drivers/hv/hyperv_vmbus.h - kernel/msm-4.19 - Gitiles

 /*
  *
  * 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 <haiyangz@microsoft.com>
  *   Hank Janssen  <hjanssen@microsoft.com>
  *   K. Y. Srinivasan <kys@microsoft.com>
  *
  */

 #ifndef _HYPERV_VMBUS_H
 #define _HYPERV_VMBUS_H

 #include <linux/list.h>
 #include <asm/sync_bitops.h>
 #include <asm/hyperv-tlfs.h>
 #include <linux/atomic.h>
 #include <linux/hyperv.h>
 #include <linux/interrupt.h>

 #include "hv_trace.h"

 /*
  * Timeout for services such as KVP and fcopy.
  */
 #define HV_UTIL_TIMEOUT 30

 /*
  * Timeout for guest-host handshake for services.
  */
 #define HV_UTIL_NEGO_TIMEOUT 55

 /* Define synthetic interrupt controller flag constants. */
 #define HV_EVENT_FLAGS_COUNT		(256 * 8)
 #define HV_EVENT_FLAGS_LONG_COUNT	(256 / sizeof(unsigned long))

 /*
  * Timer configuration register.
  */
 union hv_timer_config {
 	u64 as_uint64;
 	struct {
 		u64 enable:1;
 		u64 periodic:1;
 		u64 lazy:1;
 		u64 auto_enable:1;
 		u64 apic_vector:8;
 		u64 direct_mode:1;
 		u64 reserved_z0:3;
 		u64 sintx:4;
 		u64 reserved_z1:44;
 	};
 };


 /* Define the synthetic interrupt controller event flags format. */
 union hv_synic_event_flags {
 	unsigned long flags[HV_EVENT_FLAGS_LONG_COUNT];
 };

 /* Define SynIC control register. */
 union hv_synic_scontrol {
 	u64 as_uint64;
 	struct {
 		u64 enable:1;
 		u64 reserved:63;
 	};
 };

 /* Define synthetic interrupt source. */
 union hv_synic_sint {
 	u64 as_uint64;
 	struct {
 		u64 vector:8;
 		u64 reserved1:8;
 		u64 masked:1;
 		u64 auto_eoi:1;
 		u64 reserved2:46;
 	};
 };

 /* Define the format of the SIMP register */
 union hv_synic_simp {
 	u64 as_uint64;
 	struct {
 		u64 simp_enabled:1;
 		u64 preserved:11;
 		u64 base_simp_gpa:52;
 	};
 };

 /* Define the format of the SIEFP register */
 union hv_synic_siefp {
 	u64 as_uint64;
 	struct {
 		u64 siefp_enabled:1;
 		u64 preserved:11;
 		u64 base_siefp_gpa:52;
 	};
 };

 /* Definitions for the monitored notification facility */
 union hv_monitor_trigger_group {
 	u64 as_uint64;
 	struct {
 		u32 pending;
 		u32 armed;
 	};
 };

 struct hv_monitor_parameter {
 	union hv_connection_id connectionid;
 	u16 flagnumber;
 	u16 rsvdz;
 };

 union hv_monitor_trigger_state {
 	u32 asu32;

 	struct {
 		u32 group_enable:4;
 		u32 rsvdz:28;
 	};
 };

 /* struct hv_monitor_page Layout */
 /* ------------------------------------------------------ */
 /* | 0   | TriggerState (4 bytes) | Rsvd1 (4 bytes)     | */
 /* | 8   | TriggerGroup[0]                              | */
 /* | 10  | TriggerGroup[1]                              | */
 /* | 18  | TriggerGroup[2]                              | */
 /* | 20  | TriggerGroup[3]                              | */
 /* | 28  | Rsvd2[0]                                     | */
 /* | 30  | Rsvd2[1]                                     | */
 /* | 38  | Rsvd2[2]                                     | */
 /* | 40  | NextCheckTime[0][0]    | NextCheckTime[0][1] | */
 /* | ...                                                | */
 /* | 240 | Latency[0][0..3]                             | */
 /* | 340 | Rsvz3[0]                                     | */
 /* | 440 | Parameter[0][0]                              | */
 /* | 448 | Parameter[0][1]                              | */
 /* | ...                                                | */
 /* | 840 | Rsvd4[0]                                     | */
 /* ------------------------------------------------------ */
 struct hv_monitor_page {
 	union hv_monitor_trigger_state trigger_state;
 	u32 rsvdz1;

 	union hv_monitor_trigger_group trigger_group[4];
 	u64 rsvdz2[3];

 	s32 next_checktime[4][32];

 	u16 latency[4][32];
 	u64 rsvdz3[32];

 	struct hv_monitor_parameter parameter[4][32];

 	u8 rsvdz4[1984];
 };

 #define HV_HYPERCALL_PARAM_ALIGN	sizeof(u64)

 /* Definition of the hv_post_message hypercall input structure. */
 struct hv_input_post_message {
 	union hv_connection_id connectionid;
 	u32 reserved;
 	u32 message_type;
 	u32 payload_size;
 	u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
 };


 enum {
 	VMBUS_MESSAGE_CONNECTION_ID	= 1,
 	VMBUS_MESSAGE_PORT_ID		= 1,
 	VMBUS_EVENT_CONNECTION_ID	= 2,
 	VMBUS_EVENT_PORT_ID		= 2,
 	VMBUS_MONITOR_CONNECTION_ID	= 3,
 	VMBUS_MONITOR_PORT_ID		= 3,
 	VMBUS_MESSAGE_SINT		= 2,
 };

 /*
  * Per cpu state for channel handling
  */
 struct hv_per_cpu_context {
 	void *synic_message_page;
 	void *synic_event_page;
 	/*
 	 * buffer to post messages to the host.
 	 */
 	void *post_msg_page;

 	/*
 	 * Starting with win8, we can take channel interrupts on any CPU;
 	 * we will manage the tasklet that handles events messages on a per CPU
 	 * basis.
 	 */
 	struct tasklet_struct msg_dpc;

 	/*
 	 * To optimize the mapping of relid to channel, maintain
 	 * per-cpu list of the channels based on their CPU affinity.
 	 */
 	struct list_head chan_list;
 	struct clock_event_device *clk_evt;
 };

 struct hv_context {
 	/* We only support running on top of Hyper-V
 	 * So at this point this really can only contain the Hyper-V ID
 	 */
 	u64 guestid;

 	void *tsc_page;

 	bool synic_initialized;

 	struct hv_per_cpu_context __percpu *cpu_context;

 	/*
 	 * To manage allocations in a NUMA node.
 	 * Array indexed by numa node ID.
 	 */
 	struct cpumask *hv_numa_map;
 };

 extern struct hv_context hv_context;

 /* Hv Interface */

 extern int hv_init(void);

 extern int hv_post_message(union hv_connection_id connection_id,
 			 enum hv_message_type message_type,
 			 void *payload, size_t payload_size);

 extern int hv_synic_alloc(void);

 extern void hv_synic_free(void);

 extern int hv_synic_init(unsigned int cpu);

 extern int hv_synic_cleanup(unsigned int cpu);

 extern void hv_synic_clockevents_cleanup(void);

 /* Interface */


 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		       struct page *pages, u32 pagecnt);

 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);

 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count);

 int hv_ringbuffer_read(struct vmbus_channel *channel,
 		       void *buffer, u32 buflen, u32 *buffer_actual_len,
 		       u64 *requestid, bool raw);

 /*
  * Maximum channels is determined by the size of the interrupt page
  * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
  * and the other is receive endpoint interrupt
  */
 #define MAX_NUM_CHANNELS	((PAGE_SIZE >> 1) << 3)	/* 16348 channels */

 /* The value here must be in multiple of 32 */
 /* TODO: Need to make this configurable */
 #define MAX_NUM_CHANNELS_SUPPORTED	256


 enum vmbus_connect_state {
 	DISCONNECTED,
 	CONNECTING,
 	CONNECTED,
 	DISCONNECTING
 };

 #define MAX_SIZE_CHANNEL_MESSAGE	HV_MESSAGE_PAYLOAD_BYTE_COUNT

 struct vmbus_connection {
 	/*
 	 * CPU on which the initial host contact was made.
 	 */
 	int connect_cpu;

 	atomic_t offer_in_progress;

 	enum vmbus_connect_state conn_state;

 	atomic_t next_gpadl_handle;

 	struct completion  unload_event;
 	/*
 	 * Represents channel interrupts. Each bit position represents a
 	 * channel.  When a channel sends an interrupt via VMBUS, it finds its
 	 * bit in the sendInterruptPage, set it and calls Hv to generate a port
 	 * event. The other end receives the port event and parse the
 	 * recvInterruptPage to see which bit is set
 	 */
 	void *int_page;
 	void *send_int_page;
 	void *recv_int_page;

 	/*
 	 * 2 pages - 1st page for parent->child notification and 2nd
 	 * is child->parent notification
 	 */
 	struct hv_monitor_page *monitor_pages[2];
 	struct list_head chn_msg_list;
 	spinlock_t channelmsg_lock;

 	/* List of channels */
 	struct list_head chn_list;
 	struct mutex channel_mutex;

 	struct workqueue_struct *work_queue;
 };


 struct vmbus_msginfo {
 	/* Bookkeeping stuff */
 	struct list_head msglist_entry;

 	/* The message itself */
 	unsigned char msg[0];
 };


 extern struct vmbus_connection vmbus_connection;

 static inline void vmbus_send_interrupt(u32 relid)
 {
 	sync_set_bit(relid, vmbus_connection.send_int_page);
 }

 enum vmbus_message_handler_type {
 	/* The related handler can sleep. */
 	VMHT_BLOCKING = 0,

 	/* The related handler must NOT sleep. */
 	VMHT_NON_BLOCKING = 1,
 };

 struct vmbus_channel_message_table_entry {
 	enum vmbus_channel_message_type message_type;
 	enum vmbus_message_handler_type handler_type;
 	void (*message_handler)(struct vmbus_channel_message_header *msg);
 };

 extern const struct vmbus_channel_message_table_entry
 	channel_message_table[CHANNELMSG_COUNT];


 /* General vmbus interface */

 struct hv_device *vmbus_device_create(const uuid_le *type,
 				      const uuid_le *instance,
 				      struct vmbus_channel *channel);

 int vmbus_device_register(struct hv_device *child_device_obj);
 void vmbus_device_unregister(struct hv_device *device_obj);
 int vmbus_add_channel_kobj(struct hv_device *device_obj,
 			   struct vmbus_channel *channel);

 struct vmbus_channel *relid2channel(u32 relid);

 void vmbus_free_channels(void);

 /* Connection interface */

 int vmbus_connect(void);
 void vmbus_disconnect(void);

 int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep);

 void vmbus_on_event(unsigned long data);
 void vmbus_on_msg_dpc(unsigned long data);

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

 int hv_vss_init(struct hv_util_service *srv);
 void hv_vss_deinit(void);
 void hv_vss_onchannelcallback(void *context);

 int hv_fcopy_init(struct hv_util_service *srv);
 void hv_fcopy_deinit(void);
 void hv_fcopy_onchannelcallback(void *context);
 void vmbus_initiate_unload(bool crash);

 static inline void hv_poll_channel(struct vmbus_channel *channel,
 				   void (*cb)(void *))
 {
 	if (!channel)
 		return;

 	if (in_interrupt() && (channel->target_cpu == smp_processor_id())) {
 		cb(channel);
 		return;
 	}
 	smp_call_function_single(channel->target_cpu, cb, channel, true);
 }

 enum hvutil_device_state {
 	HVUTIL_DEVICE_INIT = 0,  /* driver is loaded, waiting for userspace */
 	HVUTIL_READY,            /* userspace is registered */
 	HVUTIL_HOSTMSG_RECEIVED, /* message from the host was received */
 	HVUTIL_USERSPACE_REQ,    /* request to userspace was sent */
 	HVUTIL_USERSPACE_RECV,   /* reply from userspace was received */
 	HVUTIL_DEVICE_DYING,     /* driver unload is in progress */
 };

 #endif /* _HYPERV_VMBUS_H */
	/*
	*
	* 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 <haiyangz@microsoft.com>
	* Hank Janssen <hjanssen@microsoft.com>
	* K. Y. Srinivasan <kys@microsoft.com>
	*
	*/

	#ifndef _HYPERV_VMBUS_H
	#define _HYPERV_VMBUS_H

	#include <linux/list.h>
	#include <asm/sync_bitops.h>
	#include <asm/hyperv-tlfs.h>
	#include <linux/atomic.h>
	#include <linux/hyperv.h>
	#include <linux/interrupt.h>

	#include "hv_trace.h"

	/*
	* Timeout for services such as KVP and fcopy.
	*/
	#define HV_UTIL_TIMEOUT 30

	/*
	* Timeout for guest-host handshake for services.
	*/
	#define HV_UTIL_NEGO_TIMEOUT 55

	/* Define synthetic interrupt controller flag constants. */
	#define HV_EVENT_FLAGS_COUNT (256 * 8)
	#define HV_EVENT_FLAGS_LONG_COUNT (256 / sizeof(unsigned long))

	/*
	* Timer configuration register.
	*/
	union hv_timer_config {
	u64 as_uint64;
	struct {
	u64 enable:1;
	u64 periodic:1;
	u64 lazy:1;
	u64 auto_enable:1;
	u64 apic_vector:8;
	u64 direct_mode:1;
	u64 reserved_z0:3;
	u64 sintx:4;
	u64 reserved_z1:44;
	};
	};


	/* Define the synthetic interrupt controller event flags format. */
	union hv_synic_event_flags {
	unsigned long flags[HV_EVENT_FLAGS_LONG_COUNT];
	};

	/* Define SynIC control register. */
	union hv_synic_scontrol {
	u64 as_uint64;
	struct {
	u64 enable:1;
	u64 reserved:63;
	};
	};

	/* Define synthetic interrupt source. */
	union hv_synic_sint {
	u64 as_uint64;
	struct {
	u64 vector:8;
	u64 reserved1:8;
	u64 masked:1;
	u64 auto_eoi:1;
	u64 reserved2:46;
	};
	};

	/* Define the format of the SIMP register */
	union hv_synic_simp {
	u64 as_uint64;
	struct {
	u64 simp_enabled:1;
	u64 preserved:11;
	u64 base_simp_gpa:52;
	};
	};

	/* Define the format of the SIEFP register */
	union hv_synic_siefp {
	u64 as_uint64;
	struct {
	u64 siefp_enabled:1;
	u64 preserved:11;
	u64 base_siefp_gpa:52;
	};
	};

	/* Definitions for the monitored notification facility */
	union hv_monitor_trigger_group {
	u64 as_uint64;
	struct {
	u32 pending;
	u32 armed;
	};
	};

	struct hv_monitor_parameter {
	union hv_connection_id connectionid;
	u16 flagnumber;
	u16 rsvdz;
	};

	union hv_monitor_trigger_state {
	u32 asu32;

	struct {
	u32 group_enable:4;
	u32 rsvdz:28;
	};
	};

	/* struct hv_monitor_page Layout */
	/* ------------------------------------------------------ */
	/* \| 0 \| TriggerState (4 bytes) \| Rsvd1 (4 bytes) \| */
	/* \| 8 \| TriggerGroup[0] \| */
	/* \| 10 \| TriggerGroup[1] \| */
	/* \| 18 \| TriggerGroup[2] \| */
	/* \| 20 \| TriggerGroup[3] \| */
	/* \| 28 \| Rsvd2[0] \| */
	/* \| 30 \| Rsvd2[1] \| */
	/* \| 38 \| Rsvd2[2] \| */
	/* \| 40 \| NextCheckTime[0][0] \| NextCheckTime[0][1] \| */
	/* \| ... \| */
	/* \| 240 \| Latency[0][0..3] \| */
	/* \| 340 \| Rsvz3[0] \| */
	/* \| 440 \| Parameter[0][0] \| */
	/* \| 448 \| Parameter[0][1] \| */
	/* \| ... \| */
	/* \| 840 \| Rsvd4[0] \| */
	/* ------------------------------------------------------ */
	struct hv_monitor_page {
	union hv_monitor_trigger_state trigger_state;
	u32 rsvdz1;

	union hv_monitor_trigger_group trigger_group[4];
	u64 rsvdz2[3];

	s32 next_checktime[4][32];

	u16 latency[4][32];
	u64 rsvdz3[32];

	struct hv_monitor_parameter parameter[4][32];

	u8 rsvdz4[1984];
	};

	#define HV_HYPERCALL_PARAM_ALIGN sizeof(u64)

	/* Definition of the hv_post_message hypercall input structure. */
	struct hv_input_post_message {
	union hv_connection_id connectionid;
	u32 reserved;
	u32 message_type;
	u32 payload_size;
	u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
	};


	enum {
	VMBUS_MESSAGE_CONNECTION_ID = 1,
	VMBUS_MESSAGE_PORT_ID = 1,
	VMBUS_EVENT_CONNECTION_ID = 2,
	VMBUS_EVENT_PORT_ID = 2,
	VMBUS_MONITOR_CONNECTION_ID = 3,
	VMBUS_MONITOR_PORT_ID = 3,
	VMBUS_MESSAGE_SINT = 2,
	};

	/*
	* Per cpu state for channel handling
	*/
	struct hv_per_cpu_context {
	void *synic_message_page;
	void *synic_event_page;
	/*
	* buffer to post messages to the host.
	*/
	void *post_msg_page;

	/*
	* Starting with win8, we can take channel interrupts on any CPU;
	* we will manage the tasklet that handles events messages on a per CPU
	* basis.
	*/
	struct tasklet_struct msg_dpc;

	/*
	* To optimize the mapping of relid to channel, maintain
	* per-cpu list of the channels based on their CPU affinity.
	*/
	struct list_head chan_list;
	struct clock_event_device *clk_evt;
	};

	struct hv_context {
	/* We only support running on top of Hyper-V
	* So at this point this really can only contain the Hyper-V ID
	*/
	u64 guestid;

	void *tsc_page;

	bool synic_initialized;

	struct hv_per_cpu_context __percpu *cpu_context;

	/*
	* To manage allocations in a NUMA node.
	* Array indexed by numa node ID.
	*/
	struct cpumask *hv_numa_map;
	};

	extern struct hv_context hv_context;

	/* Hv Interface */

	extern int hv_init(void);

	extern int hv_post_message(union hv_connection_id connection_id,
	enum hv_message_type message_type,
	void *payload, size_t payload_size);

	extern int hv_synic_alloc(void);

	extern void hv_synic_free(void);

	extern int hv_synic_init(unsigned int cpu);

	extern int hv_synic_cleanup(unsigned int cpu);

	extern void hv_synic_clockevents_cleanup(void);

	/* Interface */


	int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
	struct page *pages, u32 pagecnt);

	void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);

	int hv_ringbuffer_write(struct vmbus_channel *channel,
	const struct kvec *kv_list, u32 kv_count);

	int hv_ringbuffer_read(struct vmbus_channel *channel,
	void buffer, u32 buflen, u32 buffer_actual_len,
	u64 *requestid, bool raw);

	/*
	* Maximum channels is determined by the size of the interrupt page
	* which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
	* and the other is receive endpoint interrupt
	*/
	#define MAX_NUM_CHANNELS ((PAGE_SIZE >> 1) << 3) /* 16348 channels */

	/* The value here must be in multiple of 32 */
	/* TODO: Need to make this configurable */
	#define MAX_NUM_CHANNELS_SUPPORTED 256


	enum vmbus_connect_state {
	DISCONNECTED,
	CONNECTING,
	CONNECTED,
	DISCONNECTING
	};

	#define MAX_SIZE_CHANNEL_MESSAGE HV_MESSAGE_PAYLOAD_BYTE_COUNT

	struct vmbus_connection {
	/*
	* CPU on which the initial host contact was made.
	*/
	int connect_cpu;

	atomic_t offer_in_progress;

	enum vmbus_connect_state conn_state;

	atomic_t next_gpadl_handle;

	struct completion unload_event;
	/*
	* Represents channel interrupts. Each bit position represents a
	* channel. When a channel sends an interrupt via VMBUS, it finds its
	* bit in the sendInterruptPage, set it and calls Hv to generate a port
	* event. The other end receives the port event and parse the
	* recvInterruptPage to see which bit is set
	*/
	void *int_page;
	void *send_int_page;
	void *recv_int_page;

	/*
	* 2 pages - 1st page for parent->child notification and 2nd
	* is child->parent notification
	*/
	struct hv_monitor_page *monitor_pages[2];
	struct list_head chn_msg_list;
	spinlock_t channelmsg_lock;

	/* List of channels */
	struct list_head chn_list;
	struct mutex channel_mutex;

	struct workqueue_struct *work_queue;
	};


	struct vmbus_msginfo {
	/* Bookkeeping stuff */
	struct list_head msglist_entry;

	/* The message itself */
	unsigned char msg[0];
	};


	extern struct vmbus_connection vmbus_connection;

	static inline void vmbus_send_interrupt(u32 relid)
	{
	sync_set_bit(relid, vmbus_connection.send_int_page);
	}

	enum vmbus_message_handler_type {
	/* The related handler can sleep. */
	VMHT_BLOCKING = 0,

	/* The related handler must NOT sleep. */
	VMHT_NON_BLOCKING = 1,
	};

	struct vmbus_channel_message_table_entry {
	enum vmbus_channel_message_type message_type;
	enum vmbus_message_handler_type handler_type;
	void (message_handler)(struct vmbus_channel_message_header msg);
	};

	extern const struct vmbus_channel_message_table_entry
	channel_message_table[CHANNELMSG_COUNT];


	/* General vmbus interface */

	struct hv_device vmbus_device_create(const uuid_le type,
	const uuid_le *instance,
	struct vmbus_channel *channel);

	int vmbus_device_register(struct hv_device *child_device_obj);
	void vmbus_device_unregister(struct hv_device *device_obj);
	int vmbus_add_channel_kobj(struct hv_device *device_obj,
	struct vmbus_channel *channel);

	struct vmbus_channel *relid2channel(u32 relid);

	void vmbus_free_channels(void);

	/* Connection interface */

	int vmbus_connect(void);
	void vmbus_disconnect(void);

	int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep);

	void vmbus_on_event(unsigned long data);
	void vmbus_on_msg_dpc(unsigned long data);

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

	int hv_vss_init(struct hv_util_service *srv);
	void hv_vss_deinit(void);
	void hv_vss_onchannelcallback(void *context);

	int hv_fcopy_init(struct hv_util_service *srv);
	void hv_fcopy_deinit(void);
	void hv_fcopy_onchannelcallback(void *context);
	void vmbus_initiate_unload(bool crash);

	static inline void hv_poll_channel(struct vmbus_channel *channel,
	void (cb)(void ))
	{
	if (!channel)
	return;

	if (in_interrupt() && (channel->target_cpu == smp_processor_id())) {
	cb(channel);
	return;
	}
	smp_call_function_single(channel->target_cpu, cb, channel, true);
	}

	enum hvutil_device_state {
	HVUTIL_DEVICE_INIT = 0, /* driver is loaded, waiting for userspace */
	HVUTIL_READY, /* userspace is registered */
	HVUTIL_HOSTMSG_RECEIVED, /* message from the host was received */
	HVUTIL_USERSPACE_REQ, /* request to userspace was sent */
	HVUTIL_USERSPACE_RECV, /* reply from userspace was received */
	HVUTIL_DEVICE_DYING, /* driver unload is in progress */
	};

	#endif /* _HYPERV_VMBUS_H */