Re: [PATCH 4/6] x86: Convert users of INTEL_FAM6_MODEL() to X86_MATCH_VFM()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 17/07/2025 8:44 am, Jan Beulich wrote:
> On 16.07.2025 19:31, Andrew Cooper wrote:
>> --- a/xen/arch/x86/acpi/cpu_idle.c
>> +++ b/xen/arch/x86/acpi/cpu_idle.c
>> @@ -583,7 +583,6 @@ bool errata_c6_workaround(void)
>>  
>>      if ( unlikely(fix_needed == -1) )
>>      {
>> -#define INTEL_FAM6_MODEL(m) { X86_VENDOR_INTEL, 6, m, X86_FEATURE_ALWAYS }
>>          /*
>>           * Errata AAJ72: EOI Transaction May Not be Sent if Software Enters
>>           * Core C6 During an Interrupt Service Routine"
>> @@ -594,12 +593,12 @@ bool errata_c6_workaround(void)
>>           * there is an EOI pending.
>>           */
>>          static const struct x86_cpu_id eoi_errata[] = {
>> -            INTEL_FAM6_MODEL(0x1a),
>> -            INTEL_FAM6_MODEL(0x1e),
>> -            INTEL_FAM6_MODEL(0x1f),
>> -            INTEL_FAM6_MODEL(0x25),
>> -            INTEL_FAM6_MODEL(0x2c),
>> -            INTEL_FAM6_MODEL(0x2f),
>> +            X86_MATCH_VFM(INTEL_NEHALEM_EP,   NULL),
>> +            X86_MATCH_VFM(INTEL_NEHALEM,      NULL),
>> +            X86_MATCH_VFM(INTEL_NEHALEM_G,    NULL),
>> +            X86_MATCH_VFM(INTEL_WESTMERE,     NULL),
>> +            X86_MATCH_VFM(INTEL_WESTMERE_EP,  NULL),
>> +            X86_MATCH_VFM(INTEL_WESTMERE_EX,  NULL),
>>              { }
>>          };
> Along the lines of a comment further down, maybe make explicit that Nehalem-EX
> is intentionally omitted here (assuming that's not in fact an oversight)?

It looks to be an oversight.  I've submitted a separate patch, so it can
be backported more easily.

In practice, it's covered by probe_c3_errata() which blanket disables C3
and C6 on Nehalem.

>
>> --- a/xen/arch/x86/cpu/intel.c
>> +++ b/xen/arch/x86/cpu/intel.c
>> @@ -382,16 +382,12 @@ static void cf_check early_init_intel(struct 
>> cpuinfo_x86 *c)
>>   */
>>  static void probe_c3_errata(const struct cpuinfo_x86 *c)
>>  {
>> -#define INTEL_FAM6_MODEL(m) { X86_VENDOR_INTEL, 6, m, X86_FEATURE_ALWAYS }
>>      static const struct x86_cpu_id models[] = {
>> -        /* Nehalem */
>> -        INTEL_FAM6_MODEL(0x1a),
>> -        INTEL_FAM6_MODEL(0x1e),
>> -        INTEL_FAM6_MODEL(0x1f),
>> -        INTEL_FAM6_MODEL(0x2e),
>> -        /* Westmere (note Westmere-EX is not affected) */
>> -        INTEL_FAM6_MODEL(0x2c),
>> -        INTEL_FAM6_MODEL(0x25),
>> +        X86_MATCH_VFM(INTEL_NEHALEM_EP,   NULL),
>> +        X86_MATCH_VFM(INTEL_NEHALEM,      NULL),
>> +        X86_MATCH_VFM(INTEL_NEHALEM_G,    NULL),
>> +        X86_MATCH_VFM(INTEL_WESTMERE,     NULL),
>> +        X86_MATCH_VFM(INTEL_WESTMERE_EP,  NULL),
>>          { }
>>      };
> You lost NEHALEM_EX here.

Oops, too much copy/paste.

>  For Westmere-EX I think the comment (part) would
> better be retained, to clarify that this isn't an oversight.

I can't find anything which looks related for Westmere EX.  I'll retain
the comment.

~Andrew