On 05.07.2023 16:13, Andrew Cooper wrote:
> On 29/06/2023 4:26 pm, Alejandro Vallejo wrote:
>> diff --git a/xen/arch/x86/cpu/microcode/core.c
>> b/xen/arch/x86/cpu/microcode/core.c
>> index bec8b55db2..b620e3bfa6 100644
>> --- a/xen/arch/x86/cpu/microcode/core.c
>> +++ b/xen/arch/x86/cpu/microcode/core.c
>> @@ -867,10 +867,22 @@ int __init early_microcode_init(unsigned long
>> *module_map,
>> return -ENODEV;
>> }
>>
>> - microcode_grab_module(module_map, mbi);
>> -
>> ucode_ops.collect_cpu_info();
>>
>> + /*
>> + * Some hypervisors deliberately report a microcode revision of -1 to
>> + * mean that they will not accept microcode updates. We take the hint
>> + * and ignore the microcode interface in that case.
>> + */
>> + if ( this_cpu(cpu_sig).rev == ~0 )
>> + {
>> + printk(XENLOG_WARNING "Microcode loading disabled\n");
>
> XENLOG_INFO "Found microcode revision ~0; Disabling loading because of
> virt\n"
>
> It's normal (and not a warning) when running under other hypervisors,
Except that INFO won't be visible by default in release configurations.
Jan
> and just "loading disabled" is too little information.
>
> Happy to fix on commit. Everything else looks ok.
>
> ~Andrew
