On Fri, Aug 11, 2023, Mika Penttilä wrote: > > @@ -252,11 +252,10 @@ SYM_START(srso_untrain_ret, SYM_L_GLOBAL, SYM_A_NONE) > > .byte 0x48, 0xb8 > > SYM_INNER_LABEL(srso_safe_ret, SYM_L_GLOBAL) > > - add $8, %_ASM_SP > > + lea 8(%_ASM_SP), %_ASM_SP > > ret > > int3 > > int3 > > - int3 > > lfence > > call srso_safe_ret > > int3 > > > > base-commit: 25aa0bebba72b318e71fe205bfd1236550cc9534 > > Don't we have the same kind of problems with __x86_return_skl ? Yep, forcing that path via "retbleed=force retbleed=stuff spectre_v2=retpoline,generic" yields the same failures. I have no idea how to go about cleanly fixing that. The logic effectively requires modifying flags, the only thing I can think of is to save/restore flags across the thunk, which seems beyond gross. Given that no one has complained about this, I think I'd vote to simply disable KVM if call depth tracking is being used.
