On 15/05/18 10:04, Jan Beulich wrote: >>>> On 15.05.18 at 10:37, <[email protected]> wrote: >> Commit 62b1879693e0 ("x86: further CPUID handling adjustments") added >> FEATURESET_7d0 reporting but forgot to update calculate_raw_featureset() >> function. As result, the value reported by xen-cpuid contains 0. >> >> Fix that by properly filling raw_featureset[FEATURESET_7d0]. >> >> Signed-off-by: Sergey Dyasli <[email protected]> > Thanks, technically > Acked-by: Jan Beulich <[email protected]> > >> --- >> I see that at least 4.8 also contains this bug, so other releases also >> need checking. > The commit in question being only on the two branches, I think no other one > would need the change. > > I'm certainly going to apply this to 4.8; I'm uncertain about 4.7 though > <snip>
The entirety of that changeset is broken in feature levelling scenarios, which is a consequence of missing this hunk which Sergey identified. The result is that, when trying to level STIBP/IBPB out of guests view, the CPUID bits remain visible, but attempts to use the MSR bits will fail. I'm rewriting the change from scratch. ~Andrew _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
