drivers/staging/hv/ChannelMgmt.c

/*
 *
 * Copyright (c) 2009, 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>
 *
 */


#include "include/osd.h"
#include "include/logging.h"

#include "VmbusPrivate.h"

//
// Defines
//

//
// Data types
//

typedef void (*PFN_CHANNEL_MESSAGE_HANDLER)(VMBUS_CHANNEL_MESSAGE_HEADER* msg);

typedef struct _VMBUS_CHANNEL_MESSAGE_TABLE_ENTRY {
	VMBUS_CHANNEL_MESSAGE_TYPE	messageType;
	PFN_CHANNEL_MESSAGE_HANDLER messageHandler;
} VMBUS_CHANNEL_MESSAGE_TABLE_ENTRY;

//
// Internal routines
//

static void
VmbusChannelOnOffer(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);
static void
VmbusChannelOnOpenResult(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelOnOfferRescind(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelOnGpadlCreated(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelOnGpadlTorndown(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelOnOffersDelivered(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelOnVersionResponse(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	);

static void
VmbusChannelProcessOffer(
	void * context
	);

static void
VmbusChannelProcessRescindOffer(
	void * context
	);


//
// Globals
//

#define MAX_NUM_DEVICE_CLASSES_SUPPORTED 4

const GUID gSupportedDeviceClasses[MAX_NUM_DEVICE_CLASSES_SUPPORTED]= {
	//{ba6163d9-04a1-4d29-b605-72e2ffb1dc7f}
	{.Data  = {0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d, 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f}},// Storage - SCSI
	//{F8615163-DF3E-46c5-913F-F2D2F965ED0E}
	{.Data = {0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46, 0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E}},	// Network
	//{CFA8B69E-5B4A-4cc0-B98B-8BA1A1F3F95A}
	{.Data = {0x9E, 0xB6, 0xA8, 0xCF, 0x4A, 0x5B, 0xc0, 0x4c, 0xB9, 0x8B, 0x8B, 0xA1, 0xA1, 0xF3, 0xF9, 0x5A}}, // Input
	//{32412632-86cb-44a2-9b5c-50d1417354f5}
	{.Data = {0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44, 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5}}, // IDE

};

// Channel message dispatch table
VMBUS_CHANNEL_MESSAGE_TABLE_ENTRY gChannelMessageTable[ChannelMessageCount]= {
    {ChannelMessageInvalid,					NULL},
    {ChannelMessageOfferChannel,            VmbusChannelOnOffer},
    {ChannelMessageRescindChannelOffer,     VmbusChannelOnOfferRescind},
    {ChannelMessageRequestOffers,           NULL},
    {ChannelMessageAllOffersDelivered,      VmbusChannelOnOffersDelivered},
    {ChannelMessageOpenChannel,             NULL},
    {ChannelMessageOpenChannelResult,       VmbusChannelOnOpenResult},
    {ChannelMessageCloseChannel,            NULL},
    {ChannelMessageGpadlHeader,             NULL},
    {ChannelMessageGpadlBody,               NULL},
	{ChannelMessageGpadlCreated,			VmbusChannelOnGpadlCreated},
    {ChannelMessageGpadlTeardown,           NULL},
    {ChannelMessageGpadlTorndown,           VmbusChannelOnGpadlTorndown},
    {ChannelMessageRelIdReleased,           NULL},
	{ChannelMessageInitiateContact,			NULL},
	{ChannelMessageVersionResponse,			VmbusChannelOnVersionResponse},
	{ChannelMessageUnload,					NULL},
};

/*++

Name:
	AllocVmbusChannel()

Description:
	Allocate and initialize a vmbus channel object

--*/
VMBUS_CHANNEL* AllocVmbusChannel(void)
{
	VMBUS_CHANNEL* channel;

	channel = (VMBUS_CHANNEL*) MemAllocAtomic(sizeof(VMBUS_CHANNEL));
	if (!channel)
	{
		return NULL;
	}

	memset(channel, 0,sizeof(VMBUS_CHANNEL));
	channel->InboundLock = SpinlockCreate();
	if (!channel->InboundLock)
	{
		MemFree(channel);
		return NULL;
	}

	channel->PollTimer = TimerCreate(VmbusChannelOnTimer, channel);
	if (!channel->PollTimer)
	{
		SpinlockClose(channel->InboundLock);
		MemFree(channel);
		return NULL;
	}

	//channel->dataWorkQueue = WorkQueueCreate("data");
	channel->ControlWQ = WorkQueueCreate("control");
	if (!channel->ControlWQ)
	{
		TimerClose(channel->PollTimer);
		SpinlockClose(channel->InboundLock);
		MemFree(channel);
		return NULL;
	}

	return channel;
}

/*++

Name:
	ReleaseVmbusChannel()

Description:
	Release the vmbus channel object itself

--*/
static inline void ReleaseVmbusChannel(void* Context)
{
	VMBUS_CHANNEL* channel = (VMBUS_CHANNEL*)Context;

	DPRINT_ENTER(VMBUS);

	DPRINT_DBG(VMBUS, "releasing channel (%p)", channel);
	WorkQueueClose(channel->ControlWQ);
	DPRINT_DBG(VMBUS, "channel released (%p)", channel);

	MemFree(channel);

	DPRINT_EXIT(VMBUS);
}

/*++

Name:
	FreeVmbusChannel()

Description:
	Release the resources used by the vmbus channel object

--*/
void FreeVmbusChannel(VMBUS_CHANNEL* Channel)
{
	SpinlockClose(Channel->InboundLock);
	TimerClose(Channel->PollTimer);

	// We have to release the channel's workqueue/thread in the vmbus's workqueue/thread context
	// ie we can't destroy ourselves.
	WorkQueueQueueWorkItem(gVmbusConnection.WorkQueue, ReleaseVmbusChannel, (void*)Channel);
}


/*++

Name:
	VmbusChannelProcessOffer()

Description:
	Process the offer by creating a channel/device associated with this offer

--*/
static void
VmbusChannelProcessOffer(
	void * context
	)
{
	int ret=0;
	VMBUS_CHANNEL* newChannel=(VMBUS_CHANNEL*)context;
	LIST_ENTRY* anchor;
	LIST_ENTRY* curr;
	BOOL fNew=TRUE;
	VMBUS_CHANNEL* channel;

	DPRINT_ENTER(VMBUS);

	// Make sure this is a new offer
	SpinlockAcquire(gVmbusConnection.ChannelLock);

	ITERATE_LIST_ENTRIES(anchor, curr, &gVmbusConnection.ChannelList)
	{
		channel = CONTAINING_RECORD(curr, VMBUS_CHANNEL, ListEntry);

		if (!memcmp(&channel->OfferMsg.Offer.InterfaceType, &newChannel->OfferMsg.Offer.InterfaceType,sizeof(GUID)) &&
			!memcmp(&channel->OfferMsg.Offer.InterfaceInstance, &newChannel->OfferMsg.Offer.InterfaceInstance, sizeof(GUID)))
		{
			fNew = FALSE;
			break;
		}
	}

	if (fNew)
	{
		INSERT_TAIL_LIST(&gVmbusConnection.ChannelList, &newChannel->ListEntry);
	}
	SpinlockRelease(gVmbusConnection.ChannelLock);

	if (!fNew)
	{
		DPRINT_DBG(VMBUS, "Ignoring duplicate offer for relid (%d)", newChannel->OfferMsg.ChildRelId);
		FreeVmbusChannel(newChannel);
		DPRINT_EXIT(VMBUS);
		return;
	}

	// Start the process of binding this offer to the driver
	// We need to set the DeviceObject field before calling VmbusChildDeviceAdd()
	newChannel->DeviceObject = VmbusChildDeviceCreate(
		newChannel->OfferMsg.Offer.InterfaceType,
		newChannel->OfferMsg.Offer.InterfaceInstance,
		newChannel);

	DPRINT_DBG(VMBUS, "child device object allocated - %p", newChannel->DeviceObject);

	// Add the new device to the bus. This will kick off device-driver binding
	// which eventually invokes the device driver's AddDevice() method.
	ret = VmbusChildDeviceAdd(newChannel->DeviceObject);
	if (ret != 0)
	{
		DPRINT_ERR(VMBUS, "unable to add child device object (relid %d)",
			newChannel->OfferMsg.ChildRelId);

		SpinlockAcquire(gVmbusConnection.ChannelLock);
		REMOVE_ENTRY_LIST(&newChannel->ListEntry);
		SpinlockRelease(gVmbusConnection.ChannelLock);

		FreeVmbusChannel(newChannel);
	}
	else
	{
		// This state is used to indicate a successful open so that when we do close the channel normally,
		// we can cleanup properly
		newChannel->State = CHANNEL_OPEN_STATE;
	}
	DPRINT_EXIT(VMBUS);
}

/*++

Name:
	VmbusChannelProcessRescindOffer()

Description:
	Rescind the offer by initiating a device removal

--*/
static void
VmbusChannelProcessRescindOffer(
	void * context
	)
{
	VMBUS_CHANNEL* channel=(VMBUS_CHANNEL*)context;

	DPRINT_ENTER(VMBUS);

	VmbusChildDeviceRemove(channel->DeviceObject);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnOffer()

Description:
	Handler for channel offers from vmbus in parent partition. We ignore all offers except
	network and storage offers. For each network and storage offers, we create a channel object
	and queue a work item to the channel object to process the offer synchronously

--*/
static void
VmbusChannelOnOffer(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	VMBUS_CHANNEL_OFFER_CHANNEL* offer = (VMBUS_CHANNEL_OFFER_CHANNEL*)hdr;
	VMBUS_CHANNEL* newChannel;

	GUID *guidType;
	GUID *guidInstance;
	int i;
	int fSupported=0;

	DPRINT_ENTER(VMBUS);

	for (i=0; i<MAX_NUM_DEVICE_CLASSES_SUPPORTED; i++)
	{
		if (memcmp(&offer->Offer.InterfaceType, &gSupportedDeviceClasses[i], sizeof(GUID)) == 0)
		{
			fSupported = 1;
			break;
		}
	}

	if (!fSupported)
	{
		DPRINT_DBG(VMBUS, "Ignoring channel offer notification for child relid %d", offer->ChildRelId);
		DPRINT_EXIT(VMBUS);

		return;
	}

	guidType = &offer->Offer.InterfaceType;
	guidInstance = &offer->Offer.InterfaceInstance;

	DPRINT_INFO(VMBUS, "Channel offer notification - child relid %d monitor id %d allocated %d, "
		"type {%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x%02x%02x} "
		"instance {%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x%02x%02x}",
		offer->ChildRelId,
		offer->MonitorId,
		offer->MonitorAllocated,
		guidType->Data[3], guidType->Data[2], guidType->Data[1], guidType->Data[0], guidType->Data[5], guidType->Data[4], guidType->Data[7], guidType->Data[6], guidType->Data[8], guidType->Data[9], guidType->Data[10], guidType->Data[11], guidType->Data[12], guidType->Data[13], guidType->Data[14], guidType->Data[15],
		guidInstance->Data[3], guidInstance->Data[2], guidInstance->Data[1], guidInstance->Data[0], guidInstance->Data[5], guidInstance->Data[4], guidInstance->Data[7], guidInstance->Data[6], guidInstance->Data[8], guidInstance->Data[9], guidInstance->Data[10], guidInstance->Data[11], guidInstance->Data[12], guidInstance->Data[13], guidInstance->Data[14], guidInstance->Data[15]);

	// Allocate the channel object and save this offer.
	newChannel = AllocVmbusChannel();
	if (!newChannel)
	{
		DPRINT_ERR(VMBUS, "unable to allocate channel object");
		return;
	}

	DPRINT_DBG(VMBUS, "channel object allocated - %p", newChannel);

	memcpy(&newChannel->OfferMsg, offer, sizeof(VMBUS_CHANNEL_OFFER_CHANNEL));
	newChannel->MonitorGroup = (UINT8)offer->MonitorId / 32;
	newChannel->MonitorBit = (UINT8)offer->MonitorId % 32;

	// TODO: Make sure the offer comes from our parent partition
	WorkQueueQueueWorkItem(newChannel->ControlWQ, VmbusChannelProcessOffer, newChannel);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnOfferRescind()

Description:
	Rescind offer handler. We queue a work item to process this offer
	synchronously

--*/
static void
VmbusChannelOnOfferRescind(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	VMBUS_CHANNEL_RESCIND_OFFER* rescind = (VMBUS_CHANNEL_RESCIND_OFFER*)hdr;
	VMBUS_CHANNEL* channel;

	DPRINT_ENTER(VMBUS);

	channel = GetChannelFromRelId(rescind->ChildRelId);
	if (channel == NULL)
	{
		DPRINT_DBG(VMBUS, "channel not found for relId %d", rescind->ChildRelId);
		return;
	}

	WorkQueueQueueWorkItem(channel->ControlWQ, VmbusChannelProcessRescindOffer, channel);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnOffersDelivered()

Description:
	This is invoked when all offers have been delivered.
	Nothing to do here.

--*/
static void
VmbusChannelOnOffersDelivered(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	DPRINT_ENTER(VMBUS);
	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnOpenResult()

Description:
	Open result handler. This is invoked when we received a response
	to our channel open request. Find the matching request, copy the
	response and signal the requesting thread.

--*/
static void
VmbusChannelOnOpenResult(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	VMBUS_CHANNEL_OPEN_RESULT* result = (VMBUS_CHANNEL_OPEN_RESULT*)hdr;
	LIST_ENTRY* anchor;
	LIST_ENTRY* curr;
	VMBUS_CHANNEL_MSGINFO* msgInfo;
	VMBUS_CHANNEL_MESSAGE_HEADER* requestHeader;
	VMBUS_CHANNEL_OPEN_CHANNEL* openMsg;

	DPRINT_ENTER(VMBUS);

	DPRINT_DBG(VMBUS, "vmbus open result - %d", result->Status);

	// Find the open msg, copy the result and signal/unblock the wait event
	SpinlockAcquire(gVmbusConnection.ChannelMsgLock);

	ITERATE_LIST_ENTRIES(anchor, curr, &gVmbusConnection.ChannelMsgList)
	{
		msgInfo = (VMBUS_CHANNEL_MSGINFO*) curr;
		requestHeader = (VMBUS_CHANNEL_MESSAGE_HEADER*)msgInfo->Msg;

		if (requestHeader->MessageType == ChannelMessageOpenChannel)
		{
			openMsg = (VMBUS_CHANNEL_OPEN_CHANNEL*)msgInfo->Msg;
			if (openMsg->ChildRelId == result->ChildRelId &&
				openMsg->OpenId == result->OpenId)
			{
				memcpy(&msgInfo->Response.OpenResult, result, sizeof(VMBUS_CHANNEL_OPEN_RESULT));
				WaitEventSet(msgInfo->WaitEvent);
				break;
			}
		}
	}
	SpinlockRelease(gVmbusConnection.ChannelMsgLock);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnGpadlCreated()

Description:
	GPADL created handler. This is invoked when we received a response
	to our gpadl create request. Find the matching request, copy the
	response and signal the requesting thread.

--*/
static void
VmbusChannelOnGpadlCreated(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	VMBUS_CHANNEL_GPADL_CREATED *gpadlCreated = (VMBUS_CHANNEL_GPADL_CREATED*)hdr;
	LIST_ENTRY *anchor;
	LIST_ENTRY *curr;
	VMBUS_CHANNEL_MSGINFO *msgInfo;
	VMBUS_CHANNEL_MESSAGE_HEADER *requestHeader;
	VMBUS_CHANNEL_GPADL_HEADER *gpadlHeader;

	DPRINT_ENTER(VMBUS);

	DPRINT_DBG(VMBUS, "vmbus gpadl created result - %d", gpadlCreated->CreationStatus);

	// Find the establish msg, copy the result and signal/unblock the wait event
	SpinlockAcquire(gVmbusConnection.ChannelMsgLock);

	ITERATE_LIST_ENTRIES(anchor, curr, &gVmbusConnection.ChannelMsgList)
	{
		msgInfo = (VMBUS_CHANNEL_MSGINFO*) curr;
		requestHeader = (VMBUS_CHANNEL_MESSAGE_HEADER*)msgInfo->Msg;

		if (requestHeader->MessageType == ChannelMessageGpadlHeader)
		{
			gpadlHeader = (VMBUS_CHANNEL_GPADL_HEADER*)requestHeader;

			if ((gpadlCreated->ChildRelId == gpadlHeader->ChildRelId) &&
					(gpadlCreated->Gpadl == gpadlHeader->Gpadl))
			{
				memcpy(&msgInfo->Response.GpadlCreated, gpadlCreated, sizeof(VMBUS_CHANNEL_GPADL_CREATED));
				WaitEventSet(msgInfo->WaitEvent);
				break;
			}
		}
	}
	SpinlockRelease(gVmbusConnection.ChannelMsgLock);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnGpadlTorndown()

Description:
	GPADL torndown handler. This is invoked when we received a response
	to our gpadl teardown request. Find the matching request, copy the
	response and signal the requesting thread.

--*/
static void
VmbusChannelOnGpadlTorndown(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	VMBUS_CHANNEL_GPADL_TORNDOWN* gpadlTorndown  = (VMBUS_CHANNEL_GPADL_TORNDOWN*)hdr;
	LIST_ENTRY* anchor;
	LIST_ENTRY* curr;
	VMBUS_CHANNEL_MSGINFO* msgInfo;
	VMBUS_CHANNEL_MESSAGE_HEADER *requestHeader;
	VMBUS_CHANNEL_GPADL_TEARDOWN *gpadlTeardown;

	DPRINT_ENTER(VMBUS);

	// Find the open msg, copy the result and signal/unblock the wait event
	SpinlockAcquire(gVmbusConnection.ChannelMsgLock);

	ITERATE_LIST_ENTRIES(anchor, curr, &gVmbusConnection.ChannelMsgList)
	{
		msgInfo = (VMBUS_CHANNEL_MSGINFO*) curr;
		requestHeader = (VMBUS_CHANNEL_MESSAGE_HEADER*)msgInfo->Msg;

		if (requestHeader->MessageType == ChannelMessageGpadlTeardown)
		{
			gpadlTeardown = (VMBUS_CHANNEL_GPADL_TEARDOWN*)requestHeader;

			if (gpadlTorndown->Gpadl == gpadlTeardown->Gpadl)
			{
				memcpy(&msgInfo->Response.GpadlTorndown, gpadlTorndown, sizeof(VMBUS_CHANNEL_GPADL_TORNDOWN));
				WaitEventSet(msgInfo->WaitEvent);
				break;
			}
		}
	}
	SpinlockRelease(gVmbusConnection.ChannelMsgLock);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelOnVersionResponse()

Description:
	Version response handler. This is invoked when we received a response
	to our initiate contact request. Find the matching request, copy the
	response and signal the requesting thread.

--*/
static void
VmbusChannelOnVersionResponse(
	PVMBUS_CHANNEL_MESSAGE_HEADER hdr
	)
{
	LIST_ENTRY* anchor;
	LIST_ENTRY* curr;
	VMBUS_CHANNEL_MSGINFO *msgInfo;
	VMBUS_CHANNEL_MESSAGE_HEADER *requestHeader;
	VMBUS_CHANNEL_INITIATE_CONTACT *initiate;
	VMBUS_CHANNEL_VERSION_RESPONSE *versionResponse  = (VMBUS_CHANNEL_VERSION_RESPONSE*)hdr;

	DPRINT_ENTER(VMBUS);

	SpinlockAcquire(gVmbusConnection.ChannelMsgLock);

	ITERATE_LIST_ENTRIES(anchor, curr, &gVmbusConnection.ChannelMsgList)
	{
		msgInfo = (VMBUS_CHANNEL_MSGINFO*) curr;
		requestHeader = (VMBUS_CHANNEL_MESSAGE_HEADER*)msgInfo->Msg;

		if (requestHeader->MessageType == ChannelMessageInitiateContact)
		{
			initiate = (VMBUS_CHANNEL_INITIATE_CONTACT*)requestHeader;
			memcpy(&msgInfo->Response.VersionResponse, versionResponse, sizeof(VMBUS_CHANNEL_VERSION_RESPONSE));
			WaitEventSet(msgInfo->WaitEvent);
		}
	}
	SpinlockRelease(gVmbusConnection.ChannelMsgLock);

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusOnChannelMessage()

Description:
	Handler for channel protocol messages.
	This is invoked in the vmbus worker thread context.

--*/
void
VmbusOnChannelMessage(
	void *Context
	)
{
	HV_MESSAGE *msg=(HV_MESSAGE*)Context;
	VMBUS_CHANNEL_MESSAGE_HEADER* hdr;
	int size;

	DPRINT_ENTER(VMBUS);

	hdr = (VMBUS_CHANNEL_MESSAGE_HEADER*)msg->u.Payload;
	size=msg->Header.PayloadSize;

	DPRINT_DBG(VMBUS, "message type %d size %d", hdr->MessageType, size);

	if (hdr->MessageType >= ChannelMessageCount)
	{
		DPRINT_ERR(VMBUS, "Received invalid channel message type %d size %d", hdr->MessageType, size);
		PrintBytes((unsigned char *)msg->u.Payload, size);
		MemFree(msg);
		return;
	}

	if (gChannelMessageTable[hdr->MessageType].messageHandler)
	{
		gChannelMessageTable[hdr->MessageType].messageHandler(hdr);
	}
	else
	{
		DPRINT_ERR(VMBUS, "Unhandled channel message type %d", hdr->MessageType);
	}

	// Free the msg that was allocated in VmbusOnMsgDPC()
	MemFree(msg);
	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusChannelRequestOffers()

Description:
	Send a request to get all our pending offers.

--*/
int
VmbusChannelRequestOffers(
	void
	)
{
	int ret=0;
	VMBUS_CHANNEL_MESSAGE_HEADER* msg;
	VMBUS_CHANNEL_MSGINFO* msgInfo;

	DPRINT_ENTER(VMBUS);

	msgInfo =
		(VMBUS_CHANNEL_MSGINFO*)MemAlloc(sizeof(VMBUS_CHANNEL_MSGINFO) + sizeof(VMBUS_CHANNEL_MESSAGE_HEADER));
	ASSERT(msgInfo != NULL);

	msgInfo->WaitEvent = WaitEventCreate();
	msg = (VMBUS_CHANNEL_MESSAGE_HEADER*)msgInfo->Msg;

	msg->MessageType = ChannelMessageRequestOffers;

	/*SpinlockAcquire(gVmbusConnection.channelMsgLock);
	INSERT_TAIL_LIST(&gVmbusConnection.channelMsgList, &msgInfo->msgListEntry);
	SpinlockRelease(gVmbusConnection.channelMsgLock);*/

	ret = VmbusPostMessage(msg, sizeof(VMBUS_CHANNEL_MESSAGE_HEADER));
	if (ret != 0)
	{
		DPRINT_ERR(VMBUS, "Unable to request offers - %d", ret);

		/*SpinlockAcquire(gVmbusConnection.channelMsgLock);
		REMOVE_ENTRY_LIST(&msgInfo->msgListEntry);
		SpinlockRelease(gVmbusConnection.channelMsgLock);*/

		goto Cleanup;
	}
	//WaitEventWait(msgInfo->waitEvent);

	/*SpinlockAcquire(gVmbusConnection.channelMsgLock);
	REMOVE_ENTRY_LIST(&msgInfo->msgListEntry);
	SpinlockRelease(gVmbusConnection.channelMsgLock);*/


Cleanup:
	if (msgInfo)
	{
		WaitEventClose(msgInfo->WaitEvent);
		MemFree(msgInfo);
	}

	DPRINT_EXIT(VMBUS);

	return ret;
}

/*++

Name:
	VmbusChannelReleaseUnattachedChannels()

Description:
	Release channels that are unattached/unconnected ie (no drivers associated)

--*/
void
VmbusChannelReleaseUnattachedChannels(
	void
	)
{
	LIST_ENTRY *entry;
	VMBUS_CHANNEL *channel;
	VMBUS_CHANNEL *start=NULL;

	SpinlockAcquire(gVmbusConnection.ChannelLock);

	while (!IsListEmpty(&gVmbusConnection.ChannelList))
	{
		entry = TOP_LIST_ENTRY(&gVmbusConnection.ChannelList);
		channel = CONTAINING_RECORD(entry, VMBUS_CHANNEL, ListEntry);

		if (channel == start)
			break;

		if (!channel->DeviceObject->Driver)
		{
			REMOVE_ENTRY_LIST(&channel->ListEntry);
			DPRINT_INFO(VMBUS, "Releasing unattached device object %p", channel->DeviceObject);

			VmbusChildDeviceRemove(channel->DeviceObject);
			FreeVmbusChannel(channel);
		}
		else
		{
			if (!start)
			{
				start = channel;
			}
		}
	}

	SpinlockRelease(gVmbusConnection.ChannelLock);
}

// eof