xen: add backend driver support
Impact: backend device support
Add the basic machinery to support backend drivers.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
[corresponds to 79727b851bac in git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 10b6bef..84bf17b 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -29,6 +29,14 @@
firing.
If in doubt, say yes.
+config XEN_BACKEND
+ tristate "Backend driver support"
+ depends on XEN_DOM0
+ default y
+ help
+ Support for backend device drivers that provide I/O services
+ to other virtual machines.
+
config XENFS
tristate "Xen filesystem"
default y
diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile
index 33e8cf8..8dca685 100644
--- a/drivers/xen/xenbus/Makefile
+++ b/drivers/xen/xenbus/Makefile
@@ -6,4 +6,7 @@
xenbus-objs += xenbus_xs.o
xenbus-objs += xenbus_probe.o
+xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
+xenbus-objs += $(xenbus-be-objs-y)
+
obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c
index 090c61e..700dc77 100644
--- a/drivers/xen/xenbus/xenbus_comms.c
+++ b/drivers/xen/xenbus/xenbus_comms.c
@@ -49,6 +49,7 @@
static irqreturn_t wake_waiting(int irq, void *unused)
{
if (unlikely(xenstored_ready == 0)) {
+ printk(KERN_CRIT "xenbus_probe wake_waiting\n");
xenstored_ready = 1;
schedule_work(&probe_work);
}
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index d462058..b09eb17 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -95,17 +95,6 @@
EXPORT_SYMBOL_GPL(xenbus_match);
-int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env)
-{
- struct xenbus_device *dev = to_xenbus_device(_dev);
-
- if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype))
- return -ENOMEM;
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(xenbus_uevent);
-
static void free_otherend_details(struct xenbus_device *dev)
{
kfree(dev->otherend);
@@ -690,6 +679,8 @@
{
xenstored_ready = 1;
+ printk(KERN_CRIT "xenbus_probe wake_waiting\n");
+
/* Notify others that xenstore is up */
blocking_notifier_call_chain(&xenstore_chain, 0, NULL);
}
diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h
index be390ce..0e5fc4c 100644
--- a/drivers/xen/xenbus/xenbus_probe.h
+++ b/drivers/xen/xenbus/xenbus_probe.h
@@ -60,7 +60,6 @@
extern void xenbus_dev_changed(const char *node, struct xen_bus_type *bus);
-extern int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env);
extern void xenbus_dev_shutdown(struct device *_dev);
extern int xenbus_dev_suspend(struct device *dev, pm_message_t state);
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
new file mode 100644
index 0000000..7459cce
--- /dev/null
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -0,0 +1,300 @@
+/******************************************************************************
+ * Talks to Xen Store to figure out what devices we have (backend half).
+ *
+ * Copyright (C) 2005 Rusty Russell, IBM Corporation
+ * Copyright (C) 2005 Mike Wray, Hewlett-Packard
+ * Copyright (C) 2005, 2006 XenSource Ltd
+ * Copyright (C) 2007 Solarflare Communications, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define DPRINTK(fmt, args...) \
+ pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \
+ __func__, __LINE__, ##args)
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/notifier.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/hypervisor.h>
+#include <xen/xenbus.h>
+#include <xen/evtchn.h>
+#include <xen/features.h>
+
+#include "xenbus_comms.h"
+#include "xenbus_probe.h"
+
+/* backend/<type>/<fe-uuid>/<id> => <type>-<fe-domid>-<id> */
+static int backend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename)
+{
+ int domid, err;
+ const char *devid, *type, *frontend;
+ unsigned int typelen;
+
+ type = strchr(nodename, '/');
+ if (!type)
+ return -EINVAL;
+ type++;
+ typelen = strcspn(type, "/");
+ if (!typelen || type[typelen] != '/')
+ return -EINVAL;
+
+ devid = strrchr(nodename, '/') + 1;
+
+ err = xenbus_gather(XBT_NIL, nodename, "frontend-id", "%i", &domid,
+ "frontend", NULL, &frontend,
+ NULL);
+ if (err)
+ return err;
+ if (strlen(frontend) == 0)
+ err = -ERANGE;
+ if (!err && !xenbus_exists(XBT_NIL, frontend, ""))
+ err = -ENOENT;
+ kfree(frontend);
+
+ if (err)
+ return err;
+
+ if (snprintf(bus_id, XEN_BUS_ID_SIZE,
+ "%.*s-%i-%s", typelen, type, domid, devid) >= XEN_BUS_ID_SIZE)
+ return -ENOSPC;
+ return 0;
+}
+
+static int xenbus_uevent_backend(struct device *dev,
+ struct kobj_uevent_env *env)
+{
+ struct xenbus_device *xdev;
+ struct xenbus_driver *drv;
+ struct xen_bus_type *bus;
+
+ DPRINTK("");
+
+ if (dev == NULL)
+ return -ENODEV;
+
+ xdev = to_xenbus_device(dev);
+ bus = container_of(xdev->dev.bus, struct xen_bus_type, bus);
+ if (xdev == NULL)
+ return -ENODEV;
+
+ /* stuff we want to pass to /sbin/hotplug */
+ if (add_uevent_var(env, "XENBUS_TYPE=%s", xdev->devicetype))
+ return -ENOMEM;
+
+ if (add_uevent_var(env, "XENBUS_PATH=%s", xdev->nodename))
+ return -ENOMEM;
+
+ if (add_uevent_var(env, "XENBUS_BASE_PATH=%s", bus->root))
+ return -ENOMEM;
+
+ if (dev->driver) {
+ drv = to_xenbus_driver(dev->driver);
+ if (drv && drv->uevent)
+ return drv->uevent(xdev, env);
+ }
+
+ return 0;
+}
+
+/* backend/<typename>/<frontend-uuid>/<name> */
+static int xenbus_probe_backend_unit(struct xen_bus_type *bus,
+ const char *dir,
+ const char *type,
+ const char *name)
+{
+ char *nodename;
+ int err;
+
+ nodename = kasprintf(GFP_KERNEL, "%s/%s", dir, name);
+ if (!nodename)
+ return -ENOMEM;
+
+ DPRINTK("%s\n", nodename);
+
+ err = xenbus_probe_node(bus, type, nodename);
+ kfree(nodename);
+ return err;
+}
+
+/* backend/<typename>/<frontend-domid> */
+static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type, const char *domid)
+{
+ char *nodename;
+ int err = 0;
+ char **dir;
+ unsigned int i, dir_n = 0;
+
+ DPRINTK("");
+
+ nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", bus->root, type, domid);
+ if (!nodename)
+ return -ENOMEM;
+
+ dir = xenbus_directory(XBT_NIL, nodename, "", &dir_n);
+ if (IS_ERR(dir)) {
+ kfree(nodename);
+ return PTR_ERR(dir);
+ }
+
+ for (i = 0; i < dir_n; i++) {
+ err = xenbus_probe_backend_unit(bus, nodename, type, dir[i]);
+ if (err)
+ break;
+ }
+ kfree(dir);
+ kfree(nodename);
+ return err;
+}
+
+static void frontend_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ xenbus_otherend_changed(watch, vec, len, 0);
+}
+
+static struct device_attribute xenbus_backend_dev_attrs[] = {
+ __ATTR_NULL
+};
+
+static struct xen_bus_type xenbus_backend = {
+ .root = "backend",
+ .levels = 3, /* backend/type/<frontend>/<id> */
+ .get_bus_id = backend_bus_id,
+ .probe = xenbus_probe_backend,
+ .otherend_changed = frontend_changed,
+ .bus = {
+ .name = "xen-backend",
+ .match = xenbus_match,
+ .uevent = xenbus_uevent_backend,
+ .probe = xenbus_dev_probe,
+ .remove = xenbus_dev_remove,
+ .shutdown = xenbus_dev_shutdown,
+ .dev_attrs = xenbus_backend_dev_attrs,
+ },
+};
+
+static void backend_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ DPRINTK("");
+
+ xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_backend);
+}
+
+static struct xenbus_watch be_watch = {
+ .node = "backend",
+ .callback = backend_changed,
+};
+
+static int read_frontend_details(struct xenbus_device *xendev)
+{
+ return xenbus_read_otherend_details(xendev, "frontend-id", "frontend");
+}
+
+//void xenbus_backend_suspend(int (*fn)(struct device *, void *))
+//{
+// DPRINTK("");
+// bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, fn);
+//}
+
+//void xenbus_backend_resume(int (*fn)(struct device *, void *))
+//{
+// DPRINTK("");
+// bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, fn);
+//}
+
+//int xenbus_for_each_backend(void *arg, int (*fn)(struct device *, void *))
+//{
+// return bus_for_each_dev(&xenbus_backend.bus, NULL, arg, fn);
+//}
+//EXPORT_SYMBOL_GPL(xenbus_for_each_backend);
+
+int xenbus_dev_is_online(struct xenbus_device *dev)
+{
+ int rc, val;
+
+ rc = xenbus_scanf(XBT_NIL, dev->nodename, "online", "%d", &val);
+ if (rc != 1)
+ val = 0; /* no online node present */
+
+ return val;
+}
+EXPORT_SYMBOL_GPL(xenbus_dev_is_online);
+
+int __xenbus_register_backend(struct xenbus_driver *drv,
+ struct module *owner, const char *mod_name)
+{
+ drv->read_otherend_details = read_frontend_details;
+
+ return xenbus_register_driver_common(drv, &xenbus_backend,
+ owner, mod_name);
+}
+EXPORT_SYMBOL_GPL(__xenbus_register_backend);
+
+static int backend_probe_and_watch(struct notifier_block *notifier,
+ unsigned long event,
+ void *data)
+{
+ /* Enumerate devices in xenstore and watch for changes. */
+ xenbus_probe_devices(&xenbus_backend);
+ printk(KERN_CRIT "%s devices probed ok\n", __func__);
+ register_xenbus_watch(&be_watch);
+ printk(KERN_CRIT "%s watch add ok ok\n", __func__);
+ printk(KERN_CRIT "%s all done\n", __func__);
+ return NOTIFY_DONE;
+}
+
+static int __init xenbus_probe_backend_init(void)
+{
+ static struct notifier_block xenstore_notifier = {
+ .notifier_call = backend_probe_and_watch
+ };
+ int err;
+
+ DPRINTK("");
+
+ /* Register ourselves with the kernel bus subsystem */
+ err = bus_register(&xenbus_backend.bus);
+ if (err) {
+ printk(KERN_CRIT "%s didn't register bus!\n", __func__);
+ return err;
+ }
+ printk(KERN_CRIT "%s bus registered ok\n", __func__);
+
+ register_xenstore_notifier(&xenstore_notifier);
+
+ return 0;
+}
+
+module_init(xenbus_probe_backend_init);
diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c
index 04c4f01..dd31d5a4 100644
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -62,6 +62,17 @@
return err;
}
+static int xenbus_uevent_frontend(struct device *_dev, struct kobj_uevent_env *env)
+{
+ struct xenbus_device *dev = to_xenbus_device(_dev);
+
+ if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype))
+ return -ENOMEM;
+
+ return 0;
+}
+
+
static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
@@ -81,7 +92,7 @@
.bus = {
.name = "xen",
.match = xenbus_match,
- .uevent = xenbus_uevent,
+ .uevent = xenbus_uevent_frontend,
.probe = xenbus_dev_probe,
.remove = xenbus_dev_remove,
.shutdown = xenbus_dev_shutdown,
@@ -232,8 +243,25 @@
}
EXPORT_SYMBOL_GPL(__xenbus_register_frontend);
+static int frontend_probe_and_watch(struct notifier_block *notifier,
+ unsigned long event,
+ void *data)
+{
+ /* Enumerate devices in xenstore and watch for changes. */
+ xenbus_probe_devices(&xenbus_frontend);
+ printk(KERN_CRIT "%s devices probed ok\n", __func__);
+ register_xenbus_watch(&fe_watch);
+ printk(KERN_CRIT "%s watch add ok ok\n", __func__);
+ printk(KERN_CRIT "%s all done\n", __func__);
+ return NOTIFY_DONE;
+}
+
+
static int __init xenbus_probe_frontend_init(void)
{
+ static struct notifier_block xenstore_notifier = {
+ .notifier_call = frontend_probe_and_watch
+ };
int err;
DPRINTK("");
@@ -246,14 +274,7 @@
}
printk(KERN_CRIT "%s bus registered ok\n", __func__);
- if (!xen_initial_domain()) {
- /* Enumerate devices in xenstore and watch for changes. */
- xenbus_probe_devices(&xenbus_frontend);
- printk(KERN_CRIT "%s devices probed ok\n", __func__);
- register_xenbus_watch(&fe_watch);
- printk(KERN_CRIT "%s watch add ok ok\n", __func__);
- printk(KERN_CRIT "%s all done\n", __func__);
- }
+ register_xenstore_notifier(&xenstore_notifier);
return 0;
}
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 43e2d7d..7a1d15f 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -94,7 +94,7 @@
int (*remove)(struct xenbus_device *dev);
int (*suspend)(struct xenbus_device *dev, pm_message_t state);
int (*resume)(struct xenbus_device *dev);
- int (*uevent)(struct xenbus_device *, char **, int, char *, int);
+ int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
struct device_driver driver;
int (*read_otherend_details)(struct xenbus_device *dev);
int (*is_ready)(struct xenbus_device *dev);
