[PATCH 6/6] xen/xenbus-backend: Only register device if communication ring is local

From: Bastian Blank
Date: Sat Dec 10 2011 - 13:30:49 EST


Signed-off-by: Bastian Blank <waldi@xxxxxxxxxx>
---
drivers/xen/xenbus/Makefile | 2 +-
drivers/xen/xenbus/xenbus_dev_backend.c | 13 ++-----------
drivers/xen/xenbus/xenbus_dev_backend.h | 2 ++
drivers/xen/xenbus/xenbus_probe.c | 18 ++++++++++++++++++
4 files changed, 23 insertions(+), 12 deletions(-)
create mode 100644 drivers/xen/xenbus/xenbus_dev_backend.h

diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile
index 31e2e90..d751f45 100644
--- a/drivers/xen/xenbus/Makefile
+++ b/drivers/xen/xenbus/Makefile
@@ -7,8 +7,8 @@ xenbus-objs += xenbus_comms.o
xenbus-objs += xenbus_xs.o
xenbus-objs += xenbus_probe.o

+xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o
xenbus-be-objs-$(CONFIG_XEN_BACKEND) += xenbus_probe_backend.o
xenbus-objs += $(xenbus-be-objs-y)

-obj-$(CONFIG_XEN_BACKEND) += xenbus_dev_backend.o
obj-$(CONFIG_XEN_XENBUS_FRONTEND) += xenbus_probe_frontend.o
diff --git a/drivers/xen/xenbus/xenbus_dev_backend.c b/drivers/xen/xenbus/xenbus_dev_backend.c
index a2092bd..fb87f1b 100644
--- a/drivers/xen/xenbus/xenbus_dev_backend.c
+++ b/drivers/xen/xenbus/xenbus_dev_backend.c
@@ -3,7 +3,6 @@
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
-#include <linux/module.h>
#include <linux/capability.h>

#include <xen/page.h>
@@ -11,8 +10,6 @@

#include "xenbus_comms.h"

-MODULE_LICENSE("GPL");
-
static int xenbus_backend_open(struct inode *inode, struct file *filp)
{
if (!capable(CAP_SYS_ADMIN))
@@ -67,23 +64,17 @@ static struct miscdevice xenbus_backend_dev = {
.fops = &xenbus_backend_fops,
};

-static int __init xenbus_backend_init(void)
+int __init xenbus_backend_init(void)
{
int err;

- if (!xen_initial_domain())
- return -ENODEV;
-
err = misc_register(&xenbus_backend_dev);
if (err)
printk(KERN_ERR "Could not register xenbus backend device\n");
return err;
}

-static void __exit xenbus_backend_exit(void)
+void __exit xenbus_backend_exit(void)
{
misc_deregister(&xenbus_backend_dev);
}
-
-module_init(xenbus_backend_init);
-module_exit(xenbus_backend_exit);
diff --git a/drivers/xen/xenbus/xenbus_dev_backend.h b/drivers/xen/xenbus/xenbus_dev_backend.h
new file mode 100644
index 0000000..d986853
--- /dev/null
+++ b/drivers/xen/xenbus/xenbus_dev_backend.h
@@ -0,0 +1,2 @@
+int xenbus_backend_init(void);
+void xenbus_backend_exit(void);
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 1b178c6..4eff095 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -60,6 +60,7 @@
#include <xen/hvm.h>

#include "xenbus_comms.h"
+#include "xenbus_dev_backend.h"
#include "xenbus_probe.h"


@@ -641,6 +642,10 @@ EXPORT_SYMBOL_GPL(xenbus_dev_cancel);
/* A flag to determine if xenstored is 'ready' (i.e. has started) */
int xenstored_ready;

+/* A flag to determine if xenstored is 'local' */
+#ifdef CONFIG_XEN_BACKEND
+static int xenstored_local;
+#endif

int register_xenstore_notifier(struct notifier_block *nb)
{
@@ -675,6 +680,14 @@ static int __init xenbus_probe_initcall(void)
if (!xen_domain())
return -ENODEV;

+#ifdef CONFIG_XEN_BACKEND
+ if (xenstored_local) {
+ int ret = xenbus_backend_init();
+ if (ret)
+ return ret;
+ }
+#endif
+
if (xen_initial_domain() || xen_hvm_domain())
return 0;

@@ -747,9 +760,14 @@ static int __init xenbus_init(void)
if (xen_store_evtchn)
xenstored_ready = 1;
else {
+#ifdef CONFIG_XEN_BACKEND
+ xenstored_local = 1;
err = xenstored_local_init();
if (err)
goto out_error;
+#else
+ BUG();
+#endif
}
xen_store_interface = mfn_to_virt(xen_store_mfn);
}
--
1.7.7.3

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