From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B860C4360F for ; Fri, 5 Apr 2019 14:48:33 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9408221726 for ; Fri, 5 Apr 2019 14:48:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9408221726 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44bN3f2zq7zDqTQ for ; Sat, 6 Apr 2019 01:48:30 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=redhat.com (client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=jpoimboe@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44bMyc2TzMzDqW9 for ; Sat, 6 Apr 2019 01:44:08 +1100 (AEDT) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AFEB43005148; Fri, 5 Apr 2019 14:44:05 +0000 (UTC) Received: from treble (ovpn-123-87.rdu2.redhat.com [10.10.123.87]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DDE991001E81; Fri, 5 Apr 2019 14:43:59 +0000 (UTC) Date: Fri, 5 Apr 2019 09:43:56 -0500 From: Josh Poimboeuf To: Steven Price Subject: Re: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Message-ID: <20190405144356.zdi7fwoanz72xduh@treble> References: <5f70df57b19bbccc4a0d5d76134b4681c9a50b0b.1554396090.git.jpoimboe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 05 Apr 2019 14:44:06 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Catalin Marinas , Heiko Carstens , Paul Mackerras , "H . Peter Anvin" , Ingo Molnar , Andrea Arcangeli , linux-s390@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, Waiman Long , linux-arch@vger.kernel.org, Will Deacon , Jiri Kosina , linuxppc-dev@lists.ozlabs.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Jon Masters , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Tyler Hicks , Martin Schwidefsky , Linus Torvalds Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Apr 05, 2019 at 03:39:58PM +0100, Steven Price wrote: > On 04/04/2019 17:44, 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(+) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index e838af96daa4..0b54385ee7a8 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2553,11 +2553,13 @@ > > off > > Disable all speculative CPU mitigations. > > Equivalent to: nopti [x86, powerpc] > > + kpti=0 [arm64] > > nospectre_v1 [powerpc] > > nospectre_v2 [x86, powerpc, s390] > > spectre_v2_user=off [x86] > > nobp=0 [s390] > > spec_store_bypass_disable=off [x86, powerpc] > > + ssbd=force-off [arm64] > > l1tf=off [x86] > > > > auto (default) > > diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c > > index 9950bb0cbd52..db8d27e3fb1c 100644 > > --- a/arch/arm64/kernel/cpu_errata.c > > +++ b/arch/arm64/kernel/cpu_errata.c > > @@ -19,6 +19,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -385,6 +386,9 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry, > > return false; > > } > > > > + if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF) > > + ssbd_state = ARM64_SSBD_FORCE_DISABLE; > > + > > switch (psci_ops.conduit) { > > case PSCI_CONDUIT_HVC: > > arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > > index 4061de10cea6..4512b582d50f 100644 > > --- a/arch/arm64/kernel/cpufeature.c > > +++ b/arch/arm64/kernel/cpufeature.c > > @@ -25,6 +25,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -978,6 +979,11 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, > > __kpti_forced = -1; > > } > > > > + if (cpu_spec_mitigations == CPU_SPEC_MITIGATIONS_OFF) { > > + str = "cpu_spec_mitigations=off"; > > Might also be worth changing the initialisation of str, currently it is: > > > char const *str = "command line option"; > > But now we have two command line options, perhaps "kpti command line > option". Yes, agreed, thanks. -- Josh