4 files changed, 63 insertions, 11 deletions

diff --git a/drivers/staging/hv/channel_mgmt.c b/drivers/staging/hv/channel_mgmt.c
index 3f53b4d1e4cf..12db555a3a5d 100644
--- a/drivers/staging/hv/channel_mgmt.c
+++ b/drivers/staging/hv/channel_mgmt.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/completion.h>
 #include "osd.h"
 #include "logging.h"
 #include "vmbus_private.h"
@@ -293,6 +294,25 @@ void FreeVmbusChannel(struct vmbus_channel *Channel)
 			      Channel);
 }
 
+
+DECLARE_COMPLETION(hv_channel_ready);
+
+/*
+ * Count initialized channels, and ensure all channels are ready when hv_vmbus
+ * module loading completes.
+ */
+static void count_hv_channel(void)
+{
+	static int counter;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
+	if (++counter == MAX_MSG_TYPES)
+		complete(&hv_channel_ready);
+	spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);
+}
+
+
 /*
  * VmbusChannelProcessOffer - Process the offer by creating a channel/device
  * associated with this offer
@@ -373,22 +393,21 @@ static void VmbusChannelProcessOffer(void *context)
 		 * can cleanup properly
 		 */
 		newChannel->State = CHANNEL_OPEN_STATE;
-		cnt = 0;
 
-		while (cnt != MAX_MSG_TYPES) {
+		/* Open IC channels */
+		for (cnt = 0; cnt < MAX_MSG_TYPES; cnt++) {
 			if (memcmp(&newChannel->OfferMsg.Offer.InterfaceType,
 				   &hv_cb_utils[cnt].data,
-				   sizeof(struct hv_guid)) == 0) {
+				   sizeof(struct hv_guid)) == 0 &&
+				VmbusChannelOpen(newChannel, 2 * PAGE_SIZE,
+						 2 * PAGE_SIZE, NULL, 0,
+						 hv_cb_utils[cnt].callback,
+						 newChannel) == 0) {
+				hv_cb_utils[cnt].channel = newChannel;
 				DPRINT_INFO(VMBUS, "%s",
-					    hv_cb_utils[cnt].log_msg);
-
-				if (VmbusChannelOpen(newChannel, 2 * PAGE_SIZE,
-						    2 * PAGE_SIZE, NULL, 0,
-						    hv_cb_utils[cnt].callback,
-						    newChannel) == 0)
-					hv_cb_utils[cnt].channel = newChannel;
+						hv_cb_utils[cnt].log_msg);
+				count_hv_channel();
 			}
-			cnt++;
 		}
 	}
 	DPRINT_EXIT(VMBUS);
diff --git a/drivers/staging/hv/hv_utils.c b/drivers/staging/hv/hv_utils.c
index 8a49aafea37a..2adc9b48ca9c 100644
--- a/drivers/staging/hv/hv_utils.c
+++ b/drivers/staging/hv/hv_utils.c
@@ -24,6 +24,8 @@
 #include <linux/slab.h>
 #include <linux/sysctl.h>
 #include <linux/reboot.h>
+#include <linux/dmi.h>
+#include <linux/pci.h>
 
 #include "logging.h"
 #include "osd.h"
@@ -251,10 +253,36 @@ static void heartbeat_onchannelcallback(void *context)
 	DPRINT_EXIT(VMBUS);
 }
 
+static const struct pci_device_id __initconst
+hv_utils_pci_table[] __maybe_unused = {
+	{ PCI_DEVICE(0x1414, 0x5353) }, /* Hyper-V emulated VGA controller */
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(pci, hv_utils_pci_table);
+
+
+static const struct dmi_system_id __initconst
+hv_utils_dmi_table[] __maybe_unused  = {
+	{
+		.ident = "Hyper-V",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"),
+			DMI_MATCH(DMI_BOARD_NAME, "Virtual Machine"),
+		},
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, hv_utils_dmi_table);
+
+
 static int __init init_hyperv_utils(void)
 {
 	printk(KERN_INFO "Registering HyperV Utility Driver\n");
 
+	if (!dmi_check_system(hv_utils_dmi_table))
+		return -ENODEV;
+
 	hv_cb_utils[HV_SHUTDOWN_MSG].channel->OnChannelCallback =
 		&shutdown_onchannelcallback;
 	hv_cb_utils[HV_SHUTDOWN_MSG].callback = &shutdown_onchannelcallback;
diff --git a/drivers/staging/hv/vmbus.h b/drivers/staging/hv/vmbus.h
index 0c6ee0f487f3..3c14b2926e00 100644
--- a/drivers/staging/hv/vmbus.h
+++ b/drivers/staging/hv/vmbus.h
@@ -74,4 +74,6 @@ int vmbus_child_driver_register(struct driver_context *driver_ctx);
 void vmbus_child_driver_unregister(struct driver_context *driver_ctx);
 void vmbus_get_interface(struct vmbus_channel_interface *interface);
 
+extern struct completion hv_channel_ready;
+
 #endif /* _VMBUS_H_ */
diff --git a/drivers/staging/hv/vmbus_drv.c b/drivers/staging/hv/vmbus_drv.c
index c21731a12ca7..22c80ece6388 100644
--- a/drivers/staging/hv/vmbus_drv.c
+++ b/drivers/staging/hv/vmbus_drv.c
@@ -27,6 +27,7 @@
 #include <linux/pci.h>
 #include <linux/dmi.h>
 #include <linux/slab.h>
+#include <linux/completion.h>
 #include "version_info.h"
 #include "osd.h"
 #include "logging.h"
@@ -356,6 +357,8 @@ static int vmbus_bus_init(int (*drv_init)(struct hv_driver *drv))
 
 	vmbus_drv_obj->GetChannelOffers();
 
+	wait_for_completion(&hv_channel_ready);
+
 cleanup:
 	DPRINT_EXIT(VMBUS_DRV);