Merge tag 'kvm-x86-vmx-6.18' of https://github.com/kvm-x86/linux into HEAD

Merge tag 'kvm-x86-vmx-6.18' of https://github.com/kvm-x86/linux into HEAD

KVM VMX changes for 6.18

 - Add read/write helpers for MSRs that need to be accessed with preemption
   disable to prepare for virtualizing FRED RSP0.

 - Fix a bug where KVM would return 0/success from __tdx_bringup() on error,
   i.e. where KVM would load with enable_tdx=true despite TDX not being usable.

 - Minor cleanups.