host_info_ebx;
 515 extern unsigned int host_info_ecx;
 516 extern unsigned int host_info_edx;
 517
 518 /* Interface */
 519
 520
 521 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer,
 522                    u32 buflen);
 523
 524 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 525
 526 int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
 527                     struct kvec *kv_list,
 528                     u32 kv_count, bool *signal);
 529
 530 int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 531                        void *buffer, u32 buflen, u32 *buffer_actual_len,
 532                        u64 *requestid, bool *signal, bool raw);
 533
 534 void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 535                             struct hv_ring_buffer_debug_info *debug_info);
 536
 537 void hv_begin_read(struct hv_ring_buffer_info *rbi);
 538
 539 u32 hv_end_read(struct hv_ring_buffer_info *rbi);
 540
 541 /*
 542  * Maximum channels is determined by the size of the interrupt page
 543  * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
 544  * and the other is receive endpoint interrupt
 545  */
 546 #define MAX_NUM_CHANNELS        ((PAGE_SIZE >> 1) << 3) /* 16348 channels */
 547
 548 /* The value here must be in multiple of 32 */
 549 /* TODO: Need to make this configurable */
 550 #define MAX_NUM_CHANNELS_SUPPORTED      256
 551
 552
 553 enum vmbus_connect_state {
 554         DISCONNECTED,
 555         CONNECTING,
 556         CONNECTED,
 557         DISCONNECTING
 558 };
 559
 560 #define MAX_SIZE_CHANNEL_MESSAGE        HV_MESSAGE_PAYLOAD_BYTE_COUNT
 561
 562 struct vmbus_connection {
 563         enum vmbus_connect_state conn_state;
 564
 565         atomic_t next_gpadl_handle;
 566
 567         struct completion  unload_event;
 568         /*
 569          * Represents channel interrupts. Each bit position represents a
 570          * channel.  When a channel sends an interrupt via VMBUS, it finds its
 571          * bit in the sendInterruptPage, set it and calls Hv to generate a port
 572          * event. The other end receives the port event and parse the
 573          * recvInterruptPage to see which bit is set
 574          */
 575         void *int_page;
 576         void *send_int_page;
 577         void *recv_int_page;
 578
 579         /*
 580          * 2 pages - 1st page for parent->child notification and 2nd
 581          * is child->parent notification
 582          */
 583         struct hv_monitor_page *monitor_pages[2];
 584         struct list_head chn_msg_list;
 585         spinlock_t channelmsg_lock;
 586
 587         /* List of channels */
 588         struct list_head chn_list;
 589         struct mutex channel_mutex;
 590
 591         struct workqueue_struct *work_queue;
 592 };
 593
 594
 595 struct vmbus_msginfo {
 596         /* Bookkeeping stuff */
 597         struct list_head msglist_entry;
 598
 599         /* The message itself */
 600         unsigned char msg[0];
 601 };
 602
 603
 604 extern struct vmbus_connection vmbus_connection;
 605
 606 enum vmbus_message_handler_type {
 607         /* The related handler can sleep. */
 608         VMHT_BLOCKING = 0,
 609
 610         /* The related handler must NOT sleep. */
 611         VMHT_NON_BLOCKING = 1,
 612 };
 613
 614 struct vmbus_channel_message_table_entry {
 615         enum vmbus_channel_message_type message_type;
 616         enum vmbus_message_handler_type handler_type;
 617         void (*message_handler)(struct vmbus_channel_message_header *msg);
 618 };
 619
 620 extern struct vmbus_channel_message_table_entry
 621         channel_message_table[CHANNELMSG_COUNT];
 622
 623 /* General vmbus interface */
 624
 625 struct hv_device *vmbus_device_create(const uuid_le *type,
 626                                       const uuid_le *instance,
 627                                       struct vmbus_channel *channel);
 628
 629 int vmbus_device_register(struct hv_device *child_device_obj);
 630 void vmbus_device_unregister(struct hv_device *device_obj);
 631
 632 /* static void */
 633 /* VmbusChildDeviceDestroy( */
 634 /* struct hv_device *); */
 635
 636 struct vmbus_channel *relid2channel(u32 relid);
 637
 638 void vmbus_free_channels(void);
 639
 640 /* Connection interface */
 641
 642 int vmbus_connect(void);
 643 void vmbus_disconnect(void);
 644
 645 int vmbus_post_msg(void *buffer, size_t buflen);
 646
 647 int vmbus_set_event(struct vmbus_channel *channel);
 648
 649 void vmbus_on_event(unsigned long data);
 650
 651 int hv_kvp_init(struct hv_util_service *);
 652 void hv_kvp_deinit(void);
 653 void hv_kvp_onchannelcallback(void *);
 654
 655 int hv_vss_init(struct hv_util_service *);
 656 void hv_vss_deinit(void);
 657 void hv_vss_onchannelcallback(void *);
 658
 659 int hv_fcopy_init(struct hv_util_service *);
 660 void hv_fcopy_deinit(void);
 661 void hv_fcopy_onchannelcallback(void *);
 662 void vmbus_initiate_unload(void);
 663
 664 static inline void hv_poll_channel(struct vmbus_channel *channel,
 665                                    void (*cb)(void *))
 666 {
 667         if (!channel)
 668                 return;
 669
 670         smp_call_function_single(channel->target_cpu, cb, channel, true);
 671 }
 672
 673 enum hvutil_device_state {
 674         HVUTIL_DEVICE_INIT = 0,  /* driver is loaded, waiting for userspace */
 675         HVUTIL_READY,            /* userspace is registered */
 676         HVUTIL_HOSTMSG_RECEIVED, /* message from the host was received */
 677         HVUTIL_USERSPACE_REQ,    /* request to userspace was sent */
 678         HVUTIL_USERSPACE_RECV,   /* reply from userspace was received */
 679         HVUTIL_DEVICE_DYING,     /* driver unload is in progress */
 680 };
 681
 682 #endif /* _HYPERV_VMBUS_H */