VLan support for SR-IOV

[jellonek]

This change is 

[jellonek]

Tests on real hardware (with mellanox NIC) showed that netlink library has still issues even after increasing receive msg buffer so for time of fixing that in proper way on library side i'll provide there a workaround based on invocation of ip link command and parsing its text output.

[ivan4th]

Reviewable status: 0 of 2 LGTMs obtained

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pkg/nettools/nettools.go, line 678 at r2 (raw file):

// setMacAndVlanOnVf uses VF pci address to locate its parent device and uses
// it to set mac address and Vlan id on VF.  It needs to be called from host netns.

VLAN...
from the host netns

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pkg/nettools/nettools.go, line 707 at r2 (raw file):

		return 0, err
	}
	iplinkOutput, err := exec.Command("ip", "link", "show", masterLink.Attrs().Name).CombinedOutput()

pls add a comment why ip link show command needs to be used here. It's due to a bug in netlink library related to the netlink message size, right?

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pkg/nettools/nettools.go, line 781 at r2 (raw file):

			// Jump into host netns to get vlan id of VF using its
			// master device.

Switch to the host netns to get VLAN ID of the VF using its master device.

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pkg/nettools/nettools.go, line 825 at r2 (raw file):

						glog.V(3).Infof("Warning, error during umount of /sys: %v", err)
					}
				}()

This code is repeated. Maybe consider adding function like withHostNetnsAndSysfsRemounted(toCall func() error) ?

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pkg/nettools/nettools.go, line 941 at r2 (raw file):

			// devices as was used before reboot, but in meantime there is small chance that they
			// were used already by sriov cni plugin (for which reboot means it's starting everything
			// from clean situation) by other containers, before even virtlet was started

"for some other pods" not "by other containers" maybe?

[jellonek]

Reviewable status: 0 of 2 LGTMs obtained

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pkg/nettools/nettools.go, line 678 at r2 (raw file):

Previously, ivan4th (Ivan Shvedunov) wrote…

VLAN...
from the host netns

Done.

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pkg/nettools/nettools.go, line 707 at r2 (raw file):

Previously, ivan4th (Ivan Shvedunov) wrote…

pls add a comment why ip link show command needs to be used here. It's due to a bug in netlink library related to the netlink message size, right?

I had same EINVAL even after increasing message size buffer in netlink, so the real reason is unknown for the moment.
Comment added.

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pkg/nettools/nettools.go, line 825 at r2 (raw file):

Previously, ivan4th (Ivan Shvedunov) wrote…

This code is repeated. Maybe consider adding function like withHostNetnsAndSysfsRemounted(toCall func() error) ?

I planed to do that at the beginning of q3, as a part of bigger cleanup in this packager. I plan to extract all related to sriov things to separate file, as this currently contains imo too much spagetti code.
But ok, can add that there now.

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pkg/nettools/nettools.go, line 941 at r2 (raw file):

Previously, ivan4th (Ivan Shvedunov) wrote…

"for some other pods" not "by other containers" maybe?

Done.

[ivan4th]

Reviewed 3 of 7 files at r1, 3 of 4 files at r2, 5 of 5 files at r3.
Reviewable status: 0 of 2 LGTMs obtained

[ivan4th]

Reviewable status: 0 of 2 LGTMs obtained, and 1 stale

[pigmej]

Reviewed 3 of 7 files at r1, 3 of 4 files at r2, 5 of 5 files at r3.
Reviewable status: 1 of 2 LGTMs obtained

[pigmej]

Reviewable status: 1 of 2 LGTMs obtained, and 1 stale