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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08A87C48BDF for ; Tue, 15 Jun 2021 17:26:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFCC861414 for ; Tue, 15 Jun 2021 17:26:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230084AbhFOR2J (ORCPT ); Tue, 15 Jun 2021 13:28:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230058AbhFOR2I (ORCPT ); Tue, 15 Jun 2021 13:28:08 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E221BC061574; Tue, 15 Jun 2021 10:26:02 -0700 (PDT) Received: from zn.tnic (p200300ec2f0f270048ecafc2d258032c.dip0.t-ipconnect.de [IPv6:2003:ec:2f0f:2700:48ec:afc2:d258:32c]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 859DF1EC030E; Tue, 15 Jun 2021 19:26:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1623777961; 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:in-reply-to:in-reply-to: references:references; bh=xH8sUazIxzaovKLfiQftgZitdVavZKBYSHXtkR2AkLI=; b=mE9aVezxi1CKEkQdM/Nv2RkUwuh2FsSENzA2o4vsQrE4Kx4D0YgavaWSorAerScoj1vy5X QQqG12MNdHmYIgyEZxDigAOoySJJdGKkL7EJLSXhRmNBxsYywBsQvTgp/m8dVO2zpDreaI xO/EX3kcRdjftoykItEaF/skvaa5lek= Date: Tue, 15 Jun 2021 19:25:57 +0200 From: Borislav Petkov To: Yazen Ghannam Cc: "Luck, Tony" , Smita Koralahalli , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "linux-edac@vger.kernel.org" , Mauro Carvalho Chehab , James Morse , Robert Richter Subject: Re: [PATCH] EDAC/mce_amd: Reduce unnecessary spew in dmesg if SMCA feature bit is not exposed Message-ID: References: <20210614212129.227698-1-Smita.KoralahalliChannabasappa@amd.com> <16a34b6834f94f139444c2ff172645e9@intel.com> <20210615150846.GA409@aus-x-yghannam.amd.com> <20210615160009.GA29258@aus-x-yghannam.amd.com> <20210615163221.GA2991@aus-x-yghannam.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210615163221.GA2991@aus-x-yghannam.amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On Tue, Jun 15, 2021 at 12:32:21PM -0400, Yazen Ghannam wrote: > Yes, I agree. I was a bit confused about the X86_FEATURE_HYPERVISOR > thing, but I think I get it. This definitely looks simple to do. Yeah, if you look at the qemu repo: kvm_arch_get_supported_cpuid: ... } else if (function == 1 && reg == R_ECX) { /* We can set the hypervisor flag, even if KVM does not return it on * GET_SUPPORTED_CPUID */ ret |= CPUID_EXT_HYPERVISOR; so long story short, that thing is set by the HV and there's an "agreement" of sorts and APM v3 even says so: "CPUID Fn0000_0001_ECX Feature Identifiers ... 31: RAZ. Reserved for use by hypervisor to indicate guest status." HTH. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette