Index: sys/dev/virtio/pci/virtio_pci.c
===================================================================
--- sys/dev/virtio/pci/virtio_pci.c
+++ sys/dev/virtio/pci/virtio_pci.c
@@ -67,6 +67,7 @@
 
 struct vtpci_softc {
 	device_t			 vtpci_dev;
+	int				 vtpci_res_type;
 	struct resource			*vtpci_res;
 	struct resource			*vtpci_msix_res;
 	uint64_t			 vtpci_features;
@@ -285,11 +286,22 @@
 	pci_enable_busmaster(dev);
 
 	rid = PCIR_BAR(0);
+	sc->vtpci_res_type = SYS_RES_IOPORT;
 	sc->vtpci_res = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &rid,
 	    RF_ACTIVE);
 	if (sc->vtpci_res == NULL) {
-		device_printf(dev, "cannot map I/O space\n");
-		return (ENXIO);
+		/*
+		 * We should try harder as the common configuration structure is
+		 * possible to be in memory space.
+		 */
+		rid = PCIR_BAR(0);
+		sc->vtpci_res_type = SYS_RES_MEMORY;
+		sc->vtpci_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
+		    RF_ACTIVE);
+		if (sc->vtpci_res == NULL) {
+			device_printf(dev, "cannot map I/O nor memory space\n");
+			return (ENXIO);
+		}
 	}
 
 	if (pci_find_cap(dev, PCIY_MSI, NULL) != 0)
@@ -347,7 +359,7 @@
 	}
 
 	if (sc->vtpci_res != NULL) {
-		bus_release_resource(dev, SYS_RES_IOPORT, PCIR_BAR(0),
+		bus_release_resource(dev, sc->vtpci_res_type, PCIR_BAR(0),
 		    sc->vtpci_res);
 		sc->vtpci_res = NULL;
 	}