[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] Re: [PATCH] Xen watchdog driver
On 09/30/2010 11:56 PM, Jan Beulich wrote: > >>> On 30.09.10 at 18:16, Jeremy Fitzhardinge <jeremy@xxxxxxxx> 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@xxxxxxxxxx> >>> >>> --- >>> 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@xxxxxxxxxx>"); >>> +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@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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