Re: [PATCH v4 14/14] QLogic VNIC: sysfs Documentation

Since I didn't receive anything but a "its too complex" in
response to my previous question, let me ask again: why are
you inventing a new sysfs interface (combined with ~15 module
parameters) instead of using the existing standard interfaces
for this?

Ramachandra K wrote:

+sysfs interface:
+----------------
+
+The QLogic Virtual NIC module when loaded on host creates following set of
+files into the sysfs:
+
+/sys/class/infiniband_qlgc_vnic/interfaces
+
+	create_vnic	(0200)	To create a new VNIC interface, write the name
+				of the interface to this file.
+
+	delete_vnic	(0200)	To delete an existing VNIC interface, write
+				name of that VNIC interface to this file.

This is exactly what rtnl_link is for.

+/sys/class/infiniband_qlgc_vnic/interfaces/<VNIC-interface-name>/
+
+	vnic_state	(0444)	State of the VNIC interface.

This I don't understand - you seem to be registering and
unregistering the net_device based some state machine,
in some cases even triggered by timers.

Whats the idea behind this?

+
+	current_path	(0444)	In case of failover configuration, which
+				connection among the primary and secondary is
+				currently being used.
+
+	multicast	(0644)	Get/Set IB multicast value for the VNIC
+				interface.  Only root can Enable/Disable IB
+				multicast for that VNIC interface.
+
+	rx_csum		(0644)	Get/Set receive checksum boolean value for VNIC
+				interface.  Only root can Enable/Disable the
+				receive checksum operation for that VNIC
+				interface.
+
+	tx_csum		(0644)	Get/Set transmit checksum boolean value for VNIC
+				interface.  Only root can Enable/Disable the
+				transmit checksum operation for that VNIC
+				interface.

Why is this not done using ethtool?

+Example:
+--------
+
+QLogic VNIC sysfs interface can be used directly to create a VNIC interface.
+
+# echo the name of new VNIC interface to create_vnic
+echo -n veth1 > /sys/class/infiniband_qlgc_vnic/interfaces/create_vnic
+
+# echo parameters to configure the VNIC interface. Some of these are 
+# interface level parameters which needs to be passed only once per VNIC
+# interface.
+
+echo -n true  > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/rx_csum
+echo -n false > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/tx_csum
+echo -n false > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/multicast
+
+echo -n 00066a01de000037 		 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/ioc_guid
+echo -n fe8000000000000100066a11de000037 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/dgid
+echo -n ffff 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/pkey
+echo -n 0 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/instance
+echo -n 100 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/heartbeat
+string="EVIC in Chassis 0x00066a00db000010, Slot 4, Ioc 1"
+echo -n $string 			 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/primary_path/ioc_string
+
+# Trigger the connection establishment process for the path by choosing required
+# HCA and IB port combination.
+
+echo -n veth1 > /sys/class/infiniband_qlgc_vnic/vnic-mlx4_0-1/create_primary
+
+# In case of failover configuration, pass the parameters of the failover
+# connection to the driver and trigger its connection establishment
+# process.
+
+echo -n 00066a01de000037 		 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/ioc_guid
+echo -n fe8000000000000100066a11de000037 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/dgid
+echo -n ffff 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/pkey
+echo -n 1 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/instance
+echo -n 100 				 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/heartbeat
+string="EVIC in Chassis 0x00066a00db000010, Slot 4, Ioc 1"
+echo -n $string 			 > /sys/class/infiniband_qlgc_vnic/interfaces/veth1/secondary_path/ioc_string
+
+echo -n veth1 > /sys/class/infiniband_qlgc_vnic/vnic-mlx4_0-2/create_secondary
+
+# An interface can be deleted by echoing the name of the interface to be deleted
+# to delete_vnic file
+echo -n veth1 > /sys/class/infiniband_qlgc_vnic/interfaces/delete_vnic

This clearly shows the advantage of being able to use echo
for configuration.