From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Date: Fri, 5 Apr 2019 15:44:14 +0100 Message-ID: <20190405144414.GB7662@fuggles.cambridge.arm.com> References: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Josh Poimboeuf Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Jiri Kosina , Waiman Long , Andrea Arcangeli , Jon Masters , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org, Catalin Marinas , linux-arm-kernel@lists.infradead.orglinux List-Id: linux-arch.vger.kernel.org Hi Josh, On Thu, Apr 04, 2019 at 11:44:15AM -0500, Josh Poimboeuf wrote: > Configure arm64 runtime CPU speculation bug mitigations in accordance > with the 'cpu_spec_mitigations=' cmdline options. This affects > Meltdown and Speculative Store Bypass. > > The default behavior is unchanged. > > Signed-off-by: Josh Poimboeuf > --- > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > arch/arm64/kernel/cpu_errata.c | 4 ++++ > arch/arm64/kernel/cpufeature.c | 6 ++++++ > 3 files changed, 12 insertions(+) Just wanted to make you aware that this is probably going to conflict badly with some patches we have pending to hook up the sysfs entries: http://lists.infradead.org/pipermail/linux-arm-kernel/2019-March/640326.html That patch series isn't quite there yet, so I'm expecting a v7, but I think it will change the shape of this patch quite a lot. Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:50792 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbfDEOoV (ORCPT ); Fri, 5 Apr 2019 10:44:21 -0400 Date: Fri, 5 Apr 2019 15:44:14 +0100 From: Will Deacon Subject: Re: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Message-ID: <20190405144414.GB7662@fuggles.cambridge.arm.com> References: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Josh Poimboeuf Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Jiri Kosina , Waiman Long , Andrea Arcangeli , Jon Masters , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org, Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, Greg Kroah-Hartman , Tyler Hicks , Linus Torvalds Message-ID: <20190405144414.nk-UumeN0sm2XyB05ZZDspKvSwX8qAkPSsQ9oDw_tKQ@z> Hi Josh, On Thu, Apr 04, 2019 at 11:44:15AM -0500, Josh Poimboeuf wrote: > Configure arm64 runtime CPU speculation bug mitigations in accordance > with the 'cpu_spec_mitigations=' cmdline options. This affects > Meltdown and Speculative Store Bypass. > > The default behavior is unchanged. > > Signed-off-by: Josh Poimboeuf > --- > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > arch/arm64/kernel/cpu_errata.c | 4 ++++ > arch/arm64/kernel/cpufeature.c | 6 ++++++ > 3 files changed, 12 insertions(+) Just wanted to make you aware that this is probably going to conflict badly with some patches we have pending to hook up the sysfs entries: http://lists.infradead.org/pipermail/linux-arm-kernel/2019-March/640326.html That patch series isn't quite there yet, so I'm expecting a v7, but I think it will change the shape of this patch quite a lot. Will