KVM VMX changes for 6.15
- Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and thus
modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1.
- Pass XFD_ERR as a psueo-payload when injecting #NM as a preparatory step
for upcoming FRED virtualization support.
- Decouple the EPT entry RWX protection bit macros from the EPT Violation bits
as a general cleanup, and in anticipation of adding support for emulating
Mode-Based Execution (MBEC).
- Reject KVM_RUN if userspace manages to gain control and stuff invalid guest
state while KVM is in the middle of emulating nested VM-Enter.
- Add a macro to handle KVM's sanity checks on entry/exit VMCS control pairs
in anticipation of adding sanity checks for secondary exit controls (the
primary field is out of bits).