libxl: add FreeBSD OS support

Create a new libxl_freebsd.c file that contains OS-specific bits used
by libxl.

This currently defines which backend to use to handle disks, and
which hotplug scripts to execute.

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

tools/libxl/Makefile

@@ -52,10 +52,14 @@ else
 ifeq ($(CONFIG_Linux),y)
 LIBXL_OBJS-y += libxl_linux.o
 else
+ifeq ($(CONFIG_FreeBSD),y)
+LIBXL_OBJS-y += libxl_freebsd.o
+else
 $(error Your Operating System is not supported by libxenlight, \
 please check libxl_linux.c and libxl_netbsd.c to see how to get it ported)
 endif
 endif
+endif
 
 ifeq ($(FLEX),)
 %.c %.h:: %.l

tools/libxl/libxl_freebsd.c

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2014
+ * Author Roger Pau Monne <roger.pau@entel.upc.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl_osdeps.h" /* must come before any other headers */
+
+#include "libxl_internal.h"
+
+int libxl__try_phy_backend(mode_t st_mode)
+{
+    if (S_ISREG(st_mode) || S_ISBLK(st_mode) || S_ISCHR(st_mode))
+        return 1;
+
+    return 0;
+}
+
+char *libxl__devid_to_localdev(libxl__gc *gc, int devid)
+{
+    /* TODO */
+    return NULL;
+}
+
+/* Hotplug scripts caller functions */
+static int libxl__hotplug_env_nic(libxl__gc *gc, libxl__device *dev, char ***env,
+                                  int num_exec)
+{
+    int nr = 0;
+    const int arraysize = 5;
+    libxl_nic_type type;
+
+    assert(dev->backend_kind == LIBXL__DEVICE_KIND_VIF);
+
+    /*
+     * On the first pass the PV interface is added to the bridge,
+     * on the second pass the tap interface will also be added.
+     */
+    type = num_exec == 0 ? LIBXL_NIC_TYPE_VIF : LIBXL_NIC_TYPE_VIF_IOEMU;
+
+    GCNEW_ARRAY(*env, arraysize);
+    (*env)[nr++] = "iface_dev";
+    (*env)[nr++] = (char *) libxl__device_nic_devname(gc, dev->domid,
+                                                      dev->devid, type);
+    (*env)[nr++] = "emulated";
+    (*env)[nr++] = type == LIBXL_NIC_TYPE_VIF_IOEMU ? "1" : "0";
+    (*env)[nr++] = NULL;
+    assert(nr == arraysize);
+
+    return 0;
+}
+
+static int libxl__hotplug_nic(libxl__gc *gc, libxl__device *dev, char ***args,
+                              libxl__device_action action)
+{
+    char *be_path = libxl__device_backend_path(gc, dev);
+    char *script;
+    int nr = 0, rc = 0, arraysize = 4;
+
+    assert(dev->backend_kind == LIBXL__DEVICE_KIND_VIF);
+
+    script = libxl__xs_read(gc, XBT_NULL,
+                            GCSPRINTF("%s/%s", be_path, "script"));
+    if (!script) {
+        LOGEV(ERROR, errno, "unable to read script from %s", be_path);
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    GCNEW_ARRAY(*args, arraysize);
+    (*args)[nr++] = script;
+    (*args)[nr++] = be_path;
+    (*args)[nr++] = GCSPRINTF("%s", action == LIBXL__DEVICE_ACTION_ADD ?
+                                    "add" : "remove");
+    (*args)[nr++] = NULL;
+    assert(nr == arraysize);
+
+out:
+    return rc;
+}
+
+int libxl__get_hotplug_script_info(libxl__gc *gc, libxl__device *dev,
+                                   char ***args, char ***env,
+                                   libxl__device_action action,
+                                   int num_exec)
+{
+    libxl_nic_type nictype;
+    int rc;
+
+    if (dev->backend_kind != LIBXL__DEVICE_KIND_VIF || num_exec == 2)
+        return 0;
+
+    rc = libxl__nic_type(gc, dev, &nictype);
+    if (rc) {
+        LOG(ERROR, "error when fetching nic type");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    /*
+     * For PV domains only one pass is needed (because there's no emulated
+     * interface). For HVM domains two passes are needed in order to add
+     * both the PV and the tap interfaces to the bridge.
+     */
+    if (nictype == LIBXL_NIC_TYPE_VIF && num_exec != 0) {
+        rc = 0;
+        goto out;
+    }
+
+    rc = libxl__hotplug_env_nic(gc, dev, env, num_exec);
+    if (rc)
+        goto out;
+
+    rc = libxl__hotplug_nic(gc, dev, args, action);
+    if (!rc) rc = 1;
+
+out:
+    return rc;
+}
+
+libxl_device_model_version libxl__default_device_model(libxl__gc *gc)
+{
+    return LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN;
+}

tools/libxl/libxl_osdeps.h

@@ -37,6 +37,11 @@
 #include <pty.h>
 #elif defined(__sun__)
 #include <stropts.h>
+#elif defined(__FreeBSD__)
+#define SYSFS_PCI_DEV          "/dev/null"
+#define SYSFS_PCIBACK_DRIVER   "/dev/null"
+#define NETBACK_NIC_NAME       "xnb%u.%d"
+#include <libutil.h>
 #endif
 
 #ifndef SYSFS_PCIBACK_DRIVER