On Apr 7 12:06, Jeff Kirsher wrote: > On Wed, 2017-04-05 at 15:46 +0200, Corinna Vinschen wrote: > > Before libvirt modifies the MAC address and vlan tag for an SRIOV > > VF > > for use by a virtual machine (either using vfio device assignment > > or > > macvtap passthru mode), it saves the current MAC address and vlan > > tag > > so that it can reset them to their original value when the guest is > > done. Libvirt can't leave the VF MAC set to the value used by the > > now-defunct guest since it may be started again later using a > > different VF, but it certainly shouldn't just pick any random > > value, > > either. So it saves the state of everything prior to using the VF, > > and > > resets it to that. > > > > The igb driver initializes the MAC addresses of all VFs to > > 00:00:00:00:00:00, and reports that when asked (via an RTM_GETLINK > > netlink message, also visible in the list of VFs in the output of > > "ip > > link show"). But when libvirt attempts to restore the MAC address > > back > > to 00:00:00:00:00:00 (using an RTM_SETLINK netlink message) the > > kernel > > responds with "Invalid argument". > > > > Forbidding a reset back to the original value leaves the VF MAC at > > the > > value set for the now-defunct virtual machine. Especially on a > > system > > with NetworkManager enabled, this has very bad consequences, since > > NetworkManager forces all interfacess to be IFF_UP all the time - > > if > > the same virtual machine is restarted using a different VF (or even > > on > > a different host), there will be multiple interfaces watching for > > traffic with the same MAC address. > > > > To allow libvirt to revert to the original state, we need a way to > > remove the administrative set MAC on a VF, to allow normal host > > operation again, and to reset/overwrite the VF MAC via VF netdev. > > > > This patch implements the outlined scenario by allowing to set the > > VF MAC to 00:00:00:00:00:00 via RTM_SETLINK on the PF. > > igb_ndo_set_vf_mac resets the IGB_VF_FLAG_PF_SET_MAC flag to 0, > > so it's possible to reset the VF MAC back to the original value via > > the VF netdev. > > > > Note: Recent patches to libvirt allow for a workaround if the NIC > > isn't capable of resetting the administrative MAC back to all 0, > > but > > in theory the NIC should allow resetting the MAC in the first > > place. > > > > Signed-off-by: Corinna Vinschen <vinsc...@redhat.com> > > --- > > drivers/net/ethernet/intel/igb/igb_main.c | 42 > > +++++++++++++++++++++++-------- > > 1 file changed, 31 insertions(+), 11 deletions(-) > > This patch does not apply (not even close). Please make sure to base > you patch off my dev-queue branch of my next-queue tree on kernel.org.
Right, I applied the patch against net-next. Actually, only the first hunk didn't apply to dev-queue because of the change from igb_rar_set_qsel to igb_rar_set_index. I'll send a v3 agains dev-queue in a bit. Corinna
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