[Xen-changelog] Extend EVTCHNOP_alloc_unbound to allocate a specified port, if

[BitKeeper Bot <riel@xxxxxxxxxxx>]

ChangeSet 1.1674, 2005/06/05 11:11:05+01:00, kaf24@xxxxxxxxxxxxxxxxxxxx

        Extend EVTCHNOP_alloc_unbound to allocate a specified port, if
        non-zero value is passed in.
        Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>



 tools/libxc/xc_evtchn.c            |    5 +++--
 tools/python/xen/lowlevel/xc/xc.c  |    7 ++++---
 xen/common/event_channel.c         |   37 ++++++++++++++++++++++++++++---------
 xen/include/public/event_channel.h |    7 ++++---
 4 files changed, 39 insertions(+), 17 deletions(-)


diff -Nru a/tools/libxc/xc_evtchn.c b/tools/libxc/xc_evtchn.c
--- a/tools/libxc/xc_evtchn.c   2005-06-05 07:02:27 -04:00
+++ b/tools/libxc/xc_evtchn.c   2005-06-05 07:02:27 -04:00
@@ -39,8 +39,9 @@
     int         rc;
 
     op.cmd = EVTCHNOP_alloc_unbound;
-    op.u.alloc_unbound.dom = (domid_t)dom;
-   
+    op.u.alloc_unbound.dom  = (domid_t)dom;
+    op.u.alloc_unbound.port = (port != NULL) ? *port : 0;
+
     if ( (rc = do_evtchn_op(xc_handle, &op)) == 0 )
     {
         if ( port != NULL )
diff -Nru a/tools/python/xen/lowlevel/xc/xc.c 
b/tools/python/xen/lowlevel/xc/xc.c
--- a/tools/python/xen/lowlevel/xc/xc.c 2005-06-05 07:02:27 -04:00
+++ b/tools/python/xen/lowlevel/xc/xc.c 2005-06-05 07:02:27 -04:00
@@ -494,11 +494,12 @@
     XcObject *xc = (XcObject *)self;
 
     u32 dom;
-    int port;
+    int port = 0;
 
-    static char *kwd_list[] = { "dom", NULL };
+    static char *kwd_list[] = { "dom", "port", NULL };
 
-    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "i", kwd_list, &dom) )
+    if ( !PyArg_ParseTupleAndKeywords(args, kwds, "i|i", kwd_list,
+                                      &dom, &port) )
         return NULL;
 
     if ( xc_evtchn_alloc_unbound(xc->xc_handle, dom, &port) != 0 )
diff -Nru a/xen/common/event_channel.c b/xen/common/event_channel.c
--- a/xen/common/event_channel.c        2005-06-05 07:02:27 -04:00
+++ b/xen/common/event_channel.c        2005-06-05 07:02:27 -04:00
@@ -35,6 +35,8 @@
 #define evtchn_from_port(d,p) \
     (&(bucket_from_port(d,p))[(p)&(EVTCHNS_PER_BUCKET-1)])
 
+#define ERROR_EXIT(_errno) do { rc = (_errno); goto out; } while ( 0 )
+
 static int get_free_port(struct domain *d)
 {
     struct evtchn *chn;
@@ -61,30 +63,48 @@
 {
     struct evtchn *chn;
     struct domain *d = current->domain;
-    int            port;
+    int            port = alloc->port;
+    long           rc = 0;
 
     spin_lock(&d->evtchn_lock);
 
-    if ( (port = get_free_port(d)) >= 0 )
+    /* Obtain, or ensure that we already have, a valid <port>. */
+    if ( port == 0 )
     {
-        chn = evtchn_from_port(d, port);
+        if ( (port = get_free_port(d)) < 0 )
+            ERROR_EXIT(port);
+    }
+    else if ( !port_is_valid(d, port) )
+        ERROR_EXIT(-EINVAL);
+    chn = evtchn_from_port(d, port);
+
+    /* Validate channel's current state. */
+    switch ( chn->state )
+    {
+    case ECS_FREE:
         chn->state = ECS_UNBOUND;
         chn->u.unbound.remote_domid = alloc->dom;
+        break;
+
+    case ECS_UNBOUND:
+        if ( chn->u.unbound.remote_domid != alloc->dom )
+            ERROR_EXIT(-EINVAL);
+        break;
+
+    default:
+        ERROR_EXIT(-EINVAL);
     }
 
+ out:
     spin_unlock(&d->evtchn_lock);
 
-    if ( port < 0 )
-        return port;
-
     alloc->port = port;
-    return 0;
+    return rc;
 }
 
 
 static long evtchn_bind_interdomain(evtchn_bind_interdomain_t *bind)
 {
-#define ERROR_EXIT(_errno) do { rc = (_errno); goto out; } while ( 0 )
     struct evtchn *chn1, *chn2;
     struct domain *d1, *d2;
     int            port1 = bind->port1, port2 = bind->port2;
@@ -217,7 +237,6 @@
     bind->port2 = port2;
 
     return rc;
-#undef ERROR_EXIT
 }
 
 
diff -Nru a/xen/include/public/event_channel.h 
b/xen/include/public/event_channel.h
--- a/xen/include/public/event_channel.h        2005-06-05 07:02:27 -04:00
+++ b/xen/include/public/event_channel.h        2005-06-05 07:02:27 -04:00
@@ -10,15 +10,16 @@
 #define __XEN_PUBLIC_EVENT_CHANNEL_H__
 
 /*
- * EVTCHNOP_alloc_unbound: Allocate a fresh local port and prepare
- * it for binding to <dom>.
+ * EVTCHNOP_alloc_unbound: Prepare a local port for binding to <dom>.
+ * <port> may be wildcarded by setting to zero, in which case a fresh port
+ * will be allocated, and the field filled in on return.
  */
 #define EVTCHNOP_alloc_unbound    6
 typedef struct {
     /* IN parameters */
     domid_t dom;                      /*  0 */
     u16     __pad;
-    /* OUT parameters */
+    /* IN/OUT parameters */
     u32     port;                     /*  4 */
 } PACKED evtchn_alloc_unbound_t; /* 8 bytes */
 

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog