[PATCH v2 08/14] platform/x86/intel/ifs: Add metadata support

Jithu Joseph
2022-11-07T22:55:25Z

From: Ashok Raj <ashok.raj@intel.com>

One of the existing reserved fields in microcode header has been
allocated to indicate the size for metadata structures.

The metadata section within microcode header is as shown below:

Microcode Format
+----------------------+ Base
|Header Version |
+----------------------+
|Update revision |
+----------------------+
|Date DDMMYYYY |
+----------------------+
|Sig |
+----------------------+
|Checksum |
+----------------------+
|Loader Version |
+----------------------+
|Processor Flags |
+----------------------+
|Data Size |
+----------------------+
|Total Size |
+----------------------+
|Meta Size |
+----------------------+
|Reserved |
+----------------------+
|Reserved |
+----------------------+ Base+48
| |
| |
| |
| |
| Microcode |
| |
| Data |
| |
| |
+----------------------+ Base+48+data_size-
| | meta_size
| Meta Data |
| structure(s) |
| |
+----------------------+ Base+48+data_size
| Extended Signature |
| Table |
| |
| |
| |
| |
| |
+----------------------+ Base+total_size

Add an accessor function which will return a pointer to the
start of a specific meta_type being queried.

In subsequent patches, IFS test image file (which reuse microcode header
format) will make use of metadata section.

Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
---
drivers/platform/x86/intel/ifs/load.c | 32 +++++++++++++++++++++++++++
1 file changed, 32 insertions(+)

diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 89ce265887ea..60ba5a057f91 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -44,6 +44,38 @@ static const char * const scan_authentication_status[] = {
[2] = "Chunk authentication error. The hash of chunk did not match expected value"
};

+#define META_TYPE_END (0)
+
+struct metadata_header {
+ unsigned int type;
+ unsigned int blk_size;
+};
+
+static struct metadata_header *ifs_find_meta_data(void *ucode, unsigned int meta_type)
+{
+ struct metadata_header *meta_header;
+ unsigned long data_size, total_meta;
+ unsigned long meta_size = 0;
+
+ data_size = get_datasize(ucode);
+ total_meta = ((struct microcode_intel *)ucode)->hdr.metasize;
+
+ if (!total_meta)
+ return NULL;
+
+ meta_header = (ucode + MC_HEADER_SIZE + data_size) - total_meta;
+
+ while ((meta_header->type != META_TYPE_END) && meta_header->blk_size &&
+ meta_size < total_meta) {
+ meta_size += meta_header->blk_size;
+ if (meta_header->type == meta_type)
+ return meta_header;
+
+ meta_header = (void *)meta_header + meta_header->blk_size;
+ }
+ return NULL;
+}
+
/*
* To copy scan hashes and authenticate test chunks, the initiating cpu must point
* to the EDX:EAX to the test image in linear address.
--
2.25.1