From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (193.142.43.55:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 24 Oct 2019 20:55:48 -0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iNk94-0001QJ-LW for speck@linutronix.de; Thu, 24 Oct 2019 22:55:47 +0200 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1B2D4AB98 for ; Thu, 24 Oct 2019 20:55:41 +0000 (UTC) Date: Thu, 24 Oct 2019 22:55:32 +0200 From: Borislav Petkov Subject: [MODERATED] Re: [PATCH 3/9] TAA 3 Message-ID: <20191024205532.GN14115@zn.tnic> References: <580e02757c3e639bff00fcea830aa46eba46a92f.1571905227.git.bp@suse.de> <6f1ab744-622c-179b-276b-5506b2fd9ae1@citrix.com> <20191024194503.GH14115@zn.tnic> <20191024195959.nvdja4kxlbjrgq24@treble> <20191024200558.GJ14115@zn.tnic> <20191024201403.tibjxoywbd2rrjzq@treble> <20191024203600.GM14115@zn.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 Thu, Oct 24, 2019 at 09:43:56PM +0100, speck for Andrew Cooper wrote: > The first TSX problem in Haswell/Broadwell lead to chaos when a > microcode update took feature bits out. Yeap, not worky with our current non-reentrant feature detection OSes. :-P > When the second problem came around, I understand from IRL conversations > that several vendors firmly expressed their opinion about whether > feature bits should disappear in microcode. >=20 > As HLE is a hint bit at best, it was left visible despite being disabled > behind the scenes. Yeah, and it being a hint bit only, I don't know whether we should care about a box where RTM=3D0 but HLE=3D1. I guess the relevant use case is big fat hypervisor. But perhaps the easiest thing would be if the migration code gets told to ignore HLE. --=20 Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Felix Imend=C3=B6rffer, HRB 36809, = AG N=C3=BCrnberg --=20