Re: [PATCH v2 4/4] KVM: Do compatibility checks on hotplugged CPUs

[Sean Christopherson]

On Tue, Jan 18, 2022, Chao Gao wrote:
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 528741601122..83f87fb1fa0a 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -4858,7 +4858,13 @@ static void hardware_enable_nolock(void *junk)
>  
>  static int kvm_online_cpu(unsigned int cpu)
>  {
> -	int ret = 0;
> +	int ret;
> +
> +	ret = kvm_arch_check_processor_compat();
> +	if (ret) {
> +		pr_warn("kvm: CPU%d is incompatible with online CPUs", cpu);

Hmm, I'd say omit the pr_warn() here too and instead add a pr_err() for the
setup_vmcs_config() path in vmx_check_processor_compat().

> +		return ret;
> +	}