177132df5e
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 <vinschen@redhat.com> Tested-by: Aaron Brown <arron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
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| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.