On Mon, Feb 20, 2023 at 11:02 AM Borislav Petkov <bp@xxxxxxxxx> wrote: > > On Mon, Feb 20, 2023 at 10:56:38AM -0800, KP Singh wrote: > > Sure, it looks like an omission to me, we wrote a POC on Skylake that > > was able to do cross-thread training with the current set of > > mitigations. > > Right. > > > STIBP with IBRS is still correct if spectre_v2=ibrs had really meant > > IBRS everywhere, > > Yeah, IBRS everywhere got shot down as a no-no very early in the game, > for apparent reasons. As you said in the other thread, this needs to be documented both in the code and the kernel documentation. > > > but just means KERNEL_IBRS, which means only kernel is protected, > > userspace is still unprotected. > > Yes, that was always the intent with IBRS: enable on kernel entry and > disable on exit. > > Thx. > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette
