KVM: vmx: handle_dr does not handle RSP correctly

The RSP register is not automatically cached, causing mov DR instruction with
RSP to fail.  Instead the regular register accessing interface should be used.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -5143,7 +5143,7 @@ static int handle_dr(struct kvm_vcpu *vcpu)
 			return 1;
 		kvm_register_write(vcpu, reg, val);
 	} else
-		if (kvm_set_dr(vcpu, dr, vcpu->arch.regs[reg]))
+		if (kvm_set_dr(vcpu, dr, kvm_register_read(vcpu, reg)))
 			return 1;
 
 	skip_emulated_instruction(vcpu);