From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH RFC 2/5] x86/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Date: Fri, 5 Apr 2019 08:18:09 -0700 Message-ID: <5ccc7515-33e6-b726-833e-9553ab0f4c6a@infradead.org> References: <78c63cb08f36f55407f534d49cc2543079e44dbb.1554396090.git.jpoimboe@redhat.com> <20190405135712.GF23348@zn.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190405135712.GF23348@zn.tnic> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Borislav Petkov , Josh Poimboeuf Cc: Peter Zijlstra , Benjamin Herrenschmidt , Heiko Carstens , Paul Mackerras , "H . Peter Anvin" , Ingo Molnar , Andrea Arcangeli , linux-s390@vger.kernel.org, Michael Ellerman , x86@kernel.org, Will Deacon , Linus Torvalds , Catalin Marinas , Waiman Long , linux-arch@vger.kernel.org, Jon Masters , Jiri Kosina , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Tyler Hicks , Martin Schwidefsky l List-Id: linux-arch.vger.kernel.org On 4/5/19 6:57 AM, Borislav Petkov wrote: > On Thu, Apr 04, 2019 at 11:44:12AM -0500, Josh Poimboeuf wrote: >> Configure x86 runtime CPU speculation bug mitigations in accordance with >> the 'cpu_spec_mitigations=' cmdline options. This affects Meltdown, >> Spectre v2, Speculative Store Bypass, and L1TF. >> >> The default behavior is unchanged. >> >> Signed-off-by: Josh Poimboeuf >> --- >> .../admin-guide/kernel-parameters.txt | 15 +++++++++ >> arch/x86/include/asm/processor.h | 1 + >> arch/x86/kernel/cpu/bugs.c | 32 ++++++++++++++++--- >> arch/x86/kvm/vmx/vmx.c | 2 ++ >> arch/x86/mm/pti.c | 4 ++- >> 5 files changed, 49 insertions(+), 5 deletions(-) >> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index ac42e510bd6e..29dc03971630 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -2552,6 +2552,11 @@ >> >> off >> Disable all speculative CPU mitigations. >> + Equivalent to: nopti [x86] >> + nospectre_v2 [x86] >> + spectre_v2_user=off [x86] >> + spec_store_bypass_disable=off [x86] >> + l1tf=off [x86] >> >> auto (default) >> Mitigate all speculative CPU vulnerabilities, >> @@ -2560,12 +2565,22 @@ >> surprised by SMT getting disabled across kernel >> upgrades, or who have other ways of avoiding >> SMT-based attacks. >> + Equivalent to: pti=auto [x86] >> + spectre_v2=auto [x86] >> + spectre_v2_user=auto [x86] >> + spec_store_bypass_disable=auto [x86] >> + l1tf=flush [x86] >> >> auto,nosmt >> Mitigate all speculative CPU vulnerabilities, >> disabling SMT if needed. This is for users who >> always want to be fully mitigated, even if it >> means losing SMT. >> + Equivalent to: pti=auto [x86] >> + spectre_v2=auto [x86] >> + spectre_v2_user=auto [x86] >> + spec_store_bypass_disable=auto [x86] >> + l1tf=flush,nosmt [x86] >> >> mminit_loglevel= >> [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this > > Yap, those sets look ok. nit: s/x86/X86/g according to Documentation/admin-guide/kernel-parameters.rst -- ~Randy From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:46656 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731519AbfDEPSR (ORCPT ); Fri, 5 Apr 2019 11:18:17 -0400 Subject: Re: [PATCH RFC 2/5] x86/speculation: Add support for 'cpu_spec_mitigations=' cmdline options References: <78c63cb08f36f55407f534d49cc2543079e44dbb.1554396090.git.jpoimboe@redhat.com> <20190405135712.GF23348@zn.tnic> From: Randy Dunlap Message-ID: <5ccc7515-33e6-b726-833e-9553ab0f4c6a@infradead.org> Date: Fri, 5 Apr 2019 08:18:09 -0700 MIME-Version: 1.0 In-Reply-To: <20190405135712.GF23348@zn.tnic> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Borislav Petkov , Josh Poimboeuf Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , "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 , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, Greg Kroah-Hartman , Tyler Hicks , Linus Torvalds Message-ID: <20190405151809.loO3BRPkxdSIbjhaOkHcgSzX7AEXml11-UID3nahj9s@z> On 4/5/19 6:57 AM, Borislav Petkov wrote: > On Thu, Apr 04, 2019 at 11:44:12AM -0500, Josh Poimboeuf wrote: >> Configure x86 runtime CPU speculation bug mitigations in accordance with >> the 'cpu_spec_mitigations=' cmdline options. This affects Meltdown, >> Spectre v2, Speculative Store Bypass, and L1TF. >> >> The default behavior is unchanged. >> >> Signed-off-by: Josh Poimboeuf >> --- >> .../admin-guide/kernel-parameters.txt | 15 +++++++++ >> arch/x86/include/asm/processor.h | 1 + >> arch/x86/kernel/cpu/bugs.c | 32 ++++++++++++++++--- >> arch/x86/kvm/vmx/vmx.c | 2 ++ >> arch/x86/mm/pti.c | 4 ++- >> 5 files changed, 49 insertions(+), 5 deletions(-) >> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index ac42e510bd6e..29dc03971630 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -2552,6 +2552,11 @@ >> >> off >> Disable all speculative CPU mitigations. >> + Equivalent to: nopti [x86] >> + nospectre_v2 [x86] >> + spectre_v2_user=off [x86] >> + spec_store_bypass_disable=off [x86] >> + l1tf=off [x86] >> >> auto (default) >> Mitigate all speculative CPU vulnerabilities, >> @@ -2560,12 +2565,22 @@ >> surprised by SMT getting disabled across kernel >> upgrades, or who have other ways of avoiding >> SMT-based attacks. >> + Equivalent to: pti=auto [x86] >> + spectre_v2=auto [x86] >> + spectre_v2_user=auto [x86] >> + spec_store_bypass_disable=auto [x86] >> + l1tf=flush [x86] >> >> auto,nosmt >> Mitigate all speculative CPU vulnerabilities, >> disabling SMT if needed. This is for users who >> always want to be fully mitigated, even if it >> means losing SMT. >> + Equivalent to: pti=auto [x86] >> + spectre_v2=auto [x86] >> + spectre_v2_user=auto [x86] >> + spec_store_bypass_disable=auto [x86] >> + l1tf=flush,nosmt [x86] >> >> mminit_loglevel= >> [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this > > Yap, those sets look ok. nit: s/x86/X86/g according to Documentation/admin-guide/kernel-parameters.rst -- ~Randy