Re: [PATCH v3 02/10] x86/virt/tdx: Convert the version metadata reader

[Chao Gao <chao.gao@intel.com>]

On Thu, Oct 01, 2026 at 09:27:57AM -0700, Dave Hansen wrote:
>On 10/1/26 09:24, Nikolay Borisov wrote:
>> nit: I personally dislike adding this level of indirection, albeit
>> rather shallow just so you don't have to repeat 'struct xxxx' in every
>> TDX_SYS_INFO_MAP. Same goes for the rest of the patches. In the past I
>> remember TDX code also suffered from, in my opinion, excessive macro
>> nesting.
>> 
>> Dave, what's your take on this?
>> 
>>> +
>>> +static const struct field_mapping version_mappings[] = {
>>> +    TDX_SYSINFO_MAP_VERSION(TDX_FIELD_MINOR_VERSION,  minor_version),
>>> +    TDX_SYSINFO_MAP_VERSION(TDX_FIELD_MAJOR_VERSION,  major_version),
>>> +    TDX_SYSINFO_MAP_VERSION(TDX_FIELD_UPDATE_VERSION, update_version),
>>> +}; 
>
>I'm kinda ambivalent on it. The width of the structure doesn't really
>matter much. It's readable either way and it's already got *PLENTY* of
>duplicate gunk in it.
>
>I'd try to remove the macro, and make sure the structure definition
>doesn't get too icky.

OK, I will remove the per-structure macros. I would also rename
TDX_SYSINFO_MAP() to FIELD_MAP(), which keeps the table definitions
within 100 columns apart from MAX_RESERVED_PER_TDMR and
PAMT_PAGE_BITMAP_ENTRY_BITS.

static const struct field_mapping version_mappings[] = {
	FIELD_MAP(TDX_FIELD_MINOR_VERSION,	struct tdx_sys_info_version, minor_version),
	FIELD_MAP(TDX_FIELD_MAJOR_VERSION,	struct tdx_sys_info_version, major_version),
	FIELD_MAP(TDX_FIELD_UPDATE_VERSION,	struct tdx_sys_info_version, update_version),
};

static const struct field_mapping feature_mappings[] __initconst = {
	FIELD_MAP(TDX_FIELD_TDX_FEATURES0, struct tdx_sys_info_features, tdx_features0),
};

static const struct field_mapping tdmr_mappings[] __initconst = {
	FIELD_MAP(TDX_FIELD_MAX_TDMRS,		struct tdx_sys_info_tdmr, max_tdmrs),
	FIELD_MAP(TDX_FIELD_PAMT_4K_ENTRY_SIZE,	struct tdx_sys_info_tdmr, pamt_4k_entry_size),
	FIELD_MAP(TDX_FIELD_PAMT_2M_ENTRY_SIZE,	struct tdx_sys_info_tdmr, pamt_2m_entry_size),
	FIELD_MAP(TDX_FIELD_PAMT_1G_ENTRY_SIZE,	struct tdx_sys_info_tdmr, pamt_1g_entry_size),
	FIELD_MAP(TDX_FIELD_MAX_RESERVED_PER_TDMR, struct tdx_sys_info_tdmr,
		  max_reserved_per_tdmr),
};

static const struct field_mapping dpamt_mappings[] __initconst = {
	FIELD_MAP(TDX_FIELD_PAMT_PAGE_BITMAP_ENTRY_BITS, struct tdx_sys_info_tdmr,
		  pamt_page_bitmap_entry_bits),
};

static const struct field_mapping td_ctrl_mappings[] __initconst = {
	FIELD_MAP(TDX_FIELD_TDR_BASE_SIZE,	struct tdx_sys_info_td_ctrl, tdr_base_size),
	FIELD_MAP(TDX_FIELD_TDCS_BASE_SIZE,	struct tdx_sys_info_td_ctrl, tdcs_base_size),
	FIELD_MAP(TDX_FIELD_TDVPS_BASE_SIZE,	struct tdx_sys_info_td_ctrl, tdvps_base_size),
};

static const struct field_mapping handoff_mappings[] = {
	FIELD_MAP(TDX_FIELD_MODULE_HV, struct tdx_sys_info_handoff, module_hv),
};

static const struct field_mapping td_conf_mappings[] __initconst = {
	FIELD_MAP(TDX_FIELD_ATTRIBUTES_FIXED0,	struct tdx_sys_info_td_conf, attributes_fixed0),
	FIELD_MAP(TDX_FIELD_ATTRIBUTES_FIXED1,	struct tdx_sys_info_td_conf, attributes_fixed1),
	FIELD_MAP(TDX_FIELD_XFAM_FIXED0,	struct tdx_sys_info_td_conf, xfam_fixed0),
	FIELD_MAP(TDX_FIELD_XFAM_FIXED1,	struct tdx_sys_info_td_conf, xfam_fixed1),
	FIELD_MAP(TDX_FIELD_NUM_CPUID_CONFIG,	struct tdx_sys_info_td_conf, num_cpuid_config),
	FIELD_MAP(TDX_FIELD_MAX_VCPUS_PER_TD,	struct tdx_sys_info_td_conf, max_vcpus_per_td),
};