From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 06484FC0E; Tue, 7 Jan 2025 12:37:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736253465; cv=none; b=p8GtXNP/t5TI7scz1yrJfE4g+PeManHzCuKaIQE8j2seWqyh6meZEf4NiR4mxnvn2uUyUMILz3/2S/LdNCZEwys0VuNu6oFE2x0IkEcDGVnvdrvy3VoBZnMPQUc2xL/QMYeZO4WFeO9s/Hi/ftqSebCFrkuQJ+WItCiNVYEYYd0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736253465; c=relaxed/simple; bh=3CHsslgHpJpawee/gvsUvCHadiF1wWhSK1n06g4WblQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=goO0GQ3En15dNxQAFO2uQiuYMkYZhYbBT8BqRLA3odv+lsAT6vm3tw4s9vrXGIG5sj+DHrgoHXziLf4+mTzqel/52oVyZZjE73xr5zv32n0ngdlZFA4mTf2y0IgiGcJIegUIhBlE8xwb4vlFb90ndhg3JWvb0bSvjWg6x0LY8OY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=Rr25qKON; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="Rr25qKON" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id EBA2F40E0163; Tue, 7 Jan 2025 12:37:40 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id XSzZzGf8wPkp; Tue, 7 Jan 2025 12:37:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1736253448; bh=ISji3lVCWeh5JUXkN/3WOm1xt+5joVQtVcCRL5EuvzU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Rr25qKONzTxSP7kYtQE/nX6ewQ4YxZtcDsw0JiP6J3JzmQg273UUx49rpriD6bh94 Go9DA+f/AnjaRTQ9ugQN0/uekCq4VgQ+7lDeD5Cr2wYNpPBFhw6oH0kDhKIa4cql2h BGB8JCgSbZ+Dgw8+FKZhqW6mWfteHxU1UaXivEzOkjjvc6PHti1CpHGTfCRku1O4Ht c0iXGhT0No9zcVahejZMbC8Vja09ue8jH4C9/ZDDb2u1ZX4WyEBdUZYBJdhL654O/K a2zE6yoaQXT23GrQQt+doHPSatOYejr/rGzmK9fB0pR4rEnBq/wCQYK7QSfGRlnBQG o1pCwtjWSAV4aWPuGQPvu3s9XQWRSs9l5NO55jUfpEYIr85JyemYwtSKtXzTiWOJrl 9EWjlRtlP1ufCXRsxBq4XRZboSqoIRPWS/q454UGheh3FoTc+RObc1xMJyevgVYVsb MwSseHsUcDqXSJRf1bagFbYsksVvB+664lXn5EbD4e30m2aYsBryL7jiytB9nWomY9 56K2Ha0EozV58ZqsbwrahUyRdPu9cjVres7RgubXvOZN+5cSeCnC6M8CVfeLCUVQ5i 4hW5VqTkDGg6b7lnGZYJXXo1QXrrXUZF7nkwZTujjc8kfThqmqslQf4YmlQxVGR63T cnIpy/hKFlydi463EAG0Ah9I= Received: from zn.tnic (p200300ea971f9314329C23FFfea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:971f:9314:329c:23ff:fea6:a903]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id B97AE40E0266; Tue, 7 Jan 2025 12:37:16 +0000 (UTC) Date: Tue, 7 Jan 2025 13:37:11 +0100 From: Borislav Petkov To: "Nikunj A. Dadhania" Cc: linux-kernel@vger.kernel.org, thomas.lendacky@amd.com, x86@kernel.org, kvm@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, dave.hansen@linux.intel.com, pgonda@google.com, seanjc@google.com, pbonzini@redhat.com, francescolavra.fl@gmail.com Subject: Re: [PATCH v16 05/13] x86/sev: Add Secure TSC support for SNP guests Message-ID: <20250107123711.GEZ30f9_OzOcJSF10o@fat_crate.local> References: <20250106124633.1418972-1-nikunj@amd.com> <20250106124633.1418972-6-nikunj@amd.com> <20250107104227.GEZ30FE1kUWP2ArRkD@fat_crate.local> <465c5636-d535-453b-b1ea-4610a0227715@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <465c5636-d535-453b-b1ea-4610a0227715@amd.com> On Tue, Jan 07, 2025 at 05:13:03PM +0530, Nikunj A. Dadhania wrote: > >> + case CC_ATTR_GUEST_SNP_SECURE_TSC: > >> + return (sev_status & MSR_AMD64_SEV_SNP_ENABLED) && > > > > This is new here? > > Yes, this was suggested by Tom here [1] Either of you care to explain why this is needed? > >> + (sev_status & MSR_AMD64_SNP_SECURE_TSC); I would strongly assume that whatever sets MSR_AMD64_SNP_SECURE_TSC will have checked/set MSR_AMD64_SEV_SNP_ENABLED already. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette