From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 281A433554B for ; Mon, 27 Apr 2026 15:29:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777303800; cv=none; b=aaUqouX7BniQSNK7CKBQ8W09aaYR1MpnP/NYQuuFWh1VvZklxDX/KXlA878PRUR5tbWp4AnEUxbtIZezIot581vsRSBYGIItrzsRiSyGFZKVxqc5c6lzzTCPUpQB3dD38IUIQ39+IBBkD8xrd16JIfVTmiRrTYTqf7vR9zzhfQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777303800; c=relaxed/simple; bh=BFgvtbrE3FcSwCiBnjfown4byVqzj/3t5unOa5DC0IY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jLyd+DIDe4nvZYhZE+oho7oSH/kCOZalHqev1jWz+MrnVJYbUP2BDoW9lqz42gyDaHKInkzz68+3dRCtEyRHLAfd8dRgSXcdlbFICKDUpNfA8UlPoxmA3QOsxNRI6+jH+X8+NArjnOlQN+uqxc0BLdz3ITE9yRDmgtB4OH/tFNw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=GG23hJ9Q; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="GG23hJ9Q" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777303798; x=1808839798; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=BFgvtbrE3FcSwCiBnjfown4byVqzj/3t5unOa5DC0IY=; b=GG23hJ9QlQ+/OdXA0FMtvsFXeKjzYzVpfalzV6WWbG3xz7A7YZ7LQApB RBAdz1UP+1QQPNodh0lBoWWjeIfltn6NQuwFfbmyIwXv7Y5WG+9dqoYbx WUNpmveRSFxEUX/GuIgCd/GKdU9yNejhoKQnpDliIYVt4xsvuTwb3y3Yg EqtiQHB7gDnq5EXWByhJP8NcsESVubqEnDdhevIlBBX3mL49qKUDWMh+b TtcqJJcm6n1kDlZEtmItoYkfzlLPy60aDRkpcdhnrMguTJTBI6AdsO1bd bLvh+qt2smd7wjnLgXw53YDwwBXk3wLoSwMwrv9z6aYDwalu2aPMMsY4Q Q==; X-CSE-ConnectionGUID: BGGwpgdASAa8+3JDHlhTlw== X-CSE-MsgGUID: y2ihKeaZQTGfbMevwUVPJQ== X-IronPort-AV: E=McAfee;i="6800,10657,11769"; a="77900650" X-IronPort-AV: E=Sophos;i="6.23,202,1770624000"; d="scan'208";a="77900650" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2026 08:29:55 -0700 X-CSE-ConnectionGUID: D1nZGu4LRG2Gm0KzgSIzFw== X-CSE-MsgGUID: o3IxNR7TQo2mIoKHYWZdWA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,202,1770624000"; d="scan'208";a="232673205" Received: from 984fee019967.jf.intel.com ([10.23.153.244]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2026 08:29:55 -0700 From: Chao Gao To: kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, x86@kernel.org Cc: binbin.wu@linux.intel.com, dave.hansen@linux.intel.com, djbw@kernel.org, ira.weiny@intel.com, kai.huang@intel.com, kas@kernel.org, nik.borisov@suse.com, paulmck@kernel.org, pbonzini@redhat.com, reinette.chatre@intel.com, rick.p.edgecombe@intel.com, sagis@google.com, seanjc@google.com, tony.lindgren@linux.intel.com, vannapurve@google.com, vishal.l.verma@intel.com, yilun.xu@linux.intel.com, xiaoyao.li@intel.com, yan.y.zhao@intel.com, Chao Gao , Dan Williams , Jonathan Cameron , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Subject: [PATCH v8 02/21] coco/tdx-host: Introduce a "tdx_host" device Date: Mon, 27 Apr 2026 08:27:56 -0700 Message-ID: <20260427152854.101171-3-chao.gao@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260427152854.101171-1-chao.gao@intel.com> References: <20260427152854.101171-1-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-Transfer-Encoding: 8bit TDX depends on a platform firmware module that is invoked via instructions similar to vmenter (i.e. enter into a new privileged "root-mode" context to manage private memory and private device mechanisms). It is a software construct that depends on the CPU vmxon state to enable invocation of TDX module ABIs. Unlike other Trusted Execution Environment (TEE) platform implementations that employ a firmware module running on a PCI device with an MMIO mailbox for communication, TDX has no hardware device to point to as the TEE Secure Manager (TSM). Create a virtual device not only to align with other implementations but also to make it easier to - expose metadata (e.g., TDX module version, seamldr version etc) to the userspace as device attributes - implement firmware uploader APIs which are tied to a device. This is needed to support TDX module runtime updates - enable TDX Connect which will share a common infrastructure with other platform implementations. In the TDX Connect context, every architecture has a TSM, represented by a PCIe or virtual device. The new "tdx_host" device will serve the TSM role. A faux device is used for TDX because the TDX module is singular within the system and lacks associated platform resources. Using a faux device eliminates the need to create a stub bus. The call to tdx_get_sysinfo() ensures that the TDX module is ready to provide services. Note that AMD has a PCI device for the PSP for SEV and ARM CCA will likely have a faux device [1]. Co-developed-by: Xu Yilun Signed-off-by: Xu Yilun Signed-off-by: Dan Williams Signed-off-by: Chao Gao Reviewed-by: Jonathan Cameron Reviewed-by: Tony Lindgren Reviewed-by: Xu Yilun Reviewed-by: Kai Huang Reviewed-by: Kiryl Shutsemau (Meta) Reviewed-by: Xiaoyao Li Link: https://lore.kernel.org/all/2025073035-bulginess-rematch-b92e@gregkh/ # [1] --- arch/x86/virt/vmx/tdx/tdx.c | 2 +- drivers/virt/coco/Kconfig | 2 ++ drivers/virt/coco/Makefile | 1 + drivers/virt/coco/tdx-host/Kconfig | 10 +++++++ drivers/virt/coco/tdx-host/Makefile | 1 + drivers/virt/coco/tdx-host/tdx-host.c | 43 +++++++++++++++++++++++++++ 6 files changed, 58 insertions(+), 1 deletion(-) create mode 100644 drivers/virt/coco/tdx-host/Kconfig create mode 100644 drivers/virt/coco/tdx-host/Makefile create mode 100644 drivers/virt/coco/tdx-host/tdx-host.c diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 7fe4b9234c72..05d241626e48 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -1487,7 +1487,7 @@ const struct tdx_sys_info *tdx_get_sysinfo(void) return (const struct tdx_sys_info *)&tdx_sysinfo; } -EXPORT_SYMBOL_FOR_KVM(tdx_get_sysinfo); +EXPORT_SYMBOL_FOR_MODULES(tdx_get_sysinfo, "kvm-intel,tdx-host"); u32 tdx_get_nr_guest_keyids(void) { diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig index df1cfaf26c65..f7691f64fbe3 100644 --- a/drivers/virt/coco/Kconfig +++ b/drivers/virt/coco/Kconfig @@ -17,5 +17,7 @@ source "drivers/virt/coco/arm-cca-guest/Kconfig" source "drivers/virt/coco/guest/Kconfig" endif +source "drivers/virt/coco/tdx-host/Kconfig" + config TSM bool diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile index cb52021912b3..b323b0ae4f82 100644 --- a/drivers/virt/coco/Makefile +++ b/drivers/virt/coco/Makefile @@ -6,6 +6,7 @@ obj-$(CONFIG_EFI_SECRET) += efi_secret/ obj-$(CONFIG_ARM_PKVM_GUEST) += pkvm-guest/ obj-$(CONFIG_SEV_GUEST) += sev-guest/ obj-$(CONFIG_INTEL_TDX_GUEST) += tdx-guest/ +obj-$(CONFIG_INTEL_TDX_HOST) += tdx-host/ obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest/ obj-$(CONFIG_TSM) += tsm-core.o obj-$(CONFIG_TSM_GUEST) += guest/ diff --git a/drivers/virt/coco/tdx-host/Kconfig b/drivers/virt/coco/tdx-host/Kconfig new file mode 100644 index 000000000000..d35d85ef91c0 --- /dev/null +++ b/drivers/virt/coco/tdx-host/Kconfig @@ -0,0 +1,10 @@ +config TDX_HOST_SERVICES + tristate "TDX Host Services Driver" + depends on INTEL_TDX_HOST + default m + help + Enable access to TDX host services like module update and + extensions (e.g. TDX Connect). + + Say y or m if enabling support for confidential virtual machine + support (CONFIG_INTEL_TDX_HOST). The module is called tdx_host.ko. diff --git a/drivers/virt/coco/tdx-host/Makefile b/drivers/virt/coco/tdx-host/Makefile new file mode 100644 index 000000000000..e61e749a8dff --- /dev/null +++ b/drivers/virt/coco/tdx-host/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_TDX_HOST_SERVICES) += tdx-host.o diff --git a/drivers/virt/coco/tdx-host/tdx-host.c b/drivers/virt/coco/tdx-host/tdx-host.c new file mode 100644 index 000000000000..c77885392b09 --- /dev/null +++ b/drivers/virt/coco/tdx-host/tdx-host.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TDX host user interface driver + * + * Copyright (C) 2025 Intel Corporation + */ + +#include +#include +#include + +#include +#include + +static const struct x86_cpu_id tdx_host_ids[] = { + X86_MATCH_FEATURE(X86_FEATURE_TDX_HOST_PLATFORM, NULL), + {} +}; +MODULE_DEVICE_TABLE(x86cpu, tdx_host_ids); + +static struct faux_device *fdev; + +static int __init tdx_host_init(void) +{ + if (!x86_match_cpu(tdx_host_ids) || !tdx_get_sysinfo()) + return -ENODEV; + + fdev = faux_device_create(KBUILD_MODNAME, NULL, NULL); + if (!fdev) + return -ENODEV; + + return 0; +} +module_init(tdx_host_init); + +static void __exit tdx_host_exit(void) +{ + faux_device_destroy(fdev); +} +module_exit(tdx_host_exit); + +MODULE_DESCRIPTION("TDX Host Services"); +MODULE_LICENSE("GPL"); -- 2.47.1