From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 5 Apr 2019 17:26:50 +0200 From: Borislav Petkov Subject: Re: [PATCH RFC 2/5] x86/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Message-ID: <20190405152650.GH23348@zn.tnic> References: <78c63cb08f36f55407f534d49cc2543079e44dbb.1554396090.git.jpoimboe@redhat.com> <20190405135712.GF23348@zn.tnic> <20190405143101.ksj7ayjis4p52dgt@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190405143101.ksj7ayjis4p52dgt@treble> Sender: linux-arch-owner@vger.kernel.org Message-ID: <20190405152650.DqBCc8B5pVR8hG3DaAapjrpOZ6Bf20rzQgqS0JGbMCs@z> List-Archive: List-Post: To: 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 List-ID: On Fri, Apr 05, 2019 at 09:31:01AM -0500, Josh Poimboeuf wrote: > My thinking was that the individual options could be used to override > the global option. But maybe that's overkill? I dunno. You mean if the user deliberately types: "cpu_spec_mitigations=off spectre_v2=auto" on the cmdline to turn off all and then enable only one? Hmm, yap, sounds like an overkill to me. Then I'd probably do: pr_err("Make up your mind already!\n"); return; :-)) I'd say let's do the simpler and cleaner thing now and think about supporting this overkill when it really turns out that it is needed. > I assume you mean just the part where L1TF_MITIGATION_DEFAULT is added? Yap. Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.