Date:   Thu, 10 Nov 2022 22:11:56 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Jithu Joseph <jithu.joseph@...el.com>, markgross@...nel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
        dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
        gregkh@...uxfoundation.org, ashok.raj@...el.com,
        tony.luck@...el.com, linux-kernel@...r.kernel.org,
        platform-driver-x86@...r.kernel.org, patches@...ts.linux.dev,
        ravi.v.shankar@...el.com, thiago.macieira@...el.com,
        athenas.jimenez.gonzalez@...el.com, sohil.mehta@...el.com
Subject: Re: [PATCH v2 09/14] platform/x86/intel/ifs: Use generic microcode
 headers and functions

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@...el.com>
> Signed-off-by: Jithu Joseph <jithu.joseph@...el.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@...hat.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);

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