From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB032330B17 for ; Mon, 26 Jan 2026 10:28:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769423339; cv=none; b=RfGjkwHYLbKNYS+09WVBdTZwuNmmHks+aWoX6Nej5NaLZJqlrnHacpGWtrQrovCzDbUrUaNB0/6S93zUb+quagI9EGV3TGWU9E59Yi017Gg0fGsM/q82ZE9BW5ndNIVKOAAhXE9g21JpPUYpG0EhvTMUAhxjGM+2Zo6V4yNoAXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769423339; c=relaxed/simple; bh=bhG3gelob0jmBkWsdn8PSBSfhQbeTB63h3+j1LDrLzg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jxij91fcQk0QpdW7XPqjMNJMZPe21/LB0YRhMpNtI8ccNzJMSX9LYXAlVKV+kS33ZZvEQipfWwF530D9E6llRW3c9gdS15fYs/8+G6DVMn+JV4L1wvXSgc89msNs7VovqKTW2slN4opRMXHIjnTTFkN97oMPnOS0U/2lgUgggVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=A553/T4i; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="A553/T4i" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769423337; x=1800959337; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=bhG3gelob0jmBkWsdn8PSBSfhQbeTB63h3+j1LDrLzg=; b=A553/T4i7SG2AWXuR0TTwT0eTSkJXC/yWw6XSWvxxH/12w5iMnLiM6uZ BjSMGeQXMhm4sGHRb1RLsHgKr+MVvroVUY7+60XuQNU8K9Gl3fp4FGXqN 4wpL6vPktW5yKn7Kx6VS3Txdq2Rn5/OAOp06JJkCQ0DW2hzhRY7i80hd+ 72MEaxyN3jWWSd60S5XqYd0JoG647x8aK7JoLgFUqWdyShoPxIYx1CDvf YtLp8J61OwELSvfREWZEJE2ZT/XuymNlb77C0znOMp+9/zCIgIPtisyVQ p8l5EoSJ6Ewcq1bFc33M3Xry3XTfwKYxOH2yKetUbE67elZkosJKKa2jn A==; X-CSE-ConnectionGUID: ThkiAYbKQGGNAkDStvY9Dg== X-CSE-MsgGUID: nKDqrbP3RIiBY73XbbO3Sw== X-IronPort-AV: E=McAfee;i="6800,10657,11682"; a="96061531" X-IronPort-AV: E=Sophos;i="6.21,254,1763452800"; d="scan'208";a="96061531" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2026 02:28:55 -0800 X-CSE-ConnectionGUID: R+VAUD2tRu6HjQMScxaVrg== X-CSE-MsgGUID: 2slZUXjlQii4kQlJeWwFeQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,254,1763452800"; d="scan'208";a="207248608" Received: from krybak-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.55]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2026 02:28:47 -0800 Date: Mon, 26 Jan 2026 12:28:44 +0200 From: Tony Lindgren To: Chao Gao Cc: linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, reinette.chatre@intel.com, ira.weiny@intel.com, kai.huang@intel.com, dan.j.williams@intel.com, yilun.xu@linux.intel.com, sagis@google.com, vannapurve@google.com, paulmck@kernel.org, nik.borisov@suse.com, zhenzhong.duan@intel.com, seanjc@google.com, rick.p.edgecombe@intel.com, kas@kernel.org, dave.hansen@linux.intel.com, vishal.l.verma@intel.com, Farrah Chen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Subject: Re: [PATCH v3 14/26] x86/virt/seamldr: Introduce skeleton for TDX Module updates Message-ID: References: <20260123145645.90444-1-chao.gao@intel.com> <20260123145645.90444-15-chao.gao@intel.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260123145645.90444-15-chao.gao@intel.com> On Fri, Jan 23, 2026 at 06:55:22AM -0800, Chao Gao wrote: > The P-SEAMLDR requires that no TDX Module SEAMCALLs are invoked during a > runtime TDX Module update. > > But currently, TDX Module SEAMCALLs are invoked in various contexts and in > parallel across CPUs. Additionally, considering the need to force all vCPUs > out of guest mode, no single lock primitive, except for stop_machine(), can > meet this requirement. > > Perform TDX Module updates within stop_machine() as it achieves the > P-SEAMLDR requirements and is an existing well understood mechanism. Reviewed-by: Tony Lindgren