This patch addresses: https://bugzilla.redhat.com/show_bug.cgi?id=781562
Along with the "rombar" option that controls whether or not a boot rom
is made visible to the guest, qemu also has a "romfile" option that
allows specifying a binary file to present as the ROM BIOS of any
emulated or passthrough PCI device. This patch adds support for
specifying romfile to both passthrough PCI devices, and emulated
network devices that attach to the guest's PCI bus (just about
everything other than ne2k_isa).
One example of the usefulness of this option is described in the
bugzilla report: 82576 sriov network adapters don't provide a ROM BIOS
for the cards virtual functions (VF), but an image of such a ROM is
available, and with this ROM visible to the guest, it can PXE boot.
In libvirt's xml, the new option is configured like this:
<hostdev>
...
<rom file='/etc/fake/boot.bin'/>
...
</hostdev
(similarly for <interface>).
When support for the rombar option was added, it was only added for
PCI passthrough devices, configured with <hostdev>. The same option is
available for any network device that is attached to the guest's PCI
bus. This patch allows setting rombar for any PCI network device type.
After adding cases to test this to qemuxml2argv-hostdev-pci-rombar.*,
I decided to rename those files (to qemuxml2argv-pci-rom.*) to more
accurately reflect the additional tests, and also noticed that up to
now we've only been performing a domainschematest for that case, so I
added the "pci-rom" test to both qemuxml2argv and qemuxml2xml (and in
the process found some bugs whose fixes I squashed into previous
commits of this series).
