linux-kernel - Re: [PATCH 4/7] x86/microcode: Distinguish NMI control path on stop-machine callback

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Message-ID: <c73f1a1d-b448-49cb-acb5-3f12e8248a7c@intel.com>
Date: Thu, 29 Jan 2026 08:32:17 -0800
From: "Chang S. Bae" <chang.seok.bae@...el.com>
To: Thomas Gleixner <tglx@...nel.org>, <linux-kernel@...r.kernel.org>
CC: <x86@...nel.org>, <mingo@...hat.com>, <bp@...en8.de>,
	<dave.hansen@...ux.intel.com>, <peterz@...radead.org>, <david.kaplan@....com>
Subject: Re: [PATCH 4/7] x86/microcode: Distinguish NMI control path on
 stop-machine callback

On 1/28/2026 12:11 AM, Thomas Gleixner wrote:
> On Sun, Jan 25 2026 at 01:42, Chang S. Bae wrote:
>>   static int load_cpus_stopped(void *unused)
>>   {
>> -	if (microcode_ops->use_nmi) {
>> -		/* Enable the NMI handler and raise NMI */
>> -		this_cpu_write(ucode_ctrl.nmi_enabled, true);
>> -		apic->send_IPI(smp_processor_id(), NMI_VECTOR);
>> -	} else {
>> -		/* Just invoke the handler directly */
>> -		microcode_update_handler();
>> -	}
>> +	/* Enable the NMI handler and raise NMI */
>> +	this_cpu_write(ucode_ctrl.nmi_enabled, true);
>> +	apic->send_IPI(smp_processor_id(), NMI_VECTOR);
>> +
> 
> With this change the function name is completely bogus.

Yes, you're right. The change should stand in a sensible shape if the 
series were to stop here. I think stop_this_cpu_nmi() that you mentioned 
on patch1 sounds aligned, or maybe stop_cpu_in_nmi() like that.