When support for <interface type='ethernet'> was added in commit
9a4b705f back in 2010, it erroneously looked at <source dev='blah'/>
for a user-specified guest-side interface name. This was never
documented though. (that attribute already existed at the time in the
data.ethernet union member of virDomainNetDef, but apparently had no
practical use - it was only used as a storage place for a NetDef's
bridge name during qemuDomainXMLToNative(), but even then that was
never used for anything).
When support for similar guest-side device naming was added to the lxc
driver several years later, it was put in a new subelement <guest
dev='blah'/>.
In the intervening years, since there was no validation that
ethernet.dev was NULL in the other drivers that didn't actually use
it, innocent souls who were adding other features assuming they needed
to account for non-NULL ethernet.dev when really they didn't, so
little bits of the usual pointless cargo-cult code showed up.
This patch not only switches the openvz driver to use the documented
<guest dev='blah'/> notation for naming the guest-side device (just in
case anyone is still using the openvz driver), and logs an error if
anyone tries to set <source dev='blah'/> for a type='ethernet'
interface, it also removes the cargo-cult uses of ethernet.dev and
<source dev='blah'/>, and eliminates if from the RNG and from
virDomainNetDef.
NB: I decided on this course of action after mentioning the
inconsistency here:
https://www.redhat.com/archives/libvir-list/2016-May/msg02038.html
and getting encouragement do eliminate it in a later IRC discussion
with danpb.
libvirt library code README
===========================
The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.
The files directly in this directory are supporting the public API
entry points & data structures.
There are two core shared modules to be aware of:
* util/ - a collection of shared APIs that can be used by any
code. This directory is always in the include path
for all things built
* conf/ - APIs for parsing / manipulating all the official XML
files used by the public API. This directory is only
in the include path for driver implementation modules
* vmx/ - VMware VMX config handling (used by esx/ and vmware/)
Then there are the hypervisor implementations:
* bhyve - bhyve - The BSD Hypervisor
* esx/ - VMware ESX and GSX support using vSphere API over SOAP
* hyperv/ - Microsoft Hyper-V support using WinRM
* lxc/ - Linux Native Containers
* openvz/ - OpenVZ containers using cli tools
* phyp/ - IBM Power Hypervisor using CLI tools over SSH
* qemu/ - QEMU / KVM using qemu CLI/monitor
* remote/ - Generic libvirt native RPC client
* test/ - A "mock" driver for testing
* uml/ - User Mode Linux
* vbox/ - Virtual Box using native API
* vmware/ - VMware Workstation and Player using the vmrun tool
* xen/ - Xen using hypercalls, XenD SEXPR & XenStore
* xenapi/ - Xen using libxenserver
Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU, UML and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly
* cpu/ - CPU feature management
* interface/ - Host network interface management
* network/ - Virtual NAT networking
* nwfilter/ - Network traffic filtering rules
* node_device/ - Host device enumeration
* secret/ - Secret management
* security/ - Mandatory access control drivers
* storage/ - Storage management drivers
Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories