Merge tag 'kvm-x86-misc-6.9' of https://github.com/kvm-x86/linux into HEAD

Merge tag 'kvm-x86-misc-6.9' of https://github.com/kvm-x86/linux into HEAD

KVM x86 misc changes for 6.9:

 - Explicitly initialize a variety of on-stack variables in the emulator that
   triggered KMSAN false positives (though in fairness in KMSAN, it's comically
   difficult to see that the uninitialized memory is never truly consumed).

 - Fix the deubgregs ABI for 32-bit KVM, and clean up code related to reading
   DR6 and DR7.

 - Rework the "force immediate exit" code so that vendor code ultimately
   decides how and when to force the exit.  This allows VMX to further optimize
   handling preemption timer exits, and allows SVM to avoid sending a duplicate
   IPI (SVM also has a need to force an exit).

 - Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if
   vCPU creation ultimately failed, and add WARN to guard against similar bugs.

 - Provide a dedicated arch hook for checking if a different vCPU was in-kernel
   (for directed yield), and simplify the logic for checking if the currently
   loaded vCPU is in-kernel.

 - Misc cleanups and fixes.