Merge tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here's the big set of char/misc patches for 4.5-rc1.

  Nothing major, lots of different driver subsystem updates, full
  details in the shortlog.  All of these have been in linux-next for a
  while"

* tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (71 commits)
  mei: fix fasync return value on error
  parport: avoid assignment in if
  parport: remove unneeded space
  parport: change style of NULL comparison
  parport: remove unnecessary out of memory message
  parport: remove braces
  parport: quoted strings should not be split
  parport: code indent should use tabs
  parport: fix coding style
  parport: EXPORT_SYMBOL should follow function
  parport: remove trailing white space
  parport: fix a trivial typo
  coresight: Fix a typo in Kconfig
  coresight: checking for NULL string in coresight_name_match()
  Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical
  Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy
  Drivers: hv: vmbus: fix the building warning with hyperv-keyboard
  extcon: add Maxim MAX3355 driver
  Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()
  Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()
  ...

Documentation/devicetree/bindings/extcon/extcon-arizona.txt

@@ -13,3 +13,63 @@ Optional properties:
     ARIZONA_ACCDET_MODE_HPR or 2 - Headphone detect mode is set to HPDETR
     If this node is not mentioned or if the value is unknown, then
     headphone detection mode is set to HPDETL.
+
+  - wlf,use-jd2 : Use the additional JD input along with JD1 for dual pin jack
+    detection.
+  - wlf,use-jd2-nopull : Internal pull on JD2 is disabled when used for
+    jack detection.
+  - wlf,jd-invert : Invert the polarity of the jack detection switch
+
+  - wlf,micd-software-compare : Use a software comparison to determine mic
+    presence
+  - wlf,micd-detect-debounce : Additional software microphone detection
+    debounce specified in milliseconds.
+  - wlf,micd-pol-gpio : GPIO specifier for the GPIO controlling the headset
+    polarity if one exists.
+  - wlf,micd-bias-start-time : Time allowed for MICBIAS to startup prior to
+    performing microphone detection, specified as per the ARIZONA_MICD_TIME_XXX
+    defines.
+  - wlf,micd-rate : Delay between successive microphone detection measurements,
+    specified as per the ARIZONA_MICD_TIME_XXX defines.
+  - wlf,micd-dbtime : Microphone detection hardware debounces specified as the
+    number of measurements to take, valid values being 2 and 4.
+  - wlf,micd-timeout-ms : Timeout for microphone detection, specified in
+    milliseconds.
+  - wlf,micd-force-micbias : Force MICBIAS continuously on during microphone
+    detection.
+  - wlf,micd-configs : Headset polarity configurations (generally used for
+    detection of CTIA / OMTP headsets), the field can be of variable length
+    but should always be a multiple of 3 cells long, each three cell group
+    represents one polarity configuration.
+    The first cell defines the accessory detection pin, zero will use MICDET1
+    and all other values will use MICDET2.
+    The second cell represents the MICBIAS to be used.
+    The third cell represents the value of the micd-pol-gpio pin.
+
+  - wlf,gpsw : Settings for the general purpose switch
+
+Example:
+
+codec: wm8280@0 {
+	compatible = "wlf,wm8280";
+	reg = <0>;
+	...
+
+	wlf,use-jd2;
+	wlf,use-jd2-nopull;
+	wlf,jd-invert;
+
+	wlf,micd-software-compare;
+	wlf,micd-detect-debounce = <0>;
+	wlf,micd-pol-gpio = <&codec 2 0>;
+	wlf,micd-rate = <ARIZONA_MICD_TIME_8MS>;
+	wlf,micd-dbtime = <4>;
+	wlf,micd-timeout-ms = <100>;
+	wlf,micd-force-micbias;
+	wlf,micd-configs = <
+		0 1 0 /* MICDET1 MICBIAS1 GPIO=low */
+		1 2 1 /* MICDET2 MICBIAS2 GPIO=high */
+	>;
+
+	wlf,gpsw = <0>;
+};

Documentation/devicetree/bindings/extcon/extcon-max3355.txt

+Maxim Integrated MAX3355 USB OTG chip
+-------------------------------------
+
+MAX3355 integrates a charge pump and comparators to enable a system with an
+integrated USB OTG dual-role transceiver to function as a USB OTG dual-role
+device.
+
+Required properties:
+- compatible: should be "maxim,max3355";
+- maxim,shdn-gpios: should contain a phandle and GPIO specifier for the GPIO pin
+		    connected to the MAX3355's SHDN# pin;
+- id-gpios: should contain a phandle and GPIO specifier for the GPIO pin
+	    connected to the MAX3355's ID_OUT pin.
+
+Example:
+
+	usb-otg {
+		compatible = "maxim,max3355";
+		maxim,shdn-gpios = <&gpio2 4 GPIO_ACTIVE_LOW>;
+		id-gpios = <&gpio5 31 GPIO_ACTIVE_HIGH>;
+	};

drivers/extcon/Kconfig

@@ -52,6 +52,15 @@ config EXTCON_MAX14577
 	  Maxim MAX14577/77836. The MAX14577/77836 MUIC is a USB port accessory
 	  detector and switch.
 
+config EXTCON_MAX3355
+	tristate "Maxim MAX3355 USB OTG EXTCON Support"
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  If you say yes here you get support for the USB OTG role detection by
+	  MAX3355. The MAX3355 chip integrates a charge pump and comparators to
+	  enable a system with an integrated USB OTG dual-role transceiver to
+	  function as an USB OTG dual-role device.
+
 config EXTCON_MAX77693
 	tristate "Maxim MAX77693 EXTCON Support"
 	depends on MFD_MAX77693 && INPUT

drivers/extcon/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-arizona.o
 obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
 obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
 obj-$(CONFIG_EXTCON_MAX14577)	+= extcon-max14577.o
+obj-$(CONFIG_EXTCON_MAX3355)	+= extcon-max3355.o
 obj-$(CONFIG_EXTCON_MAX77693)	+= extcon-max77693.o
 obj-$(CONFIG_EXTCON_MAX77843)	+= extcon-max77843.o
 obj-$(CONFIG_EXTCON_MAX8997)	+= extcon-max8997.o

drivers/extcon/extcon-arizona.c

@@ -1201,10 +1201,58 @@ static void arizona_micd_set_level(struct arizona *arizona, int index,
 	regmap_update_bits(arizona->regmap, reg, mask, level);
 }
 
-static int arizona_extcon_device_get_pdata(struct arizona *arizona)
+static int arizona_extcon_get_micd_configs(struct device *dev,
+					   struct arizona *arizona)
+{
+	const char * const prop = "wlf,micd-configs";
+	const int entries_per_config = 3;
+	struct arizona_micd_config *micd_configs;
+	int nconfs, ret;
+	int i, j;
+	u32 *vals;
+
+	nconfs = device_property_read_u32_array(arizona->dev, prop, NULL, 0);
+	if (nconfs <= 0)
+		return 0;
+
+	vals = kcalloc(nconfs, sizeof(u32), GFP_KERNEL);
+	if (!vals)
+		return -ENOMEM;
+
+	ret = device_property_read_u32_array(arizona->dev, prop, vals, nconfs);
+	if (ret < 0)
+		goto out;
+
+	nconfs /= entries_per_config;
+
+	micd_configs = devm_kzalloc(dev,
+				    nconfs * sizeof(struct arizona_micd_range),
+				    GFP_KERNEL);
+	if (!micd_configs) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (i = 0, j = 0; i < nconfs; ++i) {
+		micd_configs[i].src = vals[j++] ? ARIZONA_ACCDET_SRC : 0;
+		micd_configs[i].bias = vals[j++];
+		micd_configs[i].gpio = vals[j++];
+	}
+
+	arizona->pdata.micd_configs = micd_configs;
+	arizona->pdata.num_micd_configs = nconfs;
+
+out:
+	kfree(vals);
+	return ret;
+}
+
+static int arizona_extcon_device_get_pdata(struct device *dev,
+					   struct arizona *arizona)
 {
 	struct arizona_pdata *pdata = &arizona->pdata;
 	unsigned int val = ARIZONA_ACCDET_MODE_HPL;
+	int ret;
 
 	device_property_read_u32(arizona->dev, "wlf,hpdet-channel", &val);
 	switch (val) {
@@ -1230,12 +1278,29 @@ static int arizona_extcon_device_get_pdata(struct arizona *arizona)
 	device_property_read_u32(arizona->dev, "wlf,micd-dbtime",
 				 &pdata->micd_dbtime);
 
-	device_property_read_u32(arizona->dev, "wlf,micd-timeout",
+	device_property_read_u32(arizona->dev, "wlf,micd-timeout-ms",
 				 &pdata->micd_timeout);
 
 	pdata->micd_force_micbias = device_property_read_bool(arizona->dev,
 						"wlf,micd-force-micbias");
 
+	pdata->micd_software_compare = device_property_read_bool(arizona->dev,
+						"wlf,micd-software-compare");
+
+	pdata->jd_invert = device_property_read_bool(arizona->dev,
+						     "wlf,jd-invert");
+
+	device_property_read_u32(arizona->dev, "wlf,gpsw", &pdata->gpsw);
+
+	pdata->jd_gpio5 = device_property_read_bool(arizona->dev,
+						    "wlf,use-jd2");
+	pdata->jd_gpio5_nopull = device_property_read_bool(arizona->dev,
+						"wlf,use-jd2-nopull");
+
+	ret = arizona_extcon_get_micd_configs(dev, arizona);
+	if (ret < 0)
+		dev_err(arizona->dev, "Failed to read micd configs: %d\n", ret);
+
 	return 0;
 }
 
@@ -1257,7 +1322,7 @@ static int arizona_extcon_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	if (!dev_get_platdata(arizona->dev))
-		arizona_extcon_device_get_pdata(arizona);
+		arizona_extcon_device_get_pdata(&pdev->dev, arizona);
 
 	info->micvdd = devm_regulator_get(&pdev->dev, "MICVDD");
 	if (IS_ERR(info->micvdd)) {

drivers/extcon/extcon-max14577.c

@@ -692,7 +692,7 @@ static int max14577_muic_probe(struct platform_device *pdev)
 	/* Support irq domain for max14577 MUIC device */
 	for (i = 0; i < info->muic_irqs_num; i++) {
 		struct max14577_muic_irq *muic_irq = &info->muic_irqs[i];
-		unsigned int virq = 0;
+		int virq = 0;
 
 		virq = regmap_irq_get_virq(max14577->irq_data, muic_irq->irq);
 		if (virq <= 0)

drivers/extcon/extcon-max3355.c

+/*
+ * Maxim Integrated MAX3355 USB OTG chip extcon driver
+ *
+ * Copyright (C)  2014-2015 Cogent Embedded, Inc.
+ * Author: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ */
+
+#include <linux/extcon.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct max3355_data {
+	struct extcon_dev *edev;
+	struct gpio_desc *id_gpiod;
+	struct gpio_desc *shdn_gpiod;
+};
+
+static const unsigned int max3355_cable[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+	EXTCON_NONE,
+};
+
+static irqreturn_t max3355_id_irq(int irq, void *dev_id)
+{
+	struct max3355_data *data = dev_id;
+	int id = gpiod_get_value_cansleep(data->id_gpiod);
+
+	if (id) {
+		/*
+		 * ID = 1 means USB HOST cable detached.
+		 * As we don't have event for USB peripheral cable attached,
+		 * we simulate USB peripheral attach here.
+		 */
+		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, false);
+		extcon_set_cable_state_(data->edev, EXTCON_USB, true);
+	} else {
+		/*
+		 * ID = 0 means USB HOST cable attached.
+		 * As we don't have event for USB peripheral cable detached,
+		 * we simulate USB peripheral detach here.
+		 */
+		extcon_set_cable_state_(data->edev, EXTCON_USB, false);
+		extcon_set_cable_state_(data->edev, EXTCON_USB_HOST, true);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int max3355_probe(struct platform_device *pdev)
+{
+	struct max3355_data *data;
+	struct gpio_desc *gpiod;
+	int irq, err;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct max3355_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
+	if (IS_ERR(gpiod)) {
+		dev_err(&pdev->dev, "failed to get ID_OUT GPIO\n");
+		return PTR_ERR(gpiod);
+	}
+	data->id_gpiod = gpiod;
+
+	gpiod = devm_gpiod_get(&pdev->dev, "maxim,shdn", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod)) {
+		dev_err(&pdev->dev, "failed to get SHDN# GPIO\n");
+		return PTR_ERR(gpiod);
+	}
+	data->shdn_gpiod = gpiod;
+
+	data->edev = devm_extcon_dev_allocate(&pdev->dev, max3355_cable);
+	if (IS_ERR(data->edev)) {
+		dev_err(&pdev->dev, "failed to allocate extcon device\n");
+		return PTR_ERR(data->edev);
+	}
+
+	err = devm_extcon_dev_register(&pdev->dev, data->edev);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return err;
+	}
+
+	irq = gpiod_to_irq(data->id_gpiod);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to translate ID_OUT GPIO to IRQ\n");
+		return irq;
+	}
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, NULL, max3355_id_irq,
+					IRQF_ONESHOT | IRQF_NO_SUSPEND |
+					IRQF_TRIGGER_RISING |
+					IRQF_TRIGGER_FALLING,
+					pdev->name, data);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to request ID_OUT IRQ\n");
+		return err;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	/* Perform initial detection */
+	max3355_id_irq(irq, data);
+
+	return 0;
+}
+
+static int max3355_remove(struct platform_device *pdev)
+{
+	struct max3355_data *data = platform_get_drvdata(pdev);
+
+	gpiod_set_value_cansleep(data->shdn_gpiod, 0);
+
+	return 0;
+}
+
+static const struct of_device_id max3355_match_table[] = {
+	{ .compatible = "maxim,max3355", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max3355_match_table);
+
+static struct platform_driver max3355_driver = {
+	.probe		= max3355_probe,
+	.remove		= max3355_remove,
+	.driver		= {
+		.name	= "extcon-max3355",
+		.of_match_table = max3355_match_table,
+	},
+};
+
+module_platform_driver(max3355_driver);
+
+MODULE_AUTHOR("Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>");
+MODULE_DESCRIPTION("Maxim MAX3355 extcon driver");
+MODULE_LICENSE("GPL v2");

drivers/extcon/extcon-max77693.c

@@ -1127,11 +1127,11 @@ static int max77693_muic_probe(struct platform_device *pdev)
 	/* Support irq domain for MAX77693 MUIC device */
 	for (i = 0; i < ARRAY_SIZE(muic_irqs); i++) {
 		struct max77693_muic_irq *muic_irq = &muic_irqs[i];
-		unsigned int virq = 0;
+		int virq;
 
 		virq = regmap_irq_get_virq(max77693->irq_data_muic,
 					muic_irq->irq);
-		if (!virq)
+		if (virq <= 0)
 			return -EINVAL;
 		muic_irq->virq = virq;
 

drivers/extcon/extcon-max77843.c

@@ -811,7 +811,7 @@ static int max77843_muic_probe(struct platform_device *pdev)
 
 	for (i = 0; i < ARRAY_SIZE(max77843_muic_irqs); i++) {
 		struct max77843_muic_irq *muic_irq = &max77843_muic_irqs[i];
-		unsigned int virq = 0;
+		int virq = 0;
 
 		virq = regmap_irq_get_virq(max77843->irq_data_muic,
 				muic_irq->irq);

drivers/extcon/extcon-rt8973a.c

@@ -603,7 +603,7 @@ static int rt8973a_muic_i2c_probe(struct i2c_client *i2c,
 
 		ret = devm_request_threaded_irq(info->dev, virq, NULL,
 						rt8973a_muic_irq_handler,
-						IRQF_NO_SUSPEND,
+						IRQF_NO_SUSPEND | IRQF_ONESHOT,
 						muic_irq->name, info);
 		if (ret) {
 			dev_err(info->dev,

drivers/hv/channel.c

@@ -28,6 +28,7 @@
 #include <linux/module.h>
 #include <linux/hyperv.h>
 #include <linux/uio.h>
+#include <linux/interrupt.h>
 
 #include "hyperv_vmbus.h"
 
@@ -496,8 +497,33 @@ static void reset_channel_cb(void *arg)
 static int vmbus_close_internal(struct vmbus_channel *channel)
 {
 	struct vmbus_channel_close_channel *msg;
+	struct tasklet_struct *tasklet;
 	int ret;
 
+	/*
+	 * process_chn_event(), running in the tasklet, can race
+	 * with vmbus_close_internal() in the case of SMP guest, e.g., when
+	 * the former is accessing channel->inbound.ring_buffer, the latter
+	 * could be freeing the ring_buffer pages.
+	 *
+	 * To resolve the race, we can serialize them by disabling the
+	 * tasklet when the latter is running here.
+	 */
+	tasklet = hv_context.event_dpc[channel->target_cpu];
+	tasklet_disable(tasklet);
+
+	/*
+	 * In case a device driver's probe() fails (e.g.,
+	 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
+	 * rescinded later (e.g., we dynamically disble an Integrated Service
+	 * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
+	 * here we should skip most of the below cleanup work.
+	 */
+	if (channel->state != CHANNEL_OPENED_STATE) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	channel->state = CHANNEL_OPEN_STATE;
 	channel->sc_creation_callback = NULL;
 	/* Stop callback and cancel the timer asap */
@@ -525,7 +551,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 		 * If we failed to post the close msg,
 		 * it is perhaps better to leak memory.
 		 */
-		return ret;
+		goto out;
 	}
 
 	/* Tear down the gpadl for the channel's ring buffer */
@@ -538,7 +564,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 			 * If we failed to teardown gpadl,
 			 * it is perhaps better to leak memory.
 			 */
-			return ret;
+			goto out;
 		}
 	}
 
@@ -549,12 +575,9 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	free_pages((unsigned long)channel->ringbuffer_pages,
 		get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 
-	/*
-	 * If the channel has been rescinded; process device removal.
-	 */
-	if (channel->rescind)
-		hv_process_channel_removal(channel,
-					   channel->offermsg.child_relid);
+out:
+	tasklet_enable(tasklet);
+
 	return ret;
 }
 
@@ -630,10 +653,19 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	 *    on the ring. We will not signal if more data is
 	 *    to be placed.
 	 *
+	 * Based on the channel signal state, we will decide
+	 * which signaling policy will be applied.
+	 *
 	 * If we cannot write to the ring-buffer; signal the host
 	 * even if we may not have written anything. This is a rare
 	 * enough condition that it should not matter.
 	 */
+
+	if (channel->signal_policy)
+		signal = true;
+	else
+		kick_q = true;
+
 	if (((ret == 0) && kick_q && signal) || (ret))
 		vmbus_setevent(channel);
 
@@ -733,10 +765,19 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	 *    on the ring. We will not signal if more data is
 	 *    to be placed.
 	 *
+	 * Based on the channel signal state, we will decide
+	 * which signaling policy will be applied.
+	 *
 	 * If we cannot write to the ring-buffer; signal the host
 	 * even if we may not have written anything. This is a rare
 	 * enough condition that it should not matter.
 	 */
+
+	if (channel->signal_policy)
+		signal = true;
+	else
+		kick_q = true;
+
 	if (((ret == 0) && kick_q && signal) || (ret))
 		vmbus_setevent(channel);
 
@@ -881,46 +922,29 @@ EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
  *
  * Mainly used by Hyper-V drivers.
  */
-int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
-			u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
+static inline int
+__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
+		   u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
+		   bool raw)
 {
-	struct vmpacket_descriptor desc;
-	u32 packetlen;
-	u32 userlen;
 	int ret;
 	bool signal = false;
 
-	*buffer_actual_len = 0;
-	*requestid = 0;
-
-
-	ret = hv_ringbuffer_peek(&channel->inbound, &desc,
-			     sizeof(struct vmpacket_descriptor));
-	if (ret != 0)
-		return 0;
-
-	packetlen = desc.len8 << 3;
-	userlen = packetlen - (desc.offset8 << 3);
-
-	*buffer_actual_len = userlen;
-
-	if (userlen > bufferlen) {
-
-		pr_err("Buffer too small - got %d needs %d\n",
-			   bufferlen, userlen);
-		return -ETOOSMALL;
-	}
-
-	*requestid = desc.trans_id;
-
-	/* Copy over the packet to the user buffer */
-	ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
-			     (desc.offset8 << 3), &signal);
+	ret = hv_ringbuffer_read(&channel->inbound, buffer, bufferlen,
+				 buffer_actual_len, requestid, &signal, raw);
 
 	if (signal)
 		vmbus_setevent(channel);
 
-	return 0;
+	return ret;
+}
+
+int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
+		     u32 bufferlen, u32 *buffer_actual_len,
+		     u64 *requestid)
+{
+	return __vmbus_recvpacket(channel, buffer, bufferlen,
+				  buffer_actual_len, requestid, false);
 }
 EXPORT_SYMBOL(vmbus_recvpacket);
 
@@ -931,37 +955,7 @@ int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 			      u32 bufferlen, u32 *buffer_actual_len,
 			      u64 *requestid)
 {
-	struct vmpacket_descriptor desc;
-	u32 packetlen;
-	int ret;
-	bool signal = false;
-
-	*buffer_actual_len = 0;
-	*requestid = 0;
-
-
-	ret = hv_ringbuffer_peek(&channel->inbound, &desc,
-			     sizeof(struct vmpacket_descriptor));
-	if (ret != 0)
-		return 0;
-
-
-	packetlen = desc.len8 << 3;
-
-	*buffer_actual_len = packetlen;
-
-	if (packetlen > bufferlen)
-		return -ENOBUFS;
-
-	*requestid = desc.trans_id;
-
-	/* Copy over the entire packet to the user buffer */
-	ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
-				 &signal);
-
-	if (signal)
-		vmbus_setevent(channel);
-
-	return ret;
+	return __vmbus_recvpacket(channel, buffer, bufferlen,
+				  buffer_actual_len, requestid, true);
 }
 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);

drivers/hv/channel_mgmt.c

@@ -177,19 +177,24 @@ static void percpu_channel_deq(void *arg)
 }
 
 
-void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
+static void vmbus_release_relid(u32 relid)
 {
 	struct vmbus_channel_relid_released msg;
-	unsigned long flags;
-	struct vmbus_channel *primary_channel;
 
 	memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
 	msg.child_relid = relid;
 	msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
 	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
+}
 
-	if (channel == NULL)
-		return;
+void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
+{
+	unsigned long flags;
+	struct vmbus_channel *primary_channel;
+
+	vmbus_release_relid(relid);
+
+	BUG_ON(!channel->rescind);
 
 	if (channel->target_cpu != get_cpu()) {
 		put_cpu();
@@ -201,9 +206,9 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
 	}
 
 	if (channel->primary_channel == NULL) {
-		spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+		mutex_lock(&vmbus_connection.channel_mutex);
 		list_del(&channel->listentry);
-		spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+		mutex_unlock(&vmbus_connection.channel_mutex);
 
 		primary_channel = channel;
 	} else {
@@ -230,9 +235,7 @@ void vmbus_free_channels(void)
 
 	list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list,
 		listentry) {
-		/* if we don't set rescind to true, vmbus_close_internal()
-		 * won't invoke hv_process_channel_removal().
-		 */
+		/* hv_process_channel_removal() needs this */
 		channel->rescind = true;
 
 		vmbus_device_unregister(channel->device_obj);
@@ -250,7 +253,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	unsigned long flags;
 
 	/* Make sure this is a new offer */
-	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+	mutex_lock(&vmbus_connection.channel_mutex);
 
 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 		if (!uuid_le_cmp(channel->offermsg.offer.if_type,
@@ -266,7 +269,7 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 		list_add_tail(&newchannel->listentry,
 			      &vmbus_connection.chn_list);
 
-	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	mutex_unlock(&vmbus_connection.channel_mutex);
 
 	if (!fnew) {
 		/*
@@ -336,9 +339,11 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	return;
 
 err_deq_chan:
-	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+	vmbus_release_relid(newchannel->offermsg.child_relid);
+
+	mutex_lock(&vmbus_connection.channel_mutex);
 	list_del(&newchannel->listentry);
-	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	mutex_unlock(&vmbus_connection.channel_mutex);
 
 	if (newchannel->target_cpu != get_cpu()) {
 		put_cpu();
@@ -356,8 +361,10 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 enum {
 	IDE = 0,
 	SCSI,
+	FC,
 	NIC,
 	ND_NIC,
+	PCIE,
 	MAX_PERF_CHN,
 };
 
@@ -371,10 +378,14 @@ static const struct hv_vmbus_device_id hp_devs[] = {
 	{ HV_IDE_GUID, },
 	/* Storage - SCSI */
 	{ HV_SCSI_GUID, },
+	/* Storage - FC */
+	{ HV_SYNTHFC_GUID, },
 	/* Network */
 	{ HV_NIC_GUID, },
 	/* NetworkDirect Guest RDMA */
 	{ HV_ND_GUID, },
+	/* PCI Express Pass Through */
+	{ HV_PCIE_GUID, },
 };
 
 
@@ -405,8 +416,7 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui
 	struct cpumask *alloced_mask;
 
 	for (i = IDE; i < MAX_PERF_CHN; i++) {
-		if (!memcmp(type_guid->b, hp_devs[i].guid,
-				 sizeof(uuid_le))) {
+		if (!uuid_le_cmp(*type_guid, hp_devs[i].guid)) {
 			perf_chn = true;
 			break;
 		}
@@ -585,7 +595,11 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 	channel = relid2channel(rescind->child_relid);
 
 	if (channel == NULL) {
-		hv_process_channel_removal(NULL, rescind->child_relid);
+		/*
+		 * This is very impossible, because in
+		 * vmbus_process_offer(), we have already invoked
+		 * vmbus_release_relid() on error.
+		 */
 		return;
 	}
 

drivers/hv/connection.c

@@ -83,10 +83,13 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
 	msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
 	msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
-	if (version >= VERSION_WIN8_1) {
-		msg->target_vcpu = hv_context.vp_index[get_cpu()];
-		put_cpu();
-	}
+	/*
+	 * We want all channel messages to be delivered on CPU 0.
+	 * This has been the behavior pre-win8. This is not
+	 * perf issue and having all channel messages delivered on CPU 0
+	 * would be ok.
+	 */
+	msg->target_vcpu = 0;
 
 	/*
 	 * Add to list before we send the request since we may
@@ -146,7 +149,7 @@ int vmbus_connect(void)
 	spin_lock_init(&vmbus_connection.channelmsg_lock);
 
 	INIT_LIST_HEAD(&vmbus_connection.chn_list);
-	spin_lock_init(&vmbus_connection.channel_lock);
+	mutex_init(&vmbus_connection.channel_mutex);
 
 	/*
 	 * Setup the vmbus event connection for channel interrupt
@@ -282,11 +285,10 @@ struct vmbus_channel *relid2channel(u32 relid)
 {
 	struct vmbus_channel *channel;
 	struct vmbus_channel *found_channel  = NULL;
-	unsigned long flags;
 	struct list_head *cur, *tmp;
 	struct vmbus_channel *cur_sc;
 
-	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+	mutex_lock(&vmbus_connection.channel_mutex);
 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 		if (channel->offermsg.child_relid == relid) {
 			found_channel = channel;
@@ -305,7 +307,7 @@ struct vmbus_channel *relid2channel(u32 relid)
 			}
 		}
 	}
-	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	mutex_unlock(&vmbus_connection.channel_mutex);
 
 	return found_channel;
 }

drivers/hv/hv.c

@@ -89,9 +89,9 @@ static int query_hypervisor_info(void)
 }
 
 /*
- * do_hypercall- Invoke the specified hypercall
+ * hv_do_hypercall- Invoke the specified hypercall
  */
-static u64 do_hypercall(u64 control, void *input, void *output)
+u64 hv_do_hypercall(u64 control, void *input, void *output)
 {
 	u64 input_address = (input) ? virt_to_phys(input) : 0;
 	u64 output_address = (output) ? virt_to_phys(output) : 0;
@@ -132,6 +132,7 @@ static u64 do_hypercall(u64 control, void *input, void *output)
 	return hv_status_lo | ((u64)hv_status_hi << 32);
 #endif /* !x86_64 */
 }
+EXPORT_SYMBOL_GPL(hv_do_hypercall);
 
 #ifdef CONFIG_X86_64
 static cycle_t read_hv_clock_tsc(struct clocksource *arg)
@@ -139,7 +140,7 @@ static cycle_t read_hv_clock_tsc(struct clocksource *arg)
 	cycle_t current_tick;
 	struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
 
-	if (tsc_pg->tsc_sequence != -1) {
+	if (tsc_pg->tsc_sequence != 0) {
 		/*
 		 * Use the tsc page to compute the value.
 		 */
@@ -161,7 +162,7 @@ static cycle_t read_hv_clock_tsc(struct clocksource *arg)
 			if (tsc_pg->tsc_sequence == sequence)
 				return current_tick;
 
-			if (tsc_pg->tsc_sequence != -1)
+			if (tsc_pg->tsc_sequence != 0)
 				continue;
 			/*
 			 * Fallback using MSR method.
@@ -192,9 +193,7 @@ int hv_init(void)
 {
 	int max_leaf;
 	union hv_x64_msr_hypercall_contents hypercall_msr;
-	union hv_x64_msr_hypercall_contents tsc_msr;
 	void *virtaddr = NULL;
-	void *va_tsc = NULL;
 
 	memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
 	memset(hv_context.synic_message_page, 0,
@@ -240,6 +239,9 @@ int hv_init(void)
 
 #ifdef CONFIG_X86_64
 	if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
+		union hv_x64_msr_hypercall_contents tsc_msr;
+		void *va_tsc;
+
 		va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
 		if (!va_tsc)
 			goto cleanup;
@@ -315,7 +317,7 @@ int hv_post_message(union hv_connection_id connection_id,
 {
 
 	struct hv_input_post_message *aligned_msg;
-	u16 status;
+	u64 status;
 
 	if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 		return -EMSGSIZE;
@@ -329,11 +331,10 @@ int hv_post_message(union hv_connection_id connection_id,
 	aligned_msg->payload_size = payload_size;
 	memcpy((void *)aligned_msg->payload, payload, payload_size);
 
-	status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
-		& 0xFFFF;
+	status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
 
 	put_cpu();
-	return status;
+	return status & 0xFFFF;
 }
 
 
@@ -343,13 +344,13 @@ int hv_post_message(union hv_connection_id connection_id,
  *
  * This involves a hypercall.
  */
-u16 hv_signal_event(void *con_id)
+int hv_signal_event(void *con_id)
 {
-	u16 status;
+	u64 status;
 
-	status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
+	status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
 
-	return status;
+	return status & 0xFFFF;
 }
 
 static int hv_ce_set_next_event(unsigned long delta,

drivers/hv/hv_fcopy.c

@@ -51,7 +51,6 @@ static struct {
 	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
 	struct vmbus_channel *recv_channel; /* chn we got the request */
 	u64 recv_req_id; /* request ID. */
-	void *fcopy_context; /* for the channel callback */
 } fcopy_transaction;
 
 static void fcopy_respond_to_host(int error);
@@ -67,6 +66,13 @@ static struct hvutil_transport *hvt;
  */
 static int dm_reg_value;
 
+static void fcopy_poll_wrapper(void *channel)
+{
+	/* Transaction is finished, reset the state here to avoid races. */
+	fcopy_transaction.state = HVUTIL_READY;
+	hv_fcopy_onchannelcallback(channel);
+}
+
 static void fcopy_timeout_func(struct work_struct *dummy)
 {
 	/*
@@ -74,13 +80,7 @@ static void fcopy_timeout_func(struct work_struct *dummy)
 	 * process the pending transaction.
 	 */
 	fcopy_respond_to_host(HV_E_FAIL);
-
-	/* Transaction is finished, reset the state. */
-	if (fcopy_transaction.state > HVUTIL_READY)
-		fcopy_transaction.state = HVUTIL_READY;
-
-	hv_poll_channel(fcopy_transaction.fcopy_context,
-			hv_fcopy_onchannelcallback);
+	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 }
 
 static int fcopy_handle_handshake(u32 version)
@@ -108,9 +108,7 @@ static int fcopy_handle_handshake(u32 version)
 		return -EINVAL;
 	}
 	pr_debug("FCP: userspace daemon ver. %d registered\n", version);
-	fcopy_transaction.state = HVUTIL_READY;
-	hv_poll_channel(fcopy_transaction.fcopy_context,
-			hv_fcopy_onchannelcallback);
+	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 	return 0;
 }
 
@@ -227,15 +225,8 @@ void hv_fcopy_onchannelcallback(void *context)
 	int util_fw_version;
 	int fcopy_srv_version;
 
-	if (fcopy_transaction.state > HVUTIL_READY) {
-		/*
-		 * We will defer processing this callback once
-		 * the current transaction is complete.
-		 */
-		fcopy_transaction.fcopy_context = context;
+	if (fcopy_transaction.state > HVUTIL_READY)
 		return;
-	}
-	fcopy_transaction.fcopy_context = NULL;
 
 	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
 			 &requestid);
@@ -275,7 +266,8 @@ void hv_fcopy_onchannelcallback(void *context)
 		 * Send the information to the user-level daemon.
 		 */
 		schedule_work(&fcopy_send_work);
-		schedule_delayed_work(&fcopy_timeout_work, 5*HZ);
+		schedule_delayed_work(&fcopy_timeout_work,
+				      HV_UTIL_TIMEOUT * HZ);
 		return;
 	}
 	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
@@ -304,9 +296,8 @@ static int fcopy_on_msg(void *msg, int len)
 	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
 		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
 		fcopy_respond_to_host(*val);
-		fcopy_transaction.state = HVUTIL_READY;
-		hv_poll_channel(fcopy_transaction.fcopy_context,
-				hv_fcopy_onchannelcallback);
+		hv_poll_channel(fcopy_transaction.recv_channel,
+				fcopy_poll_wrapper);
 	}
 
 	return 0;

drivers/hv/hv_kvp.c

@@ -66,7 +66,6 @@ static struct {
 	struct hv_kvp_msg  *kvp_msg; /* current message */
 	struct vmbus_channel *recv_channel; /* chn we got the request */
 	u64 recv_req_id; /* request ID. */
-	void *kvp_context; /* for the channel callback */
 } kvp_transaction;
 
 /*
@@ -94,6 +93,13 @@ static struct hvutil_transport *hvt;
  */
 #define HV_DRV_VERSION           "3.1"
 
+static void kvp_poll_wrapper(void *channel)
+{
+	/* Transaction is finished, reset the state here to avoid races. */
+	kvp_transaction.state = HVUTIL_READY;
+	hv_kvp_onchannelcallback(channel);
+}
+
 static void
 kvp_register(int reg_value)
 {
@@ -121,12 +127,7 @@ static void kvp_timeout_func(struct work_struct *dummy)
 	 */
 	kvp_respond_to_host(NULL, HV_E_FAIL);
 
-	/* Transaction is finished, reset the state. */
-	if (kvp_transaction.state > HVUTIL_READY)
-		kvp_transaction.state = HVUTIL_READY;
-
-	hv_poll_channel(kvp_transaction.kvp_context,
-			hv_kvp_onchannelcallback);
+	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 }
 
 static int kvp_handle_handshake(struct hv_kvp_msg *msg)
@@ -153,7 +154,7 @@ static int kvp_handle_handshake(struct hv_kvp_msg *msg)
 	pr_debug("KVP: userspace daemon ver. %d registered\n",
 		 KVP_OP_REGISTER);
 	kvp_register(dm_reg_value);
-	kvp_transaction.state = HVUTIL_READY;
+	hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 
 	return 0;
 }
@@ -218,9 +219,7 @@ static int kvp_on_msg(void *msg, int len)
 	 */
 	if (cancel_delayed_work_sync(&kvp_timeout_work)) {
 		kvp_respond_to_host(message, error);
-		kvp_transaction.state = HVUTIL_READY;
-		hv_poll_channel(kvp_transaction.kvp_context,
-				hv_kvp_onchannelcallback);
+		hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
 	}
 
 	return 0;
@@ -596,15 +595,8 @@ void hv_kvp_onchannelcallback(void *context)
 	int util_fw_version;
 	int kvp_srv_version;
 
-	if (kvp_transaction.state > HVUTIL_READY) {
-		/*
-		 * We will defer processing this callback once
-		 * the current transaction is complete.
-		 */
-		kvp_transaction.kvp_context = context;
+	if (kvp_transaction.state > HVUTIL_READY)
 		return;
-	}
-	kvp_transaction.kvp_context = NULL;
 
 	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
 			 &requestid);
@@ -668,7 +660,8 @@ void hv_kvp_onchannelcallback(void *context)
 			 * user-mode not responding.
 			 */
 			schedule_work(&kvp_sendkey_work);
-			schedule_delayed_work(&kvp_timeout_work, 5*HZ);
+			schedule_delayed_work(&kvp_timeout_work,
+					      HV_UTIL_TIMEOUT * HZ);
 
 			return;
 

drivers/hv/hv_snapshot.c

@@ -53,7 +53,6 @@ static struct {
 	struct vmbus_channel *recv_channel; /* chn we got the request */
 	u64 recv_req_id; /* request ID. */
 	struct hv_vss_msg  *msg; /* current message */
-	void *vss_context; /* for the channel callback */
 } vss_transaction;
 
 
@@ -74,6 +73,13 @@ static void vss_timeout_func(struct work_struct *dummy);
 static DECLARE_DELAYED_WORK(vss_timeout_work, vss_timeout_func);
 static DECLARE_WORK(vss_send_op_work, vss_send_op);
 
+static void vss_poll_wrapper(void *channel)
+{
+	/* Transaction is finished, reset the state here to avoid races. */
+	vss_transaction.state = HVUTIL_READY;
+	hv_vss_onchannelcallback(channel);
+}
+
 /*
  * Callback when data is received from user mode.
  */
@@ -86,12 +92,7 @@ static void vss_timeout_func(struct work_struct *dummy)
 	pr_warn("VSS: timeout waiting for daemon to reply\n");
 	vss_respond_to_host(HV_E_FAIL);
 
-	/* Transaction is finished, reset the state. */
-	if (vss_transaction.state > HVUTIL_READY)
-		vss_transaction.state = HVUTIL_READY;
-
-	hv_poll_channel(vss_transaction.vss_context,
-			hv_vss_onchannelcallback);
+	hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper);
 }
 
 static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
@@ -112,7 +113,7 @@ static int vss_handle_handshake(struct hv_vss_msg *vss_msg)
 	default:
 		return -EINVAL;
 	}
-	vss_transaction.state = HVUTIL_READY;
+	hv_poll_channel(vss_transaction.recv_channel, vss_poll_wrapper);
 	pr_debug("VSS: userspace daemon ver. %d registered\n", dm_reg_value);
 	return 0;
 }
@@ -138,9 +139,8 @@ static int vss_on_msg(void *msg, int len)
 		if (cancel_delayed_work_sync(&vss_timeout_work)) {
 			vss_respond_to_host(vss_msg->error);
 			/* Transaction is finished, reset the state. */
-			vss_transaction.state = HVUTIL_READY;
-			hv_poll_channel(vss_transaction.vss_context,
-					hv_vss_onchannelcallback);
+			hv_poll_channel(vss_transaction.recv_channel,
+					vss_poll_wrapper);
 		}
 	} else {
 		/* This is a spurious call! */
@@ -238,15 +238,8 @@ void hv_vss_onchannelcallback(void *context)
 	struct icmsg_hdr *icmsghdrp;
 	struct icmsg_negotiate *negop = NULL;
 
-	if (vss_transaction.state > HVUTIL_READY) {
-		/*
-		 * We will defer processing this callback once
-		 * the current transaction is complete.
-		 */
-		vss_transaction.vss_context = context;
+	if (vss_transaction.state > HVUTIL_READY)
 		return;
-	}
-	vss_transaction.vss_context = NULL;
 
 	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
 			 &requestid);
@@ -338,6 +331,11 @@ static void vss_on_reset(void)
 int
 hv_vss_init(struct hv_util_service *srv)
 {
+	if (vmbus_proto_version < VERSION_WIN8_1) {
+		pr_warn("Integration service 'Backup (volume snapshot)'"
+			" not supported on this host version.\n");
+		return -ENOTSUPP;
+	}
 	recv_buffer = srv->recv_buffer;
 
 	/*

drivers/hv/hv_utils_transport.c

@@ -27,11 +27,9 @@ static struct list_head hvt_list = LIST_HEAD_INIT(hvt_list);
 
 static void hvt_reset(struct hvutil_transport *hvt)
 {
-	mutex_lock(&hvt->outmsg_lock);
 	kfree(hvt->outmsg);
 	hvt->outmsg = NULL;
 	hvt->outmsg_len = 0;
-	mutex_unlock(&hvt->outmsg_lock);
 	if (hvt->on_reset)
 		hvt->on_reset();
 }
@@ -44,10 +42,17 @@ static ssize_t hvt_op_read(struct file *file, char __user *buf,
 
 	hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
-	if (wait_event_interruptible(hvt->outmsg_q, hvt->outmsg_len > 0))
+	if (wait_event_interruptible(hvt->outmsg_q, hvt->outmsg_len > 0 ||
+				     hvt->mode != HVUTIL_TRANSPORT_CHARDEV))
 		return -EINTR;
 
-	mutex_lock(&hvt->outmsg_lock);
+	mutex_lock(&hvt->lock);
+
+	if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) {
+		ret = -EBADF;
+		goto out_unlock;
+	}
+
 	if (!hvt->outmsg) {
 		ret = -EAGAIN;
 		goto out_unlock;
@@ -68,7 +73,7 @@ static ssize_t hvt_op_read(struct file *file, char __user *buf,
 	hvt->outmsg_len = 0;
 
 out_unlock:
-	mutex_unlock(&hvt->outmsg_lock);
+	mutex_unlock(&hvt->lock);
 	return ret;
 }
 
@@ -77,19 +82,22 @@ static ssize_t hvt_op_write(struct file *file, const char __user *buf,
 {
 	struct hvutil_transport *hvt;
 	u8 *inmsg;
+	int ret;
 
 	hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
-	inmsg = kzalloc(count, GFP_KERNEL);
-	if (copy_from_user(inmsg, buf, count)) {
-		kfree(inmsg);
-		return -EFAULT;
-	}
-	if (hvt->on_msg(inmsg, count))
-		return -EFAULT;
+	inmsg = memdup_user(buf, count);
+	if (IS_ERR(inmsg))
+		return PTR_ERR(inmsg);
+
+	if (hvt->mode == HVUTIL_TRANSPORT_DESTROY)
+		ret = -EBADF;
+	else
+		ret = hvt->on_msg(inmsg, count);
+
 	kfree(inmsg);
 
-	return count;
+	return ret ? ret : count;
 }
 
 static unsigned int hvt_op_poll(struct file *file, poll_table *wait)
@@ -99,6 +107,10 @@ static unsigned int hvt_op_poll(struct file *file, poll_table *wait)
 	hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
 	poll_wait(file, &hvt->outmsg_q, wait);
+
+	if (hvt->mode == HVUTIL_TRANSPORT_DESTROY)
+		return POLLERR | POLLHUP;
+
 	if (hvt->outmsg_len > 0)
 		return POLLIN | POLLRDNORM;
 
@@ -108,40 +120,68 @@ static unsigned int hvt_op_poll(struct file *file, poll_table *wait)
 static int hvt_op_open(struct inode *inode, struct file *file)
 {
 	struct hvutil_transport *hvt;
+	int ret = 0;
+	bool issue_reset = false;
 
 	hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
-	/*
-	 * Switching to CHARDEV mode. We switch bach to INIT when device
-	 * gets released.
-	 */
-	if (hvt->mode == HVUTIL_TRANSPORT_INIT)
+	mutex_lock(&hvt->lock);
+
+	if (hvt->mode == HVUTIL_TRANSPORT_DESTROY) {
+		ret = -EBADF;
+	} else if (hvt->mode == HVUTIL_TRANSPORT_INIT) {
+		/*
+		 * Switching to CHARDEV mode. We switch bach to INIT when
+		 * device gets released.
+		 */
 		hvt->mode = HVUTIL_TRANSPORT_CHARDEV;
+	}
 	else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) {
 		/*
 		 * We're switching from netlink communication to using char
 		 * device. Issue the reset first.
 		 */
-		hvt_reset(hvt);
+		issue_reset = true;
 		hvt->mode = HVUTIL_TRANSPORT_CHARDEV;
-	} else
-		return -EBUSY;
+	} else {
+		ret = -EBUSY;
+	}
 
-	return 0;
+	if (issue_reset)
+		hvt_reset(hvt);
+
+	mutex_unlock(&hvt->lock);
+
+	return ret;
+}
+
+static void hvt_transport_free(struct hvutil_transport *hvt)
+{
+	misc_deregister(&hvt->mdev);
+	kfree(hvt->outmsg);
+	kfree(hvt);
 }
 
 static int hvt_op_release(struct inode *inode, struct file *file)
 {
 	struct hvutil_transport *hvt;
+	int mode_old;
 
 	hvt = container_of(file->f_op, struct hvutil_transport, fops);
 
-	hvt->mode = HVUTIL_TRANSPORT_INIT;
+	mutex_lock(&hvt->lock);
+	mode_old = hvt->mode;
+	if (hvt->mode != HVUTIL_TRANSPORT_DESTROY)
+		hvt->mode = HVUTIL_TRANSPORT_INIT;
 	/*
 	 * Cleanup message buffers to avoid spurious messages when the daemon
 	 * connects back.
 	 */
 	hvt_reset(hvt);
+	mutex_unlock(&hvt->lock);
+
+	if (mode_old == HVUTIL_TRANSPORT_DESTROY)
+		hvt_transport_free(hvt);
 
 	return 0;
 }
@@ -168,6 +208,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 	 * Switching to NETLINK mode. Switching to CHARDEV happens when someone
 	 * opens the device.
 	 */
+	mutex_lock(&hvt->lock);
 	if (hvt->mode == HVUTIL_TRANSPORT_INIT)
 		hvt->mode = HVUTIL_TRANSPORT_NETLINK;
 
@@ -175,6 +216,7 @@ static void hvt_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 		hvt_found->on_msg(msg->data, msg->len);
 	else
 		pr_warn("hvt_cn_callback: unexpected netlink message!\n");
+	mutex_unlock(&hvt->lock);
 }
 
 int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len)
@@ -182,7 +224,8 @@ int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len)
 	struct cn_msg *cn_msg;
 	int ret = 0;
 
-	if (hvt->mode == HVUTIL_TRANSPORT_INIT) {
+	if (hvt->mode == HVUTIL_TRANSPORT_INIT ||
+	    hvt->mode == HVUTIL_TRANSPORT_DESTROY) {
 		return -EINVAL;
 	} else if (hvt->mode == HVUTIL_TRANSPORT_NETLINK) {
 		cn_msg = kzalloc(sizeof(*cn_msg) + len, GFP_ATOMIC);
@@ -197,18 +240,26 @@ int hvutil_transport_send(struct hvutil_transport *hvt, void *msg, int len)
 		return ret;
 	}
 	/* HVUTIL_TRANSPORT_CHARDEV */
-	mutex_lock(&hvt->outmsg_lock);
+	mutex_lock(&hvt->lock);
+	if (hvt->mode != HVUTIL_TRANSPORT_CHARDEV) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
 	if (hvt->outmsg) {
 		/* Previous message wasn't received */
 		ret = -EFAULT;
 		goto out_unlock;
 	}
 	hvt->outmsg = kzalloc(len, GFP_KERNEL);
-	memcpy(hvt->outmsg, msg, len);
-	hvt->outmsg_len = len;
-	wake_up_interruptible(&hvt->outmsg_q);
+	if (hvt->outmsg) {
+		memcpy(hvt->outmsg, msg, len);
+		hvt->outmsg_len = len;
+		wake_up_interruptible(&hvt->outmsg_q);
+	} else
+		ret = -ENOMEM;
 out_unlock:
-	mutex_unlock(&hvt->outmsg_lock);
+	mutex_unlock(&hvt->lock);
 	return ret;
 }
 
@@ -239,7 +290,7 @@ struct hvutil_transport *hvutil_transport_init(const char *name,
 	hvt->mdev.fops = &hvt->fops;
 
 	init_waitqueue_head(&hvt->outmsg_q);
-	mutex_init(&hvt->outmsg_lock);
+	mutex_init(&hvt->lock);
 
 	spin_lock(&hvt_list_lock);
 	list_add(&hvt->list, &hvt_list);
@@ -265,12 +316,25 @@ struct hvutil_transport *hvutil_transport_init(const char *name,
 
 void hvutil_transport_destroy(struct hvutil_transport *hvt)
 {
+	int mode_old;
+
+	mutex_lock(&hvt->lock);
+	mode_old = hvt->mode;
+	hvt->mode = HVUTIL_TRANSPORT_DESTROY;
+	wake_up_interruptible(&hvt->outmsg_q);
+	mutex_unlock(&hvt->lock);
+
+	/*
+	 * In case we were in 'chardev' mode we still have an open fd so we
+	 * have to defer freeing the device. Netlink interface can be freed
+	 * now.
+	 */
 	spin_lock(&hvt_list_lock);
 	list_del(&hvt->list);
 	spin_unlock(&hvt_list_lock);
 	if (hvt->cn_id.idx > 0 && hvt->cn_id.val > 0)
 		cn_del_callback(&hvt->cn_id);
-	misc_deregister(&hvt->mdev);
-	kfree(hvt->outmsg);
-	kfree(hvt);
+
+	if (mode_old != HVUTIL_TRANSPORT_CHARDEV)
+		hvt_transport_free(hvt);
 }

drivers/hv/hv_utils_transport.h

@@ -25,6 +25,7 @@ enum hvutil_transport_mode {
 	HVUTIL_TRANSPORT_INIT = 0,
 	HVUTIL_TRANSPORT_NETLINK,
 	HVUTIL_TRANSPORT_CHARDEV,
+	HVUTIL_TRANSPORT_DESTROY,
 };
 
 struct hvutil_transport {
@@ -38,7 +39,7 @@ struct hvutil_transport {
 	u8 *outmsg;                         /* message to the userspace */
 	int outmsg_len;                     /* its length */
 	wait_queue_head_t outmsg_q;         /* poll/read wait queue */
-	struct mutex outmsg_lock;           /* protects outmsg */
+	struct mutex lock;                  /* protects struct members */
 };
 
 struct hvutil_transport *hvutil_transport_init(const char *name,

drivers/hv/hyperv_vmbus.h

@@ -30,6 +30,11 @@
 #include <linux/atomic.h>
 #include <linux/hyperv.h>
 
+/*
+ * Timeout for services such as KVP and fcopy.
+ */
+#define HV_UTIL_TIMEOUT 30
+
 /*
  * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
  * is set by CPUID(HVCPUID_VERSION_FEATURES).
@@ -496,7 +501,7 @@ extern int hv_post_message(union hv_connection_id connection_id,
 			 enum hv_message_type message_type,
 			 void *payload, size_t payload_size);
 
-extern u16 hv_signal_event(void *con_id);
+extern int hv_signal_event(void *con_id);
 
 extern int hv_synic_alloc(void);
 
@@ -528,14 +533,9 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
 		    struct kvec *kv_list,
 		    u32 kv_count, bool *signal);
 
-int hv_ringbuffer_peek(struct hv_ring_buffer_info *ring_info, void *buffer,
-		   u32 buflen);
-
-int hv_ringbuffer_read(struct hv_ring_buffer_info *ring_info,
-		   void *buffer,
-		   u32 buflen,
-		   u32 offset, bool *signal);
-
+int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
+		       void *buffer, u32 buflen, u32 *buffer_actual_len,
+		       u64 *requestid, bool *signal, bool raw);
 
 void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 			    struct hv_ring_buffer_debug_info *debug_info);
@@ -592,7 +592,7 @@ struct vmbus_connection {
 
 	/* List of channels */
 	struct list_head chn_list;
-	spinlock_t channel_lock;
+	struct mutex channel_mutex;
 
 	struct workqueue_struct *work_queue;
 };
@@ -673,11 +673,7 @@ static inline void hv_poll_channel(struct vmbus_channel *channel,
 	if (!channel)
 		return;
 
-	if (channel->target_cpu != smp_processor_id())
-		smp_call_function_single(channel->target_cpu,
-					 cb, channel, true);
-	else
-		cb(channel);
+	smp_call_function_single(channel->target_cpu, cb, channel, true);
 }
 
 enum hvutil_device_state {

drivers/hv/ring_buffer.c

@@ -112,9 +112,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz,
 	u32 read_loc = rbi->ring_buffer->read_index;
 	u32 pending_sz = rbi->ring_buffer->pending_send_sz;
 
-	/*
-	 * If the other end is not blocked on write don't bother.
-	 */
+	/* If the other end is not blocked on write don't bother. */
 	if (pending_sz == 0)
 		return false;
 
@@ -128,12 +126,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz,
 	return false;
 }
 
-/*
- * hv_get_next_write_location()
- *
- * Get the next write location for the specified ring buffer
- *
- */
+/* Get the next write location for the specified ring buffer. */
 static inline u32
 hv_get_next_write_location(struct hv_ring_buffer_info *ring_info)
 {
@@ -142,12 +135,7 @@ hv_get_next_write_location(struct hv_ring_buffer_info *ring_info)
 	return next;
 }
 
-/*
- * hv_set_next_write_location()
- *
- * Set the next write location for the specified ring buffer
- *
- */
+/* Set the next write location for the specified ring buffer. */
 static inline void
 hv_set_next_write_location(struct hv_ring_buffer_info *ring_info,
 		     u32 next_write_location)
@@ -155,11 +143,7 @@ hv_set_next_write_location(struct hv_ring_buffer_info *ring_info,
 	ring_info->ring_buffer->write_index = next_write_location;
 }
 
-/*
- * hv_get_next_read_location()
- *
- * Get the next read location for the specified ring buffer
- */
+/* Get the next read location for the specified ring buffer. */
 static inline u32
 hv_get_next_read_location(struct hv_ring_buffer_info *ring_info)
 {
@@ -169,10 +153,8 @@ hv_get_next_read_location(struct hv_ring_buffer_info *ring_info)
 }
 
 /*
- * hv_get_next_readlocation_withoffset()
- *
  * Get the next read location + offset for the specified ring buffer.
- * This allows the caller to skip
+ * This allows the caller to skip.
  */
 static inline u32
 hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info,
@@ -186,13 +168,7 @@ hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info,
 	return next;
 }
 
-/*
- *
- * hv_set_next_read_location()
- *
- * Set the next read location for the specified ring buffer
- *
- */
+/* Set the next read location for the specified ring buffer. */
 static inline void
 hv_set_next_read_location(struct hv_ring_buffer_info *ring_info,
 		    u32 next_read_location)
@@ -201,12 +177,7 @@ hv_set_next_read_location(struct hv_ring_buffer_info *ring_info,
 }
 
 
-/*
- *
- * hv_get_ring_buffer()
- *
- * Get the start of the ring buffer
- */
+/* Get the start of the ring buffer. */
 static inline void *
 hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info)
 {
@@ -214,25 +185,14 @@ hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info)
 }
 
 
-/*
- *
- * hv_get_ring_buffersize()
- *
- * Get the size of the ring buffer
- */
+/* Get the size of the ring buffer. */
 static inline u32
 hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info)
 {
 	return ring_info->ring_datasize;
 }
 
-/*
- *
- * hv_get_ring_bufferindices()
- *
- * Get the read and write indices as u64 of the specified ring buffer
- *
- */
+/* Get the read and write indices as u64 of the specified ring buffer. */
 static inline u64
 hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info)
 {
@@ -240,12 +200,8 @@ hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info)
 }
 
 /*
- *
- * hv_copyfrom_ringbuffer()
- *
  * Helper routine to copy to source from ring buffer.
  * Assume there is enough room. Handles wrap-around in src case only!!
- *
  */
 static u32 hv_copyfrom_ringbuffer(
 	struct hv_ring_buffer_info	*ring_info,
@@ -277,12 +233,8 @@ static u32 hv_copyfrom_ringbuffer(
 
 
 /*
- *
- * hv_copyto_ringbuffer()
- *
  * Helper routine to copy from source to ring buffer.
  * Assume there is enough room. Handles wrap-around in dest case only!!
- *
  */
 static u32 hv_copyto_ringbuffer(
 	struct hv_ring_buffer_info	*ring_info,
@@ -308,13 +260,7 @@ static u32 hv_copyto_ringbuffer(
 	return start_write_offset;
 }
 
-/*
- *
- * hv_ringbuffer_get_debuginfo()
- *
- * Get various debug metrics for the specified ring buffer
- *
- */
+/* Get various debug metrics for the specified ring buffer. */
 void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 			    struct hv_ring_buffer_debug_info *debug_info)
 {
@@ -337,13 +283,7 @@ void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
 	}
 }
 
-/*
- *
- * hv_ringbuffer_init()
- *
- *Initialize the ring buffer
- *
- */
+/* Initialize the ring buffer. */
 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 		   void *buffer, u32 buflen)
 {
@@ -356,9 +296,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 	ring_info->ring_buffer->read_index =
 		ring_info->ring_buffer->write_index = 0;
 
-	/*
-	 * Set the feature bit for enabling flow control.
-	 */
+	/* Set the feature bit for enabling flow control. */
 	ring_info->ring_buffer->feature_bits.value = 1;
 
 	ring_info->ring_size = buflen;
@@ -369,24 +307,12 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
 	return 0;
 }
 
-/*
- *
- * hv_ringbuffer_cleanup()
- *
- * Cleanup the ring buffer
- *
- */
+/* Cleanup the ring buffer. */
 void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 {
 }
 
-/*
- *
- * hv_ringbuffer_write()
- *
- * Write to the ring buffer
- *
- */
+/* Write to the ring buffer. */
 int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 		    struct kvec *kv_list, u32 kv_count, bool *signal)
 {
@@ -411,10 +337,11 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 				&bytes_avail_toread,
 				&bytes_avail_towrite);
 
-
-	/* If there is only room for the packet, assume it is full. */
-	/* Otherwise, the next time around, we think the ring buffer */
-	/* is empty since the read index == write index */
+	/*
+	 * If there is only room for the packet, assume it is full.
+	 * Otherwise, the next time around, we think the ring buffer
+	 * is empty since the read index == write index.
+	 */
 	if (bytes_avail_towrite <= totalbytes_towrite) {
 		spin_unlock_irqrestore(&outring_info->ring_lock, flags);
 		return -EAGAIN;
@@ -453,80 +380,59 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 	return 0;
 }
 
-
-/*
- *
- * hv_ringbuffer_peek()
- *
- * Read without advancing the read index
- *
- */
-int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info,
-		   void *Buffer, u32 buflen)
-{
-	u32 bytes_avail_towrite;
-	u32 bytes_avail_toread;
-	u32 next_read_location = 0;
-	unsigned long flags;
-
-	spin_lock_irqsave(&Inring_info->ring_lock, flags);
-
-	hv_get_ringbuffer_availbytes(Inring_info,
-				&bytes_avail_toread,
-				&bytes_avail_towrite);
-
-	/* Make sure there is something to read */
-	if (bytes_avail_toread < buflen) {
-
-		spin_unlock_irqrestore(&Inring_info->ring_lock, flags);
-
-		return -EAGAIN;
-	}
-
-	/* Convert to byte offset */
-	next_read_location = hv_get_next_read_location(Inring_info);
-
-	next_read_location = hv_copyfrom_ringbuffer(Inring_info,
-						Buffer,
-						buflen,
-						next_read_location);
-
-	spin_unlock_irqrestore(&Inring_info->ring_lock, flags);
-
-	return 0;
-}
-
-
-/*
- *
- * hv_ringbuffer_read()
- *
- * Read and advance the read index
- *
- */
-int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
-		   u32 buflen, u32 offset, bool *signal)
+int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
+		       void *buffer, u32 buflen, u32 *buffer_actual_len,
+		       u64 *requestid, bool *signal, bool raw)
 {
 	u32 bytes_avail_towrite;
 	u32 bytes_avail_toread;
 	u32 next_read_location = 0;
 	u64 prev_indices = 0;
 	unsigned long flags;
+	struct vmpacket_descriptor desc;
+	u32 offset;
+	u32 packetlen;
+	int ret = 0;
 
 	if (buflen <= 0)
 		return -EINVAL;
 
 	spin_lock_irqsave(&inring_info->ring_lock, flags);
 
+	*buffer_actual_len = 0;
+	*requestid = 0;
+
 	hv_get_ringbuffer_availbytes(inring_info,
 				&bytes_avail_toread,
 				&bytes_avail_towrite);
 
 	/* Make sure there is something to read */
-	if (bytes_avail_toread < buflen) {
-		spin_unlock_irqrestore(&inring_info->ring_lock, flags);
+	if (bytes_avail_toread < sizeof(desc)) {
+		/*
+		 * No error is set when there is even no header, drivers are
+		 * supposed to analyze buffer_actual_len.
+		 */
+		goto out_unlock;
+	}
 
-		return -EAGAIN;
+	next_read_location = hv_get_next_read_location(inring_info);
+	next_read_location = hv_copyfrom_ringbuffer(inring_info, &desc,
+						    sizeof(desc),
+						    next_read_location);
+
+	offset = raw ? 0 : (desc.offset8 << 3);
+	packetlen = (desc.len8 << 3) - offset;
+	*buffer_actual_len = packetlen;
+	*requestid = desc.trans_id;
+
+	if (bytes_avail_toread < packetlen + offset) {
+		ret = -EAGAIN;
+		goto out_unlock;
+	}
+
+	if (packetlen > buflen) {
+		ret = -ENOBUFS;
+		goto out_unlock;
 	}
 
 	next_read_location =
@@ -534,7 +440,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
 
 	next_read_location = hv_copyfrom_ringbuffer(inring_info,
 						buffer,
-						buflen,
+						packetlen,
 						next_read_location);
 
 	next_read_location = hv_copyfrom_ringbuffer(inring_info,
@@ -542,17 +448,19 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer,
 						sizeof(u64),
 						next_read_location);
 
-	/* Make sure all reads are done before we update the read index since */
-	/* the writer may start writing to the read area once the read index */
-	/*is updated */
+	/*
+	 * Make sure all reads are done before we update the read index since
+	 * the writer may start writing to the read area once the read index
+	 * is updated.
+	 */
 	mb();
 
 	/* Update the read index */
 	hv_set_next_read_location(inring_info, next_read_location);
 
-	spin_unlock_irqrestore(&inring_info->ring_lock, flags);
-
 	*signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
 
-	return 0;
+out_unlock:
+	spin_unlock_irqrestore(&inring_info->ring_lock, flags);
+	return ret;
 }

drivers/hv/vmbus_drv.c

@@ -47,7 +47,6 @@ static struct acpi_device  *hv_acpi_dev;
 
 static struct tasklet_struct msg_dpc;
 static struct completion probe_event;
-static int irq;
 
 
 static void hyperv_report_panic(struct pt_regs *regs)
@@ -531,9 +530,9 @@ static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 
 static const uuid_le null_guid;
 
-static inline bool is_null_guid(const __u8 *guid)
+static inline bool is_null_guid(const uuid_le *guid)
 {
-	if (memcmp(guid, &null_guid, sizeof(uuid_le)))
+	if (uuid_le_cmp(*guid, null_guid))
 		return false;
 	return true;
 }
@@ -544,10 +543,10 @@ static inline bool is_null_guid(const __u8 *guid)
  */
 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 					const struct hv_vmbus_device_id *id,
-					const __u8 *guid)
+					const uuid_le *guid)
 {
-	for (; !is_null_guid(id->guid); id++)
-		if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
+	for (; !is_null_guid(&id->guid); id++)
+		if (!uuid_le_cmp(id->guid, *guid))
 			return id;
 
 	return NULL;
@@ -563,7 +562,7 @@ static int vmbus_match(struct device *device, struct device_driver *driver)
 	struct hv_driver *drv = drv_to_hv_drv(driver);
 	struct hv_device *hv_dev = device_to_hv_device(device);
 
-	if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
+	if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
 		return 1;
 
 	return 0;
@@ -580,7 +579,7 @@ static int vmbus_probe(struct device *child_device)
 	struct hv_device *dev = device_to_hv_device(child_device);
 	const struct hv_vmbus_device_id *dev_id;
 
-	dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
+	dev_id = hv_vmbus_get_id(drv->id_table, &dev->dev_type);
 	if (drv->probe) {
 		ret = drv->probe(dev, dev_id);
 		if (ret != 0)
@@ -602,23 +601,11 @@ static int vmbus_remove(struct device *child_device)
 {
 	struct hv_driver *drv;
 	struct hv_device *dev = device_to_hv_device(child_device);
-	u32 relid = dev->channel->offermsg.child_relid;
 
 	if (child_device->driver) {
 		drv = drv_to_hv_drv(child_device->driver);
 		if (drv->remove)
 			drv->remove(dev);
-		else {
-			hv_process_channel_removal(dev->channel, relid);
-			pr_err("remove not set for driver %s\n",
-				dev_name(child_device));
-		}
-	} else {
-		/*
-		 * We don't have a driver for this device; deal with the
-		 * rescind message by removing the channel.
-		 */
-		hv_process_channel_removal(dev->channel, relid);
 	}
 
 	return 0;
@@ -653,7 +640,10 @@ static void vmbus_shutdown(struct device *child_device)
 static void vmbus_device_release(struct device *device)
 {
 	struct hv_device *hv_dev = device_to_hv_device(device);
+	struct vmbus_channel *channel = hv_dev->channel;
 
+	hv_process_channel_removal(channel,
+				   channel->offermsg.child_relid);
 	kfree(hv_dev);
 
 }
@@ -835,10 +825,9 @@ static void vmbus_isr(void)
  * Here, we
  *	- initialize the vmbus driver context
  *	- invoke the vmbus hv main init routine
- *	- get the irq resource
  *	- retrieve the channel offers
  */
-static int vmbus_bus_init(int irq)
+static int vmbus_bus_init(void)
 {
 	int ret;
 
@@ -867,7 +856,7 @@ static int vmbus_bus_init(int irq)
 	on_each_cpu(hv_synic_init, NULL, 1);
 	ret = vmbus_connect();
 	if (ret)
-		goto err_alloc;
+		goto err_connect;
 
 	if (vmbus_proto_version > VERSION_WIN7)
 		cpu_hotplug_disable();
@@ -885,6 +874,8 @@ static int vmbus_bus_init(int irq)
 
 	return 0;
 
+err_connect:
+	on_each_cpu(hv_synic_cleanup, NULL, 1);
 err_alloc:
 	hv_synic_free();
 	hv_remove_vmbus_irq();
@@ -1031,9 +1022,6 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 	struct resource **prev_res = NULL;
 
 	switch (res->type) {
-	case ACPI_RESOURCE_TYPE_IRQ:
-		irq = res->data.irq.interrupts[0];
-		return AE_OK;
 
 	/*
 	 * "Address" descriptors are for bus windows. Ignore
@@ -1075,12 +1063,28 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
 	new_res->start = start;
 	new_res->end = end;
 
+	/*
+	 * Stick ranges from higher in address space at the front of the list.
+	 * If two ranges are adjacent, merge them.
+	 */
 	do {
 		if (!*old_res) {
 			*old_res = new_res;
 			break;
 		}
 
+		if (((*old_res)->end + 1) == new_res->start) {
+			(*old_res)->end = new_res->end;
+			kfree(new_res);
+			break;
+		}
+
+		if ((*old_res)->start == new_res->end + 1) {
+			(*old_res)->start = new_res->start;
+			kfree(new_res);
+			break;
+		}
+
 		if ((*old_res)->end < new_res->start) {
 			new_res->sibling = *old_res;
 			if (prev_res)
@@ -1191,6 +1195,23 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 }
 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
 
+/**
+ * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
+ * @cpu_number: CPU number in Linux terms
+ *
+ * This function returns the mapping between the Linux processor
+ * number and the hypervisor's virtual processor number, useful
+ * in making hypercalls and such that talk about specific
+ * processors.
+ *
+ * Return: Virtual processor number in Hyper-V terms
+ */
+int vmbus_cpu_number_to_vp_number(int cpu_number)
+{
+	return hv_context.vp_index[cpu_number];
+}
+EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
+
 static int vmbus_acpi_add(struct acpi_device *device)
 {
 	acpi_status result;
@@ -1275,7 +1296,7 @@ static int __init hv_acpi_init(void)
 	init_completion(&probe_event);
 
 	/*
-	 * Get irq resources first.
+	 * Get ACPI resources first.
 	 */
 	ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 
@@ -1288,12 +1309,7 @@ static int __init hv_acpi_init(void)
 		goto cleanup;
 	}
 
-	if (irq <= 0) {
-		ret = -ENODEV;
-		goto cleanup;
-	}
-
-	ret = vmbus_bus_init(irq);
+	ret = vmbus_bus_init();
 	if (ret)
 		goto cleanup;
 

drivers/hwtracing/coresight/Kconfig

@@ -8,7 +8,7 @@ menuconfig CORESIGHT
 	  This framework provides a kernel interface for the CoreSight debug
 	  and trace drivers to register themselves with. It's intended to build
 	  a topological view of the CoreSight components based on a DT
-	  specification and configure the right serie of components when a
+	  specification and configure the right series of components when a
 	  trace source gets enabled.
 
 if CORESIGHT

drivers/hwtracing/coresight/coresight.c

@@ -548,7 +548,7 @@ static int coresight_name_match(struct device *dev, void *data)
 	to_match = data;
 	i_csdev = to_coresight_device(dev);
 
-	if (!strcmp(to_match, dev_name(&i_csdev->dev)))
+	if (to_match && !strcmp(to_match, dev_name(&i_csdev->dev)))
 		return 1;
 
 	return 0;

drivers/input/serio/hyperv-keyboard.c

@@ -412,16 +412,6 @@ static int hv_kbd_remove(struct hv_device *hv_dev)
 	return 0;
 }
 
-/*
- * Keyboard GUID
- * {f912ad6d-2b17-48ea-bd65-f927a61c7684}
- */
-#define HV_KBD_GUID \
-	.guid = { \
-			0x6d, 0xad, 0x12, 0xf9, 0x17, 0x2b, 0xea, 0x48, \
-			0xbd, 0x65, 0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84 \
-	}
-
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Keyboard guid */
 	{ HV_KBD_GUID, },

drivers/misc/mei/main.c

@@ -657,7 +657,9 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
  * @file: pointer to file structure
  * @band: band bitmap
  *
- * Return: poll mask
+ * Return: negative on error,
+ *         0 if it did no changes,
+ *         and positive a process was added or deleted
  */
 static int mei_fasync(int fd, struct file *file, int band)
 {
@@ -665,7 +667,7 @@ static int mei_fasync(int fd, struct file *file, int band)
 	struct mei_cl *cl = file->private_data;
 
 	if (!mei_cl_is_connected(cl))
-		return POLLERR;
+		return -ENODEV;
 
 	return fasync_helper(fd, file, band, &cl->ev_async);
 }

include/linux/hyperv.h

@@ -141,8 +141,6 @@ hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
 {
 	u32 read_loc, write_loc, dsize;
 
-	smp_read_barrier_depends();
-
 	/* Capture the read/write indices before they changed */
 	read_loc = rbi->ring_buffer->read_index;
 	write_loc = rbi->ring_buffer->write_index;
@@ -630,6 +628,11 @@ struct hv_input_signal_event_buffer {
 	struct hv_input_signal_event event;
 };
 
+enum hv_signal_policy {
+	HV_SIGNAL_POLICY_DEFAULT = 0,
+	HV_SIGNAL_POLICY_EXPLICIT,
+};
+
 struct vmbus_channel {
 	/* Unique channel id */
 	int id;
@@ -757,8 +760,21 @@ struct vmbus_channel {
 	 * link up channels based on their CPU affinity.
 	 */
 	struct list_head percpu_list;
+	/*
+	 * Host signaling policy: The default policy will be
+	 * based on the ring buffer state. We will also support
+	 * a policy where the client driver can have explicit
+	 * signaling control.
+	 */
+	enum hv_signal_policy  signal_policy;
 };
 
+static inline void set_channel_signal_state(struct vmbus_channel *c,
+					    enum hv_signal_policy policy)
+{
+	c->signal_policy = policy;
+}
+
 static inline void set_channel_read_state(struct vmbus_channel *c, bool state)
 {
 	c->batched_reading = state;
@@ -983,16 +999,8 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 			resource_size_t size, resource_size_t align,
 			bool fb_overlap_ok);
 
-/**
- * VMBUS_DEVICE - macro used to describe a specific hyperv vmbus device
- *
- * This macro is used to create a struct hv_vmbus_device_id that matches a
- * specific device.
- */
-#define VMBUS_DEVICE(g0, g1, g2, g3, g4, g5, g6, g7,	\
-		     g8, g9, ga, gb, gc, gd, ge, gf)	\
-	.guid = { g0, g1, g2, g3, g4, g5, g6, g7,	\
-		  g8, g9, ga, gb, gc, gd, ge, gf },
+int vmbus_cpu_number_to_vp_number(int cpu_number);
+u64 hv_do_hypercall(u64 control, void *input, void *output);
 
 /*
  * GUID definitions of various offer types - services offered to the guest.
@@ -1003,118 +1011,102 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
  * {f8615163-df3e-46c5-913f-f2d2f965ed0e}
  */
 #define HV_NIC_GUID \
-	.guid = { \
-			0x63, 0x51, 0x61, 0xf8, 0x3e, 0xdf, 0xc5, 0x46, \
-			0x91, 0x3f, 0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e \
-		}
+	.guid = UUID_LE(0xf8615163, 0xdf3e, 0x46c5, 0x91, 0x3f, \
+			0xf2, 0xd2, 0xf9, 0x65, 0xed, 0x0e)
 
 /*
  * IDE GUID
  * {32412632-86cb-44a2-9b5c-50d1417354f5}
  */
 #define HV_IDE_GUID \
-	.guid = { \
-			0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44, \
-			0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5 \
-		}
+	.guid = UUID_LE(0x32412632, 0x86cb, 0x44a2, 0x9b, 0x5c, \
+			0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5)
 
 /*
  * SCSI GUID
  * {ba6163d9-04a1-4d29-b605-72e2ffb1dc7f}
  */
 #define HV_SCSI_GUID \
-	.guid = { \
-			0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d, \
-			0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f \
-		}
+	.guid = UUID_LE(0xba6163d9, 0x04a1, 0x4d29, 0xb6, 0x05, \
+			0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f)
 
 /*
  * Shutdown GUID
  * {0e0b6031-5213-4934-818b-38d90ced39db}
  */
 #define HV_SHUTDOWN_GUID \
-	.guid = { \
-			0x31, 0x60, 0x0b, 0x0e, 0x13, 0x52, 0x34, 0x49, \
-			0x81, 0x8b, 0x38, 0xd9, 0x0c, 0xed, 0x39, 0xdb \
-		}
+	.guid = UUID_LE(0x0e0b6031, 0x5213, 0x4934, 0x81, 0x8b, \
+			0x38, 0xd9, 0x0c, 0xed, 0x39, 0xdb)
 
 /*
  * Time Synch GUID
  * {9527E630-D0AE-497b-ADCE-E80AB0175CAF}
  */
 #define HV_TS_GUID \
-	.guid = { \
-			0x30, 0xe6, 0x27, 0x95, 0xae, 0xd0, 0x7b, 0x49, \
-			0xad, 0xce, 0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf \
-		}
+	.guid = UUID_LE(0x9527e630, 0xd0ae, 0x497b, 0xad, 0xce, \
+			0xe8, 0x0a, 0xb0, 0x17, 0x5c, 0xaf)
 
 /*
  * Heartbeat GUID
  * {57164f39-9115-4e78-ab55-382f3bd5422d}
  */
 #define HV_HEART_BEAT_GUID \
-	.guid = { \
-			0x39, 0x4f, 0x16, 0x57, 0x15, 0x91, 0x78, 0x4e, \
-			0xab, 0x55, 0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d \
-		}
+	.guid = UUID_LE(0x57164f39, 0x9115, 0x4e78, 0xab, 0x55, \
+			0x38, 0x2f, 0x3b, 0xd5, 0x42, 0x2d)
 
 /*
  * KVP GUID
  * {a9a0f4e7-5a45-4d96-b827-8a841e8c03e6}
  */
 #define HV_KVP_GUID \
-	.guid = { \
-			0xe7, 0xf4, 0xa0, 0xa9, 0x45, 0x5a, 0x96, 0x4d, \
-			0xb8, 0x27, 0x8a, 0x84, 0x1e, 0x8c, 0x3,  0xe6 \
-		}
+	.guid = UUID_LE(0xa9a0f4e7, 0x5a45, 0x4d96, 0xb8, 0x27, \
+			0x8a, 0x84, 0x1e, 0x8c, 0x03, 0xe6)
 
 /*
  * Dynamic memory GUID
  * {525074dc-8985-46e2-8057-a307dc18a502}
  */
 #define HV_DM_GUID \
-	.guid = { \
-			0xdc, 0x74, 0x50, 0X52, 0x85, 0x89, 0xe2, 0x46, \
-			0x80, 0x57, 0xa3, 0x07, 0xdc, 0x18, 0xa5, 0x02 \
-		}
+	.guid = UUID_LE(0x525074dc, 0x8985, 0x46e2, 0x80, 0x57, \
+			0xa3, 0x07, 0xdc, 0x18, 0xa5, 0x02)
 
 /*
  * Mouse GUID
  * {cfa8b69e-5b4a-4cc0-b98b-8ba1a1f3f95a}
  */
 #define HV_MOUSE_GUID \
-	.guid = { \
-			0x9e, 0xb6, 0xa8, 0xcf, 0x4a, 0x5b, 0xc0, 0x4c, \
-			0xb9, 0x8b, 0x8b, 0xa1, 0xa1, 0xf3, 0xf9, 0x5a \
-		}
+	.guid = UUID_LE(0xcfa8b69e, 0x5b4a, 0x4cc0, 0xb9, 0x8b, \
+			0x8b, 0xa1, 0xa1, 0xf3, 0xf9, 0x5a)
+
+/*
+ * Keyboard GUID
+ * {f912ad6d-2b17-48ea-bd65-f927a61c7684}
+ */
+#define HV_KBD_GUID \
+	.guid = UUID_LE(0xf912ad6d, 0x2b17, 0x48ea, 0xbd, 0x65, \
+			0xf9, 0x27, 0xa6, 0x1c, 0x76, 0x84)
 
 /*
  * VSS (Backup/Restore) GUID
  */
 #define HV_VSS_GUID \
-	.guid = { \
-			0x29, 0x2e, 0xfa, 0x35, 0x23, 0xea, 0x36, 0x42, \
-			0x96, 0xae, 0x3a, 0x6e, 0xba, 0xcb, 0xa4,  0x40 \
-		}
+	.guid = UUID_LE(0x35fa2e29, 0xea23, 0x4236, 0x96, 0xae, \
+			0x3a, 0x6e, 0xba, 0xcb, 0xa4, 0x40)
 /*
  * Synthetic Video GUID
  * {DA0A7802-E377-4aac-8E77-0558EB1073F8}
  */
 #define HV_SYNTHVID_GUID \
-	.guid = { \
-			0x02, 0x78, 0x0a, 0xda, 0x77, 0xe3, 0xac, 0x4a, \
-			0x8e, 0x77, 0x05, 0x58, 0xeb, 0x10, 0x73, 0xf8 \
-		}
+	.guid = UUID_LE(0xda0a7802, 0xe377, 0x4aac, 0x8e, 0x77, \
+			0x05, 0x58, 0xeb, 0x10, 0x73, 0xf8)
 
 /*
  * Synthetic FC GUID
  * {2f9bcc4a-0069-4af3-b76b-6fd0be528cda}
  */
 #define HV_SYNTHFC_GUID \
-	.guid = { \
-			0x4A, 0xCC, 0x9B, 0x2F, 0x69, 0x00, 0xF3, 0x4A, \
-			0xB7, 0x6B, 0x6F, 0xD0, 0xBE, 0x52, 0x8C, 0xDA \
-		}
+	.guid = UUID_LE(0x2f9bcc4a, 0x0069, 0x4af3, 0xb7, 0x6b, \
+			0x6f, 0xd0, 0xbe, 0x52, 0x8c, 0xda)
 
 /*
  * Guest File Copy Service
@@ -1122,20 +1114,25 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
  */
 
 #define HV_FCOPY_GUID \
-	.guid = { \
-			0xE3, 0x4B, 0xD1, 0x34, 0xE4, 0xDE, 0xC8, 0x41, \
-			0x9A, 0xE7, 0x6B, 0x17, 0x49, 0x77, 0xC1, 0x92 \
-		}
+	.guid = UUID_LE(0x34d14be3, 0xdee4, 0x41c8, 0x9a, 0xe7, \
+			0x6b, 0x17, 0x49, 0x77, 0xc1, 0x92)
 
 /*
  * NetworkDirect. This is the guest RDMA service.
  * {8c2eaf3d-32a7-4b09-ab99-bd1f1c86b501}
  */
 #define HV_ND_GUID \
-	.guid = { \
-			0x3d, 0xaf, 0x2e, 0x8c, 0xa7, 0x32, 0x09, 0x4b, \
-			0xab, 0x99, 0xbd, 0x1f, 0x1c, 0x86, 0xb5, 0x01 \
-		}
+	.guid = UUID_LE(0x8c2eaf3d, 0x32a7, 0x4b09, 0xab, 0x99, \
+			0xbd, 0x1f, 0x1c, 0x86, 0xb5, 0x01)
+
+/*
+ * PCI Express Pass Through
+ * {44C4F61D-4444-4400-9D52-802E27EDE19F}
+ */
+
+#define HV_PCIE_GUID \
+	.guid = UUID_LE(0x44c4f61d, 0x4444, 0x4400, 0x9d, 0x52, \
+			0x80, 0x2e, 0x27, 0xed, 0xe1, 0x9f)
 
 /*
  * Common header for Hyper-V ICs

include/linux/mod_devicetable.h

@@ -404,7 +404,7 @@ struct virtio_device_id {
  * For Hyper-V devices we use the device guid as the id.
  */
 struct hv_vmbus_device_id {
-	__u8 guid[16];
+	uuid_le guid;
 	kernel_ulong_t driver_data;	/* Data private to the driver */
 };
 

include/uapi/linux/hyperv.h

@@ -313,6 +313,7 @@ enum hv_kvp_exchg_pool {
 #define HV_INVALIDARG			0x80070057
 #define HV_GUID_NOTFOUND		0x80041002
 #define HV_ERROR_ALREADY_EXISTS		0x80070050
+#define HV_ERROR_DISK_FULL		0x80070070
 
 #define ADDR_FAMILY_NONE	0x00
 #define ADDR_FAMILY_IPV4	0x01

scripts/mod/file2alias.c

@@ -917,7 +917,7 @@ static int do_vmbus_entry(const char *filename, void *symval,
 	char guid_name[(sizeof(*guid) + 1) * 2];
 
 	for (i = 0; i < (sizeof(*guid) * 2); i += 2)
-		sprintf(&guid_name[i], "%02x", TO_NATIVE((*guid)[i/2]));
+		sprintf(&guid_name[i], "%02x", TO_NATIVE((guid->b)[i/2]));
 
 	strcpy(alias, "vmbus:");
 	strcat(alias, guid_name);

tools/hv/hv_fcopy_daemon.c

@@ -37,12 +37,14 @@
 
 static int target_fd;
 static char target_fname[W_MAX_PATH];
+static unsigned long long filesize;
 
 static int hv_start_fcopy(struct hv_start_fcopy *smsg)
 {
 	int error = HV_E_FAIL;
 	char *q, *p;
 
+	filesize = 0;
 	p = (char *)smsg->path_name;
 	snprintf(target_fname, sizeof(target_fname), "%s/%s",
 		 (char *)smsg->path_name, (char *)smsg->file_name);
@@ -98,14 +100,26 @@ static int hv_start_fcopy(struct hv_start_fcopy *smsg)
 static int hv_copy_data(struct hv_do_fcopy *cpmsg)
 {
 	ssize_t bytes_written;
+	int ret = 0;
 
 	bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
 				cpmsg->offset);
 
-	if (bytes_written != cpmsg->size)
-		return HV_E_FAIL;
+	filesize += cpmsg->size;
+	if (bytes_written != cpmsg->size) {
+		switch (errno) {
+		case ENOSPC:
+			ret = HV_ERROR_DISK_FULL;
+			break;
+		default:
+			ret = HV_E_FAIL;
+			break;
+		}
+		syslog(LOG_ERR, "pwrite failed to write %llu bytes: %ld (%s)",
+		       filesize, (long)bytes_written, strerror(errno));
+	}
 
-	return 0;
+	return ret;
 }
 
 static int hv_copy_finished(void)
@@ -165,7 +179,7 @@ int main(int argc, char *argv[])
 	}
 
 	openlog("HV_FCOPY", 0, LOG_USER);
-	syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid());
+	syslog(LOG_INFO, "starting; pid is:%d", getpid());
 
 	fcopy_fd = open("/dev/vmbus/hv_fcopy", O_RDWR);
 
@@ -201,7 +215,7 @@ int main(int argc, char *argv[])
 			}
 			kernel_modver = *(__u32 *)buffer;
 			in_handshake = 0;
-			syslog(LOG_INFO, "HV_FCOPY: kernel module version: %d",
+			syslog(LOG_INFO, "kernel module version: %d",
 			       kernel_modver);
 			continue;
 		}

tools/hv/hv_vss_daemon.c

@@ -254,7 +254,7 @@ int main(int argc, char *argv[])
 			syslog(LOG_ERR, "Illegal op:%d\n", op);
 		}
 		vss_msg->error = error;
-		len = write(vss_fd, &error, sizeof(struct hv_vss_msg));
+		len = write(vss_fd, vss_msg, sizeof(struct hv_vss_msg));
 		if (len != sizeof(struct hv_vss_msg)) {
 			syslog(LOG_ERR, "write failed; error: %d %s", errno,
 			       strerror(errno));