--- old/usr/src/uts/i86pc/io/isa.c	Tue Jun  2 03:58:21 2009
+++ new/usr/src/uts/i86pc/io/isa.c	Tue Jun  2 03:58:20 2009
@@ -46,6 +46,7 @@
 #include <sys/mach_intr.h>
 #include <sys/pci.h>
 #include <sys/note.h>
+#include <sys/boot_console.h>
 #if defined(__xpv)
 #include <sys/hypervisor.h>
 #include <sys/evtchn_impl.h>
@@ -1094,15 +1095,6 @@
 
 	/* serial ports */
 	for (i = 0; i < 2; i++) {
-#if defined(__xpv)
-		/*
-		 * the hypervisor may be reserving the serial ports for console
-		 * and/or debug use.  Probe the irqs to see if they are
-		 * available.
-		 */
-		if (ec_probe_pirq(asy_intrs[i]) == 0)
-			continue; /* in use */
-#endif
 		ndi_devi_alloc_sleep(isa_dip, "asy",
 		    (pnode_t)DEVI_SID_NODEID, &xdip);
 		(void) ndi_prop_update_int_array(DDI_DEV_T_NONE, xdip,
@@ -1217,47 +1209,41 @@
 			isa_extra_count++;
 		}
 	}
-#if defined(__xpv)
+
 	/*
-	 * Check each serial port to see if it is in use by the hypervisor.
-	 * If it is in use, then remove the node from the device tree.
+	 * An asy node may have been attached via ACPI enumeration, or
+	 * directly from this file.  Check each serial port to see if it
+	 * is in use by the hypervisor.  If it is in use, then remove
+	 * the node from the device tree.
 	 */
+#if defined(__xpv)
 	i = 0;
+
 	for (xdip = ddi_get_child(isa_dip); xdip != NULL; ) {
-		int asy_intr;
+		extern int console_hypervisor_device;
 		dev_info_t *curdip;
 
 		curdip = xdip;
 		xdip = ddi_get_next_sibling(xdip);
-		if (strncmp(ddi_node_name(curdip), "asy", 3) != 0) {
-			/* skip non asy */
-			continue;
-		}
-		/*
-		 * Check if the hypervisor is using the serial port by probing
-		 * the irq and if it is using it remove the node
-		 * from the device tree
-		 */
-		asy_intr = ddi_prop_get_int(DDI_DEV_T_ANY, curdip,
-		    DDI_PROP_DONTPASS, "interrupts", -1);
-		if (asy_intr == -1) {
-			/* error */
-			continue;
-		}
 
-		if (ec_probe_pirq(asy_intr)) {
+		if (strncmp(ddi_node_name(curdip), "asy", 3) != 0)
 			continue;
-		}
-		ret = ndi_devi_free(curdip);
-		if (ret != DDI_SUCCESS)
-			cmn_err(CE_WARN,
-			    "could not remove asy%d node", i);
-		else
+
+		if ((i == 0 && console_hypervisor_device == CONS_TTYA) ||
+		    (i == 1 && console_hypervisor_device == CONS_TTYB)) {
+			ret = ndi_devi_free(curdip);
+			if (ret != DDI_SUCCESS) {
+				cmn_err(CE_WARN,
+				    "could not remove asy%d node", i);
+			}
+
 			cmn_err(CE_NOTE, "!asy%d unavailable, reserved"
-			    " to hypervisor", i);
+		    	    " to hypervisor", i);
+		}
+
 		i++;
 	}
-#endif	/* __xpv */
+#endif
 
 	psm_unmap((caddr_t)bios_data, size);
 }