> Lucky they're not the ones accepting patches. If upstream adopts it they'd have to disable support in their build, which seems unlikely.
Upstream libvirt would probably be Red Hat employees. :) It would not be disabled in the RHEL build, but note that Red Hat does disable a lot of features of QEMU in RHEL. About this:
> RH usually have a lot of not-upstream patches though (at least they do for the kernel, grub, and qemu, so I assume the same for libvirt) which complicates things a bit.
Most of the patches in kernel and QEMU are backports from upstream.
For QEMU there are 20-30 patches not-upstream patches and they're mostly configuration. For the kernel it's a bit more but not many, and Libvirt probably has even fewer.