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

commands/service/service.c

@@ -1074,6 +1074,7 @@ struct
 	{ "GETREF",		VM_GETREF },
 	{ "RS_SET_PRIV",	VM_RS_SET_PRIV },
 	{ "QUERY_EXIT",		VM_QUERY_EXIT },
+	{ "WATCH_EXIT",		VM_WATCH_EXIT },
 	{ "NOTIFY_SIG",		VM_NOTIFY_SIG },
 	{ "INFO",		VM_INFO },
 	{ "RS_UPDATE",		VM_RS_UPDATE },

common/include/minix/com.h

@@ -1071,8 +1071,11 @@
 #		define VM_RS_MEM_PIN	    0	/* pin memory */
 #		define VM_RS_MEM_MAKE_VM    1	/* make VM instance */
 
+#define VM_WATCH_EXIT		(VM_RQ_BASE+43)
+#	define VM_WE_EP		m1_i1
+
 /* Total. */
-#define NR_VM_CALLS				43
+#define NR_VM_CALLS				44
 #define VM_CALL_MASK_SIZE			BITMAP_CHUNKS(NR_VM_CALLS)
 
 /* not handled as a normal VM call, thus at the end of the reserved rage */

common/include/minix/vm.h

@@ -26,7 +26,8 @@ _PROTOTYPE( int vm_notify_sig, (endpoint_t ep, endpoint_t ipc_ep));
 _PROTOTYPE( int vm_set_priv, (int procnr, void *buf));
 _PROTOTYPE( int vm_update, (endpoint_t src_e, endpoint_t dst_e));
 _PROTOTYPE( int vm_memctl, (endpoint_t ep, int req));
-_PROTOTYPE( int vm_query_exit, (int *endpt));
+_PROTOTYPE( int vm_query_exit, (endpoint_t *endpt));
+_PROTOTYPE( int vm_watch_exit, (endpoint_t ep));
 _PROTOTYPE( int vm_forgetblock, (u64_t id));
 _PROTOTYPE( void vm_forgetblocks, (void));
 _PROTOTYPE( int vm_yield_block_get_block, (u64_t yieldid, u64_t getid,

etc/system.conf

@@ -520,25 +520,6 @@ service amddev
 	uid	0;
 };
 
-service ipc
-{
-	system
-		UMAP		# 14
-		VIRCOPY         # 15
-		;
-	uid     0;
-	ipc
-		SYSTEM USER pm rs log tty ds vm
-		;
-	vm
-		REMAP
-		SHM_UNMAP
-		GETPHYS
-		GETREF
-		QUERY_EXIT
-		;
-};
-
 service osscore
 {
 	system

lib/libc/other/_vm_query_exit.c

@@ -22,3 +22,14 @@ PUBLIC int vm_query_exit(int *endpt)
 	*endpt = m.VM_QUERY_RET_PT;
 	return (m.VM_QUERY_IS_MORE ? 1 : 0);
 }
+
+PUBLIC int vm_watch_exit(endpoint_t ep)
+{
+	message m;
+	int r;
+
+	memset(&m, 0, sizeof(m));
+	m.VM_WE_EP = ep;
+	return _syscall(VM_PROC_NR, VM_WATCH_EXIT, &m);
+}
+

servers/ipc/Makefile

@@ -8,5 +8,8 @@ LDADD+=	-lsys
 MAN=
 
 BINDIR?= /usr/sbin
+FILES=ipc.conf
+FILESNAME=ipc
+FILESDIR= /etc/system.conf.d
 
 .include <minix.service.mk>

servers/ipc/ipc.conf

@@ -0,0 +1,19 @@
+service ipc
+{
+	system
+		UMAP		# 14
+		VIRCOPY         # 15
+		;
+	uid     0;
+	ipc
+		SYSTEM USER pm rs log tty ds vm
+		;
+	vm
+		REMAP
+		SHM_UNMAP
+		GETPHYS
+		GETREF
+		QUERY_EXIT
+		WATCH_EXIT
+		;
+};

servers/ipc/main.c

@@ -64,6 +64,14 @@ PUBLIC int main(int argc, char *argv[])
 
 		/* dispatch messages */
 		for (i = 0; i < SIZE(ipc_calls); i++) {
+			/* If any process does an IPC call,
+			 * we have to know about it exiting.
+			 * Tell VM to watch it for us.
+			 */
+			if(vm_watch_exit(m.m_source) != OK) {
+				printf("IPC: watch failed on %d\n", m.m_source);
+			}
+
 			if (ipc_calls[i].type == call_type) {
 				int result;
 

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