Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751549AbcLCU1z (ORCPT ); Sat, 3 Dec 2016 15:27:55 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:54553 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750795AbcLCU1y (ORCPT ); Sat, 3 Dec 2016 15:27:54 -0500 Date: Sat, 3 Dec 2016 21:27:51 +0100 From: Pavel Machek To: Grzegorz Andrejczuk Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, bp@suse.de, dave.hansen@linux.intel.com, lukasz.daniluk@intel.com, james.h.cownie@intel.com, jacob.jun.pan@intel.com, Piotr.Luc@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 0/4] Enabling Ring 3 MONITOR/MWAIT feature for Knights Landing Message-ID: <20161203202751.GC13417@amd> References: <1477662595-21011-1-git-send-email-grzegorz.andrejczuk@intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ABTtc+pdwF7KHXCz" Content-Disposition: inline In-Reply-To: <1477662595-21011-1-git-send-email-grzegorz.andrejczuk@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1176 Lines: 40 --ABTtc+pdwF7KHXCz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri 2016-10-28 15:49:51, Grzegorz Andrejczuk wrote: > These patches enable Intel Xeon Phi x200 feature to use MONITOR/MWAIT > instruction in ring 3 (userspace) Patches set MSR 0x140 for all logical CPUs. > Then expose it as CPU feature and introduces elf HWCAP capability > for x86. Elf hardware capability? Why do that? Normally CPU features go to /proc/cpuinfo... Plus... Can you elaborate on security effects of this? Does monitor allow monitoring memory the current process can not write to? Is it good idea to let userland process watch for NMIs? Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --ABTtc+pdwF7KHXCz Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlhDKscACgkQMOfwapXb+vLZPgCfWhOHDhwujnoS+y2OQgkGZkUu 05QAoLWQxH4hJK3ZYpIBcBBVJSrqYuzz =g14x -----END PGP SIGNATURE----- --ABTtc+pdwF7KHXCz--