Re: [PATCH v2 09/14] platform/x86/intel/ifs: Use generic microcode headers and functions

Hans de Goede
2022-11-10T21:13:03Z

Hi all,

On 11/7/22 23:53, Jithu Joseph wrote:
> Existing implementation (broken) of IFS used a header format (for IFS
> test images) which was very similar to microcode format, but didn’t
> accommodate extended signatures. This meant same IFS test image had to
> be duplicated for different steppings and the validation code in the
> driver was only looking at the primary header parameters. Going forward
> IFS test image headers has been tweaked to become fully compatible with
> microcode format.
>
> Newer IFS test image headers will use microcode_header_intel->hdrver = 2,
> so as to distinguish it from microcode images and older IFS test images.
>
> In light of the above, use struct microcode_header_intel directly in
> IFS driver instead of duplicating into a separate ifs_header structure.
> Further use existing microcode_sanity_check() and find_matching_signature()
> directly instead of implementing separate ones within the driver.
>
> More IFS specific checks will be added subsequently.
>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans

> ---
> arch/x86/include/asm/microcode_intel.h | 1 +
> drivers/platform/x86/intel/ifs/load.c | 102 +++++--------------------
> 2 files changed, 20 insertions(+), 83 deletions(-)
>
> diff --git a/arch/x86/include/asm/microcode_intel.h b/arch/x86/include/asm/microcode_intel.h
> index 0ff4545f72d2..f905238748fc 100644
> --- a/arch/x86/include/asm/microcode_intel.h
> +++ b/arch/x86/include/asm/microcode_intel.h
> @@ -43,6 +43,7 @@ struct extended_sigtable {
> #define EXT_HEADER_SIZE (sizeof(struct extended_sigtable))
> #define EXT_SIGNATURE_SIZE (sizeof(struct extended_signature))
> #define MICROCODE_HEADER_VER_UCODE 1
> +#define MICROCODE_HEADER_VER_IFS 2
>
> #define get_totalsize(mc) \
> (((struct microcode_intel *)mc)->hdr.datasize ? \
> diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
> index 60ba5a057f91..7c0d8602817b 100644
> --- a/drivers/platform/x86/intel/ifs/load.c
> +++ b/drivers/platform/x86/intel/ifs/load.c
> @@ -8,22 +8,8 @@
>
> #include "ifs.h"
>
> -struct ifs_header {
> - u32 header_ver;
> - u32 blob_revision;
> - u32 date;
> - u32 processor_sig;
> - u32 check_sum;
> - u32 loader_rev;
> - u32 processor_flags;
> - u32 metadata_size;
> - u32 total_size;
> - u32 fusa_info;
> - u64 reserved;
> -};
> -
> -#define IFS_HEADER_SIZE (sizeof(struct ifs_header))
> -static struct ifs_header *ifs_header_ptr; /* pointer to the ifs image header */
> +#define IFS_HEADER_SIZE (sizeof(struct microcode_header_intel))
> +static struct microcode_header_intel *ifs_header_ptr; /* pointer to the ifs image header */
> static u64 ifs_hash_ptr; /* Address of ifs metadata (hash) */
> static u64 ifs_test_image_ptr; /* 256B aligned address of test pattern */
> static DECLARE_COMPLETION(ifs_done);
> @@ -150,33 +136,18 @@ static void copy_hashes_authenticate_chunks(struct work_struct *work)
> */
> static int scan_chunks_sanity_check(struct device *dev)
> {
> - int metadata_size, curr_pkg, cpu, ret = -ENOMEM;
> struct ifs_data *ifsd = ifs_get_data(dev);
> + int curr_pkg, cpu, ret = -ENOMEM;
> bool *package_authenticated;
> struct ifs_work local_work;
> - char *test_ptr;
>
> package_authenticated = kcalloc(topology_max_packages(), sizeof(bool), GFP_KERNEL);
> if (!package_authenticated)
> return ret;
>
> - metadata_size = ifs_header_ptr->metadata_size;
>
> - /* Spec says that if the Meta Data Size = 0 then it should be treated as 2000 */
> - if (metadata_size == 0)
> - metadata_size = 2000;
> -
> - /* Scan chunk start must be 256 byte aligned */
> - if ((metadata_size + IFS_HEADER_SIZE) % 256) {
> - dev_err(dev, "Scan pattern offset within the binary is not 256 byte aligned\n");
> - return -EINVAL;
> - }
> -
> - test_ptr = (char *)ifs_header_ptr + IFS_HEADER_SIZE + metadata_size;
> ifsd->loading_error = false;
> -
> - ifs_test_image_ptr = (u64)test_ptr;
> - ifsd->loaded_version = ifs_header_ptr->blob_revision;
> + ifsd->loaded_version = ifs_header_ptr->rev;
>
> /* copy the scan hash and authenticate per package */
> cpus_read_lock();
> @@ -203,67 +174,33 @@ static int scan_chunks_sanity_check(struct device *dev)
> return ret;
> }
>
> -static int ifs_sanity_check(struct device *dev,
> - const struct microcode_header_intel *mc_header)
> +static int ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
> {
> - unsigned long total_size, data_size;
> - u32 sum, *mc;
> -
> - total_size = get_totalsize(mc_header);
> - data_size = get_datasize(mc_header);
> + struct ucode_cpu_info uci;
>
> - if ((data_size + MC_HEADER_SIZE > total_size) || (total_size % sizeof(u32))) {
> - dev_err(dev, "bad ifs data file size.\n");
> + /* Provide a specific error message when loading an older/unsupported image */
> + if (data->hdrver != MICROCODE_HEADER_VER_IFS) {
> + dev_err(dev, "Header version %d not supported\n", data->hdrver);
> return -EINVAL;
> }
>
> - if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
> - dev_err(dev, "invalid/unknown ifs update format.\n");
> + if (intel_microcode_sanity_check((void *)data, true, MICROCODE_HEADER_VER_IFS)) {
> + dev_err(dev, "sanity check failed\n");
> return -EINVAL;
> }
>
> - mc = (u32 *)mc_header;
> - sum = 0;
> - for (int i = 0; i < total_size / sizeof(u32); i++)
> - sum += mc[i];
> + intel_cpu_collect_info(&uci);
>
> - if (sum) {
> - dev_err(dev, "bad ifs data checksum, aborting.\n");
> + if (!intel_find_matching_signature((void *)data,
> + uci.cpu_sig.sig,
> + uci.cpu_sig.pf)) {
> + dev_err(dev, "cpu signature, processor flags not matching\n");
> return -EINVAL;
> }
>
> return 0;
> }
>
> -static bool find_ifs_matching_signature(struct device *dev, struct ucode_cpu_info *uci,
> - const struct microcode_header_intel *shdr)
> -{
> - unsigned int mc_size;
> -
> - mc_size = get_totalsize(shdr);
> -
> - if (!mc_size || ifs_sanity_check(dev, shdr) < 0) {
> - dev_err(dev, "ifs sanity check failure\n");
> - return false;
> - }
> -
> - if (!intel_cpu_signatures_match(uci->cpu_sig.sig, uci->cpu_sig.pf, shdr->sig, shdr->pf)) {
> - dev_err(dev, "ifs signature, pf not matching\n");
> - return false;
> - }
> -
> - return true;
> -}
> -
> -static bool ifs_image_sanity_check(struct device *dev, const struct microcode_header_intel *data)
> -{
> - struct ucode_cpu_info uci;
> -
> - intel_cpu_collect_info(&uci);
> -
> - return find_ifs_matching_signature(dev, &uci, data);
> -}
> -
> /*
> * Load ifs image. Before loading ifs module, the ifs image must be located
> * in /lib/firmware/intel/ifs and named as {family/model/stepping}.{testname}.
> @@ -284,12 +221,11 @@ void ifs_load_firmware(struct device *dev)
> goto done;
> }
>
> - if (!ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data)) {
> - dev_err(dev, "ifs header sanity check failed\n");
> + ret = ifs_image_sanity_check(dev, (struct microcode_header_intel *)fw->data);
> + if (ret)
> goto release;
> - }
>
> - ifs_header_ptr = (struct ifs_header *)fw->data;
> + ifs_header_ptr = (struct microcode_header_intel *)fw->data;
> ifs_hash_ptr = (u64)(ifs_header_ptr + 1);
>
> ret = scan_chunks_sanity_check(dev);