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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 90840C4345F for ; Sat, 13 Apr 2024 09:39:30 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=MjH6/odP; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4VGpL853msz3vbN for ; Sat, 13 Apr 2024 19:39:28 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=MjH6/odP; dkim-atps=neutral Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4VGpKN1tR0z3cJl for ; Sat, 13 Apr 2024 19:38:48 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1713001128; bh=jPYPpXrOTdq14zbY1a5WM5rZP3IYtTcbIcNsjXlJspk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=MjH6/odPeFgoAEfNG2rNSGt2thn4S+aADBoSLF86JXfv/dzzX80RNdWPYVPLWA4km WABN2/vhWdwd4HsPSsxQNyWLQDu6QVoZfSOqmsukC9DZaJ0tj27yUlx4bgXQqGe+F6 7vE+canYaQukx6oxuedLYuJav6633yNYphxX7VCQoyIkzH+qRF7Pg0GQTWkWvhtGeC TipxPPhkh9hRKBh6VFWbs16RXSaOOGQavzY0JWXgyoXZn8kw6AWo1ianMcDg4HVZWG bMW6Uy37rKrath0YVIVn6h6nF4qu8QXvzFbrGlTW+nzI3LSrKdXLIihEZkUVcNx7C2 Znym4ghrFREwQ== Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4VGpKM2sTsz4wb2; Sat, 13 Apr 2024 19:38:47 +1000 (AEST) From: Michael Ellerman To: Stephen Rothwell , Sean Christopherson Subject: Re: [PATCH 1/3] x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n In-Reply-To: <87edb9d33r.fsf@mail.lhotse> References: <20240409175108.1512861-1-seanjc@google.com> <20240409175108.1512861-2-seanjc@google.com> <20240413115324.53303a68@canb.auug.org.au> <87edb9d33r.fsf@mail.lhotse> Date: Sat, 13 Apr 2024 19:38:47 +1000 Message-ID: <87bk6dd2l4.fsf@mail.lhotse> MIME-Version: 1.0 Content-Type: text/plain 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: linux-arch@vger.kernel.org, x86@kernel.org, Will Deacon , Jonathan Corbet , Peter Zijlstra , Catalin Marinas , Heiko Carstens , Dave Hansen , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , Pawan Gupta , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, Josh Poimboeuf , Daniel Sneddon Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Michael Ellerman writes: > Stephen Rothwell writes: ... >> On Tue, 9 Apr 2024 10:51:05 -0700 Sean Christopherson wrote: ... >>> diff --git a/kernel/cpu.c b/kernel/cpu.c >>> index 8f6affd051f7..07ad53b7f119 100644 >>> --- a/kernel/cpu.c >>> +++ b/kernel/cpu.c >>> @@ -3207,7 +3207,8 @@ enum cpu_mitigations { >>> }; >>> >>> static enum cpu_mitigations cpu_mitigations __ro_after_init = >>> - CPU_MITIGATIONS_AUTO; >>> + IS_ENABLED(CONFIG_SPECULATION_MITIGATIONS) ? CPU_MITIGATIONS_AUTO : >>> + CPU_MITIGATIONS_OFF; >>> >>> static int __init mitigations_parse_cmdline(char *arg) >>> { I think a minimal workaround/fix would be: diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 2b8fd6bb7da0..290be2f9e909 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -191,6 +191,10 @@ config GENERIC_CPU_AUTOPROBE config GENERIC_CPU_VULNERABILITIES bool +config SPECULATION_MITIGATIONS + def_bool y + depends on !X86 + config SOC_BUS bool select GLOB cheers