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 DC7FEC43217 for ; Sat, 5 Nov 2022 11:11:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229754AbiKELLE (ORCPT ); Sat, 5 Nov 2022 07:11:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229511AbiKELLC (ORCPT ); Sat, 5 Nov 2022 07:11:02 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3378A101D0; Sat, 5 Nov 2022 04:11:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=1s0+3GTF0fsjeGIh0i5LncjrVKVlIP2ZMoJrLBl0D/M=; b=INLogPRLDBQuuQbiPJxIxU+i7I IbX7MxHRerkb6n4Ff/YtspDjH8U0hxIMMcxOTlxBqDYaOmUsrl5dfnFTFeteu2mT1M/Pq2ISkLOZ4 1B4S1r19xgXdBuQlGhbigeZDAJrWFCqgCJ9U6Q4acltKF+gZTrtdMF+2V3FQ4aJWLZ1rvloTTTdf8 OfWchvYQ3CIJv0KjRI4wT9s7UU0TyTP/VYCPwo0wGLjulic3eG7ivsxrt4ds1wZ7Wh2RhMf49OEgh O9KndvKz7K43ZJKWQO+i1SSw676yVm/H+i2K4sD2yZvxIgpjlkC8hcqfxXdgWjwRK+pR8rbK6PZU+ nAmmaUmQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1orH3s-009Eek-U8; Sat, 05 Nov 2022 11:10:06 +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 CBBA130012F; Sat, 5 Nov 2022 12:10:02 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B5F2820B40528; Sat, 5 Nov 2022 12:10:02 +0100 (CET) Date: Sat, 5 Nov 2022 12:10:02 +0100 From: Peter Zijlstra To: Borislav Petkov Cc: Kim Phillips , 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 Fri, Nov 04, 2022 at 10:52:13PM +0100, Borislav Petkov wrote: > On Fri, Nov 04, 2022 at 04:36:50PM -0500, Kim Phillips wrote: > > - Allow for spectre_v2=autoibrs in the kernel command line, > > reverting to auto-selection if the feature isn't available. > > Why? > > What the whole logic here should do is enable autoibrs when detected > automatically, without the need for the user to even select it as it is > the superior mitigation. Well; perhaps the whole autoibrs thing should be mapped to the existing eIBRS options. AFAICT this is the same thing under a new name, no need to invent yet more options. bugs.c is quite insane enough already.