From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 2625D474266 for ; Mon, 12 Oct 2026 09:50:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791798625; cv=none; b=EQ0CbMDP3FhpgFTqweAadUq+vHAqDVYiHGo2ORoHD1MxvclzH90M8TthDMz+k8JajLqL8l7uUdlqTnWiu7fFp5FJ3Jfwce2D+3bnoVrxz7Konn0xSUAtRpDtYjzhKBNaVmYq/HuAEMf2cqsn3LfOmp0ut95i0Oa56/LkntFqPCM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791798625; c=relaxed/simple; bh=RzLWHjemQgbwtVJ+gZtIzOuwMdap2fNgwJ8Dkzq7gnI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t74Vra6PDiyoRVn9WwU6bZMPBH78rrqvOIJTX/0ZjHib04UIkiQu+MoUmdA74DZ/jti7Wr/tRgfKGgOXBIWb2N0+2YIBbmEzT2BGTyPNld8frT30r3jXRVjasNyj2Jv/Hy3Rqd5nl71XhYYMteK/B232EGpuuUhIFy4NojFph1A= 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=DI2jfzOR; arc=none smtp.client-ip=198.175.65.10 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="DI2jfzOR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1791798621; x=1823334621; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=RzLWHjemQgbwtVJ+gZtIzOuwMdap2fNgwJ8Dkzq7gnI=; b=DI2jfzORYRbfMbzKmVYWVKdD0hENKO5raHks1bOe7vw3rw1Nu1exSLkO rUpH9/hWxBE7LN2Ccdu3DhfmyLgt75RqhJB1tyPYfVpbJ77QpLWgjk80Y vD2GxPNT5+0HYcj+T+1keBLeDj6JfOj5n1r4+F8ewNkWgzev8GfQTpqB7 5g4PvlwIBKzjLAq6RaA/eoPgJVQZvSOZh0m9C+V3x3xI/28DYY9Dhan+P YsoZ1BhnONOLhf7ciIQ2S2Xsh2FB+K1pdFMfLVOBXUgz5jtU9KT0IHbpl pmPmmF3vOoeA390IDr/8fP6vZjTVnsC65vxfL6bk2qD2EjKfx9x91GkDN Q==; X-CSE-ConnectionGUID: 7tv8r/drRJ+Xh2CKhHOqDw== X-CSE-MsgGUID: sHA8TxrmRB2G+KYP4SgUFw== X-IronPort-AV: E=McAfee;i="6800,10657,11932"; a="387986" X-IronPort-AV: E=Sophos;i="6.27,153,1787036400"; d="scan'208";a="387986" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Oct 2026 02:50:20 -0700 X-CSE-ConnectionGUID: sCJeaolgQ3m6hFPrjsSrjA== X-CSE-MsgGUID: 4ppjaFv/T9GfsF3+3DNzyw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,153,1787036400"; d="scan'208";a="776818" Received: from 984fee019967.jf.intel.com ([10.23.153.244]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Oct 2026 02:50:20 -0700 From: Chao Gao To: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org Cc: yilun.xu@linux.intel.com, chao.gao@intel.com, binbin.wu@linux.intel.com, tony.lindgren@linux.intel.com, rick.p.edgecombe@intel.com, nik.borisov@suse.com, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Kiryl Shutsemau Subject: [PATCH v4 01/10] x86/virt/tdx: Add a helper to read a table of metadata fields Date: Mon, 12 Oct 2026 02:47:28 -0700 Message-ID: <20261012094754.27702-2-chao.gao@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20261012094754.27702-1-chao.gao@intel.com> References: <20261012094754.27702-1-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 The metadata field readers get_tdx_sys_info_() in tdx_global_metadata.c were generated by an out-of-tree script. That has not worked out: the JSON file they were generated from is neither stable nor authoritative enough [1]. The goal now is to maintain the readers by hand and to establish one standard way of adding a metadata field. Take get_tdx_sys_info_version() as an example: if (!ret && !(ret = read_sys_metadata_field(0x0800000100000003, &val))) sysinfo_version->minor_version = val; if (!ret && !(ret = read_sys_metadata_field(0x0800000100000004, &val))) sysinfo_version->major_version = val; if (!ret && !(ret = read_sys_metadata_field(0x0800000100000005, &val))) sysinfo_version->update_version = val; Two patterns stand out: the read-check-store sequence repeats once per field, and the error of each read is chained into the reads that follow. Neither is common in hand-written code. Prepare to eliminate both with a loop that reads each field, stores the value into its structure member, and returns on the first error. Add 'struct field_mapping' to describe one field as its ID plus the offset and size of the member that receives its value. Add FIELD_MAP() to build such an entry from a field ID, a structure type and a member name. Add __read_sys_metadata_table() helper to read every field in a table. Annotate that helper __maybe_unused as there is no caller right now. Following changes will convert the existing readers to use the new helper. AI was used under supervision to review code and workshop logs. It suggested adding read_sys_metadata_table() macro, which avoids repeating the table name when passing both the table and its size. Signed-off-by: Chao Gao Reviewed-by: Nikolay Borisov Reviewed-by: Rick Edgecombe Link: https://lore.kernel.org/kvm/1e7bcbad-eb26-44b7-97ca-88ab53467212@intel.com/ # [1] --- v4: - Collect tags [Nikolay, Rick] - Rename TDX_SYSINFO_MAP() to FIELD_MAP() to keep table entries short - Builds the full structure name from its tdx_sys_info_ suffix [Yilun] v3: - Pass the field ID to TDX_SYSINFO_MAP() instead of pasting the TDX_MD_FIELD_ID_ prefix onto a suffix inside the macro [Rick] - Say that this patch only prepares to eliminate the two patterns. [Rick] - Define @offset in struct field_mapping as size_t [Binbin] --- arch/x86/virt/vmx/tdx/tdx.c | 42 +++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 96ced0494b68..65a6aae6fab0 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -395,6 +395,48 @@ static int read_sys_metadata_field(u64 field_id, u64 *data) return 0; } +/* + * Map a TDX global metadata field to a structure member. + * @field_id: The TDX global metadata field ID. + * @size: The size of the structure member. + * @offset: The member's offset within its containing structure. + */ +struct field_mapping { + u64 field_id; + size_t size; + size_t offset; +}; + +/* Read each metadata field listed in @mappings[] into @data. */ +static int __maybe_unused __read_sys_metadata_table(const struct field_mapping *mappings, + int num_mappings, void *data) +{ + int i, ret; + u64 val; + + for (i = 0; i < num_mappings; i++) { + ret = read_sys_metadata_field(mappings[i].field_id, &val); + if (ret) + return ret; + memcpy((char *)data + mappings[i].offset, &val, mappings[i].size); + } + + return 0; +} + +#define read_sys_metadata_table(_mappings, _data) \ + __read_sys_metadata_table(_mappings, ARRAY_SIZE(_mappings), _data) + +#define __FIELD_MAP(_field, _type, _member) \ +{ \ + .field_id = _field, \ + .offset = offsetof(_type, _member), \ + .size = sizeof_field(_type, _member), \ +} + +#define FIELD_MAP(_field, _type, _member) \ + __FIELD_MAP(_field, struct tdx_sys_info_##_type, _member) + #include "tdx_global_metadata.c" static __init int check_features(struct tdx_sys_info *sysinfo) -- 2.52.0