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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9DD1CC48BF6 for ; Thu, 29 Feb 2024 13:26:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rfgQC-00088I-LY; Thu, 29 Feb 2024 08:26:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfgQ6-00087r-4x for qemu-devel@nongnu.org; Thu, 29 Feb 2024 08:25:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rfgQ3-0006be-Ff for qemu-devel@nongnu.org; Thu, 29 Feb 2024 08:25:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1709213144; 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=m/Hl7pQ4Z4cAY4nx3F9i8aXSpaP1bJtS2DoSDq1LRJE=; b=JlG4pzGPFHvIBMmrPkIVAZA3nmQLVRY+soLKQt0mdVmw75yp51lCe71Be8F6ksB4TZbJlT N3MJObuQHd4Rs11D8bzeqagHaSj3R3IsxAgx9FJzjnxxPGxaG7apf+UZvsg1bb4C6VaI4J OmdTkMkd9N7q+uqsOl0tKSnKukL6nrg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-480-ZclP6RS-O9GnLwQcZBTHtw-1; Thu, 29 Feb 2024 08:25:40 -0500 X-MC-Unique: ZclP6RS-O9GnLwQcZBTHtw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B644083106C; Thu, 29 Feb 2024 13:25:39 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.193.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 31CC01121312; Thu, 29 Feb 2024 13:25:39 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 34C4921E6740; Thu, 29 Feb 2024 14:25:38 +0100 (CET) From: Markus Armbruster To: Xiaoyao Li Cc: Paolo Bonzini , David Hildenbrand , Igor Mammedov , Eduardo Habkost , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Yanan Wang , "Michael S. Tsirkin" , Richard Henderson , Ani Sinha , Peter Xu , Cornelia Huck , Daniel P. =?utf-8?Q?Berrang=C3=A9?= , Eric Blake , Marcelo Tosatti , kvm@vger.kernel.org, qemu-devel@nongnu.org, Michael Roth , Claudio Fontana , Gerd Hoffmann , Isaku Yamahata , Chenyi Qiang Subject: Re: [PATCH v5 30/65] i386/tdx: Support user configurable mrconfigid/mrowner/mrownerconfig In-Reply-To: (Xiaoyao Li's message of "Thu, 29 Feb 2024 18:50:04 +0800") References: <20240229063726.610065-1-xiaoyao.li@intel.com> <20240229063726.610065-31-xiaoyao.li@intel.com> <87edcv1x9j.fsf@pond.sub.org> Date: Thu, 29 Feb 2024 14:25:38 +0100 Message-ID: <871q8vxuzx.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.096, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Xiaoyao Li writes: > On 2/29/2024 4:37 PM, Markus Armbruster wrote: >> Xiaoyao Li writes: >>=20 >>> From: Isaku Yamahata >>> >>> Three sha384 hash values, mrconfigid, mrowner and mrownerconfig, of a TD >>> can be provided for TDX attestation. Detailed meaning of them can be >>> found: https://lore.kernel.org/qemu-devel/31d6dbc1-f453-4cef-ab08-4813f= 4e0ff92@intel.com/ >>> >>> Allow user to specify those values via property mrconfigid, mrowner and >>> mrownerconfig. They are all in base64 format. >>> >>> example >>> -object tdx-guest, \ >>> mrconfigid=3DASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wE= jRWeJq83v,\ >>> mrowner=3DASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRW= eJq83v,\ >>> mrownerconfig=3DASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN= 7wEjRWeJq83v >>> >>> Signed-off-by: Isaku Yamahata >>> Co-developed-by: Xiaoyao Li >>> Signed-off-by: Xiaoyao Li [...] >>> diff --git a/qapi/qom.json b/qapi/qom.json >>> index 89ed89b9b46e..cac875349a3a 100644 >>> --- a/qapi/qom.json >>> +++ b/qapi/qom.json >>> @@ -905,10 +905,25 @@ >>> # pages. Some guest OS (e.g., Linux TD guest) may require this to >>> # be set, otherwise they refuse to boot. >>> # >>> +# @mrconfigid: ID for non-owner-defined configuration of the guest TD, >>> +# e.g., run-time or OS configuration (base64 encoded SHA384 digest= ). >>> +# (A default value 0 of SHA384 is used when absent). >> >> Suggest to drop the parenthesis in the last sentence. >> >> @mrconfigid is a string, so the default value can't be 0. Actually, >> it's not just any string, but a base64 encoded SHA384 digest, which >> means it must be exactly 96 hex digits. So it can't be "0", either. It >> could be >> "00000000000000000000000000000000000000000000000000000000000000000000000= 0000000000000000000000000". > > I thought value 0 of SHA384 just means it. > > That's my fault and my poor english. "Fault" is too harsh :) It's not as precise as I want our interface documentation to be. We work together to get there. >> More on this below. >>=20 >>> +# >>> +# @mrowner: ID for the guest TD=E2=80=99s owner (base64 encoded SHA384= digest). >>> +# (A default value 0 of SHA384 is used when absent). >>> +# >>> +# @mrownerconfig: ID for owner-defined configuration of the guest TD, >>> +# e.g., specific to the workload rather than the run-time or OS >>> +# (base64 encoded SHA384 digest). (A default value 0 of SHA384 is >>> +# used when absent). >>> +# >>> # Since: 9.0 >>> ## >>> { 'struct': 'TdxGuestProperties', >>> - 'data': { '*sept-ve-disable': 'bool' } } >>> + 'data': { '*sept-ve-disable': 'bool', >>> + '*mrconfigid': 'str', >>> + '*mrowner': 'str', >>> + '*mrownerconfig': 'str' } } >>> ## >>> # @ThreadContextProperties: >>> diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c >>> index d0ad4f57b5d0..4ce2f1d082ce 100644 >>> --- a/target/i386/kvm/tdx.c >>> +++ b/target/i386/kvm/tdx.c >>> @@ -13,6 +13,7 @@ >>> #include "qemu/osdep.h" >>> #include "qemu/error-report.h" >>> +#include "qemu/base64.h" >>> #include "qapi/error.h" >>> #include "qom/object_interfaces.h" >>> #include "standard-headers/asm-x86/kvm_para.h" >>> @@ -516,6 +517,7 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **errp) >>> X86CPU *x86cpu =3D X86_CPU(cpu); >>> CPUX86State *env =3D &x86cpu->env; >>> g_autofree struct kvm_tdx_init_vm *init_vm =3D NULL; >>> + size_t data_len; >>> int r =3D 0; >>> object_property_set_bool(OBJECT(cpu), "pmu", false, &error_abort); >>> @@ -528,6 +530,38 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **err= p) >>> init_vm =3D g_malloc0(sizeof(struct kvm_tdx_init_vm) + >>> sizeof(struct kvm_cpuid_entry2) * KVM_MAX_CPUI= D_ENTRIES); >>> +#define SHA384_DIGEST_SIZE 48 >>> + >>> + if (tdx_guest->mrconfigid) { >>> + g_autofree uint8_t *data =3D qbase64_decode(tdx_guest->mrconfi= gid, >>> + strlen(tdx_guest->mrconfigid), &data_len= , errp); >>> + if (!data || data_len !=3D SHA384_DIGEST_SIZE) { >>> + error_setg(errp, "TDX: failed to decode mrconfigid"); >>> + return -1; >>> + } >>> + memcpy(init_vm->mrconfigid, data, data_len); >>> + } >> >> When @mrconfigid is absent, the property remains null, and this >> conditional is not executed. init_vm->mrconfigid[], an array of 6 >> __u64, remains all zero. How does the kernel treat that? > > A all-zero SHA384 value is still a valid value, isn't it? > > KVM treats it with no difference. Can you point me to the spot in the kernel where mrconfigid is used? [...]