Re: [RFC][PATCH 11/17] x86/cpu: Remove all SRSO interface nonsense
From: Peter Zijlstra
Date: Wed Aug 09 2023 - 10:43:54 EST
On Wed, Aug 09, 2023 at 10:05:30AM -0400, Josh Poimboeuf wrote:
> On Wed, Aug 09, 2023 at 09:12:29AM +0200, Peter Zijlstra wrote:
> > @@ -2607,26 +2447,26 @@ static ssize_t srbds_show_state(char *bu
> > static ssize_t retbleed_show_state(char *buf)
> > {
> > if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET ||
> > + retbleed_mitigation == RETBLEED_MITIGATION_UNRET_SRSO ||
> > + retbleed_mitigation == RETBLEED_MITIGATION_UNRET_SRSO_ALIAS ||
> > retbleed_mitigation == RETBLEED_MITIGATION_IBPB) {
>
> These retbleed_show_state() changes probably belong in that other patch
> which adds the retbleed= cmdline options.
Ah yes, lost hunk that. Let me move it there.
> > +
> > if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
> > boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
> > return sysfs_emit(buf, "Vulnerable: untrained return thunk / IBPB on non-AMD based uarch\n");
> >
> > - return sysfs_emit(buf, "%s; SMT %s\n", retbleed_strings[retbleed_mitigation],
> > + return sysfs_emit(buf, "%s; SMT %s%s\n", retbleed_strings[retbleed_mitigation],
> > !sched_smt_active() ? "disabled" :
> > spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
> > spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ?
> > - "enabled with STIBP protection" : "vulnerable");
> > - }
> > + "enabled with STIBP protection" : "vulnerable",
> > + cpu_has_ibpb_brtype_microcode() ? "" : ", no SRSO microcode");
>
> Hm? What does missing microcode have to do with SMT?
semi-colon then, instead of comma ?