Restore known_mpsafe=false for MP-unsafe interrupt handlers.

Previously these were established with event_set_handler, which assumes
IPL_VM is MP-unsafe and anything else -- IPL_SCHED, IPL_HIGH -- is
MP-safe.  Some of these are obviously not MP-safe, e.g. xbd(4); others
may or may not be, but let's enable that intentionally, not as an
accident of what should have been a semantics-preserving API
refactoring.

Also fix xname for xbd(4) intr.

No functional change at the moment because the Xen-specific definition
of intr_establish_xname ignores these arguments, but this will matter
when we eliminate that Xen-specific definition.

Index: sys/arch/xen/xen/if_xennet_xenbus.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xen/if_xennet_xenbus.c,v
retrieving revision 1.72
diff -p -u -r1.72 if_xennet_xenbus.c
--- sys/arch/xen/xen/if_xennet_xenbus.c	6 Nov 2017 15:27:09 -0000	1.72
+++ sys/arch/xen/xen/if_xennet_xenbus.c	11 Nov 2017 07:53:11 -0000
@@ -514,8 +514,8 @@ xennet_xenbus_resume(device_t dev, const
 		goto abort_resume;
 	aprint_verbose_dev(dev, "using event channel %d\n",
 	    sc->sc_evtchn);
-	sc->sc_ih = intr_establish_xname(0, &xen_pic, sc->sc_evtchn, IST_LEVEL, IPL_NET,
-	    &xennet_handler, sc, true, device_xname(dev));
+	sc->sc_ih = intr_establish_xname(0, &xen_pic, sc->sc_evtchn, IST_LEVEL,
+	    IPL_NET, &xennet_handler, sc, false, device_xname(dev));
 	KASSERT(sc->sc_ih != NULL);
 	return true;
 
Index: sys/arch/xen/xen/xbd_xenbus.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xen/xbd_xenbus.c,v
retrieving revision 1.77
diff -p -u -r1.77 xbd_xenbus.c
--- sys/arch/xen/xen/xbd_xenbus.c	6 Nov 2017 15:27:09 -0000	1.77
+++ sys/arch/xen/xen/xbd_xenbus.c	11 Nov 2017 07:53:11 -0000
@@ -452,8 +452,8 @@ xbd_xenbus_resume(device_t dev, const pm
 
 	aprint_verbose_dev(dev, "using event channel %d\n",
 	    sc->sc_evtchn);
-	sc->sc_ih = intr_establish_xname(0, &xen_pic, sc->sc_evtchn, IST_LEVEL, IPL_BIO, &xbd_handler, sc, true, "clock");
-	
+	sc->sc_ih = intr_establish_xname(0, &xen_pic, sc->sc_evtchn, IST_LEVEL,
+	    IPL_BIO, &xbd_handler, sc, false, device_xname(dev));
 	KASSERT(sc->sc_ih != NULL);
 
 again:
Index: sys/arch/xen/xen/xbdback_xenbus.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xen/xbdback_xenbus.c,v
retrieving revision 1.64
diff -p -u -r1.64 xbdback_xenbus.c
--- sys/arch/xen/xen/xbdback_xenbus.c	6 Nov 2017 15:27:09 -0000	1.64
+++ sys/arch/xen/xen/xbdback_xenbus.c	11 Nov 2017 07:53:11 -0000
@@ -637,8 +637,9 @@ xbdback_connect(struct xbdback_instance 
 	XENPRINTF(("xbdback %s: connect evchannel %d\n", xbusd->xbusd_path, xbdi->xbdi_evtchn));
 	xbdi->xbdi_evtchn = evop.u.bind_interdomain.local_port;
 
-	xbdi->xbdi_ih = intr_establish_xname(0, &xen_pic, xbdi->xbdi_evtchn, IST_LEVEL, IPL_BIO,
-	    xbdback_evthandler, xbdi, true, xbdi->xbdi_name);
+	xbdi->xbdi_ih = intr_establish_xname(0, &xen_pic, xbdi->xbdi_evtchn,
+	    IST_LEVEL, IPL_BIO, xbdback_evthandler, xbdi, false,
+	    xbdi->xbdi_name);
 	KASSERT(xbdi->xbdi_ih != NULL);
 	aprint_verbose("xbd backend domain %d handle %#x (%d) "
 	    "using event channel %d, protocol %s\n", xbdi->xbdi_domid,
Index: sys/arch/xen/xen/xencons.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xen/xencons.c,v
retrieving revision 1.42
diff -p -u -r1.42 xencons.c
--- sys/arch/xen/xen/xencons.c	6 Nov 2017 15:27:09 -0000	1.42
+++ sys/arch/xen/xen/xencons.c	11 Nov 2017 07:53:12 -0000
@@ -233,14 +233,16 @@ xencons_resume(device_t dev, const pmf_q
 	/* dom0 console resume is required only during first start-up */
 		if (cold) {
 			evtch = bind_virq_to_evtch(VIRQ_CONSOLE);
-			ih = intr_establish_xname(0, &xen_pic, evtch, IST_LEVEL, IPL_TTY,
-			    xencons_intr, xencons_console_device, true, "xencons");
+			ih = intr_establish_xname(0, &xen_pic, evtch,
+			    IST_LEVEL, IPL_TTY, xencons_intr,
+			    xencons_console_device, false, "xencons");
 			KASSERT(ih != NULL);
 		}
 	} else {
 		evtch = xen_start_info.console_evtchn;
-		ih = intr_establish_xname(0, &xen_pic, evtch, IST_LEVEL, IPL_TTY,
-		    xencons_handler, xencons_console_device, true, "xencons");
+		ih = intr_establish_xname(0, &xen_pic, evtch,
+		    IST_LEVEL, IPL_TTY, xencons_handler,
+		    xencons_console_device, false, "xencons");
 		KASSERT(ih != NULL);
 	}
 
Index: sys/arch/xen/xen/xennetback_xenbus.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xen/xennetback_xenbus.c,v
retrieving revision 1.60
diff -p -u -r1.60 xennetback_xenbus.c
--- sys/arch/xen/xen/xennetback_xenbus.c	6 Nov 2017 15:27:09 -0000	1.60
+++ sys/arch/xen/xen/xennetback_xenbus.c	11 Nov 2017 07:53:12 -0000
@@ -551,8 +551,9 @@ xennetback_connect(struct xnetback_insta
 	xneti->xni_status = CONNECTED;
 	xen_wmb();
 
-	xneti->xni_ih = intr_establish_xname(0, &xen_pic, xneti->xni_evtchn, IST_LEVEL, IPL_NET,
-	    xennetback_evthandler, xneti, true, xneti->xni_if.if_xname);
+	xneti->xni_ih = intr_establish_xname(0, &xen_pic, xneti->xni_evtchn,
+	    IST_LEVEL, IPL_NET, xennetback_evthandler, xneti, false,
+	    xneti->xni_if.if_xname);
 	KASSERT(xneti->xni_ih != NULL);
 	xennetback_ifinit(&xneti->xni_if);
 	hypervisor_enable_event(xneti->xni_evtchn);
Index: sys/arch/xen/xenbus/xenbus_comms.c
===================================================================
RCS file: /cvsroot/src/sys/arch/xen/xenbus/xenbus_comms.c,v
retrieving revision 1.16
diff -p -u -r1.16 xenbus_comms.c
--- sys/arch/xen/xenbus/xenbus_comms.c	6 Nov 2017 15:27:09 -0000	1.16
+++ sys/arch/xen/xenbus/xenbus_comms.c	11 Nov 2017 07:53:12 -0000
@@ -222,7 +222,7 @@ xb_init_comms(device_t dev)
 	evtchn = xen_start_info.store_evtchn;
 
 	ih = intr_establish_xname(0, &xen_pic, evtchn, IST_LEVEL, IPL_TTY,
-	    wake_waiting, NULL, true, "xenbus");
+	    wake_waiting, NULL, false, "xenbus");
 
 	hypervisor_enable_event(evtchn);
 	aprint_verbose_dev(dev, "using event channel %d\n", evtchn);