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[2620:137:e000::1:20]) by mx.google.com with ESMTP id a13-20020aa7cf0d000000b00514931bd16dsi3928237edy.303.2023.06.10.16.54.11; Sat, 10 Jun 2023 16:54:44 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=IxZafuqL; dkim=neutral (no key) header.i=@linutronix.de; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230371AbjFJWhi (ORCPT + 99 others); Sat, 10 Jun 2023 18:37:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229746AbjFJWhh (ORCPT ); Sat, 10 Jun 2023 18:37:37 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A349E5 for ; Sat, 10 Jun 2023 15:37:36 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1686436654; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=b9vitvOPG+xvJzjdSeWfwXEva3xzCwWxkPX4DK6Mf4U=; b=IxZafuqLIwQqtJkNaNtTQvkdYguIHmycvFJHzwIeFLlDzK8+xj6N29jfeGZPo2ilpTz3OE pNTFH5vMBlydFQAfgUthN91bQCyF9kpHV+vRlXBYuGDUoU/TRhpXFGujKxFx8yt45uuqnr tdZIhopQhS8tGN3jdeRl1aCR9GiZrOPBtpiutuFMgIwY71E2MRtEeLMZzFE2nYyHJVSRKl dz+Nz6zVHZpoNQFp8lh5HBFwTNfjeSfwLatjM85BVFcTk4BfD5L/S5esSDjbUvSNYGniW2 sYDRucEaIMtTfrcI02uazpDC2iegA0dOZTo7g+lLaH3/uuuBI7jn7y/fauttfg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1686436654; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=b9vitvOPG+xvJzjdSeWfwXEva3xzCwWxkPX4DK6Mf4U=; b=cv72YEIJY8cfNJhosTjM/KT7w10M44RH82b1AaRQkqLulMDQfsaBZSDo00oSzYIRezTmW4 Nu8wfbdhYH6TasDw== To: Breno Leitao , bp@alien8.de, pawan.kumar.gupta@linux.intel.com, paul@paul-moore.com Cc: leit@meta.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cpu/bugs: Disable CPU mitigations at compilation time In-Reply-To: <20230203120615.1121272-1-leitao@debian.org> References: <20230203120615.1121272-1-leitao@debian.org> Date: Sun, 11 Jun 2023 00:37:34 +0200 Message-ID: <87352z7xld.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 03 2023 at 04:06, Breno Leitao wrote: > Right now it is not possible to disable CPU vulnerabilities mitigations > at build time. Mitigation needs to be disabled passing kernel > parameters, such as 'mitigations=off'. > > Create a new config option (CONFIG_CPU_MITIGATIONS_DEFAULT_OFF) that > sets the global variable `cpu_mitigations` to OFF, instead of AUTO. This > allows the creation of kernel binaries that boots with the CPU > mitigations turned off by default, and does not require dealing kernel > parameters. Why? What's the justification Just because we do not have not enough kernel config items yet, does not count. Thanks, tglx