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 58318C46467 for ; Tue, 3 Jan 2023 11:29:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237418AbjACL3l (ORCPT ); Tue, 3 Jan 2023 06:29:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237128AbjACL31 (ORCPT ); Tue, 3 Jan 2023 06:29:27 -0500 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 744D8DF10; Tue, 3 Jan 2023 03:29:25 -0800 (PST) Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (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 2040B1EC050B; Tue, 3 Jan 2023 12:29:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1672745364; 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=hHNeXXmIEWKAYHBGGQRDhAL79D6KkvMsBbRma5cfExU=; b=NNIoSo0twPIZ1qGXBAOvS6g0W76sdRRKJAUfcPEizOgk+DopUiobxXahbjbSM/UqS5oaij 5IR4OoNV1AEVjL8M+pT+zcowSBdqyq5XWwoSes448KG+tY8ey0gB2A/tL7HE2BsRAEsNfe sqKiAjN4/vnBAsFmLLpUQfzPBxqtfR0= Date: Tue, 3 Jan 2023 12:29:23 +0100 From: Borislav Petkov To: "Nikunj A. Dadhania" Cc: David Rientjes , linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, dave.hansen@linux.intel.com, seanjc@google.com, pbonzini@redhat.com, thomas.lendacky@amd.com, michael.roth@amd.com, stable@kernel.org Subject: Re: [PATCH v3] x86/sev: Add SEV-SNP guest feature negotiation support Message-ID: References: <20230102083810.71178-1-nikunj@amd.com> <3169b54b-d990-7707-5ec4-cde7261318fe@google.com> <45487a87-764a-7ff3-292b-4a55fe29f7ba@amd.com> <02a2e641-6b6d-e1c5-2c43-8815306d92a0@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <02a2e641-6b6d-e1c5-2c43-8815306d92a0@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 03, 2023 at 09:07:14AM +0530, Nikunj A. Dadhania wrote: > Currently, GHCBData[24:63] is unused. If we intend to use the bit range(40bits), GHCB spec > will need to be updated. And probably would not be enough. My fear too... > As the termination request is done using GHCB MSR protocol, exit codes cannot be used. We need to figure out some other way of communicating to the guest owner because of which feature the guest refused booting. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette