While the hypervisor change adding SCHEDOP_watchdog support included a
daemon to make use of the new functionality, having a kernel driver
for /dev/watchdog so that user space code doesn''t need to distinguish
non-Xen and Xen seems to be preferable.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
---
drivers/watchdog/Kconfig | 10 +
drivers/watchdog/Makefile | 3
drivers/watchdog/xen_wdt.c | 359 ++++++++++++++++++++++++++++++++++++++++++
include/xen/interface/sched.h | 34 +++
4 files changed, 406 insertions(+)
--- linux-2.6.36-rc6/drivers/watchdog/Kconfig
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Kconfig
@@ -1043,6 +1043,16 @@ config WATCHDOG_RIO
# XTENSA Architecture
+# Xen Architecture
+
+config XEN_WDT
+ tristate "Xen Watchdog support"
+ depends on XEN
+ help
+ Say Y here to support the hypervisor watchdog capability provided
+ by Xen 4.0 and newer. The watchdog timeout period is normally one
+ minute but can be changed with a boot-time parameter.
+
#
# ISA-based Watchdog Cards
#
--- linux-2.6.36-rc6/drivers/watchdog/Makefile
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Makefile
@@ -145,6 +145,9 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o
# XTENSA Architecture
+# Xen
+obj-$(CONFIG_XEN_WDT) += xen_wdt.o
+
# Architecture Independant
obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
--- linux-2.6.36-rc6/drivers/watchdog/xen_wdt.c
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/xen_wdt.c
@@ -0,0 +1,359 @@
+/*
+ * Xen Watchdog Driver
+ *
+ * (c) Copyright 2010 Novell, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define DRV_NAME "wdt"
+#define DRV_VERSION "0.01"
+#define PFX DRV_NAME ": "
+
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/hrtimer.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <xen/xen.h>
+#include <asm/xen/hypercall.h>
+#include <xen/interface/sched.h>
+
+static struct platform_device *platform_device;
+static DEFINE_SPINLOCK(wdt_lock);
+static struct sched_watchdog wdt;
+static __kernel_time_t wdt_expires;
+static bool is_active, expect_release;
+
+#define WATCHDOG_TIMEOUT 60 /* in seconds */
+static unsigned int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, uint, S_IRUGO);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
+ "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, S_IRUGO);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static inline __kernel_time_t set_timeout(void)
+{
+ wdt.timeout = timeout;
+ return ktime_to_timespec(ktime_get()).tv_sec + timeout;
+}
+
+static int xen_wdt_start(void)
+{
+ __kernel_time_t expires;
+ int err;
+
+ spin_lock(&wdt_lock);
+
+ expires = set_timeout();
+ if (!wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ else
+ err = -EBUSY;
+ if (err > 0) {
+ wdt.id = err;
+ wdt_expires = expires;
+ err = 0;
+ } else
+ BUG_ON(!err);
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_stop(void)
+{
+ int err = 0;
+
+ spin_lock(&wdt_lock);
+
+ wdt.timeout = 0;
+ if (wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ if (!err)
+ wdt.id = 0;
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_kick(void)
+{
+ __kernel_time_t expires;
+ int err;
+
+ spin_lock(&wdt_lock);
+
+ expires = set_timeout();
+ if (wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ else
+ err = -ENXIO;
+ if (!err)
+ wdt_expires = expires;
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_open(struct inode *inode, struct file *file)
+{
+ int err;
+
+ /* /dev/watchdog can only be opened once */
+ if (xchg(&is_active, true))
+ return -EBUSY;
+
+ err = xen_wdt_start();
+ if (err == -EBUSY)
+ err = xen_wdt_kick();
+ return err ?: nonseekable_open(inode, file);
+}
+
+static int xen_wdt_release(struct inode *inode, struct file *file)
+{
+ if (expect_release)
+ xen_wdt_stop();
+ else {
+ printk(KERN_CRIT PFX
+ "unexpected close, not stopping watchdog!\n");
+ xen_wdt_kick();
+ }
+ is_active = false;
+ expect_release = false;
+ return 0;
+}
+
+static ssize_t xen_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* See if we got the magic character ''V'' and reload the
timer */
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* in case it was set long ago */
+ expect_release = false;
+
+ /* scan to see whether or not we got the magic
+ character */
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == ''V'')
+ expect_release = true;
+ }
+ }
+
+ /* someone wrote to us, we should reload the timer */
+ xen_wdt_kick();
+ }
+ return len;
+}
+
+static long xen_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int new_options, retval = -EINVAL;
+ int new_timeout;
+ int __user *argp = (void __user *)arg;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = DRV_NAME,
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, argp);
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(new_options, argp))
+ return -EFAULT;
+
+ if (new_options & WDIOS_DISABLECARD)
+ retval = xen_wdt_stop();
+ if (new_options & WDIOS_ENABLECARD) {
+ retval = xen_wdt_start();
+ if (retval == -EBUSY)
+ retval = xen_wdt_kick();
+ }
+ return retval;
+
+ case WDIOC_KEEPALIVE:
+ xen_wdt_kick();
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, argp))
+ return -EFAULT;
+ if (!new_timeout)
+ return -EINVAL;
+ timeout = new_timeout;
+ xen_wdt_kick();
+ /* fall through */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, argp);
+
+ case WDIOC_GETTIMELEFT:
+ retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec;
+ return put_user(retval, argp);
+ }
+
+ return -ENOTTY;
+}
+
+static const struct file_operations xen_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = xen_wdt_write,
+ .unlocked_ioctl = xen_wdt_ioctl,
+ .open = xen_wdt_open,
+ .release = xen_wdt_release,
+};
+
+static struct miscdevice xen_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &xen_wdt_fops,
+};
+
+static int __devinit xen_wdt_probe(struct platform_device *dev)
+{
+ struct sched_watchdog wd = { .id = ~0 };
+ int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd);
+
+ switch (ret) {
+ case -EINVAL:
+ if (!timeout) {
+ timeout = WATCHDOG_TIMEOUT;
+ printk(KERN_INFO PFX
+ "timeout value invalid, using %d\n", timeout);
+ }
+
+ ret = misc_register(&xen_wdt_miscdev);
+ if (ret) {
+ printk(KERN_ERR PFX
+ "cannot register miscdev on minor=%d (%d)\n",
+ WATCHDOG_MINOR, ret);
+ break;
+ }
+
+ printk(KERN_INFO PFX
+ "initialized (timeout=%ds, nowayout=%d)\n",
+ timeout, nowayout);
+ break;
+
+ case -ENOSYS:
+ printk(KERN_INFO PFX "not supported\n");
+ ret = -ENODEV;
+ break;
+
+ default:
+ printk(KERN_INFO PFX "bogus return value %d\n", ret);
+ break;
+ }
+
+ return ret;
+}
+
+static int __devexit xen_wdt_remove(struct platform_device *dev)
+{
+ /* Stop the timer before we leave */
+ if (!nowayout)
+ xen_wdt_stop();
+
+ misc_deregister(&xen_wdt_miscdev);
+
+ return 0;
+}
+
+static void xen_wdt_shutdown(struct platform_device *dev)
+{
+ xen_wdt_stop();
+}
+
+static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state)
+{
+ return xen_wdt_stop();
+}
+
+static int xen_wdt_resume(struct platform_device *dev)
+{
+ return xen_wdt_start();
+}
+
+static struct platform_driver xen_wdt_driver = {
+ .probe = xen_wdt_probe,
+ .remove = __devexit_p(xen_wdt_remove),
+ .shutdown = xen_wdt_shutdown,
+ .suspend = xen_wdt_suspend,
+ .resume = xen_wdt_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ },
+};
+
+static int __init xen_wdt_init_module(void)
+{
+ int err;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ printk(KERN_INFO PFX "Xen WatchDog Timer Driver v%s\n",
DRV_VERSION);
+
+ err = platform_driver_register(&xen_wdt_driver);
+ if (err)
+ return err;
+
+ platform_device = platform_device_register_simple(DRV_NAME,
+ -1, NULL, 0);
+ if (IS_ERR(platform_device)) {
+ err = PTR_ERR(platform_device);
+ platform_driver_unregister(&xen_wdt_driver);
+ }
+
+ return err;
+}
+
+static void __exit xen_wdt_cleanup_module(void)
+{
+ platform_device_unregister(platform_device);
+ platform_driver_unregister(&xen_wdt_driver);
+ printk(KERN_INFO PFX "module unloaded\n");
+}
+
+module_init(xen_wdt_init_module);
+module_exit(xen_wdt_cleanup_module);
+
+MODULE_AUTHOR("Jen Beulich <jbeulich@novell.com>");
+MODULE_DESCRIPTION("Xen WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
--- linux-2.6.36-rc6/include/xen/interface/sched.h
+++ 2.6.36-rc6-xen-watchdog/include/xen/interface/sched.h
@@ -65,6 +65,39 @@ struct sched_poll {
DEFINE_GUEST_HANDLE_STRUCT(sched_poll);
/*
+ * Declare a shutdown for another domain. The main use of this function is
+ * in interpreting shutdown requests and reasons for fully-virtualized
+ * domains. A para-virtualized domain may use SCHEDOP_shutdown directly.
+ * @arg == pointer to sched_remote_shutdown structure.
+ */
+#define SCHEDOP_remote_shutdown 4
+struct sched_remote_shutdown {
+ domid_t domain_id; /* Remote domain ID */
+ unsigned int reason; /* SHUTDOWN_xxx reason */
+};
+
+/*
+ * Latch a shutdown code, so that when the domain later shuts down it
+ * reports this code to the control tools.
+ * @arg == as for SCHEDOP_shutdown.
+ */
+#define SCHEDOP_shutdown_code 5
+
+/*
+ * Setup, poke and destroy a domain watchdog timer.
+ * @arg == pointer to sched_watchdog structure.
+ * With id == 0, setup a domain watchdog timer to cause domain shutdown
+ * after timeout, returns watchdog id.
+ * With id != 0 and timeout == 0, destroy domain watchdog timer.
+ * With id != 0 and timeout != 0, poke watchdog timer and set new timeout.
+ */
+#define SCHEDOP_watchdog 6
+struct sched_watchdog {
+ uint32_t id; /* watchdog ID */
+ uint32_t timeout; /* timeout */
+};
+
+/*
* Reason codes for SCHEDOP_shutdown. These may be interpreted by control
* software to determine the appropriate action. For the most part, Xen does
* not care about the shutdown code.
@@ -73,5 +106,6 @@ DEFINE_GUEST_HANDLE_STRUCT(sched_poll);
#define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. */
#define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. */
#define SHUTDOWN_crash 3 /* Tell controller we''ve crashed.
*/
+#define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. */
#endif /* __XEN_PUBLIC_SCHED_H__ */
_______________________________________________
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http://lists.xensource.com/xen-devel
On 09/30/2010 07:01 AM, Jan Beulich wrote:> While the hypervisor change adding SCHEDOP_watchdog support included a > daemon to make use of the new functionality, having a kernel driver > for /dev/watchdog so that user space code doesn''t need to distinguish > non-Xen and Xen seems to be preferable.Looks good. Are you going to submit this upstream? J> Signed-off-by: Jan Beulich <jbeulich@novell.com> > > --- > drivers/watchdog/Kconfig | 10 + > drivers/watchdog/Makefile | 3 > drivers/watchdog/xen_wdt.c | 359 ++++++++++++++++++++++++++++++++++++++++++ > include/xen/interface/sched.h | 34 +++ > 4 files changed, 406 insertions(+) > > --- linux-2.6.36-rc6/drivers/watchdog/Kconfig > +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Kconfig > @@ -1043,6 +1043,16 @@ config WATCHDOG_RIO > > # XTENSA Architecture > > +# Xen Architecture > + > +config XEN_WDT > + tristate "Xen Watchdog support" > + depends on XEN > + help > + Say Y here to support the hypervisor watchdog capability provided > + by Xen 4.0 and newer. The watchdog timeout period is normally one > + minute but can be changed with a boot-time parameter. > + > # > # ISA-based Watchdog Cards > # > --- linux-2.6.36-rc6/drivers/watchdog/Makefile > +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Makefile > @@ -145,6 +145,9 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o > > # XTENSA Architecture > > +# Xen > +obj-$(CONFIG_XEN_WDT) += xen_wdt.o > + > # Architecture Independant > obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o > obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o > --- linux-2.6.36-rc6/drivers/watchdog/xen_wdt.c > +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/xen_wdt.c > @@ -0,0 +1,359 @@ > +/* > + * Xen Watchdog Driver > + * > + * (c) Copyright 2010 Novell, Inc. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * as published by the Free Software Foundation; either version > + * 2 of the License, or (at your option) any later version. > + */ > + > +#define DRV_NAME "wdt" > +#define DRV_VERSION "0.01" > +#define PFX DRV_NAME ": " > + > +#include <linux/bug.h> > +#include <linux/errno.h> > +#include <linux/fs.h> > +#include <linux/hrtimer.h> > +#include <linux/kernel.h> > +#include <linux/ktime.h> > +#include <linux/init.h> > +#include <linux/miscdevice.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/platform_device.h> > +#include <linux/spinlock.h> > +#include <linux/uaccess.h> > +#include <linux/watchdog.h> > +#include <xen/xen.h> > +#include <asm/xen/hypercall.h> > +#include <xen/interface/sched.h> > + > +static struct platform_device *platform_device; > +static DEFINE_SPINLOCK(wdt_lock); > +static struct sched_watchdog wdt; > +static __kernel_time_t wdt_expires; > +static bool is_active, expect_release; > + > +#define WATCHDOG_TIMEOUT 60 /* in seconds */ > +static unsigned int timeout = WATCHDOG_TIMEOUT; > +module_param(timeout, uint, S_IRUGO); > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " > + "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +module_param(nowayout, bool, S_IRUGO); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " > + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +static inline __kernel_time_t set_timeout(void) > +{ > + wdt.timeout = timeout; > + return ktime_to_timespec(ktime_get()).tv_sec + timeout; > +} > + > +static int xen_wdt_start(void) > +{ > + __kernel_time_t expires; > + int err; > + > + spin_lock(&wdt_lock); > + > + expires = set_timeout(); > + if (!wdt.id) > + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); > + else > + err = -EBUSY; > + if (err > 0) { > + wdt.id = err; > + wdt_expires = expires; > + err = 0; > + } else > + BUG_ON(!err); > + > + spin_unlock(&wdt_lock); > + > + return err; > +} > + > +static int xen_wdt_stop(void) > +{ > + int err = 0; > + > + spin_lock(&wdt_lock); > + > + wdt.timeout = 0; > + if (wdt.id) > + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); > + if (!err) > + wdt.id = 0; > + > + spin_unlock(&wdt_lock); > + > + return err; > +} > + > +static int xen_wdt_kick(void) > +{ > + __kernel_time_t expires; > + int err; > + > + spin_lock(&wdt_lock); > + > + expires = set_timeout(); > + if (wdt.id) > + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); > + else > + err = -ENXIO; > + if (!err) > + wdt_expires = expires; > + > + spin_unlock(&wdt_lock); > + > + return err; > +} > + > +static int xen_wdt_open(struct inode *inode, struct file *file) > +{ > + int err; > + > + /* /dev/watchdog can only be opened once */ > + if (xchg(&is_active, true)) > + return -EBUSY; > + > + err = xen_wdt_start(); > + if (err == -EBUSY) > + err = xen_wdt_kick(); > + return err ?: nonseekable_open(inode, file); > +} > + > +static int xen_wdt_release(struct inode *inode, struct file *file) > +{ > + if (expect_release) > + xen_wdt_stop(); > + else { > + printk(KERN_CRIT PFX > + "unexpected close, not stopping watchdog!\n"); > + xen_wdt_kick(); > + } > + is_active = false; > + expect_release = false; > + return 0; > +} > + > +static ssize_t xen_wdt_write(struct file *file, const char __user *data, > + size_t len, loff_t *ppos) > +{ > + /* See if we got the magic character ''V'' and reload the timer */ > + if (len) { > + if (!nowayout) { > + size_t i; > + > + /* in case it was set long ago */ > + expect_release = false; > + > + /* scan to see whether or not we got the magic > + character */ > + for (i = 0; i != len; i++) { > + char c; > + if (get_user(c, data + i)) > + return -EFAULT; > + if (c == ''V'') > + expect_release = true; > + } > + } > + > + /* someone wrote to us, we should reload the timer */ > + xen_wdt_kick(); > + } > + return len; > +} > + > +static long xen_wdt_ioctl(struct file *file, unsigned int cmd, > + unsigned long arg) > +{ > + int new_options, retval = -EINVAL; > + int new_timeout; > + int __user *argp = (void __user *)arg; > + static const struct watchdog_info ident = { > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, > + .firmware_version = 0, > + .identity = DRV_NAME, > + }; > + > + switch (cmd) { > + case WDIOC_GETSUPPORT: > + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; > + > + case WDIOC_GETSTATUS: > + case WDIOC_GETBOOTSTATUS: > + return put_user(0, argp); > + > + case WDIOC_SETOPTIONS: > + if (get_user(new_options, argp)) > + return -EFAULT; > + > + if (new_options & WDIOS_DISABLECARD) > + retval = xen_wdt_stop(); > + if (new_options & WDIOS_ENABLECARD) { > + retval = xen_wdt_start(); > + if (retval == -EBUSY) > + retval = xen_wdt_kick(); > + } > + return retval; > + > + case WDIOC_KEEPALIVE: > + xen_wdt_kick(); > + return 0; > + > + case WDIOC_SETTIMEOUT: > + if (get_user(new_timeout, argp)) > + return -EFAULT; > + if (!new_timeout) > + return -EINVAL; > + timeout = new_timeout; > + xen_wdt_kick(); > + /* fall through */ > + case WDIOC_GETTIMEOUT: > + return put_user(timeout, argp); > + > + case WDIOC_GETTIMELEFT: > + retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec; > + return put_user(retval, argp); > + } > + > + return -ENOTTY; > +} > + > +static const struct file_operations xen_wdt_fops = { > + .owner = THIS_MODULE, > + .llseek = no_llseek, > + .write = xen_wdt_write, > + .unlocked_ioctl = xen_wdt_ioctl, > + .open = xen_wdt_open, > + .release = xen_wdt_release, > +}; > + > +static struct miscdevice xen_wdt_miscdev = { > + .minor = WATCHDOG_MINOR, > + .name = "watchdog", > + .fops = &xen_wdt_fops, > +}; > + > +static int __devinit xen_wdt_probe(struct platform_device *dev) > +{ > + struct sched_watchdog wd = { .id = ~0 }; > + int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd); > + > + switch (ret) { > + case -EINVAL: > + if (!timeout) { > + timeout = WATCHDOG_TIMEOUT; > + printk(KERN_INFO PFX > + "timeout value invalid, using %d\n", timeout); > + } > + > + ret = misc_register(&xen_wdt_miscdev); > + if (ret) { > + printk(KERN_ERR PFX > + "cannot register miscdev on minor=%d (%d)\n", > + WATCHDOG_MINOR, ret); > + break; > + } > + > + printk(KERN_INFO PFX > + "initialized (timeout=%ds, nowayout=%d)\n", > + timeout, nowayout); > + break; > + > + case -ENOSYS: > + printk(KERN_INFO PFX "not supported\n"); > + ret = -ENODEV; > + break; > + > + default: > + printk(KERN_INFO PFX "bogus return value %d\n", ret); > + break; > + } > + > + return ret; > +} > + > +static int __devexit xen_wdt_remove(struct platform_device *dev) > +{ > + /* Stop the timer before we leave */ > + if (!nowayout) > + xen_wdt_stop(); > + > + misc_deregister(&xen_wdt_miscdev); > + > + return 0; > +} > + > +static void xen_wdt_shutdown(struct platform_device *dev) > +{ > + xen_wdt_stop(); > +} > + > +static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state) > +{ > + return xen_wdt_stop(); > +} > + > +static int xen_wdt_resume(struct platform_device *dev) > +{ > + return xen_wdt_start(); > +} > + > +static struct platform_driver xen_wdt_driver = { > + .probe = xen_wdt_probe, > + .remove = __devexit_p(xen_wdt_remove), > + .shutdown = xen_wdt_shutdown, > + .suspend = xen_wdt_suspend, > + .resume = xen_wdt_resume, > + .driver = { > + .owner = THIS_MODULE, > + .name = DRV_NAME, > + }, > +}; > + > +static int __init xen_wdt_init_module(void) > +{ > + int err; > + > + if (!xen_domain()) > + return -ENODEV; > + > + printk(KERN_INFO PFX "Xen WatchDog Timer Driver v%s\n", DRV_VERSION); > + > + err = platform_driver_register(&xen_wdt_driver); > + if (err) > + return err; > + > + platform_device = platform_device_register_simple(DRV_NAME, > + -1, NULL, 0); > + if (IS_ERR(platform_device)) { > + err = PTR_ERR(platform_device); > + platform_driver_unregister(&xen_wdt_driver); > + } > + > + return err; > +} > + > +static void __exit xen_wdt_cleanup_module(void) > +{ > + platform_device_unregister(platform_device); > + platform_driver_unregister(&xen_wdt_driver); > + printk(KERN_INFO PFX "module unloaded\n"); > +} > + > +module_init(xen_wdt_init_module); > +module_exit(xen_wdt_cleanup_module); > + > +MODULE_AUTHOR("Jen Beulich <jbeulich@novell.com>"); > +MODULE_DESCRIPTION("Xen WatchDog Timer Driver"); > +MODULE_VERSION(DRV_VERSION); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); > --- linux-2.6.36-rc6/include/xen/interface/sched.h > +++ 2.6.36-rc6-xen-watchdog/include/xen/interface/sched.h > @@ -65,6 +65,39 @@ struct sched_poll { > DEFINE_GUEST_HANDLE_STRUCT(sched_poll); > > /* > + * Declare a shutdown for another domain. The main use of this function is > + * in interpreting shutdown requests and reasons for fully-virtualized > + * domains. A para-virtualized domain may use SCHEDOP_shutdown directly. > + * @arg == pointer to sched_remote_shutdown structure. > + */ > +#define SCHEDOP_remote_shutdown 4 > +struct sched_remote_shutdown { > + domid_t domain_id; /* Remote domain ID */ > + unsigned int reason; /* SHUTDOWN_xxx reason */ > +}; > + > +/* > + * Latch a shutdown code, so that when the domain later shuts down it > + * reports this code to the control tools. > + * @arg == as for SCHEDOP_shutdown. > + */ > +#define SCHEDOP_shutdown_code 5 > + > +/* > + * Setup, poke and destroy a domain watchdog timer. > + * @arg == pointer to sched_watchdog structure. > + * With id == 0, setup a domain watchdog timer to cause domain shutdown > + * after timeout, returns watchdog id. > + * With id != 0 and timeout == 0, destroy domain watchdog timer. > + * With id != 0 and timeout != 0, poke watchdog timer and set new timeout. > + */ > +#define SCHEDOP_watchdog 6 > +struct sched_watchdog { > + uint32_t id; /* watchdog ID */ > + uint32_t timeout; /* timeout */ > +}; > + > +/* > * Reason codes for SCHEDOP_shutdown. These may be interpreted by control > * software to determine the appropriate action. For the most part, Xen does > * not care about the shutdown code. > @@ -73,5 +106,6 @@ DEFINE_GUEST_HANDLE_STRUCT(sched_poll); > #define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. */ > #define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. */ > #define SHUTDOWN_crash 3 /* Tell controller we''ve crashed. */ > +#define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. */ > > #endif /* __XEN_PUBLIC_SCHED_H__ */ > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Thu, Sep 30, Jan Beulich wrote:> +MODULE_AUTHOR("Jen Beulich <jbeulich@novell.com>");s/e/a/ Olaf _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
>>> On 30.09.10 at 18:16, Jeremy Fitzhardinge <jeremy@goop.org> wrote: > On 09/30/2010 07:01 AM, Jan Beulich wrote: >> While the hypervisor change adding SCHEDOP_watchdog support included a >> daemon to make use of the new functionality, having a kernel driver >> for /dev/watchdog so that user space code doesn''t need to distinguish >> non-Xen and Xen seems to be preferable. > > Looks good. Are you going to submit this upstream?By sending it to you I thought I did. Confused, Jan>> Signed-off-by: Jan Beulich <jbeulich@novell.com> >> >> --- >> drivers/watchdog/Kconfig | 10 + >> drivers/watchdog/Makefile | 3 >> drivers/watchdog/xen_wdt.c | 359 > ++++++++++++++++++++++++++++++++++++++++++ >> include/xen/interface/sched.h | 34 +++ >> 4 files changed, 406 insertions(+) >> >> --- linux-2.6.36-rc6/drivers/watchdog/Kconfig >> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Kconfig >> @@ -1043,6 +1043,16 @@ config WATCHDOG_RIO >> >> # XTENSA Architecture >> >> +# Xen Architecture >> + >> +config XEN_WDT >> + tristate "Xen Watchdog support" >> + depends on XEN >> + help >> + Say Y here to support the hypervisor watchdog capability provided >> + by Xen 4.0 and newer. The watchdog timeout period is normally one >> + minute but can be changed with a boot-time parameter. >> + >> # >> # ISA-based Watchdog Cards >> # >> --- linux-2.6.36-rc6/drivers/watchdog/Makefile >> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Makefile >> @@ -145,6 +145,9 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o >> >> # XTENSA Architecture >> >> +# Xen >> +obj-$(CONFIG_XEN_WDT) += xen_wdt.o >> + >> # Architecture Independant >> obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o >> obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o >> --- linux-2.6.36-rc6/drivers/watchdog/xen_wdt.c >> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/xen_wdt.c >> @@ -0,0 +1,359 @@ >> +/* >> + * Xen Watchdog Driver >> + * >> + * (c) Copyright 2010 Novell, Inc. >> + * >> + * This program is free software; you can redistribute it and/or >> + * modify it under the terms of the GNU General Public License >> + * as published by the Free Software Foundation; either version >> + * 2 of the License, or (at your option) any later version. >> + */ >> + >> +#define DRV_NAME "wdt" >> +#define DRV_VERSION "0.01" >> +#define PFX DRV_NAME ": " >> + >> +#include <linux/bug.h> >> +#include <linux/errno.h> >> +#include <linux/fs.h> >> +#include <linux/hrtimer.h> >> +#include <linux/kernel.h> >> +#include <linux/ktime.h> >> +#include <linux/init.h> >> +#include <linux/miscdevice.h> >> +#include <linux/module.h> >> +#include <linux/moduleparam.h> >> +#include <linux/platform_device.h> >> +#include <linux/spinlock.h> >> +#include <linux/uaccess.h> >> +#include <linux/watchdog.h> >> +#include <xen/xen.h> >> +#include <asm/xen/hypercall.h> >> +#include <xen/interface/sched.h> >> + >> +static struct platform_device *platform_device; >> +static DEFINE_SPINLOCK(wdt_lock); >> +static struct sched_watchdog wdt; >> +static __kernel_time_t wdt_expires; >> +static bool is_active, expect_release; >> + >> +#define WATCHDOG_TIMEOUT 60 /* in seconds */ >> +static unsigned int timeout = WATCHDOG_TIMEOUT; >> +module_param(timeout, uint, S_IRUGO); >> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " >> + "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); >> + >> +static bool nowayout = WATCHDOG_NOWAYOUT; >> +module_param(nowayout, bool, S_IRUGO); >> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " >> + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); >> + >> +static inline __kernel_time_t set_timeout(void) >> +{ >> + wdt.timeout = timeout; >> + return ktime_to_timespec(ktime_get()).tv_sec + timeout; >> +} >> + >> +static int xen_wdt_start(void) >> +{ >> + __kernel_time_t expires; >> + int err; >> + >> + spin_lock(&wdt_lock); >> + >> + expires = set_timeout(); >> + if (!wdt.id) >> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >> + else >> + err = -EBUSY; >> + if (err > 0) { >> + wdt.id = err; >> + wdt_expires = expires; >> + err = 0; >> + } else >> + BUG_ON(!err); >> + >> + spin_unlock(&wdt_lock); >> + >> + return err; >> +} >> + >> +static int xen_wdt_stop(void) >> +{ >> + int err = 0; >> + >> + spin_lock(&wdt_lock); >> + >> + wdt.timeout = 0; >> + if (wdt.id) >> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >> + if (!err) >> + wdt.id = 0; >> + >> + spin_unlock(&wdt_lock); >> + >> + return err; >> +} >> + >> +static int xen_wdt_kick(void) >> +{ >> + __kernel_time_t expires; >> + int err; >> + >> + spin_lock(&wdt_lock); >> + >> + expires = set_timeout(); >> + if (wdt.id) >> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >> + else >> + err = -ENXIO; >> + if (!err) >> + wdt_expires = expires; >> + >> + spin_unlock(&wdt_lock); >> + >> + return err; >> +} >> + >> +static int xen_wdt_open(struct inode *inode, struct file *file) >> +{ >> + int err; >> + >> + /* /dev/watchdog can only be opened once */ >> + if (xchg(&is_active, true)) >> + return -EBUSY; >> + >> + err = xen_wdt_start(); >> + if (err == -EBUSY) >> + err = xen_wdt_kick(); >> + return err ?: nonseekable_open(inode, file); >> +} >> + >> +static int xen_wdt_release(struct inode *inode, struct file *file) >> +{ >> + if (expect_release) >> + xen_wdt_stop(); >> + else { >> + printk(KERN_CRIT PFX >> + "unexpected close, not stopping watchdog!\n"); >> + xen_wdt_kick(); >> + } >> + is_active = false; >> + expect_release = false; >> + return 0; >> +} >> + >> +static ssize_t xen_wdt_write(struct file *file, const char __user *data, >> + size_t len, loff_t *ppos) >> +{ >> + /* See if we got the magic character ''V'' and reload the timer */ >> + if (len) { >> + if (!nowayout) { >> + size_t i; >> + >> + /* in case it was set long ago */ >> + expect_release = false; >> + >> + /* scan to see whether or not we got the magic >> + character */ >> + for (i = 0; i != len; i++) { >> + char c; >> + if (get_user(c, data + i)) >> + return -EFAULT; >> + if (c == ''V'') >> + expect_release = true; >> + } >> + } >> + >> + /* someone wrote to us, we should reload the timer */ >> + xen_wdt_kick(); >> + } >> + return len; >> +} >> + >> +static long xen_wdt_ioctl(struct file *file, unsigned int cmd, >> + unsigned long arg) >> +{ >> + int new_options, retval = -EINVAL; >> + int new_timeout; >> + int __user *argp = (void __user *)arg; >> + static const struct watchdog_info ident = { >> + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, >> + .firmware_version = 0, >> + .identity = DRV_NAME, >> + }; >> + >> + switch (cmd) { >> + case WDIOC_GETSUPPORT: >> + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; >> + >> + case WDIOC_GETSTATUS: >> + case WDIOC_GETBOOTSTATUS: >> + return put_user(0, argp); >> + >> + case WDIOC_SETOPTIONS: >> + if (get_user(new_options, argp)) >> + return -EFAULT; >> + >> + if (new_options & WDIOS_DISABLECARD) >> + retval = xen_wdt_stop(); >> + if (new_options & WDIOS_ENABLECARD) { >> + retval = xen_wdt_start(); >> + if (retval == -EBUSY) >> + retval = xen_wdt_kick(); >> + } >> + return retval; >> + >> + case WDIOC_KEEPALIVE: >> + xen_wdt_kick(); >> + return 0; >> + >> + case WDIOC_SETTIMEOUT: >> + if (get_user(new_timeout, argp)) >> + return -EFAULT; >> + if (!new_timeout) >> + return -EINVAL; >> + timeout = new_timeout; >> + xen_wdt_kick(); >> + /* fall through */ >> + case WDIOC_GETTIMEOUT: >> + return put_user(timeout, argp); >> + >> + case WDIOC_GETTIMELEFT: >> + retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec; >> + return put_user(retval, argp); >> + } >> + >> + return -ENOTTY; >> +} >> + >> +static const struct file_operations xen_wdt_fops = { >> + .owner = THIS_MODULE, >> + .llseek = no_llseek, >> + .write = xen_wdt_write, >> + .unlocked_ioctl = xen_wdt_ioctl, >> + .open = xen_wdt_open, >> + .release = xen_wdt_release, >> +}; >> + >> +static struct miscdevice xen_wdt_miscdev = { >> + .minor = WATCHDOG_MINOR, >> + .name = "watchdog", >> + .fops = &xen_wdt_fops, >> +}; >> + >> +static int __devinit xen_wdt_probe(struct platform_device *dev) >> +{ >> + struct sched_watchdog wd = { .id = ~0 }; >> + int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd); >> + >> + switch (ret) { >> + case -EINVAL: >> + if (!timeout) { >> + timeout = WATCHDOG_TIMEOUT; >> + printk(KERN_INFO PFX >> + "timeout value invalid, using %d\n", timeout); >> + } >> + >> + ret = misc_register(&xen_wdt_miscdev); >> + if (ret) { >> + printk(KERN_ERR PFX >> + "cannot register miscdev on minor=%d (%d)\n", >> + WATCHDOG_MINOR, ret); >> + break; >> + } >> + >> + printk(KERN_INFO PFX >> + "initialized (timeout=%ds, nowayout=%d)\n", >> + timeout, nowayout); >> + break; >> + >> + case -ENOSYS: >> + printk(KERN_INFO PFX "not supported\n"); >> + ret = -ENODEV; >> + break; >> + >> + default: >> + printk(KERN_INFO PFX "bogus return value %d\n", ret); >> + break; >> + } >> + >> + return ret; >> +} >> + >> +static int __devexit xen_wdt_remove(struct platform_device *dev) >> +{ >> + /* Stop the timer before we leave */ >> + if (!nowayout) >> + xen_wdt_stop(); >> + >> + misc_deregister(&xen_wdt_miscdev); >> + >> + return 0; >> +} >> + >> +static void xen_wdt_shutdown(struct platform_device *dev) >> +{ >> + xen_wdt_stop(); >> +} >> + >> +static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state) >> +{ >> + return xen_wdt_stop(); >> +} >> + >> +static int xen_wdt_resume(struct platform_device *dev) >> +{ >> + return xen_wdt_start(); >> +} >> + >> +static struct platform_driver xen_wdt_driver = { >> + .probe = xen_wdt_probe, >> + .remove = __devexit_p(xen_wdt_remove), >> + .shutdown = xen_wdt_shutdown, >> + .suspend = xen_wdt_suspend, >> + .resume = xen_wdt_resume, >> + .driver = { >> + .owner = THIS_MODULE, >> + .name = DRV_NAME, >> + }, >> +}; >> + >> +static int __init xen_wdt_init_module(void) >> +{ >> + int err; >> + >> + if (!xen_domain()) >> + return -ENODEV; >> + >> + printk(KERN_INFO PFX "Xen WatchDog Timer Driver v%s\n", DRV_VERSION); >> + >> + err = platform_driver_register(&xen_wdt_driver); >> + if (err) >> + return err; >> + >> + platform_device = platform_device_register_simple(DRV_NAME, >> + -1, NULL, 0); >> + if (IS_ERR(platform_device)) { >> + err = PTR_ERR(platform_device); >> + platform_driver_unregister(&xen_wdt_driver); >> + } >> + >> + return err; >> +} >> + >> +static void __exit xen_wdt_cleanup_module(void) >> +{ >> + platform_device_unregister(platform_device); >> + platform_driver_unregister(&xen_wdt_driver); >> + printk(KERN_INFO PFX "module unloaded\n"); >> +} >> + >> +module_init(xen_wdt_init_module); >> +module_exit(xen_wdt_cleanup_module); >> + >> +MODULE_AUTHOR("Jen Beulich <jbeulich@novell.com>"); >> +MODULE_DESCRIPTION("Xen WatchDog Timer Driver"); >> +MODULE_VERSION(DRV_VERSION); >> +MODULE_LICENSE("GPL"); >> +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); >> --- linux-2.6.36-rc6/include/xen/interface/sched.h >> +++ 2.6.36-rc6-xen-watchdog/include/xen/interface/sched.h >> @@ -65,6 +65,39 @@ struct sched_poll { >> DEFINE_GUEST_HANDLE_STRUCT(sched_poll); >> >> /* >> + * Declare a shutdown for another domain. The main use of this function is >> + * in interpreting shutdown requests and reasons for fully-virtualized >> + * domains. A para-virtualized domain may use SCHEDOP_shutdown directly. >> + * @arg == pointer to sched_remote_shutdown structure. >> + */ >> +#define SCHEDOP_remote_shutdown 4 >> +struct sched_remote_shutdown { >> + domid_t domain_id; /* Remote domain ID */ >> + unsigned int reason; /* SHUTDOWN_xxx reason */ >> +}; >> + >> +/* >> + * Latch a shutdown code, so that when the domain later shuts down it >> + * reports this code to the control tools. >> + * @arg == as for SCHEDOP_shutdown. >> + */ >> +#define SCHEDOP_shutdown_code 5 >> + >> +/* >> + * Setup, poke and destroy a domain watchdog timer. >> + * @arg == pointer to sched_watchdog structure. >> + * With id == 0, setup a domain watchdog timer to cause domain shutdown >> + * after timeout, returns watchdog id. >> + * With id != 0 and timeout == 0, destroy domain watchdog timer. >> + * With id != 0 and timeout != 0, poke watchdog timer and set new timeout. >> + */ >> +#define SCHEDOP_watchdog 6 >> +struct sched_watchdog { >> + uint32_t id; /* watchdog ID */ >> + uint32_t timeout; /* timeout */ >> +}; >> + >> +/* >> * Reason codes for SCHEDOP_shutdown. These may be interpreted by control >> * software to determine the appropriate action. For the most part, Xen > does >> * not care about the shutdown code. >> @@ -73,5 +106,6 @@ DEFINE_GUEST_HANDLE_STRUCT(sched_poll); >> #define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. > */ >> #define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. > */ >> #define SHUTDOWN_crash 3 /* Tell controller we''ve crashed. > */ >> +#define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. > */ >> >> #endif /* __XEN_PUBLIC_SCHED_H__ */ >> >>_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On 09/30/2010 11:56 PM, Jan Beulich wrote:> >>> On 30.09.10 at 18:16, Jeremy Fitzhardinge <jeremy@goop.org> wrote: >> On 09/30/2010 07:01 AM, Jan Beulich wrote: >>> While the hypervisor change adding SCHEDOP_watchdog support included a >>> daemon to make use of the new functionality, having a kernel driver >>> for /dev/watchdog so that user space code doesn''t need to distinguish >>> non-Xen and Xen seems to be preferable. >> Looks good. Are you going to submit this upstream? > By sending it to you I thought I did.I''m not the exclusive path for upstream Xen; I''m happy to ack things and let others submit them. But I''m also happy to submit this too. J> Confused, Jan > >>> Signed-off-by: Jan Beulich <jbeulich@novell.com> >>> >>> --- >>> drivers/watchdog/Kconfig | 10 + >>> drivers/watchdog/Makefile | 3 >>> drivers/watchdog/xen_wdt.c | 359 >> ++++++++++++++++++++++++++++++++++++++++++ >>> include/xen/interface/sched.h | 34 +++ >>> 4 files changed, 406 insertions(+) >>> >>> --- linux-2.6.36-rc6/drivers/watchdog/Kconfig >>> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Kconfig >>> @@ -1043,6 +1043,16 @@ config WATCHDOG_RIO >>> >>> # XTENSA Architecture >>> >>> +# Xen Architecture >>> + >>> +config XEN_WDT >>> + tristate "Xen Watchdog support" >>> + depends on XEN >>> + help >>> + Say Y here to support the hypervisor watchdog capability provided >>> + by Xen 4.0 and newer. The watchdog timeout period is normally one >>> + minute but can be changed with a boot-time parameter. >>> + >>> # >>> # ISA-based Watchdog Cards >>> # >>> --- linux-2.6.36-rc6/drivers/watchdog/Makefile >>> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Makefile >>> @@ -145,6 +145,9 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o >>> >>> # XTENSA Architecture >>> >>> +# Xen >>> +obj-$(CONFIG_XEN_WDT) += xen_wdt.o >>> + >>> # Architecture Independant >>> obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o >>> obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o >>> --- linux-2.6.36-rc6/drivers/watchdog/xen_wdt.c >>> +++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/xen_wdt.c >>> @@ -0,0 +1,359 @@ >>> +/* >>> + * Xen Watchdog Driver >>> + * >>> + * (c) Copyright 2010 Novell, Inc. >>> + * >>> + * This program is free software; you can redistribute it and/or >>> + * modify it under the terms of the GNU General Public License >>> + * as published by the Free Software Foundation; either version >>> + * 2 of the License, or (at your option) any later version. >>> + */ >>> + >>> +#define DRV_NAME "wdt" >>> +#define DRV_VERSION "0.01" >>> +#define PFX DRV_NAME ": " >>> + >>> +#include <linux/bug.h> >>> +#include <linux/errno.h> >>> +#include <linux/fs.h> >>> +#include <linux/hrtimer.h> >>> +#include <linux/kernel.h> >>> +#include <linux/ktime.h> >>> +#include <linux/init.h> >>> +#include <linux/miscdevice.h> >>> +#include <linux/module.h> >>> +#include <linux/moduleparam.h> >>> +#include <linux/platform_device.h> >>> +#include <linux/spinlock.h> >>> +#include <linux/uaccess.h> >>> +#include <linux/watchdog.h> >>> +#include <xen/xen.h> >>> +#include <asm/xen/hypercall.h> >>> +#include <xen/interface/sched.h> >>> + >>> +static struct platform_device *platform_device; >>> +static DEFINE_SPINLOCK(wdt_lock); >>> +static struct sched_watchdog wdt; >>> +static __kernel_time_t wdt_expires; >>> +static bool is_active, expect_release; >>> + >>> +#define WATCHDOG_TIMEOUT 60 /* in seconds */ >>> +static unsigned int timeout = WATCHDOG_TIMEOUT; >>> +module_param(timeout, uint, S_IRUGO); >>> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " >>> + "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); >>> + >>> +static bool nowayout = WATCHDOG_NOWAYOUT; >>> +module_param(nowayout, bool, S_IRUGO); >>> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " >>> + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); >>> + >>> +static inline __kernel_time_t set_timeout(void) >>> +{ >>> + wdt.timeout = timeout; >>> + return ktime_to_timespec(ktime_get()).tv_sec + timeout; >>> +} >>> + >>> +static int xen_wdt_start(void) >>> +{ >>> + __kernel_time_t expires; >>> + int err; >>> + >>> + spin_lock(&wdt_lock); >>> + >>> + expires = set_timeout(); >>> + if (!wdt.id) >>> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >>> + else >>> + err = -EBUSY; >>> + if (err > 0) { >>> + wdt.id = err; >>> + wdt_expires = expires; >>> + err = 0; >>> + } else >>> + BUG_ON(!err); >>> + >>> + spin_unlock(&wdt_lock); >>> + >>> + return err; >>> +} >>> + >>> +static int xen_wdt_stop(void) >>> +{ >>> + int err = 0; >>> + >>> + spin_lock(&wdt_lock); >>> + >>> + wdt.timeout = 0; >>> + if (wdt.id) >>> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >>> + if (!err) >>> + wdt.id = 0; >>> + >>> + spin_unlock(&wdt_lock); >>> + >>> + return err; >>> +} >>> + >>> +static int xen_wdt_kick(void) >>> +{ >>> + __kernel_time_t expires; >>> + int err; >>> + >>> + spin_lock(&wdt_lock); >>> + >>> + expires = set_timeout(); >>> + if (wdt.id) >>> + err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); >>> + else >>> + err = -ENXIO; >>> + if (!err) >>> + wdt_expires = expires; >>> + >>> + spin_unlock(&wdt_lock); >>> + >>> + return err; >>> +} >>> + >>> +static int xen_wdt_open(struct inode *inode, struct file *file) >>> +{ >>> + int err; >>> + >>> + /* /dev/watchdog can only be opened once */ >>> + if (xchg(&is_active, true)) >>> + return -EBUSY; >>> + >>> + err = xen_wdt_start(); >>> + if (err == -EBUSY) >>> + err = xen_wdt_kick(); >>> + return err ?: nonseekable_open(inode, file); >>> +} >>> + >>> +static int xen_wdt_release(struct inode *inode, struct file *file) >>> +{ >>> + if (expect_release) >>> + xen_wdt_stop(); >>> + else { >>> + printk(KERN_CRIT PFX >>> + "unexpected close, not stopping watchdog!\n"); >>> + xen_wdt_kick(); >>> + } >>> + is_active = false; >>> + expect_release = false; >>> + return 0; >>> +} >>> + >>> +static ssize_t xen_wdt_write(struct file *file, const char __user *data, >>> + size_t len, loff_t *ppos) >>> +{ >>> + /* See if we got the magic character ''V'' and reload the timer */ >>> + if (len) { >>> + if (!nowayout) { >>> + size_t i; >>> + >>> + /* in case it was set long ago */ >>> + expect_release = false; >>> + >>> + /* scan to see whether or not we got the magic >>> + character */ >>> + for (i = 0; i != len; i++) { >>> + char c; >>> + if (get_user(c, data + i)) >>> + return -EFAULT; >>> + if (c == ''V'') >>> + expect_release = true; >>> + } >>> + } >>> + >>> + /* someone wrote to us, we should reload the timer */ >>> + xen_wdt_kick(); >>> + } >>> + return len; >>> +} >>> + >>> +static long xen_wdt_ioctl(struct file *file, unsigned int cmd, >>> + unsigned long arg) >>> +{ >>> + int new_options, retval = -EINVAL; >>> + int new_timeout; >>> + int __user *argp = (void __user *)arg; >>> + static const struct watchdog_info ident = { >>> + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, >>> + .firmware_version = 0, >>> + .identity = DRV_NAME, >>> + }; >>> + >>> + switch (cmd) { >>> + case WDIOC_GETSUPPORT: >>> + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; >>> + >>> + case WDIOC_GETSTATUS: >>> + case WDIOC_GETBOOTSTATUS: >>> + return put_user(0, argp); >>> + >>> + case WDIOC_SETOPTIONS: >>> + if (get_user(new_options, argp)) >>> + return -EFAULT; >>> + >>> + if (new_options & WDIOS_DISABLECARD) >>> + retval = xen_wdt_stop(); >>> + if (new_options & WDIOS_ENABLECARD) { >>> + retval = xen_wdt_start(); >>> + if (retval == -EBUSY) >>> + retval = xen_wdt_kick(); >>> + } >>> + return retval; >>> + >>> + case WDIOC_KEEPALIVE: >>> + xen_wdt_kick(); >>> + return 0; >>> + >>> + case WDIOC_SETTIMEOUT: >>> + if (get_user(new_timeout, argp)) >>> + return -EFAULT; >>> + if (!new_timeout) >>> + return -EINVAL; >>> + timeout = new_timeout; >>> + xen_wdt_kick(); >>> + /* fall through */ >>> + case WDIOC_GETTIMEOUT: >>> + return put_user(timeout, argp); >>> + >>> + case WDIOC_GETTIMELEFT: >>> + retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec; >>> + return put_user(retval, argp); >>> + } >>> + >>> + return -ENOTTY; >>> +} >>> + >>> +static const struct file_operations xen_wdt_fops = { >>> + .owner = THIS_MODULE, >>> + .llseek = no_llseek, >>> + .write = xen_wdt_write, >>> + .unlocked_ioctl = xen_wdt_ioctl, >>> + .open = xen_wdt_open, >>> + .release = xen_wdt_release, >>> +}; >>> + >>> +static struct miscdevice xen_wdt_miscdev = { >>> + .minor = WATCHDOG_MINOR, >>> + .name = "watchdog", >>> + .fops = &xen_wdt_fops, >>> +}; >>> + >>> +static int __devinit xen_wdt_probe(struct platform_device *dev) >>> +{ >>> + struct sched_watchdog wd = { .id = ~0 }; >>> + int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd); >>> + >>> + switch (ret) { >>> + case -EINVAL: >>> + if (!timeout) { >>> + timeout = WATCHDOG_TIMEOUT; >>> + printk(KERN_INFO PFX >>> + "timeout value invalid, using %d\n", timeout); >>> + } >>> + >>> + ret = misc_register(&xen_wdt_miscdev); >>> + if (ret) { >>> + printk(KERN_ERR PFX >>> + "cannot register miscdev on minor=%d (%d)\n", >>> + WATCHDOG_MINOR, ret); >>> + break; >>> + } >>> + >>> + printk(KERN_INFO PFX >>> + "initialized (timeout=%ds, nowayout=%d)\n", >>> + timeout, nowayout); >>> + break; >>> + >>> + case -ENOSYS: >>> + printk(KERN_INFO PFX "not supported\n"); >>> + ret = -ENODEV; >>> + break; >>> + >>> + default: >>> + printk(KERN_INFO PFX "bogus return value %d\n", ret); >>> + break; >>> + } >>> + >>> + return ret; >>> +} >>> + >>> +static int __devexit xen_wdt_remove(struct platform_device *dev) >>> +{ >>> + /* Stop the timer before we leave */ >>> + if (!nowayout) >>> + xen_wdt_stop(); >>> + >>> + misc_deregister(&xen_wdt_miscdev); >>> + >>> + return 0; >>> +} >>> + >>> +static void xen_wdt_shutdown(struct platform_device *dev) >>> +{ >>> + xen_wdt_stop(); >>> +} >>> + >>> +static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state) >>> +{ >>> + return xen_wdt_stop(); >>> +} >>> + >>> +static int xen_wdt_resume(struct platform_device *dev) >>> +{ >>> + return xen_wdt_start(); >>> +} >>> + >>> +static struct platform_driver xen_wdt_driver = { >>> + .probe = xen_wdt_probe, >>> + .remove = __devexit_p(xen_wdt_remove), >>> + .shutdown = xen_wdt_shutdown, >>> + .suspend = xen_wdt_suspend, >>> + .resume = xen_wdt_resume, >>> + .driver = { >>> + .owner = THIS_MODULE, >>> + .name = DRV_NAME, >>> + }, >>> +}; >>> + >>> +static int __init xen_wdt_init_module(void) >>> +{ >>> + int err; >>> + >>> + if (!xen_domain()) >>> + return -ENODEV; >>> + >>> + printk(KERN_INFO PFX "Xen WatchDog Timer Driver v%s\n", DRV_VERSION); >>> + >>> + err = platform_driver_register(&xen_wdt_driver); >>> + if (err) >>> + return err; >>> + >>> + platform_device = platform_device_register_simple(DRV_NAME, >>> + -1, NULL, 0); >>> + if (IS_ERR(platform_device)) { >>> + err = PTR_ERR(platform_device); >>> + platform_driver_unregister(&xen_wdt_driver); >>> + } >>> + >>> + return err; >>> +} >>> + >>> +static void __exit xen_wdt_cleanup_module(void) >>> +{ >>> + platform_device_unregister(platform_device); >>> + platform_driver_unregister(&xen_wdt_driver); >>> + printk(KERN_INFO PFX "module unloaded\n"); >>> +} >>> + >>> +module_init(xen_wdt_init_module); >>> +module_exit(xen_wdt_cleanup_module); >>> + >>> +MODULE_AUTHOR("Jen Beulich <jbeulich@novell.com>"); >>> +MODULE_DESCRIPTION("Xen WatchDog Timer Driver"); >>> +MODULE_VERSION(DRV_VERSION); >>> +MODULE_LICENSE("GPL"); >>> +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); >>> --- linux-2.6.36-rc6/include/xen/interface/sched.h >>> +++ 2.6.36-rc6-xen-watchdog/include/xen/interface/sched.h >>> @@ -65,6 +65,39 @@ struct sched_poll { >>> DEFINE_GUEST_HANDLE_STRUCT(sched_poll); >>> >>> /* >>> + * Declare a shutdown for another domain. The main use of this function is >>> + * in interpreting shutdown requests and reasons for fully-virtualized >>> + * domains. A para-virtualized domain may use SCHEDOP_shutdown directly. >>> + * @arg == pointer to sched_remote_shutdown structure. >>> + */ >>> +#define SCHEDOP_remote_shutdown 4 >>> +struct sched_remote_shutdown { >>> + domid_t domain_id; /* Remote domain ID */ >>> + unsigned int reason; /* SHUTDOWN_xxx reason */ >>> +}; >>> + >>> +/* >>> + * Latch a shutdown code, so that when the domain later shuts down it >>> + * reports this code to the control tools. >>> + * @arg == as for SCHEDOP_shutdown. >>> + */ >>> +#define SCHEDOP_shutdown_code 5 >>> + >>> +/* >>> + * Setup, poke and destroy a domain watchdog timer. >>> + * @arg == pointer to sched_watchdog structure. >>> + * With id == 0, setup a domain watchdog timer to cause domain shutdown >>> + * after timeout, returns watchdog id. >>> + * With id != 0 and timeout == 0, destroy domain watchdog timer. >>> + * With id != 0 and timeout != 0, poke watchdog timer and set new timeout. >>> + */ >>> +#define SCHEDOP_watchdog 6 >>> +struct sched_watchdog { >>> + uint32_t id; /* watchdog ID */ >>> + uint32_t timeout; /* timeout */ >>> +}; >>> + >>> +/* >>> * Reason codes for SCHEDOP_shutdown. These may be interpreted by control >>> * software to determine the appropriate action. For the most part, Xen >> does >>> * not care about the shutdown code. >>> @@ -73,5 +106,6 @@ DEFINE_GUEST_HANDLE_STRUCT(sched_poll); >>> #define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. >> */ >>> #define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. >> */ >>> #define SHUTDOWN_crash 3 /* Tell controller we''ve crashed. >> */ >>> +#define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. >> */ >>> >>> #endif /* __XEN_PUBLIC_SCHED_H__ */ >>> >>> >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Fri, 2010-10-01 at 07:56 +0100, Jan Beulich wrote:> >>> On 30.09.10 at 18:16, Jeremy Fitzhardinge <jeremy@goop.org> wrote: > > On 09/30/2010 07:01 AM, Jan Beulich wrote: > >> While the hypervisor change adding SCHEDOP_watchdog support included a > >> daemon to make use of the new functionality, having a kernel driver > >> for /dev/watchdog so that user space code doesn''t need to distinguish > >> non-Xen and Xen seems to be preferable. > > > > Looks good. Are you going to submit this upstream? > > By sending it to you I thought I did.I think we all need to start trying to move from the mindset that xen.git is the only target of our development efforts and instead work much more directly/closely with Linux upstream, in particular with subsystem maintainers of other areas touched by our patches. Many Xen patches differ from the norm in that they are cross-subsystem (e.g. they implement Xen functionality in the context of some other subsystem such as networking, block, watchdog subsystems) rather than being obviously single subsystem with the more normal linear progression through driver maintainer to subsystem maintainers to Linus etc. I think it should be the responsibility of the patch contributor to get review and thence an Acked-by from both/all subsystem maintainers (IOW both Jeremy and the other subsystem''s maintainers), regardless of which tree the patch eventually gets committed to. For cases where there is no impediment to sending stuff directly upstream pushing stuff only towards xen.git works against the goal of having first class Xen support in the upstream kernel. Even in cases where a patch depends on something which is currently only in xen.git I think taking it to the relevant subsystem and getting an in-principle-Acked-by makes sense in many cases and will help with the eventual upstreaming. I could even go so far as to argue that in many cases (especially for domU stuff) the primary subsystem of interest for a patch is not Xen but the other one and that only core Xen stuff really needs to go through xen.git. In other words in most cases the main target of upstreaming should be the maintainer of the relevant other subsystem, of course with Jeremy''s and/or other Xen community members'' Reviewed/Acked/Tested-by. This sort of model has already worked well for Stefano''s pvhvm drivers and is looking good for Konrad''s swiotlb/pcifront stuff too. Although the above is really intended as a more general comment on our development practices I do think a watchdog driver is another good example of a patch which could go via the watchdog subsystem maintainer rather than xen.git. Ian. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
While the hypervisor change adding SCHEDOP_watchdog support included a
daemon to make use of the new functionality, having a kernel driver
for /dev/watchdog so that user space code doesn''t need to distinguish
non-Xen and Xen seems to be preferable.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
---
drivers/watchdog/Kconfig | 10 +
drivers/watchdog/Makefile | 3
drivers/watchdog/xen_wdt.c | 359 ++++++++++++++++++++++++++++++++++++++++++
include/xen/interface/sched.h | 34 +++
4 files changed, 406 insertions(+)
--- linux-2.6.36-rc6/drivers/watchdog/Kconfig
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Kconfig
@@ -1043,6 +1043,16 @@ config WATCHDOG_RIO
# XTENSA Architecture
+# Xen Architecture
+
+config XEN_WDT
+ tristate "Xen Watchdog support"
+ depends on XEN
+ help
+ Say Y here to support the hypervisor watchdog capability provided
+ by Xen 4.0 and newer. The watchdog timeout period is normally one
+ minute but can be changed with a boot-time parameter.
+
#
# ISA-based Watchdog Cards
#
--- linux-2.6.36-rc6/drivers/watchdog/Makefile
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/Makefile
@@ -145,6 +145,9 @@ obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o
# XTENSA Architecture
+# Xen
+obj-$(CONFIG_XEN_WDT) += xen_wdt.o
+
# Architecture Independant
obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
--- linux-2.6.36-rc6/drivers/watchdog/xen_wdt.c
+++ 2.6.36-rc6-xen-watchdog/drivers/watchdog/xen_wdt.c
@@ -0,0 +1,359 @@
+/*
+ * Xen Watchdog Driver
+ *
+ * (c) Copyright 2010 Novell, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define DRV_NAME "wdt"
+#define DRV_VERSION "0.01"
+#define PFX DRV_NAME ": "
+
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/hrtimer.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <xen/xen.h>
+#include <asm/xen/hypercall.h>
+#include <xen/interface/sched.h>
+
+static struct platform_device *platform_device;
+static DEFINE_SPINLOCK(wdt_lock);
+static struct sched_watchdog wdt;
+static __kernel_time_t wdt_expires;
+static bool is_active, expect_release;
+
+#define WATCHDOG_TIMEOUT 60 /* in seconds */
+static unsigned int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, uint, S_IRUGO);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
+ "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, S_IRUGO);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static inline __kernel_time_t set_timeout(void)
+{
+ wdt.timeout = timeout;
+ return ktime_to_timespec(ktime_get()).tv_sec + timeout;
+}
+
+static int xen_wdt_start(void)
+{
+ __kernel_time_t expires;
+ int err;
+
+ spin_lock(&wdt_lock);
+
+ expires = set_timeout();
+ if (!wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ else
+ err = -EBUSY;
+ if (err > 0) {
+ wdt.id = err;
+ wdt_expires = expires;
+ err = 0;
+ } else
+ BUG_ON(!err);
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_stop(void)
+{
+ int err = 0;
+
+ spin_lock(&wdt_lock);
+
+ wdt.timeout = 0;
+ if (wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ if (!err)
+ wdt.id = 0;
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_kick(void)
+{
+ __kernel_time_t expires;
+ int err;
+
+ spin_lock(&wdt_lock);
+
+ expires = set_timeout();
+ if (wdt.id)
+ err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
+ else
+ err = -ENXIO;
+ if (!err)
+ wdt_expires = expires;
+
+ spin_unlock(&wdt_lock);
+
+ return err;
+}
+
+static int xen_wdt_open(struct inode *inode, struct file *file)
+{
+ int err;
+
+ /* /dev/watchdog can only be opened once */
+ if (xchg(&is_active, true))
+ return -EBUSY;
+
+ err = xen_wdt_start();
+ if (err == -EBUSY)
+ err = xen_wdt_kick();
+ return err ?: nonseekable_open(inode, file);
+}
+
+static int xen_wdt_release(struct inode *inode, struct file *file)
+{
+ if (expect_release)
+ xen_wdt_stop();
+ else {
+ printk(KERN_CRIT PFX
+ "unexpected close, not stopping watchdog!\n");
+ xen_wdt_kick();
+ }
+ is_active = false;
+ expect_release = false;
+ return 0;
+}
+
+static ssize_t xen_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* See if we got the magic character ''V'' and reload the
timer */
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* in case it was set long ago */
+ expect_release = false;
+
+ /* scan to see whether or not we got the magic
+ character */
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == ''V'')
+ expect_release = true;
+ }
+ }
+
+ /* someone wrote to us, we should reload the timer */
+ xen_wdt_kick();
+ }
+ return len;
+}
+
+static long xen_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ int new_options, retval = -EINVAL;
+ int new_timeout;
+ int __user *argp = (void __user *)arg;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = DRV_NAME,
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, argp);
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(new_options, argp))
+ return -EFAULT;
+
+ if (new_options & WDIOS_DISABLECARD)
+ retval = xen_wdt_stop();
+ if (new_options & WDIOS_ENABLECARD) {
+ retval = xen_wdt_start();
+ if (retval == -EBUSY)
+ retval = xen_wdt_kick();
+ }
+ return retval;
+
+ case WDIOC_KEEPALIVE:
+ xen_wdt_kick();
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, argp))
+ return -EFAULT;
+ if (!new_timeout)
+ return -EINVAL;
+ timeout = new_timeout;
+ xen_wdt_kick();
+ /* fall through */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, argp);
+
+ case WDIOC_GETTIMELEFT:
+ retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec;
+ return put_user(retval, argp);
+ }
+
+ return -ENOTTY;
+}
+
+static const struct file_operations xen_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = xen_wdt_write,
+ .unlocked_ioctl = xen_wdt_ioctl,
+ .open = xen_wdt_open,
+ .release = xen_wdt_release,
+};
+
+static struct miscdevice xen_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &xen_wdt_fops,
+};
+
+static int __devinit xen_wdt_probe(struct platform_device *dev)
+{
+ struct sched_watchdog wd = { .id = ~0 };
+ int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd);
+
+ switch (ret) {
+ case -EINVAL:
+ if (!timeout) {
+ timeout = WATCHDOG_TIMEOUT;
+ printk(KERN_INFO PFX
+ "timeout value invalid, using %d\n", timeout);
+ }
+
+ ret = misc_register(&xen_wdt_miscdev);
+ if (ret) {
+ printk(KERN_ERR PFX
+ "cannot register miscdev on minor=%d (%d)\n",
+ WATCHDOG_MINOR, ret);
+ break;
+ }
+
+ printk(KERN_INFO PFX
+ "initialized (timeout=%ds, nowayout=%d)\n",
+ timeout, nowayout);
+ break;
+
+ case -ENOSYS:
+ printk(KERN_INFO PFX "not supported\n");
+ ret = -ENODEV;
+ break;
+
+ default:
+ printk(KERN_INFO PFX "bogus return value %d\n", ret);
+ break;
+ }
+
+ return ret;
+}
+
+static int __devexit xen_wdt_remove(struct platform_device *dev)
+{
+ /* Stop the timer before we leave */
+ if (!nowayout)
+ xen_wdt_stop();
+
+ misc_deregister(&xen_wdt_miscdev);
+
+ return 0;
+}
+
+static void xen_wdt_shutdown(struct platform_device *dev)
+{
+ xen_wdt_stop();
+}
+
+static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state)
+{
+ return xen_wdt_stop();
+}
+
+static int xen_wdt_resume(struct platform_device *dev)
+{
+ return xen_wdt_start();
+}
+
+static struct platform_driver xen_wdt_driver = {
+ .probe = xen_wdt_probe,
+ .remove = __devexit_p(xen_wdt_remove),
+ .shutdown = xen_wdt_shutdown,
+ .suspend = xen_wdt_suspend,
+ .resume = xen_wdt_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ },
+};
+
+static int __init xen_wdt_init_module(void)
+{
+ int err;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ printk(KERN_INFO PFX "Xen WatchDog Timer Driver v%s\n",
DRV_VERSION);
+
+ err = platform_driver_register(&xen_wdt_driver);
+ if (err)
+ return err;
+
+ platform_device = platform_device_register_simple(DRV_NAME,
+ -1, NULL, 0);
+ if (IS_ERR(platform_device)) {
+ err = PTR_ERR(platform_device);
+ platform_driver_unregister(&xen_wdt_driver);
+ }
+
+ return err;
+}
+
+static void __exit xen_wdt_cleanup_module(void)
+{
+ platform_device_unregister(platform_device);
+ platform_driver_unregister(&xen_wdt_driver);
+ printk(KERN_INFO PFX "module unloaded\n");
+}
+
+module_init(xen_wdt_init_module);
+module_exit(xen_wdt_cleanup_module);
+
+MODULE_AUTHOR("Jan Beulich <jbeulich@novell.com>");
+MODULE_DESCRIPTION("Xen WatchDog Timer Driver");
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
--- linux-2.6.36-rc6/include/xen/interface/sched.h
+++ 2.6.36-rc6-xen-watchdog/include/xen/interface/sched.h
@@ -65,6 +65,39 @@ struct sched_poll {
DEFINE_GUEST_HANDLE_STRUCT(sched_poll);
/*
+ * Declare a shutdown for another domain. The main use of this function is
+ * in interpreting shutdown requests and reasons for fully-virtualized
+ * domains. A para-virtualized domain may use SCHEDOP_shutdown directly.
+ * @arg == pointer to sched_remote_shutdown structure.
+ */
+#define SCHEDOP_remote_shutdown 4
+struct sched_remote_shutdown {
+ domid_t domain_id; /* Remote domain ID */
+ unsigned int reason; /* SHUTDOWN_xxx reason */
+};
+
+/*
+ * Latch a shutdown code, so that when the domain later shuts down it
+ * reports this code to the control tools.
+ * @arg == as for SCHEDOP_shutdown.
+ */
+#define SCHEDOP_shutdown_code 5
+
+/*
+ * Setup, poke and destroy a domain watchdog timer.
+ * @arg == pointer to sched_watchdog structure.
+ * With id == 0, setup a domain watchdog timer to cause domain shutdown
+ * after timeout, returns watchdog id.
+ * With id != 0 and timeout == 0, destroy domain watchdog timer.
+ * With id != 0 and timeout != 0, poke watchdog timer and set new timeout.
+ */
+#define SCHEDOP_watchdog 6
+struct sched_watchdog {
+ uint32_t id; /* watchdog ID */
+ uint32_t timeout; /* timeout */
+};
+
+/*
* Reason codes for SCHEDOP_shutdown. These may be interpreted by control
* software to determine the appropriate action. For the most part, Xen does
* not care about the shutdown code.
@@ -73,5 +106,6 @@ DEFINE_GUEST_HANDLE_STRUCT(sched_poll);
#define SHUTDOWN_reboot 1 /* Clean up, kill, and then restart. */
#define SHUTDOWN_suspend 2 /* Clean up, save suspend info, kill. */
#define SHUTDOWN_crash 3 /* Tell controller we''ve crashed.
*/
+#define SHUTDOWN_watchdog 4 /* Restart because watchdog time expired. */
#endif /* __XEN_PUBLIC_SCHED_H__ */
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On 10/04/2010 02:15 AM, Ian Campbell wrote:> > I think we all need to start trying to move from the mindset that > xen.git is the only target of our development efforts and instead work > much more directly/closely with Linux upstream, in particular with > subsystem maintainers of other areas touched by our patches. > > Many Xen patches differ from the norm in that they are cross-subsystem > (e.g. they implement Xen functionality in the context of some other > subsystem such as networking, block, watchdog subsystems) rather than > being obviously single subsystem with the more normal linear progression > through driver maintainer to subsystem maintainers to Linus etc. > > I think it should be the responsibility of the patch contributor to get > review and thence an Acked-by from both/all subsystem maintainers (IOW > both Jeremy and the other subsystem''s maintainers), regardless of which > tree the patch eventually gets committed to. > > For cases where there is no impediment to sending stuff directly > upstream pushing stuff only towards xen.git works against the goal of > having first class Xen support in the upstream kernel. Even in cases > where a patch depends on something which is currently only in xen.git I > think taking it to the relevant subsystem and getting an > in-principle-Acked-by makes sense in many cases and will help with the > eventual upstreaming. > > I could even go so far as to argue that in many cases (especially for > domU stuff) the primary subsystem of interest for a patch is not Xen but > the other one and that only core Xen stuff really needs to go through > xen.git. In other words in most cases the main target of upstreaming > should be the maintainer of the relevant other subsystem, of course with > Jeremy''s and/or other Xen community members'' Reviewed/Acked/Tested-by. > > This sort of model has already worked well for Stefano''s pvhvm drivers > and is looking good for Konrad''s swiotlb/pcifront stuff too. Although > the above is really intended as a more general comment on our > development practices I do think a watchdog driver is another good > example of a patch which could go via the watchdog subsystem maintainer > rather than xen.git.Yes, exactly so. J _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel