On 24/06/2015 17:58, Eduardo Habkost wrote: > > 3) regarding "enforce", there are indeed some cases where it would break: > > > > - Haswell/Broadwell CPU model after TSX removal > > > > - qemu64 with KVM > > > > - pretty much everything including qemu64 with TCG > > - Everything involving KVM CPUID features, that change depending on the > kernel version. > > - Intel CPU models that had VMX enabled in older machine-types, > and may or may not have VMX enabled depending on kernel VMX nesting > configuration. > > > So libvirt here could allow _now_ the user to specify enforce, either > > via XML or via qemu.conf (or via XML + a default specified via qemu.conf). > > More precisely, libvirt would emulate "enforce" mode by checking the > "filtered-features", because "enforce" error messages are not > machine-friendly.
Even better, because it would let libvirt special-case stuff like TSX, VMX and SVM. Paolo
