linux-kernel - Re: [PATCH v2 7/7] x86/CPU/AMD: Output the AGESA version to the logs

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Message-ID: <bf23d7f1-9454-4141-93e4-57f1f930fd43@kernel.org>
Date: Wed, 17 Dec 2025 15:21:17 -0600
From: Mario Limonciello <superm1@...nel.org>
To: Yazen Ghannam <yazen.ghannam@....com>
Cc: "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
 Jean Delvare <jdelvare@...e.com>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
 Dave Hansen <dave.hansen@...ux.intel.com>, "H . Peter Anvin"
 <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 7/7] x86/CPU/AMD: Output the AGESA version to the logs

On 12/17/25 3:18 PM, Yazen Ghannam wrote:
> On Tue, Dec 16, 2025 at 06:33:54AM -0600, Mario Limonciello (AMD) wrote:
>> On AMD Zen platforms that are running AGESA, there is sometimes
>> DMI additional string for the AGESA version that can be helpful when
>> debugging an issue.  If this string is found output to kernel logs.
>>
>> Signed-off-by: Mario Limonciello (AMD) <superm1@...nel.org>
>> ---
>>   arch/x86/kernel/cpu/amd.c | 18 ++++++++++++++++++
>>   1 file changed, 18 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
>> index c19c4ee74dd1f..8f44439d3f993 100644
>> --- a/arch/x86/kernel/cpu/amd.c
>> +++ b/arch/x86/kernel/cpu/amd.c
>> @@ -1,6 +1,7 @@
>>   // SPDX-License-Identifier: GPL-2.0-only
>>   #define pr_fmt(fmt) "x86/amd: " fmt
>>   
>> +#include <linux/dmi.h>
>>   #include <linux/export.h>
>>   #include <linux/bitops.h>
>>   #include <linux/elf.h>
>> @@ -1406,3 +1407,20 @@ static __init int print_s5_reset_status_mmio(void)
>>   	return 0;
>>   }
>>   late_initcall(print_s5_reset_status_mmio);
>> +
>> +#ifdef CONFIG_DMI
>> +static __init int print_agesa_dmi_info(void)
>> +{
>> +	const struct dmi_device *dev = NULL;
>> +
>> +	while ((dev = dmi_find_device(DMI_DEV_TYPE_ADDITIONAL, NULL, dev))) {
>> +		if (!strncmp(dev->name, "AGESA", 5)) {
>> +			pr_info("%s\n", dev->name);
>> +			break;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +late_initcall(print_agesa_dmi_info);
>> +#endif
>>
> 
> The Zen check is gone. Is that intentional?
> 

No it's not, it's a good catch.  We don't have an AGESA version in 
SMBIOS data on pre-zen hardware.

I'll add in a check like we do for print_s5_reset_status_mmio() for the 
next spin.

         if (!cpu_feature_enabled(X86_FEATURE_ZEN))
                 return 0;

> If so, then I think the commit message should be tweaked to not mention
> Zen systems specifically.
> 
> I don't think this is a problem. I think it's better to keep things
> generic, if possible.
> 
> Thanks,
> Yazen