static int handle_set_cr4(struct kvm_vcpu *vcpu, unsigned long val)
{
	if (is_guest_mode(vcpu)) {
		struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
		unsigned long orig_val = val;

		/* analogously to handle_set_cr0 */
		val = (val & ~vmcs12->cr4_guest_host_mask) |
			(vmcs12->guest_cr4 & vmcs12->cr4_guest_host_mask);
		if (kvm_set_cr4(vcpu, val))
			return 1;
		vmcs_writel(CR4_READ_SHADOW, orig_val);
		return 0;
	} else
		return kvm_set_cr4(vcpu, val);
}
Unknown