From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 28 Jan 2019 03:33:42 -0000 Received: from mga07.intel.com ([134.134.136.100]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gnxg3-000252-4Y for speck@linutronix.de; Mon, 28 Jan 2019 04:33:41 +0100 Date: Sun, 27 Jan 2019 19:33:36 -0800 From: Andi Kleen Subject: [MODERATED] Re: [PATCH v5 07/27] MDSv5 0 Message-ID: <20190128033336.GK6118@tassilo.jf.intel.com> References: <4f18a51190afc9dbd03cc32d5659e184f1b64e0a.1547858934.git.ak@linux.intel.com> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: On Sun, Jan 27, 2019 at 11:09:31PM +0100, speck for Thomas Gleixner wrote: > On Fri, 18 Jan 2019, speck for Andi Kleen wrote: > > + > > + case X86_BUG_MDS: > > + /* Assumes Hypervisor exposed HT state to us if in guest */ > > That comment is relevant in which way? This is true for any feature bit > which is checked in a guest. FEATURE_MD_CLEAR is not special in any way. It's different in that it refers to an underlying bug. Normally if something is not exposed it is just not used and doesn't matter. But in this case it's not true, if HT is there but not exposed the code will report the wrong message. -Andi