From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f177.google.com (mail-pl1-f177.google.com [209.85.214.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B624F1EF39F for ; Sat, 25 Oct 2025 00:54:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761353696; cv=none; b=N88LDW89K8ccw2+V/AVIJPAPZCpuASIHlR2sGZbqKps7D6N3zk8yyepK+BB9+/+aSJjJCs5/Fgwf1HNkdSpm2KN/IuQk7l7O+pAtN1v4FHANoUz6gy7TkW2NHkG2Z98d9bSy1447NFH76vmiuywHdGPJcZ8LKFuwpS5Dmp9QNZw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761353696; c=relaxed/simple; bh=FAa8qh/yrZ/DivWv0HekP569K1EcOK1GynHOSo9ol4g=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=qhd8PUz2Hojw4DKCJDhAF1VbkIP9z4UwnW1na3L7opp618j4pJczqhcnfpDYMbtHjnh38KOrSt/IP5o9oPRD+ZigCPK7+0OM+T7cZZh0BzUeytYWRbHkp1HDyJnaHPfoIVXv4KaeX1IRdVkAFPD+akn0sSsLJ2pHc6hhistWRUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=AlXYA8dG; arc=none smtp.client-ip=209.85.214.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="AlXYA8dG" Received: by mail-pl1-f177.google.com with SMTP id d9443c01a7336-27eeafd4882so86025ad.0 for ; Fri, 24 Oct 2025 17:54:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1761353694; x=1761958494; darn=lists.linux.dev; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=FAa8qh/yrZ/DivWv0HekP569K1EcOK1GynHOSo9ol4g=; b=AlXYA8dG1GuFMQPIYEtTDpEaMEQc5z2l8kEGJiscSC40ibtwc0Das3Ojf3sjPejjT9 VOjXf1tWs8uWojqEbt8TV5Iuocicgn76foUvJMKsaXEFbdPDurxoMJ1DSF9fKAI5w3Nh cc+XFFSHjziZD0SgQhwKOQDYd9Rw3z22tCwmH/201dfZuh1zPeNqRdZUZ948PBHCPi/a 44lyCczydWOjxKjONjQ1sn0BXxz8vVkB96lTvDl1mIirWbxgiyrI1FbEPoPwEXBtSWir E5osMtHx2/6JS7P1oJEWbp4J2i6ZOpJVT3sJyUS/OmjqcucdsWMTpsewOAMD8j9/yAcw AoIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761353694; x=1761958494; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=FAa8qh/yrZ/DivWv0HekP569K1EcOK1GynHOSo9ol4g=; b=DWJELyC9GU4QCEf0TuMWn3k2v2QOm9VKpK/gF4yApBMIv0xPbrJ4EOK6x+CGEiDjEi GMEwPiHjtVJaooNQCpyVHRd7w83q728boC++/TDWn0lyvASCK0dLbRXsg4mFiGZEQ1rn 2yuQLSHepHWvmAlCgDGYE3OlkpJLbC4OOnSSSKPyblWU6YaSTbRCFdQPgrE6uSOvcvb3 cYilkR/dbzqaTUz7klHh4w9qWp9Z5n6orjJpk3SOjdIpgAYIp+RawxM5DnniXOy4r13r SSwhmn85+tKR9p9UhaNRyLXtcJ3lnYfL/v75UmRM6+fTPQFF0vRTl7p3COqIqSuXZ/vy 2O4w== X-Forwarded-Encrypted: i=1; AJvYcCWyEiTA7TnzqaX+A+TbPRJqCKt9kSO/nq2KuyS78+qXaftxx9Q9hxqLEmtD/ouCMZwbOVjv0Vcd8kv9@lists.linux.dev X-Gm-Message-State: AOJu0YwqKlV4n9izY/sxcsQPXxrFTiT1feID8q+ARmThBNhVKMDl1Wag EirGrMzuT8auOTvu+bTDj9TGUNL7ZZuzfnkoNfuT2+sur//fMhAOXMr1qH/Pp/REUUDRWNd1X12 4Oig++ycev0sqWhIUAEZYsB1JBI+23MMIb9kfvQG7 X-Gm-Gg: ASbGncsds4fvQI40rwDmrcYnV/dNMxyXMJAa47FgW00CLMVyEsHHzoNbstzh4lHHgmy p6qGGGMElawolUktmpX3AYNnD6vhr06mIR+c+LnviE8HaOhHFh/HquO/GQVN7+cQ6XeDdlGLGzN qWPbxphxc8Y6NDL6ck0L8aFzgUjXBnCc+6s6fVQd2mMCjiXnzLl/EQiSA3AAjX+A+NRRnKlopdQ vL6rX59ww/wZfauqtJ4lDJRUe3vzmb+mqnmhqFpI+4/aD2AUto63GwpUWmVLR27wMh3ozcOPkWl v5B3yS6cqLJ4Q3+v X-Google-Smtp-Source: AGHT+IHAZ97kNRS6LIm17OkKE+WVWsFtHlMK6rPjrAsP/+pfRZatmLGaC4FeacAc9nw5mRAZKQnmr9bJJldNrkXuH1Y= X-Received: by 2002:a17:902:ce84:b0:274:1a09:9553 with SMTP id d9443c01a7336-29497bb4f1amr2404035ad.6.1761353693538; Fri, 24 Oct 2025 17:54:53 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <5b4c2bb3-cfde-4559-a59d-0ff9f2a250b4@intel.com> <68fbd63450c7c_10e910021@dwillia2-mobl4.notmuch> <2e49e80f-fab0-4248-8dae-76543e3c6ae3@intel.com> <68fbebc54e776_10e9100fd@dwillia2-mobl4.notmuch> <10786082-94e0-454e-a581-7778b3a22e26@intel.com> In-Reply-To: <10786082-94e0-454e-a581-7778b3a22e26@intel.com> From: Vishal Annapurve Date: Fri, 24 Oct 2025 17:54:40 -0700 X-Gm-Features: AS18NWD48cIVeisP_Vz7McnMgruGX1KZ_wuEbrM37xSeUhKYSGdaLBQqN8lJETQ Message-ID: Subject: Re: [PATCH v2 00/21] Runtime TDX Module update support To: Dave Hansen Cc: dan.j.williams@intel.com, Chao Gao , "Reshetova, Elena" , "linux-coco@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "Chatre, Reinette" , "Weiny, Ira" , "Huang, Kai" , "yilun.xu@linux.intel.com" , "sagis@google.com" , "paulmck@kernel.org" , "nik.borisov@suse.com" , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Ingo Molnar , "Kirill A. Shutemov" , Paolo Bonzini , "Edgecombe, Rick P" , Thomas Gleixner Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Oct 24, 2025 at 2:19=E2=80=AFPM Dave Hansen = wrote: > > On 10/24/25 14:12, dan.j.williams@intel.com wrote: > >> The SGX solution, btw, was to at least ensure forward progress (CPUSVN > >> update) when the last enclave goes away. So new enclaves aren't > >> *prevented* from starting but the window when the first one starts > >> (enclave count going from 0->1) is leveraged to do the update. > > The status quo does ensure forward progress. The TD does get built and > > the update does complete, just the small matter of TD attestation > > failures, right? I would think that it's not a "small" problem if confidential workloads on the hosts are not able to pass attestation. > > Oh, yeah, for sure. > > If we do _nothing_ in the kernel (no build vs. module update > synchronization), then the downside is being exposed to attestation > failures if userspace either also does nothing or has bugs. > > That's actually, by far, my preferred solution to this whole mess: > Userspace plays stupid games, userspace wins stupid prizes. > IIUC, enforcing "Avoid updates during update sensitive times" is not that complex and will ensure to avoid any issues with user space logic.