diff options
author | Jeremy Fitzhardinge <jeremy@xensource.com> | 2007-07-18 05:37:07 +0400 |
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committer | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-07-18 19:47:45 +0400 |
commit | 3e2b8fbeec8f005672f2a2e862fb9c26a0bafedc (patch) | |
tree | 47bd623e5d692daf3b91316a3a715ff7356bc22b /arch/i386/xen/manage.c | |
parent | fefa629abebe328cf6d07f99fe5796dbfc3e4981 (diff) | |
download | linux-3e2b8fbeec8f005672f2a2e862fb9c26a0bafedc.tar.xz |
xen: handle external requests for shutdown, reboot and sysrq
The guest domain can be asked to shutdown or reboot itself, or have a
sysrq key injected, via xenbus. This patch adds a watcher for those
events, and does the appropriate action.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Diffstat (limited to 'arch/i386/xen/manage.c')
-rw-r--r-- | arch/i386/xen/manage.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/i386/xen/manage.c b/arch/i386/xen/manage.c new file mode 100644 index 000000000000..aa7af9e6abc0 --- /dev/null +++ b/arch/i386/xen/manage.c @@ -0,0 +1,143 @@ +/* + * Handle extern requests for shutdown, reboot and sysrq + */ +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/reboot.h> +#include <linux/sysrq.h> + +#include <xen/xenbus.h> + +#define SHUTDOWN_INVALID -1 +#define SHUTDOWN_POWEROFF 0 +#define SHUTDOWN_SUSPEND 2 +/* Code 3 is SHUTDOWN_CRASH, which we don't use because the domain can only + * report a crash, not be instructed to crash! + * HALT is the same as POWEROFF, as far as we're concerned. The tools use + * the distinction when we return the reason code to them. + */ +#define SHUTDOWN_HALT 4 + +/* Ignore multiple shutdown requests. */ +static int shutting_down = SHUTDOWN_INVALID; + +static void shutdown_handler(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + char *str; + struct xenbus_transaction xbt; + int err; + + if (shutting_down != SHUTDOWN_INVALID) + return; + + again: + err = xenbus_transaction_start(&xbt); + if (err) + return; + + str = (char *)xenbus_read(xbt, "control", "shutdown", NULL); + /* Ignore read errors and empty reads. */ + if (XENBUS_IS_ERR_READ(str)) { + xenbus_transaction_end(xbt, 1); + return; + } + + xenbus_write(xbt, "control", "shutdown", ""); + + err = xenbus_transaction_end(xbt, 0); + if (err == -EAGAIN) { + kfree(str); + goto again; + } + + if (strcmp(str, "poweroff") == 0 || + strcmp(str, "halt") == 0) + orderly_poweroff(false); + else if (strcmp(str, "reboot") == 0) + ctrl_alt_del(); + else { + printk(KERN_INFO "Ignoring shutdown request: %s\n", str); + shutting_down = SHUTDOWN_INVALID; + } + + kfree(str); +} + +static void sysrq_handler(struct xenbus_watch *watch, const char **vec, + unsigned int len) +{ + char sysrq_key = '\0'; + struct xenbus_transaction xbt; + int err; + + again: + err = xenbus_transaction_start(&xbt); + if (err) + return; + if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) { + printk(KERN_ERR "Unable to read sysrq code in " + "control/sysrq\n"); + xenbus_transaction_end(xbt, 1); + return; + } + + if (sysrq_key != '\0') + xenbus_printf(xbt, "control", "sysrq", "%c", '\0'); + + err = xenbus_transaction_end(xbt, 0); + if (err == -EAGAIN) + goto again; + + if (sysrq_key != '\0') + handle_sysrq(sysrq_key, NULL); +} + +static struct xenbus_watch shutdown_watch = { + .node = "control/shutdown", + .callback = shutdown_handler +}; + +static struct xenbus_watch sysrq_watch = { + .node = "control/sysrq", + .callback = sysrq_handler +}; + +static int setup_shutdown_watcher(void) +{ + int err; + + err = register_xenbus_watch(&shutdown_watch); + if (err) { + printk(KERN_ERR "Failed to set shutdown watcher\n"); + return err; + } + + err = register_xenbus_watch(&sysrq_watch); + if (err) { + printk(KERN_ERR "Failed to set sysrq watcher\n"); + return err; + } + + return 0; +} + +static int shutdown_event(struct notifier_block *notifier, + unsigned long event, + void *data) +{ + setup_shutdown_watcher(); + return NOTIFY_DONE; +} + +static int __init setup_shutdown_event(void) +{ + static struct notifier_block xenstore_notifier = { + .notifier_call = shutdown_event + }; + register_xenstore_notifier(&xenstore_notifier); + + return 0; +} + +subsys_initcall(setup_shutdown_event); |