Re: [PATCH 7/7] x86/microcode: Recheck IBRS features on microcode reload

From: Tim Chen
Date: Thu Jan 04 2018 - 14:10:51 EST


On 01/04/2018 10:50 AM, Borislav Petkov wrote:
> On Thu, Jan 04, 2018 at 07:34:30PM +0100, Andrea Arcangeli wrote:
>> void spec_ctrl_rescan_cpuid(void)
>> {
>> int cpu;
>>
>> if (use_ibp_disable)
>> return;
>> mutex_lock(&spec_ctrl_mutex);
>> if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL ||
>> boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
>> /* detect spec ctrl related cpuid additions */
>> init_scattered_cpuid_features(&boot_cpu_data);
>
> You don't need to noodle through all the scattered features - just the
> two bits.
>

Sure. Will update in rev 2.

Tim