diff -urp kvm-test.1/guest.s kvm-test.2/guest.s
--- kvm-test.1/guest.s	2021-04-19 23:12:10.000000000 +0200
+++ kvm-test.2/guest.s	2021-04-23 23:27:57.832780453 +0200
@@ -1,4 +1,13 @@
 _guest_start:
+	mov $0xe9, %dx
+	movb $'H', %al
+	outb %al, %dx
+	movb $'i', %al
+	outb %al, %dx
+	movb $'!', %al
+	outb %al, %dx
+	movb $'\n', %al
+	outb %al, %dx
 	movq %cr0, %rdx
 	smswl %eax
 	hlt
diff -urp kvm-test.1/test.c kvm-test.2/test.c
--- kvm-test.1/test.c	2021-04-19 23:12:10.000000000 +0200
+++ kvm-test.2/test.c	2021-04-23 23:26:11.093987426 +0200
@@ -157,6 +157,20 @@ int vm_run(int fd, struct kvm_run *r)
 	printf("EDX: %llx\n", regs.rdx); 
 
 	return 1;
+      case KVM_EXIT_IO:
+        if ((r->io.direction == KVM_EXIT_IO_OUT) && (r->io.port == 0xe9)) {
+          char *p = (char *)r;
+
+          if (r->io.size != 1) {
+          fprintf(stderr, "Bad I/O of size %d!!!\n", r->io.size);
+          } else {
+            printf("%c", *(p + r->io.data_offset));
+            fflush(stdout);
+          }
+        } else {
+          fprintf(stderr, "Bad I/O to port %d!!!\n", r->io.port);
+        }
+        break;
       default:
         fprintf(stderr,	"VM Exit reason: %d, expected KVM_EXIT_HLT (%d)\n",
                         r->exit_reason, KVM_EXIT_HLT);