Re: [libvirt] [PATCHv2 4/9] network: save bridge name in ActualNetDef when actualType==network too

When the actualType of a virDomainNetDef is "network", it means that we are connecting to a libvirt-managed network (routed, natted, or isolated) which does use a bridge device (created by libvirt). In the past we have required drivers such as qemu to call the public API to retrieve the bridge name in this case (even though it is available in the NetDef's ActualNetDef if the actualType is "bridge" (i.e., an externally-created bridge that isn't managed by libvirt). There is no real reason for this difference, and as a matter of fact it complicates things for qemu. Also, there is another bridge-related attribute (fdb) that will need to be available in both cases, so this makes things consistent. In order to avoid problems when restarting libvirtd after an update from an older version that *doesn't* store the network's bridgename in the ActualNetDef, we also need to put it in place during networkNotifyActualDevice() (this function is run for each interface of each domain whenever libvirtd is restarted). Along with making the bridge name available in the internal object, it is also now reported in the <source> element of the <interface> state XML (or the <actual> subelement in the internally-stored format). The one oddity about this change is that usually there is a separate union for every different "type" in a higher level object (e.g. in the case of a virDomainNetDef there are separate "network" and "bridge" members of the union that pivots on the type), but in this case network and bridge types both have exactly the same attributes, so the "bridge" member is used for both type==network and type==bridge. --- Changes from V1: * populate actual.brname of an active interface when libvirtd is restarted, to avoid problems during upgrade. (John had asked questions about what happens during a save/restore or a migration; the answer is that everything in the <actual> is discarded as the interface is re-allocated/re-created, so there are no upgrade issues in that case.) src/conf/domain_conf.c | 102 +++++++++++++++++++++++--------------------- src/network/bridge_driver.c | 20 +++++++++ 2 files changed, 73 insertions(+), 49 deletions(-)