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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4691C4332F for ; Wed, 27 Oct 2021 11:17:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6F23161052 for ; Wed, 27 Oct 2021 11:17:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F23161052 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=alien8.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id D9863940008; Wed, 27 Oct 2021 07:17:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D4811940007; Wed, 27 Oct 2021 07:17:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C373F940008; Wed, 27 Oct 2021 07:17:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0157.hostedemail.com [216.40.44.157]) by kanga.kvack.org (Postfix) with ESMTP id B3A73940007 for ; Wed, 27 Oct 2021 07:17:15 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 6D614183432DC for ; Wed, 27 Oct 2021 11:17:15 +0000 (UTC) X-FDA: 78741966030.05.99D2755 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf12.hostedemail.com (Postfix) with ESMTP id 94CB610003C7 for ; Wed, 27 Oct 2021 11:17:13 +0000 (UTC) Received: from zn.tnic (p200300ec2f1615002935f4cf24b5c3ba.dip0.t-ipconnect.de [IPv6:2003:ec:2f16:1500:2935:f4cf:24b5:c3ba]) (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 C06CA1EC0622; Wed, 27 Oct 2021 13:17:11 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1635333431; 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=stNjoo2XJVbCmOdEgRU5yFEgbX9ASxd3JdeLr48Zahs=; b=ebK1cCm9TusIIJya8AsuEOa2C3nQXceCim+lTIqBQiXlDB1x/eNW5KTm2nrR7tb97mQhQS vnvCswmbz10LpK/Kw8nzXp85LtQ568h2zkaEyr3nXmArdt3dd3cOUNBshF/UW+o8mvILwa acBETot9fx4OESPek0YesL84jKRUcrY= Date: Wed, 27 Oct 2021 13:17:11 +0200 From: Borislav Petkov To: Michael Roth Cc: Brijesh Singh , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v6 08/42] x86/sev-es: initialize sev_status/features within #VC handler Message-ID: References: <20211008180453.462291-1-brijesh.singh@amd.com> <20211008180453.462291-9-brijesh.singh@amd.com> <20211018184003.3ob2uxcpd2rpee3s@amd.com> <20211020161023.hzbj53ehmzjrt4xd@amd.com> <20211021204149.pof2exhwkzy2zqrg@amd.com> <20211025163518.rztqnngwggnbfxvs@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211025163518.rztqnngwggnbfxvs@amd.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 94CB610003C7 X-Stat-Signature: jn85sc3btr1mf399zjx187yryewmktyd Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=alien8.de header.s=dkim header.b=ebK1cCm9; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf12.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de X-HE-Tag: 1635333433-488921 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Oct 25, 2021 at 11:35:18AM -0500, Michael Roth wrote: > As counter-intuitive as it sounds, it actually doesn't buy us if the CPUID > table is part of the PSP attestation report, since: Thanks for taking the time to explain in detail - I think I know now what's going on, and David explained some additional stuff to me yesterday. So, to cut to the chase: - yeah, ok, I guess guest owner attestation is what should happen. - as to the boot detection, I think you should do in sme_enable(), in pseudo: bool snp_guest_detected; if (CPUID page address) { read SEV_STATUS; snp_guest_detected = SEV_STATUS & MSR_AMD64_SEV_SNP_ENABLED; } /* old SME/SEV detection path */ read 0x8000_001F_EAX and look at bits SME and SEV, yadda yadda. if (snp_guest_detected && (!SME || !SEV)) /* * HV is lying to me, do something there, dunno what. I guess we can * continue booting unencrypted so that the guest owner knows that * detection has failed and maybe the HV didn't want us to force SNP. * This way, attestation will fail and the user will know why. * Or something like that. */ /* normal feature detection continues. */ How does that sound? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette