Re: [PATCH 3/8] kvm: vmx: pass MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD down to the guest

[Paolo Bonzini]

On 13/01/2018 11:16, Longpeng (Mike) wrote:
>> +	/*
>> +	 * FIXME: this is only needed until SPEC_CTRL is supported
>> +	 * by upstream Linux in cpufeatures, then it can be replaced
>> +	 * with static_cpu_has.
>> +	 */
>> +	have_spec_ctrl = cpu_has_spec_ctrl();
>> +	if (have_spec_ctrl)
>> +		pr_info("kvm: SPEC_CTRL available\n");
>> +	else
>> +		pr_info("kvm: SPEC_CTRL not available\n");
>> +
> 
> In this approach, we must reload these modules if we update the microcode later ?

I strongly suggest using early microcode update anyway.

Paolo