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path: root/drivers/net/xen-netback/xenbus.c
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Diffstat (limited to 'drivers/net/xen-netback/xenbus.c')
-rw-r--r--drivers/net/xen-netback/xenbus.c204
1 files changed, 171 insertions, 33 deletions
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index a53782ef154..f0358992b04 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -24,6 +24,12 @@
struct backend_info {
struct xenbus_device *dev;
struct xenvif *vif;
+
+ /* This is the state that will be reflected in xenstore when any
+ * active hotplug script completes.
+ */
+ enum xenbus_state state;
+
enum xenbus_state frontend_state;
struct xenbus_watch hotplug_status_watch;
u8 have_hotplug_status_watch:1;
@@ -33,11 +39,15 @@ static int connect_rings(struct backend_info *);
static void connect(struct backend_info *);
static void backend_create_xenvif(struct backend_info *be);
static void unregister_hotplug_status_watch(struct backend_info *be);
+static void set_backend_state(struct backend_info *be,
+ enum xenbus_state state);
static int netback_remove(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
+ set_backend_state(be, XenbusStateClosed);
+
unregister_hotplug_status_watch(be);
if (be->vif) {
kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
@@ -95,6 +105,22 @@ static int netback_probe(struct xenbus_device *dev,
goto abort_transaction;
}
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
+ "%d", sg);
+ if (err) {
+ message = "writing feature-gso-tcpv6";
+ goto abort_transaction;
+ }
+
+ /* We support partial checksum setup for IPv6 packets */
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-ipv6-csum-offload",
+ "%d", 1);
+ if (err) {
+ message = "writing feature-ipv6-csum-offload";
+ goto abort_transaction;
+ }
+
/* We support rx-copy path. */
err = xenbus_printf(xbt, dev->nodename,
"feature-rx-copy", "%d", 1);
@@ -136,6 +162,8 @@ static int netback_probe(struct xenbus_device *dev,
if (err)
goto fail;
+ be->state = XenbusStateInitWait;
+
/* This kicks hotplug scripts, so do it immediately. */
backend_create_xenvif(be);
@@ -208,24 +236,113 @@ static void backend_create_xenvif(struct backend_info *be)
kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
}
-
-static void disconnect_backend(struct xenbus_device *dev)
+static void backend_disconnect(struct backend_info *be)
{
- struct backend_info *be = dev_get_drvdata(&dev->dev);
-
if (be->vif)
xenvif_disconnect(be->vif);
}
-static void destroy_backend(struct xenbus_device *dev)
+static void backend_connect(struct backend_info *be)
{
- struct backend_info *be = dev_get_drvdata(&dev->dev);
+ if (be->vif)
+ connect(be);
+}
- if (be->vif) {
- kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
- xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
- xenvif_free(be->vif);
- be->vif = NULL;
+static inline void backend_switch_state(struct backend_info *be,
+ enum xenbus_state state)
+{
+ struct xenbus_device *dev = be->dev;
+
+ pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
+ be->state = state;
+
+ /* If we are waiting for a hotplug script then defer the
+ * actual xenbus state change.
+ */
+ if (!be->have_hotplug_status_watch)
+ xenbus_switch_state(dev, state);
+}
+
+/* Handle backend state transitions:
+ *
+ * The backend state starts in InitWait and the following transitions are
+ * allowed.
+ *
+ * InitWait -> Connected
+ *
+ * ^ \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | \ |
+ * | V V
+ *
+ * Closed <-> Closing
+ *
+ * The state argument specifies the eventual state of the backend and the
+ * function transitions to that state via the shortest path.
+ */
+static void set_backend_state(struct backend_info *be,
+ enum xenbus_state state)
+{
+ while (be->state != state) {
+ switch (be->state) {
+ case XenbusStateClosed:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateConnected:
+ pr_info("%s: prepare for reconnect\n",
+ be->dev->nodename);
+ backend_switch_state(be, XenbusStateInitWait);
+ break;
+ case XenbusStateClosing:
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateInitWait:
+ switch (state) {
+ case XenbusStateConnected:
+ backend_connect(be);
+ backend_switch_state(be, XenbusStateConnected);
+ break;
+ case XenbusStateClosing:
+ case XenbusStateClosed:
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateConnected:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateClosing:
+ case XenbusStateClosed:
+ backend_disconnect(be);
+ backend_switch_state(be, XenbusStateClosing);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ case XenbusStateClosing:
+ switch (state) {
+ case XenbusStateInitWait:
+ case XenbusStateConnected:
+ case XenbusStateClosed:
+ backend_switch_state(be, XenbusStateClosed);
+ break;
+ default:
+ BUG();
+ }
+ break;
+ default:
+ BUG();
+ }
}
}
@@ -237,40 +354,33 @@ static void frontend_changed(struct xenbus_device *dev,
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
- pr_debug("frontend state %s\n", xenbus_strstate(frontend_state));
+ pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
be->frontend_state = frontend_state;
switch (frontend_state) {
case XenbusStateInitialising:
- if (dev->state == XenbusStateClosed) {
- pr_info("%s: prepare for reconnect\n", dev->nodename);
- xenbus_switch_state(dev, XenbusStateInitWait);
- }
+ set_backend_state(be, XenbusStateInitWait);
break;
case XenbusStateInitialised:
break;
case XenbusStateConnected:
- if (dev->state == XenbusStateConnected)
- break;
- if (be->vif)
- connect(be);
+ set_backend_state(be, XenbusStateConnected);
break;
case XenbusStateClosing:
- disconnect_backend(dev);
- xenbus_switch_state(dev, XenbusStateClosing);
+ set_backend_state(be, XenbusStateClosing);
break;
case XenbusStateClosed:
- xenbus_switch_state(dev, XenbusStateClosed);
+ set_backend_state(be, XenbusStateClosed);
if (xenbus_dev_is_online(dev))
break;
- destroy_backend(dev);
/* fall through if not online */
case XenbusStateUnknown:
+ set_backend_state(be, XenbusStateClosed);
device_unregister(&dev->dev);
break;
@@ -363,7 +473,9 @@ static void hotplug_status_changed(struct xenbus_watch *watch,
if (IS_ERR(str))
return;
if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
- xenbus_switch_state(be->dev, XenbusStateConnected);
+ /* Complete any pending state change */
+ xenbus_switch_state(be->dev, be->state);
+
/* Not interested in this watch anymore. */
unregister_hotplug_status_watch(be);
}
@@ -393,12 +505,8 @@ static void connect(struct backend_info *be)
err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
hotplug_status_changed,
"%s/%s", dev->nodename, "hotplug-status");
- if (err) {
- /* Switch now, since we can't do a watch. */
- xenbus_switch_state(dev, XenbusStateConnected);
- } else {
+ if (!err)
be->have_hotplug_status_watch = 1;
- }
netif_wake_queue(be->vif->dev);
}
@@ -469,20 +577,50 @@ static int connect_rings(struct backend_info *be)
val = 0;
vif->can_sg = !!val;
+ vif->gso_mask = 0;
+ vif->gso_prefix_mask = 0;
+
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
"%d", &val) < 0)
val = 0;
- vif->gso = !!val;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV4);
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
"%d", &val) < 0)
val = 0;
- vif->gso_prefix = !!val;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV4);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_mask |= GSO_BIT(TCPV6);
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
+ "%d", &val) < 0)
+ val = 0;
+ if (val)
+ vif->gso_prefix_mask |= GSO_BIT(TCPV6);
+
+ if (vif->gso_mask & vif->gso_prefix_mask) {
+ xenbus_dev_fatal(dev, err,
+ "%s: gso and gso prefix flags are not "
+ "mutually exclusive",
+ dev->otherend);
+ return -EOPNOTSUPP;
+ }
if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
"%d", &val) < 0)
val = 0;
- vif->csum = !val;
+ vif->ip_csum = !val;
+
+ if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
+ "%d", &val) < 0)
+ val = 0;
+ vif->ipv6_csum = !!val;
/* Map the shared frame, irq etc. */
err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-23 01:08:38 +0000