Drivers: hv/scsi: Implement multi-channel support

index 0b122f8..c219e9f 100644
@@ -216,6 +216,9 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	list_del(&open_info->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
+	if (err == 0)
+		newchannel->state = CHANNEL_OPENED_STATE;
+
 	kfree(open_info);
 	return err;
 

@@ -500,15 +503,14 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 }
 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 
-/*
- * vmbus_close - Close the specified channel
- */
-void vmbus_close(struct vmbus_channel *channel)
+static void vmbus_close_internal(struct vmbus_channel *channel)
 {
 	struct vmbus_channel_close_channel *msg;
 	int ret;
 	unsigned long flags;
 
+	channel->state = CHANNEL_OPEN_STATE;
+	channel->sc_creation_callback = NULL;
 	/* Stop callback and cancel the timer asap */
 	spin_lock_irqsave(&channel->inbound_lock, flags);
 	channel->onchannel_callback = NULL;

@@ -538,6 +540,37 @@ void vmbus_close(struct vmbus_channel *channel)
 
 
 }
+
+/*
+ * vmbus_close - Close the specified channel
+ */
+void vmbus_close(struct vmbus_channel *channel)
+{
+	struct list_head *cur, *tmp;
+	struct vmbus_channel *cur_channel;
+
+	if (channel->primary_channel != NULL) {
+		/*
+		 * We will only close sub-channels when
+		 * the primary is closed.
+		 */
+		return;
+	}
+	/*
+	 * Close all the sub-channels first and then close the
+	 * primary channel.
+	 */
+	list_for_each_safe(cur, tmp, &channel->sc_list) {
+		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+		if (cur_channel->state != CHANNEL_OPENED_STATE)
+			continue;
+		vmbus_close_internal(cur_channel);
+	}
+	/*
+	 * Now close the primary.
+	 */
+	vmbus_close_internal(channel);
+}
 EXPORT_SYMBOL_GPL(vmbus_close);
 
 /**

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index 405e05a..fae8bac 100644
@@ -1389,6 +1389,16 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
 		}
 
 /*
+ * 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 \
+		}
+
+/*
  * Common header for Hyper-V ICs
  */
 

index 16a3a0c..8d29a95 100644
@@ -221,6 +221,13 @@ static int storvsc_ringbuffer_size = (20 * PAGE_SIZE);
 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 
+/*
+ * Timeout in seconds for all devices managed by this driver.
+ */
+static int storvsc_timeout = 180;
+module_param(storvsc_timeout, uint, (S_IRUGO | S_IWUSR));
+MODULE_PARM_DESC(storvsc_timeout, "Device timeout (seconds)");
+
 #define STORVSC_MAX_IO_REQUESTS				128
 
 /*

@@ -1204,6 +1211,8 @@ static int storvsc_device_configure(struct scsi_device *sdevice)
 
 	blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 
+	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
+
 	sdevice->no_write_same = 1;
 
 	return 0;

index 8d29a95..a3cf85c 100644
@@ -55,10 +55,15 @@
  * V1 RC < 2008/1/31: 1.0
  * V1 RC > 2008/1/31:  2.0
  * Win7: 4.2
+ * Win8: 5.1
  */
 
-#define VMSTOR_CURRENT_MAJOR  4
-#define VMSTOR_CURRENT_MINOR  2
+
+#define VMSTOR_WIN7_MAJOR 4
+#define VMSTOR_WIN7_MINOR 2
+
+#define VMSTOR_WIN8_MAJOR 5
+#define VMSTOR_WIN8_MINOR 1
 
 
 /*  Packet structure describing virtual storage requests. */

@@ -74,18 +79,103 @@ enum vstor_packet_operation {
 	VSTOR_OPERATION_QUERY_PROTOCOL_VERSION	= 9,
 	VSTOR_OPERATION_QUERY_PROPERTIES	= 10,
 	VSTOR_OPERATION_ENUMERATE_BUS		= 11,
-	VSTOR_OPERATION_MAXIMUM			= 11
+	VSTOR_OPERATION_FCHBA_DATA              = 12,
+	VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
+	VSTOR_OPERATION_MAXIMUM                 = 13
+};
+
+/*
+ * WWN packet for Fiber Channel HBA
+ */
+
+struct hv_fc_wwn_packet {
+	bool	primary_active;
+	u8	reserved1;
+	u8	reserved2;
+	u8	primary_port_wwn[8];
+	u8	primary_node_wwn[8];
+	u8	secondary_port_wwn[8];
+	u8	secondary_node_wwn[8];
 };
 
+
+
+/*
+ * SRB Flag Bits
+ */
+
+#define SRB_FLAGS_QUEUE_ACTION_ENABLE		0x00000002
+#define SRB_FLAGS_DISABLE_DISCONNECT		0x00000004
+#define SRB_FLAGS_DISABLE_SYNCH_TRANSFER	0x00000008
+#define SRB_FLAGS_BYPASS_FROZEN_QUEUE		0x00000010
+#define SRB_FLAGS_DISABLE_AUTOSENSE		0x00000020
+#define SRB_FLAGS_DATA_IN			0x00000040
+#define SRB_FLAGS_DATA_OUT			0x00000080
+#define SRB_FLAGS_NO_DATA_TRANSFER		0x00000000
+#define SRB_FLAGS_UNSPECIFIED_DIRECTION	(SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
+#define SRB_FLAGS_NO_QUEUE_FREEZE		0x00000100
+#define SRB_FLAGS_ADAPTER_CACHE_ENABLE		0x00000200
+#define SRB_FLAGS_FREE_SENSE_BUFFER		0x00000400
+
+/*
+ * This flag indicates the request is part of the workflow for processing a D3.
+ */
+#define SRB_FLAGS_D3_PROCESSING			0x00000800
+#define SRB_FLAGS_IS_ACTIVE			0x00010000
+#define SRB_FLAGS_ALLOCATED_FROM_ZONE		0x00020000
+#define SRB_FLAGS_SGLIST_FROM_POOL		0x00040000
+#define SRB_FLAGS_BYPASS_LOCKED_QUEUE		0x00080000
+#define SRB_FLAGS_NO_KEEP_AWAKE			0x00100000
+#define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE	0x00200000
+#define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT	0x00400000
+#define SRB_FLAGS_DONT_START_NEXT_PACKET	0x00800000
+#define SRB_FLAGS_PORT_DRIVER_RESERVED		0x0F000000
+#define SRB_FLAGS_CLASS_DRIVER_RESERVED		0xF0000000
+
+
 /*
  * Platform neutral description of a scsi request -
  * this remains the same across the write regardless of 32/64 bit
  * note: it's patterned off the SCSI_PASS_THROUGH structure
  */
 #define STORVSC_MAX_CMD_LEN			0x10
-#define STORVSC_SENSE_BUFFER_SIZE		0x12
+
+#define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE	0x14
+#define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE	0x12
+
+#define STORVSC_SENSE_BUFFER_SIZE		0x14
 #define STORVSC_MAX_BUF_LEN_WITH_PADDING	0x14
 
+/*
+ * Sense buffer size changed in win8; have a run-time
+ * variable to track the size we should use.
+ */
+static int sense_buffer_size;
+
+/*
+ * The size of the vmscsi_request has changed in win8. The
+ * additional size is because of new elements added to the
+ * structure. These elements are valid only when we are talking
+ * to a win8 host.
+ * Track the correction to size we need to apply.
+ */
+
+static int vmscsi_size_delta;
+static int vmstor_current_major;
+static int vmstor_current_minor;
+
+struct vmscsi_win8_extension {
+	/*
+	 * The following were added in Windows 8
+	 */
+	u16 reserve;
+	u8  queue_tag;
+	u8  queue_action;
+	u32 srb_flags;
+	u32 time_out_value;
+	u32 queue_sort_ey;
+} __packed;
+
 struct vmscsi_request {
 	u16 length;
 	u8 srb_status;

@@ -108,6 +198,11 @@ struct vmscsi_request {
 		u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 		u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 	};
+	/*
+	 * The following was added in win8.
+	 */
+	struct vmscsi_win8_extension win8_extension;
+
 } __attribute((packed));
 
 

@@ -115,22 +210,18 @@ struct vmscsi_request {
  * This structure is sent during the intialization phase to get the different
  * properties of the channel.
  */
+
+#define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL		0x1
+
 struct vmstorage_channel_properties {
-	u16 protocol_version;
-	u8  path_id;
-	u8 target_id;
+	u32 reserved;
+	u16 max_channel_cnt;
+	u16 reserved1;
 
-	/* Note: port number is only really known on the client side */
-	u32  port_number;
-	u32  flags;
+	u32 flags;
 	u32   max_transfer_bytes;
 
-	/*
-	 * This id is unique for each channel and will correspond with
-	 * vendor specific data in the inquiry data.
-	 */
-
-	u64  unique_id;
+	u64  reserved2;
 } __packed;
 
 /*  This structure is sent during the storage protocol negotiations. */

@@ -175,6 +266,15 @@ struct vstor_packet {
 
 		/* Used during version negotiations. */
 		struct vmstorage_protocol_version version;
+
+		/* Fiber channel address packet */
+		struct hv_fc_wwn_packet wwn_packet;
+
+		/* Number of sub-channels to create */
+		u16 sub_channel_count;
+
+		/* This will be the maximum of the union members */
+		u8  buffer[0x34];
 	};
 } __packed;
 

@@ -681,7 +781,8 @@ static int storvsc_channel_init(struct hv_device *device)
 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 
 	ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+			       vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -705,7 +806,7 @@ static int storvsc_channel_init(struct hv_device *device)
 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 
 	vstor_packet->version.major_minor =
-		storvsc_get_version(VMSTOR_CURRENT_MAJOR, VMSTOR_CURRENT_MINOR);
+		storvsc_get_version(vmstor_current_major, vmstor_current_minor);
 
 	/*
 	 * The revision number is only used in Windows; set it to 0.

@@ -713,7 +814,8 @@ static int storvsc_channel_init(struct hv_device *device)
 	vstor_packet->version.revision = 0;
 
 	ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -734,11 +836,10 @@ static int storvsc_channel_init(struct hv_device *device)
 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
-	vstor_packet->storage_channel_properties.port_number =
-					stor_device->port_number;
 
 	ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -756,16 +857,13 @@ static int storvsc_channel_init(struct hv_device *device)
 	    vstor_packet->status != 0)
 		goto cleanup;
 
-	stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
-	stor_device->target_id
-		= vstor_packet->storage_channel_properties.target_id;
-
 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 
 	ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -1019,7 +1117,8 @@ static void storvsc_on_channel_callback(void *context)
 
 	do {
 		ret = vmbus_recvpacket(device->channel, packet,
-				       ALIGN(sizeof(struct vstor_packet), 8),
+				       ALIGN((sizeof(struct vstor_packet) -
+					     vmscsi_size_delta), 8),
 				       &bytes_recvd, &request_id);
 		if (ret == 0 && bytes_recvd > 0) {
 

@@ -1030,7 +1129,8 @@ static void storvsc_on_channel_callback(void *context)
 			    (request == &stor_device->reset_request)) {
 
 				memcpy(&request->vstor_packet, packet,
-				       sizeof(struct vstor_packet));
+				       (sizeof(struct vstor_packet) -
+					vmscsi_size_delta));
 				complete(&request->wait_event);
 			} else {
 				storvsc_on_receive(device,

@@ -1123,10 +1223,11 @@ static int storvsc_do_io(struct hv_device *device,
 
 	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 
-	vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
+	vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
+					vmscsi_size_delta);
 
 
-	vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
+	vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
 
 
 	vstor_packet->vm_srb.data_transfer_length =

@@ -1138,11 +1239,13 @@ static int storvsc_do_io(struct hv_device *device,
 		ret = vmbus_sendpacket_multipagebuffer(device->channel,
 				&request->data_buffer,
 				vstor_packet,
-				sizeof(struct vstor_packet),
+				(sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 				(unsigned long)request);
 	} else {
 		ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -1266,7 +1369,8 @@ static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 	vstor_packet->vm_srb.path_id = stor_device->path_id;
 
 	ret = vmbus_sendpacket(device->channel, vstor_packet,
-			       sizeof(struct vstor_packet),
+			       (sizeof(struct vstor_packet) -
+				vmscsi_size_delta),
 			       (unsigned long)&stor_device->reset_request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

@@ -1351,18 +1455,28 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	scmnd->host_scribble = (unsigned char *)cmd_request;
 
 	vm_srb = &cmd_request->vstor_packet.vm_srb;
+	vm_srb->win8_extension.time_out_value = 60;
 
 
 	/* Build the SRB */
 	switch (scmnd->sc_data_direction) {
 	case DMA_TO_DEVICE:
 		vm_srb->data_in = WRITE_TYPE;
+		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
+		vm_srb->win8_extension.srb_flags |=
+			(SRB_FLAGS_QUEUE_ACTION_ENABLE |
+			SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
 		break;
 	case DMA_FROM_DEVICE:
 		vm_srb->data_in = READ_TYPE;
+		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
+		vm_srb->win8_extension.srb_flags |=
+			(SRB_FLAGS_QUEUE_ACTION_ENABLE |
+			SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
 		break;
 	default:
 		vm_srb->data_in = UNKNOWN_TYPE;
+		vm_srb->win8_extension.srb_flags = 0;
 		break;
 	}
 

@@ -1494,6 +1608,24 @@ static int storvsc_probe(struct hv_device *device,
 	int target = 0;
 	struct storvsc_device *stor_device;
 
+	/*
+	 * Based on the windows host we are running on,
+	 * set state to properly communicate with the host.
+	 */
+
+	if (vmbus_proto_version == VERSION_WIN8) {
+		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
+		vmscsi_size_delta = 0;
+		vmstor_current_major = VMSTOR_WIN8_MAJOR;
+		vmstor_current_minor = VMSTOR_WIN8_MINOR;
+	} else {
+		sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
+		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
+		vmstor_current_major = VMSTOR_WIN7_MAJOR;
+		vmstor_current_minor = VMSTOR_WIN7_MINOR;
+	}
+
+
 	host = scsi_host_alloc(&scsi_driver,
 			       sizeof(struct hv_host_device));
 	if (!host)

@@ -1603,7 +1735,8 @@ static int __init storvsc_drv_init(void)
 	max_outstanding_req_per_channel =
 		((storvsc_ringbuffer_size - PAGE_SIZE) /
 		ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
-		sizeof(struct vstor_packet) + sizeof(u64),
+		sizeof(struct vstor_packet) + sizeof(u64) -
+		vmscsi_size_delta,
 		sizeof(u64)));
 
 	if (max_outstanding_req_per_channel <

index a3cf85c..6bc4e3b 100644
@@ -330,6 +330,8 @@ MODULE_PARM_DESC(storvsc_timeout, "Device timeout (seconds)");
 
 #define STORVSC_MAX_IO_REQUESTS				128
 
+static void storvsc_on_channel_callback(void *context);
+
 /*
  * In Hyper-V, each port/path/target maps to 1 scsi host adapter.  In
  * reality, the path/target is not used (ie always set to 0) so our

@@ -757,12 +759,99 @@ static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 	return total_copied;
 }
 
+static void handle_sc_creation(struct vmbus_channel *new_sc)
+{
+	struct hv_device *device = new_sc->primary_channel->device_obj;
+	struct storvsc_device *stor_device;
+	struct vmstorage_channel_properties props;
+
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return;
+
+
+	memset(&props, 0, sizeof(struct vmstorage_channel_properties));
+
+	vmbus_open(new_sc,
+		   storvsc_ringbuffer_size,
+		   storvsc_ringbuffer_size,
+		   (void *)&props,
+		   sizeof(struct vmstorage_channel_properties),
+		   storvsc_on_channel_callback, new_sc);
+}
+
+static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
+{
+	struct storvsc_device *stor_device;
+	int num_cpus = num_online_cpus();
+	int num_sc;
+	struct storvsc_cmd_request *request;
+	struct vstor_packet *vstor_packet;
+	int ret, t;
+
+	num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
+	stor_device = get_out_stor_device(device);
+	if (!stor_device)
+		return;
+
+	request = &stor_device->init_request;
+	vstor_packet = &request->vstor_packet;
+
+	/*
+	 * Establish a handler for dealing with subchannels.
+	 */
+	vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
+
+	/*
+	 * Check to see if sub-channels have already been created. This
+	 * can happen when this driver is re-loaded after unloading.
+	 */
+
+	if (vmbus_are_subchannels_present(device->channel))
+		return;
+
+	/*
+	 * Request the host to create sub-channels.
+	 */
+	memset(request, 0, sizeof(struct storvsc_cmd_request));
+	init_completion(&request->wait_event);
+	vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
+	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	vstor_packet->sub_channel_count = num_sc;
+
+	ret = vmbus_sendpacket(device->channel, vstor_packet,
+			       (sizeof(struct vstor_packet) -
+			       vmscsi_size_delta),
+			       (unsigned long)request,
+			       VM_PKT_DATA_INBAND,
+			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+	if (ret != 0)
+		return;
+
+	t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
+	if (t == 0)
+		return;
+
+	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
+	    vstor_packet->status != 0)
+		return;
+
+	/*
+	 * Now that we created the sub-channels, invoke the check; this
+	 * will trigger the callback.
+	 */
+	vmbus_are_subchannels_present(device->channel);
+}
+
 static int storvsc_channel_init(struct hv_device *device)
 {
 	struct storvsc_device *stor_device;
 	struct storvsc_cmd_request *request;
 	struct vstor_packet *vstor_packet;
 	int ret, t;
+	int max_chns;
+	bool process_sub_channels = false;
 
 	stor_device = get_out_stor_device(device);
 	if (!stor_device)

@@ -857,6 +946,19 @@ static int storvsc_channel_init(struct hv_device *device)
 	    vstor_packet->status != 0)
 		goto cleanup;
 
+	/*
+	 * Check to see if multi-channel support is there.
+	 * Hosts that implement protocol version of 5.1 and above
+	 * support multi-channel.
+	 */
+	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
+	if ((vmbus_proto_version != VERSION_WIN7) &&
+	   (vmbus_proto_version != VERSION_WS2008))  {
+		if (vstor_packet->storage_channel_properties.flags &
+		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
+			process_sub_channels = true;
+	}
+
 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 	vstor_packet->flags = REQUEST_COMPLETION_FLAG;

@@ -881,6 +983,9 @@ static int storvsc_channel_init(struct hv_device *device)
 	    vstor_packet->status != 0)
 		goto cleanup;
 
+	if (process_sub_channels)
+		handle_multichannel_storage(device, max_chns);
+
 
 cleanup:
 	return ret;

@@ -1102,7 +1207,8 @@ static void storvsc_on_receive(struct hv_device *device,
 
 static void storvsc_on_channel_callback(void *context)
 {
-	struct hv_device *device = (struct hv_device *)context;
+	struct vmbus_channel *channel = (struct vmbus_channel *)context;
+	struct hv_device *device;
 	struct storvsc_device *stor_device;
 	u32 bytes_recvd;
 	u64 request_id;

@@ -1110,13 +1216,17 @@ static void storvsc_on_channel_callback(void *context)
 	struct storvsc_cmd_request *request;
 	int ret;
 
+	if (channel->primary_channel != NULL)
+		device = channel->primary_channel->device_obj;
+	else
+		device = channel->device_obj;
 
 	stor_device = get_in_stor_device(device);
 	if (!stor_device)
 		return;
 
 	do {
-		ret = vmbus_recvpacket(device->channel, packet,
+		ret = vmbus_recvpacket(channel, packet,
 				       ALIGN((sizeof(struct vstor_packet) -
 					     vmscsi_size_delta), 8),
 				       &bytes_recvd, &request_id);

@@ -1157,7 +1267,7 @@ static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 			 ring_size,
 			 (void *)&props,
 			 sizeof(struct vmstorage_channel_properties),
-			 storvsc_on_channel_callback, device);
+			 storvsc_on_channel_callback, device->channel);
 
 	if (ret != 0)
 		return ret;

@@ -1209,6 +1319,7 @@ static int storvsc_do_io(struct hv_device *device,
 {
 	struct storvsc_device *stor_device;
 	struct vstor_packet *vstor_packet;
+	struct vmbus_channel *outgoing_channel;
 	int ret = 0;
 
 	vstor_packet = &request->vstor_packet;

@@ -1219,6 +1330,11 @@ static int storvsc_do_io(struct hv_device *device,
 
 
 	request->device  = device;
+	/*
+	 * Select an an appropriate channel to send the request out.
+	 */
+
+	outgoing_channel = vmbus_get_outgoing_channel(device->channel);
 
 
 	vstor_packet->flags |= REQUEST_COMPLETION_FLAG;

@@ -1236,7 +1352,7 @@ static int storvsc_do_io(struct hv_device *device,
 	vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 
 	if (request->data_buffer.len) {
-		ret = vmbus_sendpacket_multipagebuffer(device->channel,
+		ret = vmbus_sendpacket_multipagebuffer(outgoing_channel,
 				&request->data_buffer,
 				vstor_packet,
 				(sizeof(struct vstor_packet) -

index 6bc4e3b..124cf0b 100644
@@ -1698,6 +1698,7 @@ static struct scsi_host_template scsi_driver = {
 enum {
 	SCSI_GUID,
 	IDE_GUID,
+	SFC_GUID,
 };
 
 static const struct hv_vmbus_device_id id_table[] = {

@@ -1709,6 +1710,11 @@ static const struct hv_vmbus_device_id id_table[] = {
 	{ HV_IDE_GUID,
 	  .driver_data = IDE_GUID
 	},
+	/* Fiber Channel GUID */
+	{
+	  HV_SYNTHFC_GUID,
+	  .driver_data = SFC_GUID
+	},
 	{ },
 };
 

index 124cf0b..e2ab7cd 100644
@@ -328,7 +328,7 @@ static int storvsc_timeout = 180;
 module_param(storvsc_timeout, uint, (S_IRUGO | S_IWUSR));
 MODULE_PARM_DESC(storvsc_timeout, "Device timeout (seconds)");
 
-#define STORVSC_MAX_IO_REQUESTS				128
+#define STORVSC_MAX_IO_REQUESTS				200
 
 static void storvsc_on_channel_callback(void *context);