RE: [PATCH net-next V2 1/9] liquidio CN23XX: HW config for VF support

-----Original Message-----
From: David Miller [mailto:davem@davemloft.net]
Sent: Thursday, October 20, 2016 11:13 AM
To: Vatsavayi, Raghu
Cc: netdev@vger.kernel.org; Vatsavayi, Raghu; Chickles, Derek; Burla,
Satananda; Manlunas, Felix
Subject: Re: [PATCH net-next V2 1/9] liquidio CN23XX: HW config for VF
support

From: Raghu Vatsavayi <redacted>
Date: Wed, 19 Oct 2016 22:40:38 -0700

quoted

+/* Default behaviour of Liquidio is to provide one queue per VF. But
+Liquidio
+ * can also provide multiple queues to each VF. If user wants to
+change the
+ * default behaviour HW should be provided configuration info at init
+time,
+ * based on which it will create control queues for communicating with

FW.

quoted

+ */
+static u32 max_vfs[2] = { 0, 0 };
+module_param_array(max_vfs, int, NULL, 0444);
+MODULE_PARM_DESC(max_vfs, "Assign two comma-separated unsigned
+integers that specify max number of VFs for PF0 (left of the comma)
+and PF1 (right of the comma); for 23xx only. By default HW will
+configure as many VFs as queues after allocating PF queues.To
+increase queues for VF use this parameter. Use sysfs to create these
+VFs.");
+
+static unsigned int num_queues_per_pf[2] = { 0, 0 };
+module_param_array(num_queues_per_pf, uint, NULL, 0444);
+MODULE_PARM_DESC(num_queues_per_pf, "two comma-separated

unsigned

quoted

+integers that specify number of queues per PF0 (left of the comma)
+and PF1 (right of the comma); for 23xx only");
+
 static int ptp_enable = 1;

We cannot continue to allow drivers to add custom module parameters to
control this.  It is the worst user experience possible.

We need a tree-wide generic, consistent, manner in which to configure and
control this kind of thing.

Sure Dave, I will remove max_vfs module parameter and will use tree wide generic 
sysfs interface to enable VFs. Also if user wants to have multiple queues then because 
of the way Liquidio HW works we need num_queues_per_pf and num_queues_per_vf 
module parameters at HW/module init time. This is required only in case of non-default
case of multi-queues per VF because HW has to carve these queues before FW can start
communicating with PF/VF host drivers, so we may include these two. 

I will soon forward you the patches with the changes that you recommended.

Thanks Much.
Raghu.