Staging: hv: add mouse driver

This driver adds mouse support to the hyper-v subsystem.

The code was originally written by Citrix, modified heavily by Hank at
Microsoft, and then further by me, to get it to build properly due to
all of the recent hyperv changes in the tree.

At the moment, it is marked "BROKEN" as it has not been tested well, and
it will conflict with other api changes that KY is doing, which I will
fix up later in this driver.

It still needs lots of work, and normal "cleanup".  I don't recommend
anyone running it on their machine unless they are very brave and know
how to debug kernel drivers in a hyperv system.

Signed-off-by:  Hank Janssen <hjanssen@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/Kconfig

@@ -36,4 +36,11 @@ config HYPERV_UTILS
 	help
 	  Select this option to enable the Hyper-V Utilities.
 
+config HYPERV_MOUSE
+	tristate "Microsoft Hyper-V mouse driver"
+	depends on HID && BROKEN
+	default HYPERV
+	help
+	  Select this option to enable the Hyper-V mouse driver.
+
 endif

drivers/staging/hv/Makefile

@@ -3,6 +3,7 @@ obj-$(CONFIG_HYPERV_STORAGE)	+= hv_storvsc.o
 obj-$(CONFIG_HYPERV_BLOCK)	+= hv_blkvsc.o
 obj-$(CONFIG_HYPERV_NET)	+= hv_netvsc.o
 obj-$(CONFIG_HYPERV_UTILS)	+= hv_utils.o
+obj-$(CONFIG_HYPERV_MOUSE)	+= hv_mouse.o
 
 hv_vmbus-y := vmbus_drv.o \
 		 hv.o connection.o channel.o \
@@ -11,3 +12,4 @@ hv_storvsc-y := storvsc_drv.o storvsc.o
 hv_blkvsc-y := blkvsc_drv.o blkvsc.o
 hv_netvsc-y := netvsc_drv.o netvsc.o rndis_filter.o
 hv_utils-y := hv_util.o hv_kvp.o
+hv_mouse-objs  := hv_mouse_drv.o mouse_vsc.o

drivers/staging/hv/hv_mouse_drv.c

@@ -0,0 +1,335 @@
+/*
+ *  Copyright 2009 Citrix Systems, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  For clarity, the licensor of this program does not intend that a
+ *  "derivative work" include code which compiles header information from
+ *  this program.
+ *
+ *  This code has been modified from its original by
+ *  Hank Janssen <hjanssen@microsoft.com>
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/workqueue.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/hiddev.h>
+#include <linux/pci.h>
+#include <linux/dmi.h>
+
+//#include "osd.h"
+#include "hv_api.h"
+#include "logging.h"
+#include "version_info.h"
+#include "vmbus.h"
+#include "mousevsc_api.h"
+
+#define NBITS(x) (((x)/BITS_PER_LONG)+1)
+
+
+/*
+ * Data types
+ */
+struct input_device_context {
+	struct vm_device	*device_ctx;
+	struct hid_device	*hid_device;
+	struct input_dev_info	device_info;
+	int			connected;
+};
+
+struct mousevsc_driver_context {
+	struct driver_context	drv_ctx;
+	struct mousevsc_drv_obj	drv_obj;
+};
+
+static struct mousevsc_driver_context g_mousevsc_drv;
+
+void mousevsc_deviceinfo_callback(struct hv_device *dev,
+				  struct input_dev_info *info)
+{
+	struct vm_device *device_ctx = to_vm_device(dev);
+	struct input_device_context *input_device_ctx =
+		dev_get_drvdata(&device_ctx->device);
+
+	memcpy(&input_device_ctx->device_info, info,
+	       sizeof(struct input_dev_info));
+
+	DPRINT_INFO(INPUTVSC_DRV, "mousevsc_deviceinfo_callback()");
+}
+
+void mousevsc_inputreport_callback(struct hv_device *dev, void *packet, u32 len)
+{
+	int ret = 0;
+
+	struct vm_device *device_ctx = to_vm_device(dev);
+	struct input_device_context *input_dev_ctx =
+		dev_get_drvdata(&device_ctx->device);
+
+	ret = hid_input_report(input_dev_ctx->hid_device,
+			      HID_INPUT_REPORT, packet, len, 1);
+
+	DPRINT_DBG(INPUTVSC_DRV, "hid_input_report (ret %d)", ret);
+}
+
+int mousevsc_hid_open(struct hid_device *hid)
+{
+	return 0;
+}
+
+void mousevsc_hid_close(struct hid_device *hid)
+{
+}
+
+int mousevsc_probe(struct device *device)
+{
+	int ret = 0;
+
+	struct driver_context *driver_ctx =
+		driver_to_driver_context(device->driver);
+	struct mousevsc_driver_context *mousevsc_drv_ctx =
+		(struct mousevsc_driver_context *)driver_ctx;
+	struct mousevsc_drv_obj *mousevsc_drv_obj = &mousevsc_drv_ctx->drv_obj;
+
+	struct vm_device *device_ctx = device_to_vm_device(device);
+	struct hv_device *device_obj = &device_ctx->device_obj;
+	struct input_device_context *input_dev_ctx;
+
+	input_dev_ctx = kmalloc(sizeof(struct input_device_context),
+				GFP_KERNEL);
+
+	dev_set_drvdata(device, input_dev_ctx);
+
+	/* Call to the vsc driver to add the device */
+	ret = mousevsc_drv_obj->Base.dev_add(device_obj, NULL);
+
+	if (ret != 0) {
+		DPRINT_ERR(INPUTVSC_DRV, "unable to add input vsc device");
+
+		return -1;
+	}
+
+	return 0;
+}
+
+
+int mousevsc_remove(struct device *device)
+{
+	int ret = 0;
+
+	struct driver_context *driver_ctx =
+		driver_to_driver_context(device->driver);
+	struct mousevsc_driver_context *mousevsc_drv_ctx =
+		(struct mousevsc_driver_context *)driver_ctx;
+	struct mousevsc_drv_obj *mousevsc_drv_obj = &mousevsc_drv_ctx->drv_obj;
+
+	struct vm_device *device_ctx = device_to_vm_device(device);
+	struct hv_device *device_obj = &device_ctx->device_obj;
+	struct input_device_context *input_dev_ctx;
+
+	input_dev_ctx = kmalloc(sizeof(struct input_device_context),
+				GFP_KERNEL);
+
+	dev_set_drvdata(device, input_dev_ctx);
+
+	if (input_dev_ctx->connected) {
+		hidinput_disconnect(input_dev_ctx->hid_device);
+		input_dev_ctx->connected = 0;
+	}
+
+	if (!mousevsc_drv_obj->Base.dev_rm) {
+		return -1;
+	}
+
+	/*
+	 * Call to the vsc driver to let it know that the device
+	 * is being removed
+	 */
+	ret = mousevsc_drv_obj->Base.dev_rm(device_obj);
+
+	if (ret != 0) {
+		DPRINT_ERR(INPUTVSC_DRV,
+			   "unable to remove vsc device (ret %d)", ret);
+	}
+
+	kfree(input_dev_ctx);
+
+	return ret;
+}
+
+void mousevsc_reportdesc_callback(struct hv_device *dev, void *packet, u32 len)
+{
+	struct vm_device *device_ctx = to_vm_device(dev);
+	struct input_device_context *input_device_ctx =
+		dev_get_drvdata(&device_ctx->device);
+	struct hid_device *hid_dev;
+
+	/* hid_debug = -1; */
+	hid_dev = kmalloc(sizeof(struct hid_device), GFP_KERNEL);
+
+	if (hid_parse_report(hid_dev, packet, len)) {
+		DPRINT_INFO(INPUTVSC_DRV, "Unable to call hd_parse_report");
+		return;
+	}
+
+	if (hid_dev) {
+		DPRINT_INFO(INPUTVSC_DRV, "hid_device created");
+
+		hid_dev->ll_driver->open  = mousevsc_hid_open;
+		hid_dev->ll_driver->close = mousevsc_hid_close;
+
+		hid_dev->bus =  0x06;  /* BUS_VIRTUAL */
+		hid_dev->vendor = input_device_ctx->device_info.VendorID;
+		hid_dev->product = input_device_ctx->device_info.ProductID;
+		hid_dev->version = input_device_ctx->device_info.VersionNumber;
+		hid_dev->dev = device_ctx->device;
+
+		sprintf(hid_dev->name, "%s",
+			input_device_ctx->device_info.Name);
+
+		/*
+		 * HJ Do we want to call it with a 0
+		 */
+		if (!hidinput_connect(hid_dev, 0)) {
+			hid_dev->claimed |= HID_CLAIMED_INPUT;
+
+			input_device_ctx->connected = 1;
+
+			DPRINT_INFO(INPUTVSC_DRV,
+				     "HID device claimed by input\n");
+		}
+
+		if (!hid_dev->claimed) {
+			DPRINT_ERR(INPUTVSC_DRV,
+				    "HID device not claimed by "
+				    "input or hiddev\n");
+		}
+
+		input_device_ctx->hid_device = hid_dev;
+	}
+
+	kfree(hid_dev);
+}
+
+/*
+ *
+ * Name:	mousevsc_drv_init()
+ *
+ * Desc:	Driver initialization.
+ */
+int mousevsc_drv_init(int (*pfn_drv_init)(struct hv_driver *pfn_drv_init))
+{
+	int ret = 0;
+	struct mousevsc_drv_obj *input_drv_obj = &g_mousevsc_drv.drv_obj;
+	struct driver_context *drv_ctx = &g_mousevsc_drv.drv_ctx;
+
+//	vmbus_get_interface(&input_drv_obj->Base.VmbusChannelInterface);
+
+	input_drv_obj->OnDeviceInfo = mousevsc_deviceinfo_callback;
+	input_drv_obj->OnInputReport = mousevsc_inputreport_callback;
+	input_drv_obj->OnReportDescriptor = mousevsc_reportdesc_callback;
+
+	/* Callback to client driver to complete the initialization */
+	pfn_drv_init(&input_drv_obj->Base);
+
+	drv_ctx->driver.name = input_drv_obj->Base.name;
+	memcpy(&drv_ctx->class_id, &input_drv_obj->Base.dev_type,
+	       sizeof(struct hv_guid));
+
+	drv_ctx->probe = mousevsc_probe;
+	drv_ctx->remove = mousevsc_remove;
+
+	/* The driver belongs to vmbus */
+	vmbus_child_driver_register(drv_ctx);
+
+	return ret;
+}
+
+
+int mousevsc_drv_exit_cb(struct device *dev, void *data)
+{
+	struct device **curr = (struct device **)data;
+	*curr = dev;
+
+	return 1;
+}
+
+void mousevsc_drv_exit(void)
+{
+	struct mousevsc_drv_obj *mousevsc_drv_obj = &g_mousevsc_drv.drv_obj;
+	struct driver_context *drv_ctx = &g_mousevsc_drv.drv_ctx;
+	int ret;
+
+	struct device *current_dev = NULL;
+
+	while (1) {
+		current_dev = NULL;
+
+		/* Get the device */
+		ret = driver_for_each_device(&drv_ctx->driver, NULL, (void *)&current_dev, mousevsc_drv_exit_cb);
+		if (ret)
+			printk(KERN_ERR "Can't find mouse device!\n");
+
+		if (current_dev == NULL)
+			break;
+
+		/* Initiate removal from the top-down */
+		device_unregister(current_dev);
+	}
+
+	if (mousevsc_drv_obj->Base.cleanup)
+		mousevsc_drv_obj->Base.cleanup(&mousevsc_drv_obj->Base);
+
+	vmbus_child_driver_unregister(drv_ctx);
+
+	return;
+}
+
+static int __init mousevsc_init(void)
+{
+	int ret;
+
+	DPRINT_INFO(INPUTVSC_DRV, "Hyper-V Mouse driver initializing.");
+
+	ret = mousevsc_drv_init(mouse_vsc_initialize);
+
+	return ret;
+}
+
+static void __exit mousevsc_exit(void)
+{
+	mousevsc_drv_exit();
+}
+
+/*
+ * We use a PCI table to determine if we should autoload this driver  This is
+ * needed by distro tools to determine if the hyperv drivers should be
+ * installed and/or configured.  We don't do anything else with the table, but
+ * it needs to be present.
+ */
+const static struct pci_device_id microsoft_hv_pci_table[] = {
+	{ PCI_DEVICE(0x1414, 0x5353) },	/* VGA compatible controller */
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(pci, microsoft_hv_pci_table);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HV_DRV_VERSION);
+module_init(mousevsc_init);
+module_exit(mousevsc_exit);
+

drivers/staging/hv/mouse_vsc.c

@@ -0,0 +1,763 @@
+/*
+ *  Copyright 2009 Citrix Systems, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  For clarity, the licensor of this program does not intend that a
+ *  "derivative work" include code which compiles header information from
+ *  this program.
+ *
+ *  This code has been modified from its original by
+ *  Hank Janssen <hjanssen@microsoft.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/workqueue.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/input.h>
+#include <linux/hid.h>
+#include <linux/hiddev.h>
+
+#include "hv_api.h"
+#include "vmbus.h"
+#include "vmbus_api.h"
+#include "channel.h"
+#include "logging.h"
+
+#include "mousevsc_api.h"
+#include "vmbus_packet_format.h"
+#include "vmbus_hid_protocol.h"
+
+
+enum pipe_prot_msg_type
+{
+	PipeMessageInvalid = 0,
+	PipeMessageData,
+	PipeMessageMaximum
+};
+
+
+struct pipe_prt_msg
+{
+	enum pipe_prot_msg_type PacketType;
+	u32                DataSize;
+	char               Data[1];
+};
+
+/*
+ * Data types
+ */
+struct  mousevsc_prt_msg {
+	enum pipe_prot_msg_type   PacketType;
+	u32                  DataSize;
+	union {
+		SYNTHHID_PROTOCOL_REQUEST	Request;
+		SYNTHHID_PROTOCOL_RESPONSE	Response;
+		SYNTHHID_DEVICE_INFO_ACK	Ack;
+	} u;
+};
+
+/*
+ * Represents an mousevsc device
+ */
+struct mousevsc_dev {
+	struct hv_device	*Device;
+	/* 0 indicates the device is being destroyed */
+	atomic_t		RefCount;
+	int			NumOutstandingRequests;
+	unsigned char   	bInitializeComplete;
+	struct mousevsc_prt_msg	ProtocolReq;
+	struct mousevsc_prt_msg	ProtocolResp;
+	/* Synchronize the request/response if needed */
+	wait_queue_head_t	ProtocolWaitEvent;
+	wait_queue_head_t	DeviceInfoWaitEvent;
+	int			protocol_wait_condition;
+	int			device_wait_condition;
+	int			DeviceInfoStatus;
+
+	struct hid_descriptor	*HidDesc;
+	unsigned char		*ReportDesc;
+	u32			ReportDescSize;
+	struct input_dev_info	DeviceAttr;
+};
+
+
+/*
+ * Globals
+ */
+static const char* gDriverName = "mousevsc";
+
+/* {CFA8B69E-5B4A-4cc0-B98B-8BA1A1F3F95A} */
+static const struct hv_guid gMousevscDeviceType = {
+	.data = {0x9E, 0xB6, 0xA8, 0xCF, 0x4A, 0x5B, 0xc0, 0x4c,
+		 0xB9, 0x8B, 0x8B, 0xA1, 0xA1, 0xF3, 0xF9, 0x5A}
+};
+
+/*
+ * Internal routines
+ */
+static int MousevscOnDeviceAdd(struct hv_device *Device, void *AdditionalInfo);
+
+static int MousevscOnDeviceRemove(struct hv_device *Device);
+
+static void MousevscOnCleanup(struct hv_driver *Device);
+
+static void MousevscOnChannelCallback(void *Context);
+
+static int MousevscConnectToVsp(struct hv_device *Device);
+
+static void MousevscOnReceive(struct hv_device *Device,
+			      struct vmpacket_descriptor *Packet);
+
+static inline struct mousevsc_dev *AllocInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
+
+	if (!inputDevice)
+		return NULL;
+
+	/*
+	 * Set to 2 to allow both inbound and outbound traffics
+	 * (ie GetInputDevice() and MustGetInputDevice()) to proceed.
+	 */
+	atomic_cmpxchg(&inputDevice->RefCount, 0, 2);
+
+	inputDevice->Device = Device;
+	Device->ext = inputDevice;
+
+	return inputDevice;
+}
+
+static inline void FreeInputDevice(struct mousevsc_dev *Device)
+{
+	WARN_ON(atomic_read(&Device->RefCount) == 0);
+	kfree(Device);
+}
+
+/*
+ * Get the inputdevice object if exists and its refcount > 1
+ */
+static inline struct mousevsc_dev* GetInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = (struct mousevsc_dev*)Device->ext;
+
+//	printk(KERN_ERR "-------------------------> REFCOUNT = %d",
+//	       inputDevice->RefCount);
+
+	if (inputDevice && atomic_read(&inputDevice->RefCount) > 1)
+		atomic_inc(&inputDevice->RefCount);
+	else
+		inputDevice = NULL;
+
+	return inputDevice;
+}
+
+/*
+ * Get the inputdevice object iff exists and its refcount > 0
+ */
+static inline struct mousevsc_dev* MustGetInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = (struct mousevsc_dev*)Device->ext;
+
+	if (inputDevice && atomic_read(&inputDevice->RefCount))
+		atomic_inc(&inputDevice->RefCount);
+	else
+		inputDevice = NULL;
+
+	return inputDevice;
+}
+
+static inline void PutInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = (struct mousevsc_dev*)Device->ext;
+
+	atomic_dec(&inputDevice->RefCount);
+}
+
+/*
+ * Drop ref count to 1 to effectively disable GetInputDevice()
+ */
+static inline struct mousevsc_dev* ReleaseInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = (struct mousevsc_dev*)Device->ext;
+
+	/* Busy wait until the ref drop to 2, then set it to 1  */
+	while (atomic_cmpxchg(&inputDevice->RefCount, 2, 1) != 2)
+		udelay(100);
+
+	return inputDevice;
+}
+
+/*
+ * Drop ref count to 0. No one can use InputDevice object.
+ */
+static inline struct mousevsc_dev* FinalReleaseInputDevice(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = (struct mousevsc_dev*)Device->ext;
+
+	/* Busy wait until the ref drop to 1, then set it to 0  */
+	while (atomic_cmpxchg(&inputDevice->RefCount, 1, 0) != 1)
+		udelay(100);
+
+	Device->ext = NULL;
+	return inputDevice;
+}
+
+/*
+ *
+ * Name:
+ *	MousevscInitialize()
+ *
+ * Description:
+ *	Main entry point
+ *
+ */
+int mouse_vsc_initialize(struct hv_driver *Driver)
+{
+	struct mousevsc_drv_obj *inputDriver =
+		(struct mousevsc_drv_obj *)Driver;
+	int ret = 0;
+
+	Driver->name = gDriverName;
+	memcpy(&Driver->dev_type, &gMousevscDeviceType,
+	       sizeof(struct hv_guid));
+
+	/* Setup the dispatch table */
+	inputDriver->Base.dev_add		= MousevscOnDeviceAdd;
+	inputDriver->Base.dev_rm = MousevscOnDeviceRemove;
+	inputDriver->Base.cleanup		= MousevscOnCleanup;
+
+	inputDriver->OnOpen			= NULL;
+	inputDriver->OnClose			= NULL;
+
+	return ret;
+}
+
+/*
+ *
+ * Name:
+ *	MousevscOnDeviceAdd()
+ *
+ * Description:
+ *	Callback when the device belonging to this driver is added
+ *
+ */
+int
+MousevscOnDeviceAdd(struct hv_device *Device, void *AdditionalInfo)
+{
+	int ret = 0;
+	struct mousevsc_dev *inputDevice;
+	struct mousevsc_drv_obj *inputDriver;
+	struct input_dev_info deviceInfo;
+
+	inputDevice = AllocInputDevice(Device);
+
+	if (!inputDevice) {
+		ret = -1;
+		goto Cleanup;
+	}
+
+	inputDevice->bInitializeComplete = false;
+
+	/* Open the channel */
+	ret = vmbus_open(Device->channel,
+		INPUTVSC_SEND_RING_BUFFER_SIZE,
+		INPUTVSC_RECV_RING_BUFFER_SIZE,
+		NULL,
+		0,
+		MousevscOnChannelCallback,
+		Device
+		);
+
+	if (ret != 0) {
+		pr_err("unable to open channel: %d", ret);
+		return -1;
+	}
+
+	pr_info("InputVsc channel open: %d", ret);
+
+	ret = MousevscConnectToVsp(Device);
+
+	if (ret != 0) {
+		pr_err("unable to connect channel: %d", ret);
+
+		vmbus_close(Device->channel);
+		return ret;
+	}
+
+	inputDriver = (struct mousevsc_drv_obj *)inputDevice->Device->drv;
+
+	deviceInfo.VendorID = inputDevice->DeviceAttr.VendorID;
+	deviceInfo.ProductID = inputDevice->DeviceAttr.ProductID;
+	deviceInfo.VersionNumber = inputDevice->DeviceAttr.VersionNumber;
+	strcpy(deviceInfo.Name, "Microsoft Vmbus HID-compliant Mouse");
+
+	/* Send the device info back up */
+	inputDriver->OnDeviceInfo(Device, &deviceInfo);
+
+	/* Send the report desc back up */
+	/* workaround SA-167 */
+	if (inputDevice->ReportDesc[14] == 0x25)
+		inputDevice->ReportDesc[14] = 0x29;
+
+	inputDriver->OnReportDescriptor(Device, inputDevice->ReportDesc, inputDevice->ReportDescSize);
+
+	inputDevice->bInitializeComplete = true;
+
+Cleanup:
+	return ret;
+}
+
+int
+MousevscConnectToVsp(struct hv_device *Device)
+{
+	int ret=0;
+	struct mousevsc_dev *inputDevice;
+	struct mousevsc_prt_msg *request;
+	struct mousevsc_prt_msg *response;
+
+	inputDevice = GetInputDevice(Device);
+
+	if (!inputDevice) {
+		pr_err("unable to get input device...device being destroyed?");
+		return -1;
+	}
+
+	init_waitqueue_head(&inputDevice->ProtocolWaitEvent);
+	init_waitqueue_head(&inputDevice->DeviceInfoWaitEvent);
+
+	request = &inputDevice->ProtocolReq;
+
+	/*
+	 * Now, initiate the vsc/vsp initialization protocol on the open channel
+	 */
+	memset(request, sizeof(struct mousevsc_prt_msg), 0);
+
+	request->PacketType = PipeMessageData;
+	request->DataSize = sizeof(SYNTHHID_PROTOCOL_REQUEST);
+
+	request->u.Request.Header.Type = SynthHidProtocolRequest;
+	request->u.Request.Header.Size = sizeof(unsigned long);
+	request->u.Request.VersionRequested.AsDWord =
+		SYNTHHID_INPUT_VERSION_DWORD;
+
+	pr_info("SYNTHHID_PROTOCOL_REQUEST...");
+
+	ret = vmbus_sendpacket(Device->channel, request,
+					sizeof(struct pipe_prt_msg) -
+					sizeof(unsigned char) +
+					sizeof(SYNTHHID_PROTOCOL_REQUEST),
+					(unsigned long)request,
+					VM_PKT_DATA_INBAND,
+					VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if ( ret != 0) {
+		pr_err("unable to send SYNTHHID_PROTOCOL_REQUEST");
+		goto Cleanup;
+	}
+
+	inputDevice->protocol_wait_condition = 0;
+	wait_event_timeout(inputDevice->ProtocolWaitEvent, inputDevice->protocol_wait_condition, msecs_to_jiffies(1000));
+	if (inputDevice->protocol_wait_condition == 0) {
+		ret = -ETIMEDOUT;
+		goto Cleanup;
+	}
+
+	response = &inputDevice->ProtocolResp;
+
+	if (!response->u.Response.Approved) {
+		pr_err("SYNTHHID_PROTOCOL_REQUEST failed (version %d)",
+		       SYNTHHID_INPUT_VERSION_DWORD);
+		ret = -1;
+		goto Cleanup;
+	}
+
+	inputDevice->device_wait_condition = 0;
+	wait_event_timeout(inputDevice->DeviceInfoWaitEvent, inputDevice->device_wait_condition, msecs_to_jiffies(1000));
+	if (inputDevice->device_wait_condition == 0) {
+		ret = -ETIMEDOUT;
+		goto Cleanup;
+	}
+
+	/*
+	 * We should have gotten the device attr, hid desc and report
+	 * desc at this point
+	 */
+	if (!inputDevice->DeviceInfoStatus)
+		pr_info("**** input channel up and running!! ****");
+	else
+		ret = -1;
+
+Cleanup:
+	PutInputDevice(Device);
+
+	return ret;
+}
+
+
+/*
+ *
+ * Name:
+ *	MousevscOnDeviceRemove()
+ *
+ * Description:
+ *	Callback when the our device is being removed
+ *
+ */
+int
+MousevscOnDeviceRemove(struct hv_device *Device)
+{
+	struct mousevsc_dev *inputDevice;
+	int ret=0;
+
+	pr_info("disabling input device (%p)...",
+		    Device->ext);
+
+	inputDevice = ReleaseInputDevice(Device);
+
+
+	/*
+	 * At this point, all outbound traffic should be disable. We only
+	 * allow inbound traffic (responses) to proceed
+	 *
+	 * so that outstanding requests can be completed.
+	 */
+	while (inputDevice->NumOutstandingRequests)
+	{
+		pr_info("waiting for %d requests to complete...", inputDevice->NumOutstandingRequests);
+
+		udelay(100);
+	}
+
+	pr_info("removing input device (%p)...", Device->ext);
+
+	inputDevice = FinalReleaseInputDevice(Device);
+
+	pr_info("input device (%p) safe to remove", inputDevice);
+
+	/* Close the channel */
+	vmbus_close(Device->channel);
+
+	FreeInputDevice(inputDevice);
+
+	return ret;
+}
+
+
+/*
+ *
+ * Name:
+ *	MousevscOnCleanup()
+ *
+ * Description:
+ *	Perform any cleanup when the driver is removed
+ */
+static void MousevscOnCleanup(struct hv_driver *drv)
+{
+}
+
+
+static void
+MousevscOnSendCompletion(struct hv_device *Device,
+			 struct vmpacket_descriptor *Packet)
+{
+	struct mousevsc_dev *inputDevice;
+	void *request;
+
+	inputDevice = MustGetInputDevice(Device);
+	if (!inputDevice) {
+		pr_err("unable to get input device...device being destroyed?");
+		return;
+	}
+
+	request = (void*)(unsigned long *) Packet->trans_id;
+
+	if (request == &inputDevice->ProtocolReq)
+	{
+
+	}
+
+	PutInputDevice(Device);
+}
+
+void
+MousevscOnReceiveDeviceInfo(
+	struct mousevsc_dev* InputDevice,
+	SYNTHHID_DEVICE_INFO* DeviceInfo
+	)
+{
+	int ret = 0;
+	struct hid_descriptor *desc;
+	struct mousevsc_prt_msg ack;
+
+	/* Assume success for now */
+	InputDevice->DeviceInfoStatus = 0;
+
+	/* Save the device attr */
+	memcpy(&InputDevice->DeviceAttr, &DeviceInfo->HidDeviceAttributes, sizeof(struct input_dev_info));
+
+	/* Save the hid desc */
+	desc = (struct hid_descriptor *)DeviceInfo->HidDescriptorInformation;
+	WARN_ON(desc->bLength > 0);
+
+	InputDevice->HidDesc = kzalloc(desc->bLength, GFP_KERNEL);
+
+	if (!InputDevice->HidDesc) {
+		pr_err("unable to allocate hid descriptor - size %d", desc->bLength);
+		goto Cleanup;
+	}
+
+	memcpy(InputDevice->HidDesc, desc, desc->bLength);
+
+	/* Save the report desc */
+	InputDevice->ReportDescSize = desc->desc[0].wDescriptorLength;
+	InputDevice->ReportDesc = kzalloc(InputDevice->ReportDescSize,
+					  GFP_KERNEL);
+
+	if (!InputDevice->ReportDesc) {
+		pr_err("unable to allocate report descriptor - size %d",
+			   InputDevice->ReportDescSize);
+		goto Cleanup;
+	}
+
+	memcpy(InputDevice->ReportDesc,
+	       ((unsigned char *)desc) + desc->bLength,
+	       desc->desc[0].wDescriptorLength);
+
+	/* Send the ack */
+	memset(&ack, sizeof(struct mousevsc_prt_msg), 0);
+
+	ack.PacketType = PipeMessageData;
+	ack.DataSize = sizeof(SYNTHHID_DEVICE_INFO_ACK);
+
+	ack.u.Ack.Header.Type = SynthHidInitialDeviceInfoAck;
+	ack.u.Ack.Header.Size = 1;
+	ack.u.Ack.Reserved = 0;
+
+	ret = vmbus_sendpacket(InputDevice->Device->channel,
+			&ack,
+			sizeof(struct pipe_prt_msg) - sizeof(unsigned char) + sizeof(SYNTHHID_DEVICE_INFO_ACK),
+			(unsigned long)&ack,
+			VM_PKT_DATA_INBAND,
+			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (ret != 0) {
+		pr_err("unable to send SYNTHHID_DEVICE_INFO_ACK - ret %d",
+			   ret);
+		goto Cleanup;
+	}
+
+	InputDevice->device_wait_condition = 1;
+	wake_up(&InputDevice->DeviceInfoWaitEvent);
+
+	return;
+
+Cleanup:
+	if (InputDevice->HidDesc)
+	{
+		kfree(InputDevice->HidDesc);
+		InputDevice->HidDesc = NULL;
+	}
+
+	if (InputDevice->ReportDesc)
+	{
+		kfree(InputDevice->ReportDesc);
+		InputDevice->ReportDesc = NULL;
+	}
+
+	InputDevice->DeviceInfoStatus = -1;
+	InputDevice->device_wait_condition = 1;
+	wake_up(&InputDevice->DeviceInfoWaitEvent);
+}
+
+
+void
+MousevscOnReceiveInputReport(
+	struct mousevsc_dev* InputDevice,
+	SYNTHHID_INPUT_REPORT *InputReport
+	)
+{
+	struct mousevsc_drv_obj *inputDriver;
+
+	if (!InputDevice->bInitializeComplete)
+	{
+		pr_info("Initialization incomplete...ignoring InputReport msg");
+		return;
+	}
+
+	inputDriver = (struct mousevsc_drv_obj *)InputDevice->Device->drv;
+
+	inputDriver->OnInputReport(InputDevice->Device,
+				   InputReport->ReportBuffer,
+				   InputReport->Header.Size);
+}
+
+void
+MousevscOnReceive(struct hv_device *Device, struct vmpacket_descriptor *Packet)
+{
+	struct pipe_prt_msg *pipeMsg;
+	SYNTHHID_MESSAGE *hidMsg;
+	struct mousevsc_dev *inputDevice;
+
+	inputDevice = MustGetInputDevice(Device);
+	if (!inputDevice)
+	{
+		pr_err("unable to get input device...device being destroyed?");
+		return;
+	}
+
+	pipeMsg = (struct pipe_prt_msg *)((unsigned long)Packet + (Packet->offset8 << 3));
+
+	if (pipeMsg->PacketType != PipeMessageData) {
+		pr_err("unknown pipe msg type - type %d len %d",
+			   pipeMsg->PacketType, pipeMsg->DataSize);
+		PutInputDevice(Device);
+		return ;
+	}
+
+	hidMsg = (SYNTHHID_MESSAGE*)&pipeMsg->Data[0];
+
+	switch (hidMsg->Header.Type) {
+	case SynthHidProtocolResponse:
+		memcpy(&inputDevice->ProtocolResp, pipeMsg, pipeMsg->DataSize+sizeof(struct pipe_prt_msg) - sizeof(unsigned char));
+		inputDevice->protocol_wait_condition = 1;
+		wake_up(&inputDevice->ProtocolWaitEvent);
+		break;
+
+	case SynthHidInitialDeviceInfo:
+		WARN_ON(pipeMsg->DataSize >= sizeof(struct input_dev_info));
+
+		/*
+		 * Parse out the device info into device attr,
+		 * hid desc and report desc
+		 */
+		MousevscOnReceiveDeviceInfo(inputDevice,
+					    (SYNTHHID_DEVICE_INFO*)&pipeMsg->Data[0]);
+		break;
+	case SynthHidInputReport:
+		MousevscOnReceiveInputReport(inputDevice,
+					     (SYNTHHID_INPUT_REPORT*)&pipeMsg->Data[0]);
+
+		break;
+	default:
+		pr_err("unsupported hid msg type - type %d len %d",
+		       hidMsg->Header.Type, hidMsg->Header.Size);
+		break;
+	}
+
+	PutInputDevice(Device);
+}
+
+void MousevscOnChannelCallback(void *Context)
+{
+	const int packetSize = 0x100;
+	int ret = 0;
+	struct hv_device *device = (struct hv_device *)Context;
+	struct mousevsc_dev *inputDevice;
+
+	u32 bytesRecvd;
+	u64 requestId;
+	unsigned char packet[packetSize];
+	struct vmpacket_descriptor *desc;
+	unsigned char	*buffer = packet;
+	int	bufferlen = packetSize;
+
+	inputDevice = MustGetInputDevice(device);
+
+	if (!inputDevice) {
+		pr_err("unable to get input device...device being destroyed?");
+		return;
+	}
+
+	do {
+		ret = vmbus_recvpacket_raw(device->channel, buffer, bufferlen, &bytesRecvd, &requestId);
+
+		if (ret == 0) {
+			if (bytesRecvd > 0) {
+				desc = (struct vmpacket_descriptor *)buffer;
+
+				switch (desc->type)
+				{
+					case VM_PKT_COMP:
+						MousevscOnSendCompletion(device,
+									 desc);
+						break;
+
+					case VM_PKT_DATA_INBAND:
+						MousevscOnReceive(device, desc);
+						break;
+
+					default:
+						pr_err("unhandled packet type %d, tid %llx len %d\n",
+							   desc->type,
+							   requestId,
+							   bytesRecvd);
+						break;
+				}
+
+				/* reset */
+				if (bufferlen > packetSize) {
+					kfree(buffer);
+
+					buffer = packet;
+					bufferlen = packetSize;
+				}
+			} else {
+				/*
+				 * pr_debug("nothing else to read...");
+				 * reset
+				 */
+				if (bufferlen > packetSize) {
+					kfree(buffer);
+
+					buffer = packet;
+					bufferlen = packetSize;
+				}
+				break;
+			}
+		} else if (ret == -2) {
+			/* Handle large packet */
+			bufferlen = bytesRecvd;
+			buffer = kzalloc(bytesRecvd, GFP_KERNEL);
+
+			if (buffer == NULL) {
+				buffer = packet;
+				bufferlen = packetSize;
+
+				/* Try again next time around */
+				pr_err("unable to allocate buffer of size %d!",
+				       bytesRecvd);
+				break;
+			}
+		}
+	} while (1);
+
+	PutInputDevice(device);
+
+	return;
+}
+

drivers/staging/hv/mousevsc_api.h

@@ -0,0 +1,73 @@
+/*
+ *  Copyright 2009 Citrix Systems, Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that 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.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *  For clarity, the licensor of this program does not intend that a
+ *  "derivative work" include code which compiles header information from
+ *  this program. 
+ *
+ *  This code has been modified from its original by 
+ *  Hank Janssen <hjanssen@microsoft.com>
+ *
+ */
+
+#ifndef _INPUTVSC_API_H_
+#define _INPUTVSC_API_H_
+
+#include "vmbus_api.h"
+
+/*
+ * Defines
+ */
+#define INPUTVSC_SEND_RING_BUFFER_SIZE		10*PAGE_SIZE
+#define INPUTVSC_RECV_RING_BUFFER_SIZE		10*PAGE_SIZE
+
+
+/*
+ * Data types
+ */
+struct input_dev_info {
+	unsigned short VendorID;
+	unsigned short ProductID;
+	unsigned short VersionNumber;
+	char	       Name[128];
+};
+
+/* Represents the input vsc driver */
+struct mousevsc_drv_obj {
+	struct hv_driver Base; // Must be the first field
+	/*
+	 * This is set by the caller to allow us to callback when 
+	 * we receive a packet from the "wire"
+	 */
+	void (*OnDeviceInfo)(struct hv_device *dev, 
+			     struct input_dev_info* info);
+	void (*OnInputReport)(struct hv_device *dev, void* packet, u32 len);
+	void (*OnReportDescriptor)(struct hv_device *dev, 
+				   void* packet, u32 len);
+	/* Specific to this driver */
+	int (*OnOpen)(struct hv_device *Device);
+	int (*OnClose)(struct hv_device *Device);
+	void *Context;
+};
+
+
+/*
+ * Interface
+ */
+int mouse_vsc_initialize(struct hv_driver *drv);
+
+#endif // _INPUTVSC_API_H_

drivers/staging/hv/vmbus_hid_protocol.h

@@ -0,0 +1,120 @@
+/*
+ * 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:
+ *   Hank Janssen  <hjanssen@microsoft.com>
+ */
+#ifndef _VMBUS_HID_PROTOCOL_
+#define _VMBUS_HID_PROTOCOL_
+
+/* The maximum size of a synthetic input message. */
+#define SYNTHHID_MAX_INPUT_REPORT_SIZE 16
+
+/*
+ * Current version
+ *
+ * History:
+ * Beta, RC < 2008/1/22        1,0
+ * RC > 2008/1/22              2,0
+ */
+#define SYNTHHID_INPUT_VERSION_MAJOR 2
+#define SYNTHHID_INPUT_VERSION_MINOR 0
+#define SYNTHHID_INPUT_VERSION_DWORD (SYNTHHID_INPUT_VERSION_MINOR | \
+    (SYNTHHID_INPUT_VERSION_MAJOR << 16))
+
+
+#pragma pack(push,1)
+
+/*
+ * Message types in the synthetic input protocol
+ */
+enum synthhid_msg_type
+{
+	SynthHidProtocolRequest,
+	SynthHidProtocolResponse,
+	SynthHidInitialDeviceInfo,
+	SynthHidInitialDeviceInfoAck,
+	SynthHidInputReport,
+	SynthHidMax
+};
+
+
+/*
+ * Basic message structures.
+ */
+typedef struct
+{
+	enum synthhid_msg_type  Type;    /* Type of the enclosed message */
+	u32                     Size;    /* Size of the enclosed message
+					  *  (size of the data payload)
+					  */
+} SYNTHHID_MESSAGE_HEADER, *PSYNTHHID_MESSAGE_HEADER;
+
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER Header;
+	char                    Data[1]; /* Enclosed message */
+} SYNTHHID_MESSAGE, *PSYNTHHID_MESSAGE;
+
+typedef union
+{
+	struct {
+		u16  Minor;
+		u16  Major;
+	};
+
+	u32 AsDWord;
+} SYNTHHID_VERSION, *PSYNTHHID_VERSION;
+
+/*
+ * Protocol messages
+ */
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER Header;
+	SYNTHHID_VERSION        VersionRequested;
+} SYNTHHID_PROTOCOL_REQUEST, *PSYNTHHID_PROTOCOL_REQUEST;
+
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER Header;
+	SYNTHHID_VERSION        VersionRequested;
+	unsigned char           Approved;
+} SYNTHHID_PROTOCOL_RESPONSE, *PSYNTHHID_PROTOCOL_RESPONSE;
+
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER     Header;
+	struct input_dev_info       HidDeviceAttributes;
+	unsigned char               HidDescriptorInformation[1];
+} SYNTHHID_DEVICE_INFO, *PSYNTHHID_DEVICE_INFO;
+
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER Header;
+	unsigned char           Reserved;
+} SYNTHHID_DEVICE_INFO_ACK, *PSYNTHHID_DEVICE_INFO_ACK;
+
+typedef struct
+{
+	SYNTHHID_MESSAGE_HEADER Header;
+	char                    ReportBuffer[1];
+} SYNTHHID_INPUT_REPORT, *PSYNTHHID_INPUT_REPORT;
+
+#pragma pack(pop)
+
+#endif /* _VMBUS_HID_PROTOCOL_ */
+