This patch introduces the usage of the pre-associate state of the IEEE 802.1Qbg standard on incoming VM migration on the target host. It is in response to bugzilla entry 632750.
https://bugzilla.redhat.com/show_bug.cgi?id=632750
For being able to differentiate the exact reason as to why a macvtap device is being created, either due to a VM creation or an incoming VM migration, I needed to pass that reason as a parameter from wherever qemudStartVMDaemon is being called in order to determine whether to send an ASSOCIATE (VM creation) or a PRE-ASSOCIATE (incoming VM migration) towards lldpad.
I am also fixing a problem with the virsh domainxml-to-native call on the way.
Gerhard successfully tested the patch with a recent blade network 802.1Qbg-compliant switch.
The patch should not have any side-effects on the 802.1Qbh support in libvirt, but Roopa (cc'ed) may want to verify this.
Rework and simplification of teardown of the macvtap device.
Basically all devices with the same MAC address and link device are kept
alive and not attempted to be torn down. If a macvtap device linked to a
physical interface with a certain MAC address 'M' is to be created it
will automatically fail if the interface is 'up'ed and another macvtap
with the same properties (MAC addr 'M', link dev) happens to be 'up'.
This will prevent the VM from starting or the device from being attached
to a running VM. Stale interfaces are assumed to be there for some
reason and not stem from libvirt.
In the VM shutdown path, it's assuming that an interface name is always
available so that if the device type is DIRECT it can be torn down
using its name.
* src/util/macvtap.h src/libvirt_macvtap.syms: change of deleting routine
* src/util/macvtap.c: cleanups and change of deleting routine
* src/qemu/qemu_driver.c: change cleanup on shutdown
* src/qemu/qemu_conf.c: don't delete Macvtap in qemudPhysIfaceConnect()
This patch adds build support for libvirt checking for certain contents
of /usr/include/linux/if_link.h to see whether macvtap support is
compilable on that system. One can disable macvtap support in libvirt
via --without-macvtap passed to configure.
* configure.ac src/Makefile.am: new build support
* src/libvirt_macvtap.syms: list of exported symbols
* src/util/macvtap.c: empty module to not break compilation
