From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx2.suse.de ([195.135.220.15]) by Galois.linutronix.de with esmtps (TLS1.0:DHE_RSA_CAMELLIA_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1fA16m-0005TZ-9U for speck@linutronix.de; Sun, 22 Apr 2018 00:35:53 +0200 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 3762CAC93 for ; Sat, 21 Apr 2018 22:35:46 +0000 (UTC) Date: Sun, 22 Apr 2018 00:35:38 +0200 From: Borislav Petkov Subject: [MODERATED] Re: [patch 07/11] [PATCH v2 07/10] Linux Patch #7 Message-ID: <20180421223538.GF18575@pd.tnic> References: <20180420022613.270943302@localhost.localdomain> <20180420174242.GO13977@pd.tnic> <20180421032701.GA4490@localhost.localdomain> <20180421090345.GA18575@pd.tnic> <20180421122117.GA5337@localhost.localdomain> <20180421192509.GD18575@pd.tnic> <20180421220903.GE18575@pd.tnic> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: speck@linutronix.de List-ID: On Sat, Apr 21, 2018 at 06:13:16PM -0400, speck for Jon Masters wrote: > I propose keeping either the x86 CPU capability "Memory Disambiguation" > (as you said, via the string in the define). But only for what is > displayed in /proc/cpuinfo. Actually, thinking about this more, we don't need to have any strings in /proc/cpuinfo denoting the CPU has the memory disambiguation feature because we only want to know whether we can *disable* the MD. And that we can do only on a subset of CPUs. IOW, there are other CPU models which *might* have MD but where MD cannot be disabled... yet. So having MD or whatever string we agree upon in /proc/cpuinfo will be a lie. IOW, we only need two flags: X86_FEATURE_STBUF_BYPASS X86_FEATURE_STBUF_BYPASS_MITIGATE or whatever those are going to be called and neither of the two should be visible in /proc/cpuinfo. SSB state will be visible in /sys/devices/system/cpu/vulnerabilities/ Yap, I think that should work. --=20 Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imend=C3=B6rffer, Jane Smithard, Graham Norton, HR= B 21284 (AG N=C3=BCrnberg) --=20