libxl: call hotplug scripts for nic devices from libxl

Since most of the needed work is already done in previous patches,
this patch only contains the necessary code to call hotplug scripts
for nic devices, that should be called when the device is added or
removed from a guest.

Added another parameter to libxl__get_hotplug_script_info, that is
used to know the number of times hotplug scripts have been called for
that device. This is currently used by IOEMU nics on Linux.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson<ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 56 insertions, 4 deletions

diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index a80dee846f..da0c3ea7c8 100644
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -102,6 +102,31 @@ out:
     return numdevs;
 }
 
+int libxl__nic_type(libxl__gc *gc, libxl__device *dev, libxl_nic_type *nictype)
+{
+    char *snictype, *be_path;
+    int rc = 0;
+
+    be_path = libxl__device_backend_path(gc, dev);
+    snictype = libxl__xs_read(gc, XBT_NULL,
+                              GCSPRINTF("%s/%s", be_path, "type"));
+    if (!snictype) {
+        LOGE(ERROR, "unable to read nictype from %s", be_path);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+    rc = libxl_nic_type_from_string(snictype, nictype);
+    if (rc) {
+        LOGE(ERROR, "unable to parse nictype from %s", be_path);
+        goto out;
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 int libxl__device_generic_add(libxl__gc *gc, xs_transaction_t t,
         libxl__device *device, char **bents, char **fents)
 {
@@ -638,6 +663,8 @@ static void device_hotplug_child_death_cb(libxl__egc *egc,
 
 static void device_hotplug_done(libxl__egc *egc, libxl__ao_device *aodev);
 
+static void device_hotplug_clean(libxl__gc *gc, libxl__ao_device *aodev);
+
 void libxl__wait_device_connection(libxl__egc *egc, libxl__ao_device *aodev)
 {
     STATE_AO_GC(aodev->ao);
@@ -850,7 +877,8 @@ static void device_hotplug(libxl__egc *egc, libxl__ao_device *aodev)
     /* Check if we have to execute hotplug scripts for this device
      * and return the necessary args/env vars for execution */
     hotplug = libxl__get_hotplug_script_info(gc, aodev->dev, &args, &env,
-                                             aodev->action);
+                                             aodev->action,
+                                             aodev->num_exec);
     switch (hotplug) {
     case 0:
         /* no hotplug script to execute */
@@ -930,6 +958,8 @@ static void device_hotplug_child_death_cb(libxl__egc *egc,
     char *be_path = libxl__device_backend_path(gc, aodev->dev);
     char *hotplug_error;
 
+    device_hotplug_clean(gc, aodev);
+
     if (status) {
         libxl_report_child_exitstatus(CTX, LIBXL__LOG_ERROR,
                                       aodev->what, pid, status);
@@ -938,8 +968,25 @@ static void device_hotplug_child_death_cb(libxl__egc *egc,
         if (hotplug_error)
             LOG(ERROR, "script: %s", hotplug_error);
         aodev->rc = ERROR_FAIL;
+        if (aodev->action == DEVICE_CONNECT)
+            /*
+             * Only fail on device connection, on disconnection
+             * ignore error, and continue with the remove process
+             */
+             goto error;
     }
 
+    /* Increase num_exec and call hotplug scripts again if necessary
+     * If no more executions are needed, device_hotplug will call
+     * device_hotplug_done breaking the loop.
+     */
+    aodev->num_exec++;
+    device_hotplug(egc, aodev);
+
+    return;
+
+error:
+    assert(aodev->rc);
     device_hotplug_done(egc, aodev);
 }
 
@@ -951,9 +998,7 @@ static void device_hotplug_done(libxl__egc *egc, libxl__ao_device *aodev)
     xs_transaction_t t = 0;
     int rc;
 
-    /* Clean events and check reentrancy */
-    libxl__ev_time_deregister(gc, &aodev->timeout);
-    assert(!libxl__ev_child_inuse(&aodev->child));
+    device_hotplug_clean(gc, aodev);
 
     /* Clean xenstore if it's a disconnection */
     if (aodev->action == DEVICE_DISCONNECT) {
@@ -975,6 +1020,13 @@ out:
     return;
 }
 
+static void device_hotplug_clean(libxl__gc *gc, libxl__ao_device *aodev)
+{
+    /* Clean events and check reentrancy */
+    libxl__ev_time_deregister(gc, &aodev->timeout);
+    assert(!libxl__ev_child_inuse(&aodev->child));
+}
+
 static void devices_remove_callback(libxl__egc *egc, libxl__ao_devices *aodevs,
                                     int rc)
 {