Linux 5.16 To Expose AMD PSF Disable Bit To KVM Guests

While the Linux kernel still hasn't added any formal control yet for AMD Predictive Store Forwarding to disable it short of also toggling Spectre V4 / SSBD, with the Linux 5.16 kernel the AMD PSF bit will now be exposed to KVM guest virtual machines so that they -- either with a patched/future kernel or for other operating systems -- may choose to toggle explicitly disable this AMD CPU feature...