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Sat, 15 Aug 2026 04:39:48 -0700 (PDT) Message-ID: <498af8d6a5de3ee05e0216ea075c0eebf88c7072.camel@gmail.com> Subject: Re: [PATCH v3 0/4] tdx-guest: Make Quote buffer size dynamic From: Artem Bityutskiy To: "Edgecombe, Rick P" , "seanjc@google.com" Cc: "tglx@kernel.org" , "mingo@redhat.com" , "x86@kernel.org" , "kas@kernel.org" , "binbin.wu@linux.intel.com" , "Li, Xiaoyao" , "linux-kernel@vger.kernel.org" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "dave.hansen@linux.intel.com" , "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" , "hpa@zytor.com" , "bp@alien8.de" , "Fang, Peter" Date: Sat, 15 Aug 2026 14:39:46 +0300 In-Reply-To: <21ffbb7b80c0c654c23a97cda55f43c73e49ba25.camel@intel.com> References: <20260729122939.1340412-1-peter.fang@intel.com> <80b4ea89ebf17398c3bee21d157c7f97ea32aadf.camel@intel.com> <86d532f33816cd4fa3e29c40079a6003abf89324.camel@intel.com> <20260812223707.GD1013044@pedri> <6191a69559e58e04c8e3f1efa776e9639796af3d.camel@intel.com> <98dcc8a12f117745a1cb9981dc8f0f1548e9c96f.camel@gmail.com> <4ad451969522eecb445289ca74a88ee73d51336d.camel@intel.com> <8b432c8731167e97432b2e917d0b1c855fedf47c.camel@gmail.com> <21ffbb7b80c0c654c23a97cda55f43c73e49ba25.camel@intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2026-08-14 at 15:55 +0000, Edgecombe, Rick P wrote: > On Fri, 2026-08-14 at 08:45 +0300, Artem Bityutskiy wrote: > > But why DICE-based attestation uses 2-flow design? Could TD run a > > TDCALL[TDG.GET.QUOTE2] or something directly. No concept of TD report > > would be needed. That would be my current vision of "cleanest". >=20 > We discussed this approach internally and in PUCK. The problem is there i= s a > shared resource, and so something needs to handle locking and fairness be= tween > the guests. Going to the host keeps all the scheduling type stuff in that > domain. Good point. I did not think about this aspect. I am curious if today this is an attestation-only problem or a pattern. I mean this "many TDs compete for a shared TDX capability, VMM needs to be involved to handle fairness". Thanks, Artem.