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 1FD16EB64D7 for ; Wed, 21 Jun 2023 14:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231215AbjFUOHo (ORCPT ); Wed, 21 Jun 2023 10:07:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231547AbjFUOHk (ORCPT ); Wed, 21 Jun 2023 10:07:40 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA6D01BD2 for ; Wed, 21 Jun 2023 07:06:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687356394; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TRSWaBirIMbqr4Co8ZfFUyVMNp/zcwwuITsVAzHUNt4=; b=QWbncE91uNqaW0KJVtHAWsY+AtWZofLaQ4TmeKBKF97H2jKJxvSqqzuu0I5moHGQsF5g0l fiuz4wLmuu1QpEepVpuXGHNWMAzYLyo0kcYXU1OzJniEEdhS3aP6Ly4yCjn+tPgUKSxCcC 8uFjNILDCONFC09T3t6Y+r54hzJABvs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-651-ikba25pFPVynWnHAEkub2Q-1; Wed, 21 Jun 2023 10:06:00 -0400 X-MC-Unique: ikba25pFPVynWnHAEkub2Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9B7811C16D88; Wed, 21 Jun 2023 14:02:03 +0000 (UTC) Received: from [10.22.17.140] (unknown [10.22.17.140]) by smtp.corp.redhat.com (Postfix) with ESMTP id F3617F41CE; Wed, 21 Jun 2023 14:02:02 +0000 (UTC) Message-ID: <2cdb371d-7435-ff4f-c9c0-991371833ad1@redhat.com> Date: Wed, 21 Jun 2023 10:02:02 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH v2 1/5] x86/speculation: Provide a debugfs file to dump SPEC_CTRL MSRs Content-Language: en-US To: Borislav Petkov , Peter Zijlstra Cc: Thomas Gleixner , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Josh Poimboeuf , Pawan Gupta , Jacob Pan , Len Brown , linux-kernel@vger.kernel.org, x86@kernel.org, linux-pm@vger.kernel.org, Robin Jarry , Joe Mario References: <20230620140625.1001886-1-longman@redhat.com> <20230620140625.1001886-2-longman@redhat.com> <20230621074105.GE2046280@hirez.programming.kicks-ass.net> <20230621082442.GCZJKzyjqRPMAnsWKZ@fat_crate.local> From: Waiman Long In-Reply-To: <20230621082442.GCZJKzyjqRPMAnsWKZ@fat_crate.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/21/23 04:24, Borislav Petkov wrote: > On Wed, Jun 21, 2023 at 09:41:05AM +0200, Peter Zijlstra wrote: >> On Tue, Jun 20, 2023 at 10:06:21AM -0400, Waiman Long wrote: >>> Sometimes it is useful to know the states the SPEC_CTRL MSRs to see what >>> mitigations are enabled at run time. Provide a new x86/spec_ctrl_msrs >>> debugfs file to dump the cached versions of the current SPEC_CTRL MSRs. >>> >> Pff, clearly I can't even read email anymore.. >> >> We don't do this for any of the other MSRs, so why start now? > Hell no. > > There's /sys/devices/system/cpu/vulnerabilities/ for that. > > We are abstracting MSRs away from APIs - not do the backwards thing. > OK, as I have said. This is not central to the main purpose of this patch series. It is mostly there for verification purpose. I can certainly take this out. Cheers, Longman