On 26.02.24 09:25, isaku.yamahata@xxxxxxxxx wrote:
From: Kai Huang <kai.huang@xxxxxxxxx> For now the kernel only reads TDMR related global metadata fields for module initialization. All these fields are 16-bits, and the kernel only supports reading 16-bits fields. KVM will need to read a bunch of non-TDMR related metadata to create and run TDX guests. It's essential to provide a generic metadata read infrastructure which supports reading all 8/16/32/64 bits element sizes. Extend the metadata read to support reading all these element sizes. Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> --- arch/x86/virt/vmx/tdx/tdx.c | 59 +++++++++++++++++++++++++------------ arch/x86/virt/vmx/tdx/tdx.h | 2 -- 2 files changed, 40 insertions(+), 21 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index eb208da4ff63..a19adc898df6 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -271,23 +271,35 @@ static int read_sys_metadata_field(u64 field_id, u64 *data) return 0; }-static int read_sys_metadata_field16(u64 field_id,- int offset, - void *stbuf) +/* Return the metadata field element size in bytes */ +static int get_metadata_field_bytes(u64 field_id) { - u16 *st_member = stbuf + offset; + /* + * TDX supports 8/16/32/64 bits metadata field element sizes. + * TDX module determines the metadata element size based on the + * "element size code" encoded in the field ID (see the comment + * of MD_FIELD_ID_ELE_SIZE_CODE macro for specific encodings). + */ + return 1 << MD_FIELD_ID_ELE_SIZE_CODE(field_id); +} + +static int stbuf_read_sys_metadata_field(u64 field_id, + int offset, + int bytes, + void *stbuf) +{ + void *st_member = stbuf + offset; u64 tmp; int ret;- if (WARN_ON_ONCE(MD_FIELD_ID_ELE_SIZE_CODE(field_id) !=- MD_FIELD_ID_ELE_SIZE_16BIT)) + if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes)) return -EINVAL;ret = read_sys_metadata_field(field_id, &tmp);if (ret) return ret;- *st_member = tmp;+ memcpy(st_member, &tmp, bytes);return 0;} @@ -295,11 +307,30 @@ static int read_sys_metadata_field16(u64 field_id, struct field_mapping { u64 field_id; int offset; + int size; };#define TD_SYSINFO_MAP(_field_id, _struct, _member) \{ .field_id = MD_FIELD_ID_##_field_id, \ - .offset = offsetof(_struct, _member) } + .offset = offsetof(_struct, _member), \ + .size = sizeof(typeof(((_struct *)0)->_member)) } + +static int read_sys_metadata(struct field_mapping *fields, int nr_fields,
The first parameter should be "const struct field_mapping *fields". Juergen
Attachment:
OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key
Attachment:
OpenPGP_signature.asc
Description: OpenPGP digital signature
