On Wed, Sep 21, 2022 at 08:11:29AM -0700, Jim Mattson wrote: > Yes, after the revert, KVM will treat the bit as reserved, and it will > synthesize a #GP, *in violation of the architectural specification.* Architectural, schmarchitectural... Intel hasn't implemented it so meh. > KVM can't just decide willy nilly to reserve arbitrary bits. If it is > in violation of AMD's architectural specification, the virtual CPU is > defective. Grrr, after your revert that this bit was *only* reserved and nothing else to KVM. Like every other reserved bit in EFER. Yeah, yeah, AMD specified it as architectural but Intel didn't implement it so there's this thing on paper and there's reality... Anyway, enough about this - we're on the same page. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette