From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 6EE70340A46; Tue, 4 Aug 2026 11:31:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785843070; cv=none; b=RkorAdWRjvEQlPTiAeVckaIFB+vycwCii8DucN9z3Je1NZ2+Gv+BP1Ce6CQ8dcSuYAn9fG60kh837yZHJ3dw0moVuBkQtH4KNy8J9/FKOQeuHIbBvr6IAZE/ZvQew4BN5YXftI3UzrtgP32ycTeXwK31mDkBQX4BHfyp0zW3W98= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785843070; c=relaxed/simple; bh=5RnmrpWOMDV86PTzf5eDaOGgp0G0DtsVia13f/Ss7q4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UPvD0aaGiL0I9XHY1LBGXRpTaQErVjXX5rAFr8jVm6KTRn+w3dUADiENbVYiTCLwrA2OR/Ms9xTqS6Wl5VbF1HqNYH1GJyjqDaWJvhd2KbpH4GQ6oNFImf2/gZV0FSSM0fEXLKmQKn2NM+JsuM6FiM1rM3TIokEqQJdoKVDBmLE= 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=ctniOjC5; arc=none smtp.client-ip=198.175.65.21 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="ctniOjC5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785843070; x=1817379070; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5RnmrpWOMDV86PTzf5eDaOGgp0G0DtsVia13f/Ss7q4=; b=ctniOjC5ZEAWCFZWprJRNil5sF+WshFVq4ikdj504UP0d7pzWEo9fweV 6RDNbOx06d9ufehWd5ngQKpvaWh4V6lcttpnyVQqKq0zRDfl2R5/7xjuU AzGQ/F/ifa/psWdA+EVRM+zKJVN7Xu8nkjzieeHxK3gjk+VulO7bFQx5G x1Hqwr4rr1+6rD6nGbZhKDP5x5jQiltrZqRPQ44UpPw2BvP4vzZUMMYcV mod35T4EY/EVPVNc/5Du5LWLUr7M0y1LrFTUqfyKHG2cz1Q5zMTidTb0x CajS517/M4ChOAPjyEVdpenn7NLjXkvr1vBp0KNPjbsiZfVZEBqVaczm7 w==; X-CSE-ConnectionGUID: c/wsYDyiR9q2IYinL6alNw== X-CSE-MsgGUID: cQuTRRnzQGCN29/JD8UQQg== X-IronPort-AV: E=McAfee;i="6800,10657,11864"; a="86244241" X-IronPort-AV: E=Sophos;i="6.25,204,1779174000"; d="scan'208";a="86244241" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Aug 2026 04:31:07 -0700 X-CSE-ConnectionGUID: DUTxa6/lRKO+eoBhyc0o9Q== X-CSE-MsgGUID: 7HJ9DfupSzuPOgYN5nmEhw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,204,1779174000"; d="scan'208";a="265323103" Received: from jf.jf.intel.com (HELO 984fee019967.jf.intel.com) ([10.23.153.244]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Aug 2026 04:31:07 -0700 From: Chao Gao To: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org Cc: rick.p.edgecombe@intel.com, kas@kernel.org, dave.hansen@linux.intel.com, chao.gao@intel.com Subject: [PATCH v1 3/8] x86/virt/tdx: Add a table-driven TDX global metadata reader Date: Tue, 4 Aug 2026 04:29:31 -0700 Message-ID: <20260804112941.19894-4-chao.gao@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260804112941.19894-1-chao.gao@intel.com> References: <20260804112941.19894-1-chao.gao@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Dave Hansen The auto-generated tdx_global_metadata.c populates each member of 'struct tdx_sys_info' with a chain like if (!ret && !(ret = read_sys_metadata_field(0x..., &val))) sysinfo_xxx->member = val; repeated once per field, with a bare hex literal for the field ID and an implicit narrowing assignment. Reading it requires the JSON file, and reviewing any change to it requires the out-of-tree script. Replace it with a small table-driven reader. Each table entry pairs a named MD_FIELD_ID_* with the C member that holds its value: #define MAP_FEATURES(_field_id, _member) \ TD_SYSINFO_MAP(_field_id, tdx_sys_info_features, _member) static const struct tdx_sys_field features_fields[] __initconst = { MAP_FEATURES(TDX_FEATURES0, tdx_features0), }; TD_SYSINFO_MAP() derives the destination offset and width from the struct via offsetof()/sizeof_field(). Add read_sys_metadata_table() to walk such a table, reading each field and populating the C struct. Three things fall out of this table-driven reader, all of which matter now that the code is hand-maintained rather than auto-generated: - The field-to-member pairing becomes data rather than code embedded in control flow. - The read logic exists once instead of once per field. - The width is recorded explicitly instead of being implied by a narrowing assignment. Convert the 'features' class only, as an example. The remaining classes follow in later patches. Assisted-by: Claude:claude-opus-5 Not-yet-signed-off-by: Dave Hansen Signed-off-by: Chao Gao --- arch/x86/virt/vmx/tdx/tdx.c | 60 +++++++++++++++++++++ arch/x86/virt/vmx/tdx/tdx_global_metadata.c | 11 ---- 2 files changed, 60 insertions(+), 11 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 42df8ea464c4..fb21433e7851 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -347,6 +347,66 @@ static int read_sys_metadata_field(u64 field_id, u64 *data) return 0; } +/* + * Mapping between a TDX global metadata field and the C member that + * holds its value. Use TD_SYSINFO_MAP() to populate entries. + */ +struct tdx_sys_field { + u64 field_id; + u16 offset; + u8 size; +}; + +#define TD_SYSINFO_MAP(_field_id, _struct, _member) \ + { \ + .field_id = MD_FIELD_ID_##_field_id, \ + .offset = offsetof(struct _struct, _member), \ + .size = sizeof_field(struct _struct, _member), \ + } + +/* + * Walk a table of TDX global metadata fields, read each via TDH.SYS.RD, + * and store the result into the matching C member of *@base. + */ +static int read_sys_metadata_table(const struct tdx_sys_field *fields, + int nr_fields, void *base) +{ + int i, ret; + u64 val; + + for (i = 0; i < nr_fields; i++) { + const struct tdx_sys_field *f = &fields[i]; + + ret = read_sys_metadata_field(f->field_id, &val); + if (ret) + return ret; + + switch (f->size) { + case 1: *(u8 *)(base + f->offset) = val; break; + case 2: *(u16 *)(base + f->offset) = val; break; + case 4: *(u32 *)(base + f->offset) = val; break; + case 8: *(u64 *)(base + f->offset) = val; break; + default: + return -EINVAL; + } + } + return 0; +} + +#define MAP_FEATURES(_field_id, _member) \ + TD_SYSINFO_MAP(_field_id, tdx_sys_info_features, _member) + +static const struct tdx_sys_field features_fields[] __initconst = { + MAP_FEATURES(TDX_FEATURES0, tdx_features0), +}; + +static __init int get_tdx_sys_info_features(struct tdx_sys_info_features *sysinfo_features) +{ + return read_sys_metadata_table(features_fields, + ARRAY_SIZE(features_fields), + sysinfo_features); +} + #include "tdx_global_metadata.c" static __init int check_features(struct tdx_sys_info *sysinfo) diff --git a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c index e49c300f23d4..e69c655a91a0 100644 --- a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c +++ b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c @@ -22,17 +22,6 @@ static int get_tdx_sys_info_version(struct tdx_sys_info_version *sysinfo_version return ret; } -static __init int get_tdx_sys_info_features(struct tdx_sys_info_features *sysinfo_features) -{ - int ret = 0; - u64 val; - - if (!ret && !(ret = read_sys_metadata_field(0x0A00000300000008, &val))) - sysinfo_features->tdx_features0 = val; - - return ret; -} - static __init int get_tdx_sys_info_tdmr(struct tdx_sys_info_tdmr *sysinfo_tdmr) { int ret = 0; -- 2.52.0