drivers/staging/hv/hv.c - kernel/skids - Git at Google

 /*
  * 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 <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include "osd.h"
 #include "logging.h"
 #include "vmbus_private.h"

 /* The one and only */
 struct hv_context gHvContext = {
 	.SynICInitialized	= false,
 	.HypercallPage		= NULL,
 	.SignalEventParam	= NULL,
 	.SignalEventBuffer	= NULL,
 };

 /*
  * HvQueryHypervisorPresence - Query the cpuid for presense of windows hypervisor
  */
 static int HvQueryHypervisorPresence(void)
 {
 	unsigned int eax;
 	unsigned int ebx;
 	unsigned int ecx;
 	unsigned int edx;
 	unsigned int op;

 	eax = 0;
 	ebx = 0;
 	ecx = 0;
 	edx = 0;
 	op = HvCpuIdFunctionVersionAndFeatures;
 	cpuid(op, &eax, &ebx, &ecx, &edx);

 	return ecx & HV_PRESENT_BIT;
 }

 /*
  * HvQueryHypervisorInfo - Get version info of the windows hypervisor
  */
 static int HvQueryHypervisorInfo(void)
 {
 	unsigned int eax;
 	unsigned int ebx;
 	unsigned int ecx;
 	unsigned int edx;
 	unsigned int maxLeaf;
 	unsigned int op;

 	/*
 	* Its assumed that this is called after confirming that Viridian
 	* is present. Query id and revision.
 	*/
 	eax = 0;
 	ebx = 0;
 	ecx = 0;
 	edx = 0;
 	op = HvCpuIdFunctionHvVendorAndMaxFunction;
 	cpuid(op, &eax, &ebx, &ecx, &edx);

 	DPRINT_INFO(VMBUS, "Vendor ID: %c%c%c%c%c%c%c%c%c%c%c%c",
 		    (ebx & 0xFF),
 		    ((ebx >> 8) & 0xFF),
 		    ((ebx >> 16) & 0xFF),
 		    ((ebx >> 24) & 0xFF),
 		    (ecx & 0xFF),
 		    ((ecx >> 8) & 0xFF),
 		    ((ecx >> 16) & 0xFF),
 		    ((ecx >> 24) & 0xFF),
 		    (edx & 0xFF),
 		    ((edx >> 8) & 0xFF),
 		    ((edx >> 16) & 0xFF),
 		    ((edx >> 24) & 0xFF));

 	maxLeaf = eax;
 	eax = 0;
 	ebx = 0;
 	ecx = 0;
 	edx = 0;
 	op = HvCpuIdFunctionHvInterface;
 	cpuid(op, &eax, &ebx, &ecx, &edx);

 	DPRINT_INFO(VMBUS, "Interface ID: %c%c%c%c",
 		    (eax & 0xFF),
 		    ((eax >> 8) & 0xFF),
 		    ((eax >> 16) & 0xFF),
 		    ((eax >> 24) & 0xFF));

 	if (maxLeaf >= HvCpuIdFunctionMsHvVersion) {
 		eax = 0;
 		ebx = 0;
 		ecx = 0;
 		edx = 0;
 		op = HvCpuIdFunctionMsHvVersion;
 		cpuid(op, &eax, &ebx, &ecx, &edx);
 		DPRINT_INFO(VMBUS, "OS Build:%d-%d.%d-%d-%d.%d",\
 			    eax,
 			    ebx >> 16,
 			    ebx & 0xFFFF,
 			    ecx,
 			    edx >> 24,
 			    edx & 0xFFFFFF);
 	}
 	return maxLeaf;
 }

 /*
  * HvDoHypercall - Invoke the specified hypercall
  */
 static u64 HvDoHypercall(u64 Control, void *Input, void *Output)
 {
 #ifdef CONFIG_X86_64
 	u64 hvStatus = 0;
 	u64 inputAddress = (Input) ? virt_to_phys(Input) : 0;
 	u64 outputAddress = (Output) ? virt_to_phys(Output) : 0;
 	volatile void *hypercallPage = gHvContext.HypercallPage;

 	DPRINT_DBG(VMBUS, "Hypercall <control %llx input phys %llx virt %p "
 		   "output phys %llx virt %p hypercall %p>",
 		   Control, inputAddress, Input,
 		   outputAddress, Output, hypercallPage);

 	__asm__ __volatile__("mov %0, %%r8" : : "r" (outputAddress) : "r8");
 	__asm__ __volatile__("call *%3" : "=a" (hvStatus) :
 			     "c" (Control), "d" (inputAddress),
 			     "m" (hypercallPage));

 	DPRINT_DBG(VMBUS, "Hypercall <return %llx>",  hvStatus);

 	return hvStatus;

 #else

 	u32 controlHi = Control >> 32;
 	u32 controlLo = Control & 0xFFFFFFFF;
 	u32 hvStatusHi = 1;
 	u32 hvStatusLo = 1;
 	u64 inputAddress = (Input) ? virt_to_phys(Input) : 0;
 	u32 inputAddressHi = inputAddress >> 32;
 	u32 inputAddressLo = inputAddress & 0xFFFFFFFF;
 	u64 outputAddress = (Output) ? virt_to_phys(Output) : 0;
 	u32 outputAddressHi = outputAddress >> 32;
 	u32 outputAddressLo = outputAddress & 0xFFFFFFFF;
 	volatile void *hypercallPage = gHvContext.HypercallPage;

 	DPRINT_DBG(VMBUS, "Hypercall <control %llx input %p output %p>",
 		   Control, Input, Output);

 	__asm__ __volatile__ ("call *%8" : "=d"(hvStatusHi),
 			      "=a"(hvStatusLo) : "d" (controlHi),
 			      "a" (controlLo), "b" (inputAddressHi),
 			      "c" (inputAddressLo), "D"(outputAddressHi),
 			      "S"(outputAddressLo), "m" (hypercallPage));

 	DPRINT_DBG(VMBUS, "Hypercall <return %llx>",
 		   hvStatusLo | ((u64)hvStatusHi << 32));

 	return hvStatusLo | ((u64)hvStatusHi << 32);
 #endif /* !x86_64 */
 }

 /*
  * HvInit - Main initialization routine.
  *
  * This routine must be called before any other routines in here are called
  */
 int HvInit(void)
 {
 	int ret = 0;
 	int maxLeaf;
 	union hv_x64_msr_hypercall_contents hypercallMsr;
 	void *virtAddr = NULL;

 	DPRINT_ENTER(VMBUS);

 	memset(gHvContext.synICEventPage, 0, sizeof(void *) * MAX_NUM_CPUS);
 	memset(gHvContext.synICMessagePage, 0, sizeof(void *) * MAX_NUM_CPUS);

 	if (!HvQueryHypervisorPresence()) {
 		DPRINT_ERR(VMBUS, "No Windows hypervisor detected!!");
 		goto Cleanup;
 	}

 	DPRINT_INFO(VMBUS,
 		    "Windows hypervisor detected! Retrieving more info...");

 	maxLeaf = HvQueryHypervisorInfo();
 	/* HvQueryHypervisorFeatures(maxLeaf); */

 	/*
 	 * We only support running on top of Hyper-V
 	 */
 	rdmsrl(HV_X64_MSR_GUEST_OS_ID, gHvContext.GuestId);

 	if (gHvContext.GuestId != 0) {
 		DPRINT_ERR(VMBUS, "Unknown guest id (0x%llx)!!",
 				gHvContext.GuestId);
 		goto Cleanup;
 	}

 	/* Write our OS info */
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
 	gHvContext.GuestId = HV_LINUX_GUEST_ID;

 	/* See if the hypercall page is already set */
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

 	/*
 	* Allocate the hypercall page memory
 	* virtAddr = osd_PageAlloc(1);
 	*/
 	virtAddr = osd_VirtualAllocExec(PAGE_SIZE);

 	if (!virtAddr) {
 		DPRINT_ERR(VMBUS,
 			   "unable to allocate hypercall page!!");
 		goto Cleanup;
 	}

 	hypercallMsr.Enable = 1;

 	hypercallMsr.GuestPhysicalAddress = vmalloc_to_pfn(virtAddr);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

 	/* Confirm that hypercall page did get setup. */
 	hypercallMsr.AsUINT64 = 0;
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

 	if (!hypercallMsr.Enable) {
 		DPRINT_ERR(VMBUS, "unable to set hypercall page!!");
 		goto Cleanup;
 	}

 	gHvContext.HypercallPage = virtAddr;

 	DPRINT_INFO(VMBUS, "Hypercall page VA=%p, PA=0x%0llx",
 		    gHvContext.HypercallPage,
 		    (u64)hypercallMsr.GuestPhysicalAddress << PAGE_SHIFT);

 	/* Setup the global signal event param for the signal event hypercall */
 	gHvContext.SignalEventBuffer =
 			kmalloc(sizeof(struct hv_input_signal_event_buffer),
 				GFP_KERNEL);
 	if (!gHvContext.SignalEventBuffer)
 		goto Cleanup;

 	gHvContext.SignalEventParam =
 		(struct hv_input_signal_event *)
 			(ALIGN_UP((unsigned long)gHvContext.SignalEventBuffer,
 				  HV_HYPERCALL_PARAM_ALIGN));
 	gHvContext.SignalEventParam->ConnectionId.Asu32 = 0;
 	gHvContext.SignalEventParam->ConnectionId.u.Id =
 						VMBUS_EVENT_CONNECTION_ID;
 	gHvContext.SignalEventParam->FlagNumber = 0;
 	gHvContext.SignalEventParam->RsvdZ = 0;

 	DPRINT_EXIT(VMBUS);

 	return ret;

 Cleanup:
 	if (virtAddr) {
 		if (hypercallMsr.Enable) {
 			hypercallMsr.AsUINT64 = 0;
 			wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
 		}

 		vfree(virtAddr);
 	}
 	ret = -1;
 	DPRINT_EXIT(VMBUS);

 	return ret;
 }

 /*
  * HvCleanup - Cleanup routine.
  *
  * This routine is called normally during driver unloading or exiting.
  */
 void HvCleanup(void)
 {
 	union hv_x64_msr_hypercall_contents hypercallMsr;

 	DPRINT_ENTER(VMBUS);

 	kfree(gHvContext.SignalEventBuffer);
 	gHvContext.SignalEventBuffer = NULL;
 	gHvContext.SignalEventParam = NULL;

 	if (gHvContext.HypercallPage) {
 		hypercallMsr.AsUINT64 = 0;
 		wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
 		vfree(gHvContext.HypercallPage);
 		gHvContext.HypercallPage = NULL;
 	}

 	DPRINT_EXIT(VMBUS);
 }

 /*
  * HvPostMessage - Post a message using the hypervisor message IPC.
  *
  * This involves a hypercall.
  */
 u16 HvPostMessage(union hv_connection_id connectionId,
 		  enum hv_message_type messageType,
 		  void *payload, size_t payloadSize)
 {
 	struct alignedInput {
 		u64 alignment8;
 		struct hv_input_post_message msg;
 	};

 	struct hv_input_post_message *alignedMsg;
 	u16 status;
 	unsigned long addr;

 	if (payloadSize > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 		return -1;

 	addr = (unsigned long)kmalloc(sizeof(struct alignedInput), GFP_ATOMIC);
 	if (!addr)
 		return -1;

 	alignedMsg = (struct hv_input_post_message *)
 			(ALIGN_UP(addr, HV_HYPERCALL_PARAM_ALIGN));

 	alignedMsg->ConnectionId = connectionId;
 	alignedMsg->MessageType = messageType;
 	alignedMsg->PayloadSize = payloadSize;
 	memcpy((void *)alignedMsg->Payload, payload, payloadSize);

 	status = HvDoHypercall(HvCallPostMessage, alignedMsg, NULL) & 0xFFFF;

 	kfree((void *)addr);

 	return status;
 }


 /*
  * HvSignalEvent - Signal an event on the specified connection using the hypervisor event IPC.
  *
  * This involves a hypercall.
  */
 u16 HvSignalEvent(void)
 {
 	u16 status;

 	status = HvDoHypercall(HvCallSignalEvent, gHvContext.SignalEventParam,
 			       NULL) & 0xFFFF;
 	return status;
 }

 /*
  * HvSynicInit - Initialize the Synthethic Interrupt Controller.
  *
  * If it is already initialized by another entity (ie x2v shim), we need to
  * retrieve the initialized message and event pages.  Otherwise, we create and
  * initialize the message and event pages.
  */
 void HvSynicInit(void *irqarg)
 {
 	u64 version;
 	union hv_synic_simp simp;
 	union hv_synic_siefp siefp;
 	union hv_synic_sint sharedSint;
 	union hv_synic_scontrol sctrl;

 	u32 irqVector = *((u32 *)(irqarg));
 	int cpu = smp_processor_id();

 	DPRINT_ENTER(VMBUS);

 	if (!gHvContext.HypercallPage) {
 		DPRINT_EXIT(VMBUS);
 		return;
 	}

 	/* Check the version */
 	rdmsrl(HV_X64_MSR_SVERSION, version);

 	DPRINT_INFO(VMBUS, "SynIC version: %llx", version);

 	gHvContext.synICMessagePage[cpu] = (void *)get_zeroed_page(GFP_ATOMIC);

 	if (gHvContext.synICMessagePage[cpu] == NULL) {
 		DPRINT_ERR(VMBUS,
 			   "unable to allocate SYNIC message page!!");
 		goto Cleanup;
 	}

 	gHvContext.synICEventPage[cpu] = (void *)get_zeroed_page(GFP_ATOMIC);

 	if (gHvContext.synICEventPage[cpu] == NULL) {
 		DPRINT_ERR(VMBUS,
 			   "unable to allocate SYNIC event page!!");
 		goto Cleanup;
 	}

 	/* Setup the Synic's message page */
 	rdmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);
 	simp.SimpEnabled = 1;
 	simp.BaseSimpGpa = virt_to_phys(gHvContext.synICMessagePage[cpu])
 		>> PAGE_SHIFT;

 	DPRINT_DBG(VMBUS, "HV_X64_MSR_SIMP msr set to: %llx", simp.AsUINT64);

 	wrmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);

 	/* Setup the Synic's event page */
 	rdmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);
 	siefp.SiefpEnabled = 1;
 	siefp.BaseSiefpGpa = virt_to_phys(gHvContext.synICEventPage[cpu])
 		>> PAGE_SHIFT;

 	DPRINT_DBG(VMBUS, "HV_X64_MSR_SIEFP msr set to: %llx", siefp.AsUINT64);

 	wrmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);

 	/* Setup the interception SINT. */
 	/* wrmsrl((HV_X64_MSR_SINT0 + HV_SYNIC_INTERCEPTION_SINT_INDEX), */
 	/*	  interceptionSint.AsUINT64); */

 	/* Setup the shared SINT. */
 	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

 	sharedSint.AsUINT64 = 0;
 	sharedSint.Vector = irqVector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 	sharedSint.Masked = false;
 	sharedSint.AutoEoi = true;

 	DPRINT_DBG(VMBUS, "HV_X64_MSR_SINT1 msr set to: %llx",
 		   sharedSint.AsUINT64);

 	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

 	/* Enable the global synic bit */
 	rdmsrl(HV_X64_MSR_SCONTROL, sctrl.AsUINT64);
 	sctrl.Enable = 1;

 	wrmsrl(HV_X64_MSR_SCONTROL, sctrl.AsUINT64);

 	gHvContext.SynICInitialized = true;

 	DPRINT_EXIT(VMBUS);

 	return;

 Cleanup:
 	if (gHvContext.synICEventPage[cpu])
 		osd_PageFree(gHvContext.synICEventPage[cpu], 1);

 	if (gHvContext.synICMessagePage[cpu])
 		osd_PageFree(gHvContext.synICMessagePage[cpu], 1);

 	DPRINT_EXIT(VMBUS);
 	return;
 }

 /*
  * HvSynicCleanup - Cleanup routine for HvSynicInit().
  */
 void HvSynicCleanup(void *arg)
 {
 	union hv_synic_sint sharedSint;
 	union hv_synic_simp simp;
 	union hv_synic_siefp siefp;
 	int cpu = smp_processor_id();

 	DPRINT_ENTER(VMBUS);

 	if (!gHvContext.SynICInitialized) {
 		DPRINT_EXIT(VMBUS);
 		return;
 	}

 	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

 	sharedSint.Masked = 1;

 	/* Need to correctly cleanup in the case of SMP!!! */
 	/* Disable the interrupt */
 	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

 	rdmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);
 	simp.SimpEnabled = 0;
 	simp.BaseSimpGpa = 0;

 	wrmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);

 	rdmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);
 	siefp.SiefpEnabled = 0;
 	siefp.BaseSiefpGpa = 0;

 	wrmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);

 	osd_PageFree(gHvContext.synICMessagePage[cpu], 1);
 	osd_PageFree(gHvContext.synICEventPage[cpu], 1);

 	DPRINT_EXIT(VMBUS);
 }
	/*
	* 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 <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/slab.h>
	#include <linux/vmalloc.h>
	#include "osd.h"
	#include "logging.h"
	#include "vmbus_private.h"

	/* The one and only */
	struct hv_context gHvContext = {
	.SynICInitialized = false,
	.HypercallPage = NULL,
	.SignalEventParam = NULL,
	.SignalEventBuffer = NULL,
	};

	/*
	* HvQueryHypervisorPresence - Query the cpuid for presense of windows hypervisor
	*/
	static int HvQueryHypervisorPresence(void)
	{
	unsigned int eax;
	unsigned int ebx;
	unsigned int ecx;
	unsigned int edx;
	unsigned int op;

	eax = 0;
	ebx = 0;
	ecx = 0;
	edx = 0;
	op = HvCpuIdFunctionVersionAndFeatures;
	cpuid(op, &eax, &ebx, &ecx, &edx);

	return ecx & HV_PRESENT_BIT;
	}

	/*
	* HvQueryHypervisorInfo - Get version info of the windows hypervisor
	*/
	static int HvQueryHypervisorInfo(void)
	{
	unsigned int eax;
	unsigned int ebx;
	unsigned int ecx;
	unsigned int edx;
	unsigned int maxLeaf;
	unsigned int op;

	/*
	* Its assumed that this is called after confirming that Viridian
	* is present. Query id and revision.
	*/
	eax = 0;
	ebx = 0;
	ecx = 0;
	edx = 0;
	op = HvCpuIdFunctionHvVendorAndMaxFunction;
	cpuid(op, &eax, &ebx, &ecx, &edx);

	DPRINT_INFO(VMBUS, "Vendor ID: %c%c%c%c%c%c%c%c%c%c%c%c",
	(ebx & 0xFF),
	((ebx >> 8) & 0xFF),
	((ebx >> 16) & 0xFF),
	((ebx >> 24) & 0xFF),
	(ecx & 0xFF),
	((ecx >> 8) & 0xFF),
	((ecx >> 16) & 0xFF),
	((ecx >> 24) & 0xFF),
	(edx & 0xFF),
	((edx >> 8) & 0xFF),
	((edx >> 16) & 0xFF),
	((edx >> 24) & 0xFF));

	maxLeaf = eax;
	eax = 0;
	ebx = 0;
	ecx = 0;
	edx = 0;
	op = HvCpuIdFunctionHvInterface;
	cpuid(op, &eax, &ebx, &ecx, &edx);

	DPRINT_INFO(VMBUS, "Interface ID: %c%c%c%c",
	(eax & 0xFF),
	((eax >> 8) & 0xFF),
	((eax >> 16) & 0xFF),
	((eax >> 24) & 0xFF));

	if (maxLeaf >= HvCpuIdFunctionMsHvVersion) {
	eax = 0;
	ebx = 0;
	ecx = 0;
	edx = 0;
	op = HvCpuIdFunctionMsHvVersion;
	cpuid(op, &eax, &ebx, &ecx, &edx);
	DPRINT_INFO(VMBUS, "OS Build:%d-%d.%d-%d-%d.%d",\
	eax,
	ebx >> 16,
	ebx & 0xFFFF,
	ecx,
	edx >> 24,
	edx & 0xFFFFFF);
	}
	return maxLeaf;
	}

	/*
	* HvDoHypercall - Invoke the specified hypercall
	*/
	static u64 HvDoHypercall(u64 Control, void Input, void Output)
	{
	#ifdef CONFIG_X86_64
	u64 hvStatus = 0;
	u64 inputAddress = (Input) ? virt_to_phys(Input) : 0;
	u64 outputAddress = (Output) ? virt_to_phys(Output) : 0;
	volatile void *hypercallPage = gHvContext.HypercallPage;

	DPRINT_DBG(VMBUS, "Hypercall <control %llx input phys %llx virt %p "
	"output phys %llx virt %p hypercall %p>",
	Control, inputAddress, Input,
	outputAddress, Output, hypercallPage);

	__asm__ __volatile__("mov %0, %%r8" : : "r" (outputAddress) : "r8");
	__asm__ __volatile__("call *%3" : "=a" (hvStatus) :
	"c" (Control), "d" (inputAddress),
	"m" (hypercallPage));

	DPRINT_DBG(VMBUS, "Hypercall <return %llx>", hvStatus);

	return hvStatus;

	#else

	u32 controlHi = Control >> 32;
	u32 controlLo = Control & 0xFFFFFFFF;
	u32 hvStatusHi = 1;
	u32 hvStatusLo = 1;
	u64 inputAddress = (Input) ? virt_to_phys(Input) : 0;
	u32 inputAddressHi = inputAddress >> 32;
	u32 inputAddressLo = inputAddress & 0xFFFFFFFF;
	u64 outputAddress = (Output) ? virt_to_phys(Output) : 0;
	u32 outputAddressHi = outputAddress >> 32;
	u32 outputAddressLo = outputAddress & 0xFFFFFFFF;
	volatile void *hypercallPage = gHvContext.HypercallPage;

	DPRINT_DBG(VMBUS, "Hypercall <control %llx input %p output %p>",
	Control, Input, Output);

	__asm__ __volatile__ ("call *%8" : "=d"(hvStatusHi),
	"=a"(hvStatusLo) : "d" (controlHi),
	"a" (controlLo), "b" (inputAddressHi),
	"c" (inputAddressLo), "D"(outputAddressHi),
	"S"(outputAddressLo), "m" (hypercallPage));

	DPRINT_DBG(VMBUS, "Hypercall <return %llx>",
	hvStatusLo \| ((u64)hvStatusHi << 32));

	return hvStatusLo \| ((u64)hvStatusHi << 32);
	#endif /* !x86_64 */
	}

	/*
	* HvInit - Main initialization routine.
	*
	* This routine must be called before any other routines in here are called
	*/
	int HvInit(void)
	{
	int ret = 0;
	int maxLeaf;
	union hv_x64_msr_hypercall_contents hypercallMsr;
	void *virtAddr = NULL;

	DPRINT_ENTER(VMBUS);

	memset(gHvContext.synICEventPage, 0, sizeof(void ) MAX_NUM_CPUS);
	memset(gHvContext.synICMessagePage, 0, sizeof(void ) MAX_NUM_CPUS);

	if (!HvQueryHypervisorPresence()) {
	DPRINT_ERR(VMBUS, "No Windows hypervisor detected!!");
	goto Cleanup;
	}

	DPRINT_INFO(VMBUS,
	"Windows hypervisor detected! Retrieving more info...");

	maxLeaf = HvQueryHypervisorInfo();
	/* HvQueryHypervisorFeatures(maxLeaf); */

	/*
	* We only support running on top of Hyper-V
	*/
	rdmsrl(HV_X64_MSR_GUEST_OS_ID, gHvContext.GuestId);

	if (gHvContext.GuestId != 0) {
	DPRINT_ERR(VMBUS, "Unknown guest id (0x%llx)!!",
	gHvContext.GuestId);
	goto Cleanup;
	}

	/* Write our OS info */
	wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
	gHvContext.GuestId = HV_LINUX_GUEST_ID;

	/* See if the hypercall page is already set */
	rdmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

	/*
	* Allocate the hypercall page memory
	* virtAddr = osd_PageAlloc(1);
	*/
	virtAddr = osd_VirtualAllocExec(PAGE_SIZE);

	if (!virtAddr) {
	DPRINT_ERR(VMBUS,
	"unable to allocate hypercall page!!");
	goto Cleanup;
	}

	hypercallMsr.Enable = 1;

	hypercallMsr.GuestPhysicalAddress = vmalloc_to_pfn(virtAddr);
	wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

	/* Confirm that hypercall page did get setup. */
	hypercallMsr.AsUINT64 = 0;
	rdmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

	if (!hypercallMsr.Enable) {
	DPRINT_ERR(VMBUS, "unable to set hypercall page!!");
	goto Cleanup;
	}

	gHvContext.HypercallPage = virtAddr;

	DPRINT_INFO(VMBUS, "Hypercall page VA=%p, PA=0x%0llx",
	gHvContext.HypercallPage,
	(u64)hypercallMsr.GuestPhysicalAddress << PAGE_SHIFT);

	/* Setup the global signal event param for the signal event hypercall */
	gHvContext.SignalEventBuffer =
	kmalloc(sizeof(struct hv_input_signal_event_buffer),
	GFP_KERNEL);
	if (!gHvContext.SignalEventBuffer)
	goto Cleanup;

	gHvContext.SignalEventParam =
	(struct hv_input_signal_event *)
	(ALIGN_UP((unsigned long)gHvContext.SignalEventBuffer,
	HV_HYPERCALL_PARAM_ALIGN));
	gHvContext.SignalEventParam->ConnectionId.Asu32 = 0;
	gHvContext.SignalEventParam->ConnectionId.u.Id =
	VMBUS_EVENT_CONNECTION_ID;
	gHvContext.SignalEventParam->FlagNumber = 0;
	gHvContext.SignalEventParam->RsvdZ = 0;

	DPRINT_EXIT(VMBUS);

	return ret;

	Cleanup:
	if (virtAddr) {
	if (hypercallMsr.Enable) {
	hypercallMsr.AsUINT64 = 0;
	wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
	}

	vfree(virtAddr);
	}
	ret = -1;
	DPRINT_EXIT(VMBUS);

	return ret;
	}

	/*
	* HvCleanup - Cleanup routine.
	*
	* This routine is called normally during driver unloading or exiting.
	*/
	void HvCleanup(void)
	{
	union hv_x64_msr_hypercall_contents hypercallMsr;

	DPRINT_ENTER(VMBUS);

	kfree(gHvContext.SignalEventBuffer);
	gHvContext.SignalEventBuffer = NULL;
	gHvContext.SignalEventParam = NULL;

	if (gHvContext.HypercallPage) {
	hypercallMsr.AsUINT64 = 0;
	wrmsrl(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
	vfree(gHvContext.HypercallPage);
	gHvContext.HypercallPage = NULL;
	}

	DPRINT_EXIT(VMBUS);
	}

	/*
	* HvPostMessage - Post a message using the hypervisor message IPC.
	*
	* This involves a hypercall.
	*/
	u16 HvPostMessage(union hv_connection_id connectionId,
	enum hv_message_type messageType,
	void *payload, size_t payloadSize)
	{
	struct alignedInput {
	u64 alignment8;
	struct hv_input_post_message msg;
	};

	struct hv_input_post_message *alignedMsg;
	u16 status;
	unsigned long addr;

	if (payloadSize > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
	return -1;

	addr = (unsigned long)kmalloc(sizeof(struct alignedInput), GFP_ATOMIC);
	if (!addr)
	return -1;

	alignedMsg = (struct hv_input_post_message *)
	(ALIGN_UP(addr, HV_HYPERCALL_PARAM_ALIGN));

	alignedMsg->ConnectionId = connectionId;
	alignedMsg->MessageType = messageType;
	alignedMsg->PayloadSize = payloadSize;
	memcpy((void *)alignedMsg->Payload, payload, payloadSize);

	status = HvDoHypercall(HvCallPostMessage, alignedMsg, NULL) & 0xFFFF;

	kfree((void *)addr);

	return status;
	}


	/*
	* HvSignalEvent - Signal an event on the specified connection using the hypervisor event IPC.
	*
	* This involves a hypercall.
	*/
	u16 HvSignalEvent(void)
	{
	u16 status;

	status = HvDoHypercall(HvCallSignalEvent, gHvContext.SignalEventParam,
	NULL) & 0xFFFF;
	return status;
	}

	/*
	* HvSynicInit - Initialize the Synthethic Interrupt Controller.
	*
	* If it is already initialized by another entity (ie x2v shim), we need to
	* retrieve the initialized message and event pages. Otherwise, we create and
	* initialize the message and event pages.
	*/
	void HvSynicInit(void *irqarg)
	{
	u64 version;
	union hv_synic_simp simp;
	union hv_synic_siefp siefp;
	union hv_synic_sint sharedSint;
	union hv_synic_scontrol sctrl;

	u32 irqVector = ((u32 )(irqarg));
	int cpu = smp_processor_id();

	DPRINT_ENTER(VMBUS);

	if (!gHvContext.HypercallPage) {
	DPRINT_EXIT(VMBUS);
	return;
	}

	/* Check the version */
	rdmsrl(HV_X64_MSR_SVERSION, version);

	DPRINT_INFO(VMBUS, "SynIC version: %llx", version);

	gHvContext.synICMessagePage[cpu] = (void *)get_zeroed_page(GFP_ATOMIC);

	if (gHvContext.synICMessagePage[cpu] == NULL) {
	DPRINT_ERR(VMBUS,
	"unable to allocate SYNIC message page!!");
	goto Cleanup;
	}

	gHvContext.synICEventPage[cpu] = (void *)get_zeroed_page(GFP_ATOMIC);

	if (gHvContext.synICEventPage[cpu] == NULL) {
	DPRINT_ERR(VMBUS,
	"unable to allocate SYNIC event page!!");
	goto Cleanup;
	}

	/* Setup the Synic's message page */
	rdmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);
	simp.SimpEnabled = 1;
	simp.BaseSimpGpa = virt_to_phys(gHvContext.synICMessagePage[cpu])
	>> PAGE_SHIFT;

	DPRINT_DBG(VMBUS, "HV_X64_MSR_SIMP msr set to: %llx", simp.AsUINT64);

	wrmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);

	/* Setup the Synic's event page */
	rdmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);
	siefp.SiefpEnabled = 1;
	siefp.BaseSiefpGpa = virt_to_phys(gHvContext.synICEventPage[cpu])
	>> PAGE_SHIFT;

	DPRINT_DBG(VMBUS, "HV_X64_MSR_SIEFP msr set to: %llx", siefp.AsUINT64);

	wrmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);

	/* Setup the interception SINT. */
	/* wrmsrl((HV_X64_MSR_SINT0 + HV_SYNIC_INTERCEPTION_SINT_INDEX), */
	/* interceptionSint.AsUINT64); */

	/* Setup the shared SINT. */
	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	sharedSint.AsUINT64 = 0;
	sharedSint.Vector = irqVector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
	sharedSint.Masked = false;
	sharedSint.AutoEoi = true;

	DPRINT_DBG(VMBUS, "HV_X64_MSR_SINT1 msr set to: %llx",
	sharedSint.AsUINT64);

	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	/* Enable the global synic bit */
	rdmsrl(HV_X64_MSR_SCONTROL, sctrl.AsUINT64);
	sctrl.Enable = 1;

	wrmsrl(HV_X64_MSR_SCONTROL, sctrl.AsUINT64);

	gHvContext.SynICInitialized = true;

	DPRINT_EXIT(VMBUS);

	return;

	Cleanup:
	if (gHvContext.synICEventPage[cpu])
	osd_PageFree(gHvContext.synICEventPage[cpu], 1);

	if (gHvContext.synICMessagePage[cpu])
	osd_PageFree(gHvContext.synICMessagePage[cpu], 1);

	DPRINT_EXIT(VMBUS);
	return;
	}

	/*
	* HvSynicCleanup - Cleanup routine for HvSynicInit().
	*/
	void HvSynicCleanup(void *arg)
	{
	union hv_synic_sint sharedSint;
	union hv_synic_simp simp;
	union hv_synic_siefp siefp;
	int cpu = smp_processor_id();

	DPRINT_ENTER(VMBUS);

	if (!gHvContext.SynICInitialized) {
	DPRINT_EXIT(VMBUS);
	return;
	}

	rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	sharedSint.Masked = 1;

	/* Need to correctly cleanup in the case of SMP!!! */
	/* Disable the interrupt */
	wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	rdmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);
	simp.SimpEnabled = 0;
	simp.BaseSimpGpa = 0;

	wrmsrl(HV_X64_MSR_SIMP, simp.AsUINT64);

	rdmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);
	siefp.SiefpEnabled = 0;
	siefp.BaseSiefpGpa = 0;

	wrmsrl(HV_X64_MSR_SIEFP, siefp.AsUINT64);

	osd_PageFree(gHvContext.synICMessagePage[cpu], 1);
	osd_PageFree(gHvContext.synICEventPage[cpu], 1);

	DPRINT_EXIT(VMBUS);
	}