vm/ipc: only report signals when it matters to ipc

. ipc wants to know about processes that get
	  signals, so that it can break blocking ipc operations
	. doing it for every single signal is wasteful
	  and causes the annoying 'no slot for signals' message
	. this fix tells vm on a per-process basis it (ipc)
	  wants to be notified, i.e. only when it does any ipc calls
	. move ipc config to separate config file while we're at it

servers/vm/main.c

@@ -365,6 +365,7 @@ PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
 	CALLMAP(VM_GETREF, do_get_refcount);
 	CALLMAP(VM_INFO, do_info);
 	CALLMAP(VM_QUERY_EXIT, do_query_exit);
+	CALLMAP(VM_WATCH_EXIT, do_watch_exit);
 	CALLMAP(VM_FORGETBLOCKS, do_forgetblocks);
 	CALLMAP(VM_FORGETBLOCK, do_forgetblock);
 	CALLMAP(VM_YIELDBLOCKGETBLOCK, do_yieldblockgetblock);

servers/vm/proto.h

@@ -207,5 +207,6 @@ _PROTOTYPE(int do_rs_memctl, (message *m));
 
 /* queryexit.c */
 _PROTOTYPE(int do_query_exit, (message *m));
+_PROTOTYPE(int do_watch_exit, (message *m));
 _PROTOTYPE(int do_notify_sig, (message *m));
 _PROTOTYPE(void init_query_exit, (void));

servers/vm/queryexit.c

@@ -67,10 +67,19 @@ PUBLIC int do_query_exit(message *m)
  *===========================================================================*/
 PUBLIC int do_notify_sig(message *m)
 {
-	int i, avails = 0;
+	int i, avails = 0, p;
 	endpoint_t ep = m->VM_NOTIFY_SIG_ENDPOINT;
 	endpoint_t ipc_ep = m->VM_NOTIFY_SIG_IPC;
 	int r;
+	struct vmproc *vmp;
+	int pslot;
+
+	if(vm_isokendpt(ep, &pslot) != OK) return ESRCH;
+	vmp = &vmproc[pslot];
+
+	/* Only record the event if we've been asked to report it. */
+	if(!(vmp->vm_flags & VMF_WATCHEXIT))
+		return OK;
 
 	for (i = 0; i < NR_PROCS; i++) {
 		/* its signal is already here */
@@ -80,7 +89,7 @@ PUBLIC int do_notify_sig(message *m)
 			avails++;
 	}
 	if (!avails) {
-		/* no slot for signals, impossible */
+		/* no slot for signals, unlikely */
 		printf("VM: no slot for signals!\n");
 		return ENOMEM;
 	}
@@ -106,6 +115,21 @@ out:
 	return OK;
 }
 
+/*===========================================================================*
+ *				do_watch_exit				     *
+ *===========================================================================*/
+PUBLIC int do_watch_exit(message *m)
+{
+	endpoint_t e = m->VM_WE_EP;
+	struct vmproc *vmp;
+	int p;
+	if(vm_isokendpt(e, &p) != OK) return ESRCH;
+	vmp = &vmproc[p];
+	vmp->vm_flags |= VMF_WATCHEXIT;
+
+	return OK;
+}
+
 /*===========================================================================*
  *				init_query_exit				     *
  *===========================================================================*/

servers/vm/vmproc.h

@@ -65,5 +65,6 @@ struct vmproc {
 #define VMF_HAS_DMA	0x010	/* Process directly or indirectly granted
 				 * DMA buffers.
 				 */
+#define VMF_WATCHEXIT	0x020	/* Store in queryexit table */
 
 #endif