Re: [dmidecode] [PATCH v2 1/1] dmioem: HPE OEM Record 199

[Jean Delvare]

Hi Jerry,

On Sat,  6 Mar 2021 18:49:48 -0700, Jerry Hoemann wrote:
> Decode HPE OEM Record 199: CPU Microcode Patch.
> 
> Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
> ---
>  dmioem.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/dmioem.c b/dmioem.c
> index 3cdfdea..08e4d91 100644
> --- a/dmioem.c
> +++ b/dmioem.c
> @@ -313,6 +313,31 @@ static int dmi_decode_hp(const struct dmi_header *h)
>  
>       switch (h->type)
>       {
> +             case 199:
> +                     /*
> +                      * Vendor Specific: CPU Microcode Patch
> +                      *
> +                      * Offset |  Name      | Width | Description
> +                      * -------------------------------------
> +                      *  0x00  | Type       | BYTE  | 0xC7, CPU Microcode 
> Patch
> +                      *  0x01  | Length     | BYTE  | Length of structure
> +                      *  0x02  | Handle     | WORD  | Unique handle
> +                      *  0x04  | Patch Info | Varies| { <DWORD: ID, DWORD 
> Date, DWORD CPUID> ...}
> +                      */
> +                     pr_handle_name("%s ProLiant CPU Microcode Patch Support 
> Info", company);
> +
> +                     for (ptr = 0x4; ptr + 12 <= h->length; ptr += 12) {
> +                             const u8 *cpuid = data + ptr + 2 * 4;
> +                             u32 date;
> +
> +                             dmi_print_cpuid(pr_attr, "CPU ID", cpuid_type, 
> cpuid);
> +                             date = DWORD(data + ptr + 4);
> +                             pr_subattr("Date", "%04x-%02x-%02x",
> +                                     date & 0xffff, (date >> 24) & 0xff, 
> (date >> 16) & 0xff);
> +                             pr_subattr("Patch", "0x%X",  DWORD(data + ptr));
> +                     }
> +                     break;
> +
>               case 203:
>                       /*
>                        * Vendor Specific: HP Device Correlation Record

I like it very much, thanks.

I tested it on my samples. The output makes sense for all Intel-based
systems. However for AMD-based systems, the CPU ID signature makes
little sense and doesn't match the installed CPU model. For example:

Handle 0x0003, DMI type 199, 28 bytes
HPE ProLiant CPU Microcode Patch Support Info
        CPU ID: Family 0, Model 1, Stepping 2
                Date: 2018-02-09
                Patch: 0x8001227
        CPU ID: Family 0, Model 1, Stepping 1
                Date: 2017-07-14
                Patch: 0x8001129

Handle 0x0084, DMI type 4, 48 bytes
Processor Information
        Socket Designation: Proc 1
        Type: Central Processor
        Family: Zen
        Manufacturer: Advanced Micro Devices, Inc.
        ID: 12 0F 80 00 FF FB 8B 17
        Signature: Family 23, Model 1, Stepping 2
        (...)
        Version: AMD EPYC 7451 24-Core Processor
        (...)

That's kind of confusing. Whatever is encoded in the CPU ID field, it
doesn't look like an actual CPUID number. Any idea?

-- 
Jean Delvare
SUSE L3 Support