kvm, tests: Use motherboard specific ports for testing

H. Peter Anvin suggested to use motherboard specific ports
for testing instead of ones well known. Thanks, Peter!

Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

main.c

@@ -134,7 +134,7 @@ exit_kvm:
 
 	if (dbgtest_mode) {
 		if (kvm->kvm_run->exit_reason == KVM_EXIT_IO &&
-			kvm->kvm_run->io.port == 0)
+			kvm->kvm_run->io.port == 0xe0)
 			fprintf(stderr, "KVM: this is an expected IO error\n");
 			goto out;
 	}

tests/pit/tick.S

@@ -4,7 +4,14 @@
 #define TIMER_FREQ	1193182
 #define TIMER_DIV(x)	((TIMER_FREQ+(x)/2)/(x))
 
-#define DBG_PORT	0
+/*
+ * hpa noted:
+ *
+ * 0xe0..0xef are "motherboard specific", but 0xe9 is
+ * used for Bochs debugging and 0xed is the Phoenix-reserved
+ * delay port
+ */
+#define DBG_PORT	0xe0
 
 #define TEST_COUNT	0x0200