On 24.07.2023 18:52, Alejandro Vallejo wrote:
> Some hypervisors report ~0 as the microcode revision to mean "don't issue
> microcode updates". Ignore the microcode loading interface in that case.
>
> Signed-off-by: Alejandro Vallejo <alejandro.vall...@cloud.com>
> Reviewed-by: Jan Beulich <jbeul...@suse.com>
Hmm.
> --- a/xen/arch/x86/cpu/microcode/core.c
> +++ b/xen/arch/x86/cpu/microcode/core.c
> @@ -867,10 +867,23 @@ 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_INFO "Microcode loading disabled due to: %s",
While we have tentatively agreed to adjust what _will_ be emitted by
default (subject to suitable justification in that change's
description), such a patch is yet to be sent. As it stands this message
will be invisible by default.
> + "HW toggle");
With the comment talking about hypervisors, what is this string supposed
to tell an observer of the message in a log file?
Jan
