Bug 1038379

Summary: be2net module does not give any hint when set num_vfs with out of range number(Emulex card)
Product: Red Hat Enterprise Linux 7 Reporter: Jun Li <juli>
Component: qemu-kvmAssignee: Bandan Das <bdas>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: low Docs Contact:
Priority: medium    
Version: 7.0CC: acathrow, alex.williamson, chayang, hhuang, juli, juzhang, michen, sluo, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-02-12 09:00:11 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Jun Li 2013-12-05 02:25:37 UTC 
Description of problem:
be2net module did not give any hint when set num_vfs with out of range number.
Such as:
# lspci -vvv -s 09:00.0 | grep 'Initial VFs'
		Initial VFs: 16, Total VFs: 16, Number of VFs: 0, Function Dependency Link: 00
----
So set num_vfs with 100, be2net module did not give any hint and return with success.
# modprobe -r be2net; modprobe be2net num_vfs=100
----
BTW, set num_vfs with -1, kernel will give an ERROR message. 
# modprobe -r be2net; modprobe be2net num_vfs=-1
modprobe: ERROR: could not insert 'be2net': Invalid argument

Version-Release number of selected component (if applicable):
3.10.0-57.el7.x86_64
qemu-kvm-rhev-1.5.3-20.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.
2.
3.

Actual results:
be2net module did not give any hint.

Expected results:
be2net module will give a friendly hint.

Additional info:
Comment 4 Bandan Das 2014-02-06 11:22:14 UTC 
The be2net driver behaves differently than say, for example ixgbe when it comes to trying to create more VFs than is possible.

static int be_vf_setup(struct be_adapter *adapter)
{
...
	} else {
		if (num_vfs > be_max_vfs(adapter))
			dev_info(dev, "Device supports %d VFs and not %d\n",
				 be_max_vfs(adapter), num_vfs);
		adapter->num_vfs = min_t(u16, num_vfs, be_max_vfs(adapter));
		if (!adapter->num_vfs)
			return 0;
	}

It presents a message about how many VFs can be created and also goes forward with creating the maximum possible. I see nothing wrong with that approach, except for probably a better wording of the dev_info message that we are going ahead and creating VFs anyway.

In the logs, we have -
be2net 0000:09:00.1: Device supports 16 VFs and not 100

and lspci confirms 16 VFs have been created.
Comment 8 Bandan Das 2014-02-12 09:00:11 UTC 
Closing as per comment 4