[Artful] cherry-pick KVM fix for CPUs lacking virtual NMI support

[Fabian Grünbichler]

BugLink: https://bugs.launchpad.net/1738982

== SRU Justification ==

Impact: systems with CPUs lacking virtual NMI support are no longer able
to load the kvm_intel module, and thus not able to use KVM functionality

Fix: cherry-pick re-introducing support for software NMI support

Regression Potential: applied upstream in 4.15 and 4.14.3, tested and
verified by multiple people

the original dropping of support was (functionally) reverted after
upstream got notified of how many CPUs were actually affected

see [1] for upstream patch re-introducing support

see [2] for the original upstream patch dropping support and following
discusison

1: https://lkml.kernel.org/r/<1509971473-74491-1-git-send-email-pbonzini@redhat.com>
2: https://lkml.kernel.org/r/<1490618297-10581-2-git-send-email-pbonzini@redhat.com>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-kvm-vmx-Reinstate-support-for-CPUs-without-virtual-N.patch
Type: text/x-diff
Size: 11101 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20171219/85a8fb4e/attachment.patch>