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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15BE8C4332F for ; Tue, 8 Nov 2022 08:09:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233684AbiKHIJK (ORCPT ); Tue, 8 Nov 2022 03:09:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233734AbiKHIIi (ORCPT ); Tue, 8 Nov 2022 03:08:38 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 403731FF8B; Tue, 8 Nov 2022 00:07:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=LwCgedXafwEPt8/fNTGd0hg7ywmKoM5jv7NpAinjw0o=; b=CE5kURuQzUML+Y5qGGUHpmZ+Qm 3/swCA5I5TJh09kWiZ+pcJ+7dya9D+wdxNV/UvOfrH/Op5nSb05OI8kfdht2WPzZr2EFYggM9veFL K/iULMowBAADj5VOeE84C/rD6n2MZC/i1DOgpQMAyixVY7mxZkiLU7/nGxjhSAGHDuqUvPweNffgg a/w2odk4WhnkG3hPFUHjq24hlkZ8WCnOvB2Kb6LTbbEo8NEZO4R++BsyioSD93T79KhkCiim3e1CO 5bBhwXMnpQxLJ/k8lcNKcp4pQJCBbpyIrbh9belKIJVRaivJshlcCj8YSRDlgR9xA8njloAersYPM BKDgPDog==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1osJdQ-00A65A-7X; Tue, 08 Nov 2022 08:07:04 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (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) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 3B103300244; Tue, 8 Nov 2022 09:06:50 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2347029B98571; Tue, 8 Nov 2022 09:06:50 +0100 (CET) Date: Tue, 8 Nov 2022 09:06:50 +0100 From: Peter Zijlstra To: Dave Hansen Cc: Kim Phillips , Borislav Petkov , x86@kernel.org, Boris Ostrovsky , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , Joao Martins , Jonathan Corbet , Konrad Rzeszutek Wilk , Paolo Bonzini , Sean Christopherson , Thomas Gleixner , David Woodhouse , Greg Kroah-Hartman , Juergen Gross , Tony Luck , Babu Moger , Tom Lendacky , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] x86/speculation: Support Automatic IBRS Message-ID: References: <20221104213651.141057-1-kim.phillips@amd.com> <20221104213651.141057-3-kim.phillips@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2022 at 03:41:03PM -0800, Dave Hansen wrote: > On 11/7/22 14:39, Kim Phillips wrote: > > I've started a version that has AUTOIBRS reuse SPECTRE_V2_EIBRS > > spectre_v2_mitigation enum, but, so far, it's change to bugs.c > > looks bigger: 58 lines changed vs. 34 (see below). > > > > Let me know if you want me to send it as a part of a v2 submission > > after I take care of the kvm CPUID review. > > Thanks for putting that together. I generally like how this looks. > > I think it probably goes to a _bit_ too much trouble to turn off > "eibrs,lfence/retpoline". If someone goes to the trouble of specifying > those, a warning or pr_info() is probably enough. You don't need to > actively override it. Not, even, just do it. User told you to, it's not technically impossible, so just go.