Rework metadata field reading helper to read array-typed metadata fields in a unified way. Eliminate the need to read cpuid_config_leaves/values in special manner. By adding the array index to the base field_id, the array elements can be read out. But the actual valid array index boundary should be retrieved from other metadata fields. Otherwise TDX Module returns error on an invalid field_id and the whole metadata reading process fails. That leads to the special handling of these fields. TDG.SYS.RD provides an output parameter (RDX) for next readable field_id. Use this return value to validate the next array index and detect actual array boundary. This makes the array-typed metadata fields reading self-contained. Remove all special handling for them. Signed-off-by: Xu Yilun --- arch/x86/virt/vmx/tdx/tdx_global_metadata.c | 99 +++++++++------------ 1 file changed, 44 insertions(+), 55 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c index 836d97166a7a..c366bace454e 100644 --- a/arch/x86/virt/vmx/tdx/tdx_global_metadata.c +++ b/arch/x86/virt/vmx/tdx/tdx_global_metadata.c @@ -11,6 +11,7 @@ struct field_mapping { u64 field_id; int offset; int size; + int count; }; /* @@ -34,11 +35,24 @@ struct field_mapping { #define TD_SYSINFO_CHECK_SIZE(_field_id, _size) \ __builtin_choose_expr(MD_FIELD_SIZE(_field_id) == (_size), _size, (void)0) -#define TD_SYSINFO_MAP(_field_id, _member) \ +#define _TD_SYSINFO_MAP(_field_id, _member, _count) \ { .field_id = _field_id, \ .offset = offsetof(struct tdx_sys_info, _member), \ .size = TD_SYSINFO_CHECK_SIZE(_field_id, \ - sizeof_field(struct tdx_sys_info, _member)) } + sizeof_field(struct tdx_sys_info, _member)), \ + .count = _count } + +#define TD_SYSINFO_MAP(_field_id, _member) \ + _TD_SYSINFO_MAP(_field_id, _member, 1) + +#define TD_SYSINFO_MAP_ARR(_field_id, _arr) \ + _TD_SYSINFO_MAP(_field_id, _arr[0], \ + ARRAY_SIZE(((struct tdx_sys_info *)0)->_arr)) + +#define TD_SYSINFO_MAP_2DARR(_field_id, _arr) \ + _TD_SYSINFO_MAP(_field_id, _arr[0][0], \ + ARRAY_SIZE(((struct tdx_sys_info *)0)->_arr) * \ + ARRAY_SIZE(((struct tdx_sys_info *)0)->_arr[0])) /* Map TD_SYSINFO fields into 'struct tdx_sys_info': */ static const struct field_mapping mappings[] = { @@ -60,33 +74,37 @@ static const struct field_mapping mappings[] = { TD_SYSINFO_MAP(0x1900000300000003, td_conf.xfam_fixed1), TD_SYSINFO_MAP(0x9900000100000004, td_conf.num_cpuid_config), TD_SYSINFO_MAP(0x9900000100000008, td_conf.max_vcpus_per_td), + TD_SYSINFO_MAP_ARR(0x9900000300000400, td_conf.cpuid_config_leaves), + TD_SYSINFO_MAP_2DARR(0x9900000300000500, td_conf.cpuid_config_values), }; -/* Populate the following fields in special manner, separate them out. */ -static const struct field_mapping cpuid_config_leaves = - TD_SYSINFO_MAP(0x9900000300000400, td_conf.cpuid_config_leaves[0]); - -static const struct field_mapping cpuid_config_values = - TD_SYSINFO_MAP(0x9900000300000500, td_conf.cpuid_config_values[0][0]); - -static int read_sys_metadata_field(u64 field_id, int offset, int size, +static int read_sys_metadata_field(const struct field_mapping *base, struct tdx_sys_info *ts) { - void *field = ((void *)ts) + offset; - struct tdx_module_args args = {}; - int ret; - - /* - * TDH.SYS.RD -- reads one global metadata field - * - RDX (in): the field to read - * - R8 (out): the field data - */ - args.rdx = field_id; - ret = seamcall_prerr_ret(TDH_SYS_RD, &args); - if (ret) - return ret; - - memcpy(field, &args.r8, size); + int i, ret; + + for (i = 0; i < base->count; i++) { + void *field = ((void *)ts) + base->offset + base->size * i; + u64 field_id = base->field_id + i; + struct tdx_module_args args = {}; + + /* + * TDH.SYS.RD -- reads one global metadata field + * - RDX (in): the field to read + * - RDX (out) : the next valid field ID + * - R8 (out): the field data + */ + args.rdx = field_id; + ret = seamcall_prerr_ret(TDH_SYS_RD, &args); + if (ret) + return ret; + + memcpy(field, &args.r8, base->size); + + /* field_id + 1 is invalid, the metadata array ends */ + if (args.rdx != field_id + 1) + break; + } return 0; } @@ -98,10 +116,7 @@ static int get_tdx_sys_info(struct tdx_sys_info *sysinfo) /* Populate 'tdx_sys_info' fields using the mapping structure above: */ for (i = 0; i < ARRAY_SIZE(mappings); i++) { - ret = read_sys_metadata_field(mappings[i].field_id, - mappings[i].offset, - mappings[i].size, - sysinfo); + ret = read_sys_metadata_field(&mappings[i], sysinfo); if (ret) return ret; } @@ -110,31 +125,5 @@ static int get_tdx_sys_info(struct tdx_sys_info *sysinfo) td_conf->num_cpuid_config > ARRAY_SIZE(td_conf->cpuid_config_values)) return -EINVAL; - /* - * Populate 2 special fields, td_conf.cpuid_config_leaves[] and - * td_conf.cpuid_config_values[][] - */ - for (i = 0; i < td_conf->num_cpuid_config; i++) { - ret = read_sys_metadata_field(cpuid_config_leaves.field_id + i, - cpuid_config_leaves.offset + - cpuid_config_leaves.size * i, - cpuid_config_leaves.size, - sysinfo); - if (ret) - return ret; - } - - for (i = 0; - i < td_conf->num_cpuid_config * ARRAY_SIZE(td_conf->cpuid_config_values[0]); - i++) { - ret = read_sys_metadata_field(cpuid_config_values.field_id + i, - cpuid_config_values.offset + - cpuid_config_values.size * i, - cpuid_config_values.size, - sysinfo); - if (ret) - return ret; - } - return 0; } -- 2.25.1