Move function to qemu_interface.c and rename to qemuInterfaceOpenVhostNet
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Move the misplaced function from qemu_command.c to qemu_interface.c
since it's closer in functionality there and had less to do with building
the command line.

Rename function to qemuInterfaceBridgeConnect and modify callers.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Move the misplaced function from qemu_command.c to qemu_interface.c
since it's closer in functionality there and had less to do with building
the command line.

Rename function to qemuInterfaceDirectConnect and modify callers.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>

Adds a new interface type using UDP sockets, this seems only applicable
to QEMU but have edited tree-wide to support the new interface type.

The interface type required the addition of a "localaddr" (local
address), this then maps into the following xml and qemu call.

<interface type='udp'>
  <mac address='52:54:00:5c:67:56'/>
  <source address='127.0.0.1' port='11112'>
    <local address='127.0.0.1' port='22222'/>
  </source>
  <model type='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
</interface>

QEMU call:
	-net socket,udp=127.0.0.1:11112,localaddr=127.0.0.1:22222

Notice the xml "local" entry becomes the "localaddr" for the qemu call.

reference:
http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg00629.htmlSigned-off-by: NJonathan Toppins <jtoppins@cumulusnetworks.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

A further fix for:

  https://bugzilla.redhat.com/show_bug.cgi?id=1113474

Since there is no possibility that any type of macvtap will work if
the parent physdev it's attached to is offline, we should bring the
physdev online at the same time as the macvtap. When taking the
macvtap offline, it's also necessary to take the physdev offline for
macvtap passthrough mode (because the physdev has the same MAC address
as the macvtap device, so could potentially cause problems with
misdirected packets during migration, as outlined in commits 829770
and 879c13). We can't set the physdev offline for other macvtap modes
1) because there may be other macvtap devices attached to the same
physdev (and/or the host itself may be using the device) in the other
modes whereas passthrough mode is exclusive to one macvtap at a time,
and 2) there's no practical reason to do so anyway.

When libvirt is managing a bridge's forwarding database (FDB)
(macTableManager='libvirt'), if we add FDB entries for a new guest
interface even before the qemu process is created, then in the case of
a migration any other guest attached to the "destination" bridge will
have its traffic immediately sent to the destination of the migration
even while the source domain is still running (and the destination, of
course, isn't). To make sure that traffic from other guests on the new
host continues flowing to the old guest until the new one is ready, we
have to wait until the new guest CPUs are started to add the FDB
entries.

Conversely, we need to remove the FDB entries from the bridge any time
the guest CPUs are stopped; among other things, this will assure
proper operation during a post-copy migration (which is just the
opposite of the problem described in the previous paragraph).

We now have a qemuInterfaceStartDevices() which does the final
activation needed for the host-side tap/macvtap devices that are used
for qemu network connections. It will soon make sense to have the
converse qemuInterfaceStopDevices() which will undo whatever was done
during qemuInterfaceStartDevices().

A function to "stop" a single device has also been added, and is
called from the appropriate place in qemuDomainDetachNetDevice(),
although this is currently unnecessary - the device is going to
immediately be deleted anyway, so any extra "deactivation" will be for
naught. The call is included for completeness, though, in anticipation
that in the future there may be some required action that *isn't*
nullified by deleting the device.

This patch is a part of a more complete fix for:

  https://bugzilla.redhat.com/show_bug.cgi?id=1081461

Currently, MAC registration occurs during device creation, which is
early enough that, during live migration, you end up with duplicate
MAC addresses on still-running source and target devices, even though
the target device isn't actually being used yet.
This patch proposes to defer MAC registration until right before
the guest can actually use the device -- In other words, right
before starting guest CPUs.
Signed-off-by: NMatthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: NLaine Stump <laine@laine.org>