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 5EAC6EE4993 for ; Tue, 22 Aug 2023 14:43:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qYSaL-0004pr-Ow; Tue, 22 Aug 2023 10:42:21 -0400 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 1qYSaI-0004pf-DR for qemu-devel@nongnu.org; Tue, 22 Aug 2023 10:42:18 -0400 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 1qYSaF-0003AF-Sy for qemu-devel@nongnu.org; Tue, 22 Aug 2023 10:42:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692715334; h=from:from:reply-to: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=fibOIifOIoCYjZF01dSrqWuwFTP4vh92xbvCgHNrUfI=; b=R10feiXqZ4lXbEM4A8TMX1hQ9Pi5lInzGjeT45bIkjvZ/KwLYHWj+Yag4vcM171EiMyXen oB8O18vGzoKR+Bxh1iza1hKKMn/rENmY77fGZmIv/DYDyN8AcMxTE//Ei73RjyjQtoWxgJ VHvihQgcSQujg0aeQc+jm7wUcOlSeto= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-644-x8Mv49SCOw2_F7ayOxTfzQ-1; Tue, 22 Aug 2023 10:42:11 -0400 X-MC-Unique: x8Mv49SCOw2_F7ayOxTfzQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B84E68D40D9; Tue, 22 Aug 2023 14:42:10 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.87]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EDA314A9004; Tue, 22 Aug 2023 14:42:07 +0000 (UTC) Date: Tue, 22 Aug 2023 15:42:05 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Xiaoyao Li Cc: Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" , Marcel Apfelbaum , Igor Mammedov , Ani Sinha , Peter Xu , David Hildenbrand , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Cornelia Huck , Eric Blake , Markus Armbruster , Marcelo Tosatti , Gerd Hoffmann , qemu-devel@nongnu.org, kvm@vger.kernel.org, Eduardo Habkost , Laszlo Ersek , Isaku Yamahata , erdemaktas@google.com, Chenyi Qiang Subject: Re: [PATCH v2 18/58] i386/tdx: Validate TD attributes Message-ID: References: <20230818095041.1973309-1-xiaoyao.li@intel.com> <20230818095041.1973309-19-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Aug 22, 2023 at 10:30:47PM +0800, Xiaoyao Li wrote: > On 8/21/2023 5:16 PM, Daniel P. Berrangé wrote: > > On Fri, Aug 18, 2023 at 05:50:01AM -0400, Xiaoyao Li wrote: > > > Validate TD attributes with tdx_caps that fixed-0 bits must be zero and > > > fixed-1 bits must be set. > > > > > > Besides, sanity check the attribute bits that have not been supported by > > > QEMU yet. e.g., debug bit, it will be allowed in the future when debug > > > TD support lands in QEMU. > > > > > > Signed-off-by: Xiaoyao Li > > > Acked-by: Gerd Hoffmann > > > --- > > > target/i386/kvm/tdx.c | 27 +++++++++++++++++++++++++-- > > > 1 file changed, 25 insertions(+), 2 deletions(-) > > > > > > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c > > > index 629abd267da8..73da15377ec3 100644 > > > --- a/target/i386/kvm/tdx.c > > > +++ b/target/i386/kvm/tdx.c > > > @@ -32,6 +32,7 @@ > > > (1U << KVM_FEATURE_PV_SCHED_YIELD) | \ > > > (1U << KVM_FEATURE_MSI_EXT_DEST_ID)) > > > +#define TDX_TD_ATTRIBUTES_DEBUG BIT_ULL(0) > > > #define TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE BIT_ULL(28) > > > #define TDX_TD_ATTRIBUTES_PKS BIT_ULL(30) > > > #define TDX_TD_ATTRIBUTES_PERFMON BIT_ULL(63) > > > @@ -462,13 +463,32 @@ int tdx_kvm_init(MachineState *ms, Error **errp) > > > return 0; > > > } > > > -static void setup_td_guest_attributes(X86CPU *x86cpu) > > > +static int tdx_validate_attributes(TdxGuest *tdx) > > > +{ > > > + if (((tdx->attributes & tdx_caps->attrs_fixed0) | tdx_caps->attrs_fixed1) != > > > + tdx->attributes) { > > > + error_report("Invalid attributes 0x%lx for TDX VM (fixed0 0x%llx, fixed1 0x%llx)", > > > + tdx->attributes, tdx_caps->attrs_fixed0, tdx_caps->attrs_fixed1); > > > + return -EINVAL; > > > + } > > > + > > > + if (tdx->attributes & TDX_TD_ATTRIBUTES_DEBUG) { > > > + error_report("Current QEMU doesn't support attributes.debug[bit 0] for TDX VM"); > > > + return -EINVAL; > > > + } > > > > Use error_setg() in both cases, passing in a 'Error **errp' object, > > and 'return -1' instead of returning an errno value. > > > > why return -1 instead of -EINVAL? Returning errno values is useful if the method isn't providing an "Error **errp" parameter, because it lets the caller report a more detailed error message via strerror(). Once you add a Error ** parameter though, there is almost never any reason for the caller to care about the original errno value, and so we use 0 / -1 as success/fail indicators. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|