[PATCH 0/6] Drivers: hv/scsi: Implement multi-channel support

[PATCH 0/6] Drivers: hv/scsi: Implement multi-channel support

[K. Y. Srinivasan]

This patch-set implements multi-channel support for Hyper-V devices. Also
support for synthetic Fiber Channel device is included. The first two
patches in the series are the foundational pieces for the remaining patches.

James, once Greg accepts the first two patches, you can consider the scsi
patches.


K. Y. Srinivasan (6):
  Drivers: hv: vmbus: Implement multi-channel support
  Drivers: hv: Add the GUID fot synthetic fiber channel device
  Drivers: scsi: storvsc: Make the scsi timeout a module parameter
  Drivers: scsi: storvsc: Update the storage protocol to win8 level
  Drivers: scsi: storvsc: Implement multi-channel support
  Drivers: scsi: storvsc: Support FC devices

 drivers/hv/channel.c       |   41 +++++-
 drivers/hv/channel_mgmt.c  |  117 +++++++++++++++-
 drivers/scsi/storvsc_drv.c |  340 +++++++++++++++++++++++++++++++++++++++-----
 include/linux/hyperv.h     |   70 +++++++++
 4 files changed, 522 insertions(+), 46 deletions(-)

-- 
1.7.4.1

[PATCH 1/6] Drivers: hv: vmbus: Implement multi-channel support

[K. Y. Srinivasan]

Starting with Win8, the host supports multiple sub-channels for a given
device. As in the past, the initial channel offer specifies the device and
is associated with both the type and the instance GUIDs. For performance
critical devices, the host may support multiple sub-channels. The sub-channels
share the same type and instance GUID as the primary channel. The number of
sub-channels offerrred to the guest depends on the number of virtual CPUs
assigned to the guest. The guest can request the creation of these sub-channels
and once created and opened, the guest can distribute the traffic across all
the channels (the primary and the sub-channels). A request sent on a sub-channel
will have the response delivered on the same sub-channel.

At channel (sub-channel) creation we bind the channel interrupt to a CPU and
with this sub-channel support we will be able to spread the interrupt load
of a given device across all available CPUs.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/hv/channel.c      |   41 ++++++++++++++--
 drivers/hv/channel_mgmt.c |  117 +++++++++++++++++++++++++++++++++++++++++++--
 include/linux/hyperv.h    |   62 +++++++++++++++++++++++-
 3 files changed, 211 insertions(+), 9 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 0b122f8..c219e9f 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -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);
 
 /**
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 21ef689..834dff3 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -115,6 +115,9 @@ static struct vmbus_channel *alloc_channel(void)
 		return NULL;
 
 	spin_lock_init(&channel->inbound_lock);
+	spin_lock_init(&channel->sc_lock);
+
+	INIT_LIST_HEAD(&channel->sc_list);
 
 	channel->controlwq = create_workqueue("hv_vmbus_ctl");
 	if (!channel->controlwq) {
@@ -166,6 +169,7 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
 						     struct vmbus_channel,
 						     work);
 	unsigned long flags;
+	struct vmbus_channel *primary_channel;
 	struct vmbus_channel_relid_released msg;
 
 	vmbus_device_unregister(channel->device_obj);
@@ -174,9 +178,16 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
 	msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
 	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
 
-	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
-	list_del(&channel->listentry);
-	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	if (channel->primary_channel == NULL) {
+		spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+		list_del(&channel->listentry);
+		spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	} else {
+		primary_channel = channel->primary_channel;
+		spin_lock_irqsave(&primary_channel->sc_lock, flags);
+		list_del(&channel->listentry);
+		spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
+	}
 	free_channel(channel);
 }
 
@@ -228,6 +239,21 @@ static void vmbus_process_offer(struct work_struct *work)
 	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 
 	if (!fnew) {
+		/*
+		 * Check to see if this is a sub-channel.
+		 */
+		if (newchannel->offermsg.offer.sub_channel_index != 0) {
+			/*
+			 * Process the sub-channel.
+			 */
+			newchannel->primary_channel = channel;
+			spin_lock_irqsave(&channel->sc_lock, flags);
+			list_add_tail(&newchannel->sc_list, &channel->sc_list);
+			spin_unlock_irqrestore(&channel->sc_lock, flags);
+			newchannel->state = CHANNEL_OPEN_STATE;
+			return;
+		}
+
 		free_channel(newchannel);
 		return;
 	}
@@ -685,4 +711,87 @@ cleanup:
 	return ret;
 }
 
-/* eof */
+/*
+ * Retrieve the (sub) channel on which to send an outgoing request.
+ * When a primary channel has multiple sub-channels, we choose a
+ * channel whose VCPU binding is closest to the VCPU on which
+ * this call is being made.
+ */
+struct vmbus_channel *get_outgoing_channel(struct vmbus_channel *primary)
+{
+	struct list_head *cur, *tmp;
+	int cur_cpu = hv_context.vp_index[smp_processor_id()];
+	struct vmbus_channel *cur_channel;
+	struct vmbus_channel *outgoing_channel = primary;
+	int cpu_distance, new_cpu_distance;
+
+	if (list_empty(&primary->sc_list))
+		return outgoing_channel;
+
+	list_for_each_safe(cur, tmp, &primary->sc_list) {
+		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+		if (cur_channel->state != CHANNEL_OPENED_STATE)
+			continue;
+
+		if (cur_channel->target_vp == cur_cpu)
+			return cur_channel;
+
+		cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
+				(outgoing_channel->target_vp - cur_cpu) :
+				(cur_cpu - outgoing_channel->target_vp));
+
+		new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
+				(cur_channel->target_vp - cur_cpu) :
+				(cur_cpu - cur_channel->target_vp));
+
+		if (cpu_distance < new_cpu_distance)
+			continue;
+
+		outgoing_channel = cur_channel;
+	}
+
+	return outgoing_channel;
+}
+EXPORT_SYMBOL_GPL(get_outgoing_channel);
+
+static void invoke_sc_cb(struct vmbus_channel *primary_channel)
+{
+	struct list_head *cur, *tmp;
+	struct vmbus_channel *cur_channel;
+
+	if (primary_channel->sc_creation_callback == NULL)
+		return;
+
+	list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
+		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+
+		primary_channel->sc_creation_callback(cur_channel);
+	}
+}
+
+void set_sc_create_callback(struct vmbus_channel *primary_channel,
+				void (*sc_cr_cb)(struct vmbus_channel *new_sc))
+{
+	primary_channel->sc_creation_callback = sc_cr_cb;
+	invoke_sc_cb(primary_channel);
+}
+EXPORT_SYMBOL_GPL(set_sc_create_callback);
+
+bool subchannels_present(struct vmbus_channel *primary)
+{
+	bool ret;
+
+	ret = !list_empty(&primary->sc_list);
+
+	if (ret) {
+		/*
+		 * Invoke the callback on sub-channel creation.
+		 * This will present a uniform interface to the
+		 * clients.
+		 */
+		invoke_sc_cb(primary);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(subchannels_present);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c255984..a1a97a7 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -909,6 +909,7 @@ enum vmbus_channel_state {
 	CHANNEL_OFFER_STATE,
 	CHANNEL_OPENING_STATE,
 	CHANNEL_OPEN_STATE,
+	CHANNEL_OPENED_STATE,
 };
 
 struct vmbus_channel_debug_info {
@@ -1046,6 +1047,38 @@ struct vmbus_channel {
 	 * preserve the earlier behavior.
 	 */
 	u32 target_vp;
+	/*
+	 * Support for sub-channels. For high performance devices,
+	 * it will be useful to have multiple sub-channels to support
+	 * a scalable communication infrastructure with the host.
+	 * The support for sub-channels is implemented as an extention
+	 * to the current infrastructure.
+	 * The initial offer is considered the primary channel and this
+	 * offer message will indicate if the host supports sub-channels.
+	 * The guest is free to ask for sub-channels to be offerred and can
+	 * open these sub-channels as a normal "primary" channel. However,
+	 * all sub-channels will have the same type and instance guids as the
+	 * primary channel. Requests sent on a given channel will result in a
+	 * response on the same channel.
+	 */
+
+	/*
+	 * Sub-channel creation callback. This callback will be called in
+	 * process context when a sub-channel offer is received from the host.
+	 * The guest can open the sub-channel in the context of this callback.
+	 */
+	void (*sc_creation_callback)(struct vmbus_channel *new_sc);
+
+	spinlock_t sc_lock;
+	/*
+	 * All Sub-channels of a primary channel are linked here.
+	 */
+	struct list_head sc_list;
+	/*
+	 * The primary channel this sub-channel belongs to.
+	 * This will be NULL for the primary channel.
+	 */
+	struct vmbus_channel *primary_channel;
 };
 
 static inline void set_channel_read_state(struct vmbus_channel *c, bool state)
@@ -1057,6 +1090,34 @@ void vmbus_onmessage(void *context);
 
 int vmbus_request_offers(void);
 
+/*
+ * APIs for managing sub-channels.
+ */
+
+void set_sc_create_callback(struct vmbus_channel *primary_channel,
+			void (*sc_cr_cb)(struct vmbus_channel *new_sc));
+
+/*
+ * Retrieve the (sub) channel on which to send an outgoing request.
+ * When a primary channel has multiple sub-channels, we choose a
+ * channel whose VCPU binding is closest to the VCPU on which
+ * this call is being made.
+ */
+struct vmbus_channel *get_outgoing_channel(struct vmbus_channel *primary);
+
+/*
+ * Check if sub-channels have already been offerred. This API will be useful
+ * when the driver is unloaded after establishing sub-channels. In this case,
+ * when the driver is re-loaded, the driver would have to check if the
+ * subchannels have already been established before attempting to request
+ * the creation of sub-channels.
+ * This function returns TRUE to indicate that subchannels have already been
+ * created.
+ * This function should be invoked after setting the callback function for
+ * sub-channel creation.
+ */
+bool subchannels_present(struct vmbus_channel *primary);
+
 /* The format must be the same as struct vmdata_gpa_direct */
 struct vmbus_channel_packet_page_buffer {
 	u16 type;
@@ -1327,7 +1388,6 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
 			0x8e, 0x77, 0x05, 0x58, 0xeb, 0x10, 0x73, 0xf8 \
 		}
 
-
 /*
  * Common header for Hyper-V ICs
  */
-- 
1.7.4.1

[PATCH 2/6] Drivers: hv: Add the GUID fot synthetic fiber channel device

[K. Y. Srinivasan]

In preparation for supporting synthetic Fiber Channel device, add the GUID for
this service.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 include/linux/hyperv.h |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index a1a97a7..bffee1d 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -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
  */
 
-- 
1.7.4.1

Re: [PATCH 2/6] Drivers: hv: Add the GUID fot synthetic fiber channel device

[Greg KH]

On Wed, May 15, 2013 at 03:02:30PM -0700, K. Y. Srinivasan wrote:
> In preparation for supporting synthetic Fiber Channel device, add the GUID for
> this service.
> 
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
> ---
>  include/linux/hyperv.h |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[PATCH 3/6] Drivers: scsi: storvsc: Make the scsi timeout a module parameter

[K. Y. Srinivasan]

The standard scsi timeout is not appropriate in some of the environments where
Hyper-V is deployed. Set this timeout appropriately for all devices managed
by this driver. Further make this a module parameter.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/scsi/storvsc_drv.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 16a3a0c..8d29a95 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -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;
-- 
1.7.4.1

[PATCH 4/6] Drivers: scsi: storvsc: Update the storage protocol to win8 level

[K. Y. Srinivasan]

Update the storage protocol to the win8 level.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/scsi/storvsc_drv.c |  203 ++++++++++++++++++++++++++++++++++++--------
 1 files changed, 168 insertions(+), 35 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 8d29a95..a3cf85c 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -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 <
-- 
1.7.4.1

[PATCH 5/6] Drivers: scsi: storvsc: Implement multi-channel support

[K. Y. Srinivasan]

Implement multi-channel support for the storage devices.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/scsi/storvsc_drv.c |  124 ++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 120 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index a3cf85c..bed8d23 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -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.
+	 */
+	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 (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.
+	 */
+	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 = 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) -
-- 
1.7.4.1

[PATCH 6/6] Drivers: scsi: storvsc: Support FC devices

[K. Y. Srinivasan]

Add support for synthetic Fiber Channel devices.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/scsi/storvsc_drv.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index bed8d23..14bc922 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -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
+	},
 	{ },
 };
 
-- 
1.7.4.1

Re: [PATCH 1/6] Drivers: hv: vmbus: Implement multi-channel support

[Greg KH]

On Wed, May 15, 2013 at 03:02:29PM -0700, K. Y. Srinivasan wrote:
> +/*
> + * Retrieve the (sub) channel on which to send an outgoing request.
> + * When a primary channel has multiple sub-channels, we choose a
> + * channel whose VCPU binding is closest to the VCPU on which
> + * this call is being made.
> + */
> +struct vmbus_channel *get_outgoing_channel(struct vmbus_channel *primary)

That's a _very_ vague global symbol name you are adding to the kernel.
Same goes for the other functions you are adding here, please fix that,
and make them have the vmbus_ prefix, like everything else in this
patch.

So, sorry, no ack here.

greg k-h

RE: [PATCH 1/6] Drivers: hv: vmbus: Implement multi-channel support

[KY Srinivasan]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Thursday, May 16, 2013 12:02 AM
> To: KY Srinivasan
> Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> ohering@suse.com; jbottomley@parallels.com; hch@infradead.org; linux-
> scsi@vger.kernel.org; apw@canonical.com; jasowang@redhat.com
> Subject: Re: [PATCH 1/6] Drivers: hv: vmbus: Implement multi-channel support
> 
> On Wed, May 15, 2013 at 03:02:29PM -0700, K. Y. Srinivasan wrote:
> > +/*
> > + * Retrieve the (sub) channel on which to send an outgoing request.
> > + * When a primary channel has multiple sub-channels, we choose a
> > + * channel whose VCPU binding is closest to the VCPU on which
> > + * this call is being made.
> > + */
> > +struct vmbus_channel *get_outgoing_channel(struct vmbus_channel
> *primary)
> 
> That's a _very_ vague global symbol name you are adding to the kernel.
> Same goes for the other functions you are adding here, please fix that,
> and make them have the vmbus_ prefix, like everything else in this
> patch.


Will do.

K. Y

Re: [PATCH 0/6] Drivers: hv/scsi: Implement multi-channel support

[Greg KH]

On Wed, May 15, 2013 at 03:02:00PM -0700, K. Y. Srinivasan wrote:
> This patch-set implements multi-channel support for Hyper-V devices. Also
> support for synthetic Fiber Channel device is included. The first two
> patches in the series are the foundational pieces for the remaining patches.
> 
> James, once Greg accepts the first two patches, you can consider the scsi
> patches.

I have no objection for these first two patches to go through James's
tree, I'll go add my ack to them.  That should make it easier for
everyone involved.

thanks,

greg k-h

RE: [PATCH 0/6] Drivers: hv/scsi: Implement multi-channel support

[KY Srinivasan]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Thursday, May 16, 2013 12:00 AM
> To: KY Srinivasan
> Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> ohering@suse.com; jbottomley@parallels.com; hch@infradead.org; linux-
> scsi@vger.kernel.org; apw@canonical.com; jasowang@redhat.com
> Subject: Re: [PATCH 0/6] Drivers: hv/scsi: Implement multi-channel support
> 
> On Wed, May 15, 2013 at 03:02:00PM -0700, K. Y. Srinivasan wrote:
> > This patch-set implements multi-channel support for Hyper-V devices. Also
> > support for synthetic Fiber Channel device is included. The first two
> > patches in the series are the foundational pieces for the remaining patches.
> >
> > James, once Greg accepts the first two patches, you can consider the scsi
> > patches.
> 
> I have no objection for these first two patches to go through James's
> tree, I'll go add my ack to them.  That should make it easier for
> everyone involved.

Thanks Greg.

Regards,

K. Y