X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fxen%2Fmanage.c;fp=kernel%2Fdrivers%2Fxen%2Fmanage.c;h=9e6a85104a20820ff16ef748804eb8c6a98b4201;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/xen/manage.c b/kernel/drivers/xen/manage.c new file mode 100644 index 000000000..9e6a85104 --- /dev/null +++ b/kernel/drivers/xen/manage.c @@ -0,0 +1,355 @@ +/* + * Handle extern requests for shutdown, reboot and sysrq + */ + +#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +enum shutdown_state { + SHUTDOWN_INVALID = -1, + SHUTDOWN_POWEROFF = 0, + 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. */ + SHUTDOWN_HALT = 4, +}; + +/* Ignore multiple shutdown requests. */ +static enum shutdown_state shutting_down = SHUTDOWN_INVALID; + +struct suspend_info { + int cancelled; +}; + +static RAW_NOTIFIER_HEAD(xen_resume_notifier); + +void xen_resume_notifier_register(struct notifier_block *nb) +{ + raw_notifier_chain_register(&xen_resume_notifier, nb); +} +EXPORT_SYMBOL_GPL(xen_resume_notifier_register); + +void xen_resume_notifier_unregister(struct notifier_block *nb) +{ + raw_notifier_chain_unregister(&xen_resume_notifier, nb); +} +EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister); + +#ifdef CONFIG_HIBERNATE_CALLBACKS +static int xen_suspend(void *data) +{ + struct suspend_info *si = data; + int err; + + BUG_ON(!irqs_disabled()); + + err = syscore_suspend(); + if (err) { + pr_err("%s: system core suspend failed: %d\n", __func__, err); + return err; + } + + gnttab_suspend(); + xen_arch_pre_suspend(); + + /* + * This hypercall returns 1 if suspend was cancelled + * or the domain was merely checkpointed, and 0 if it + * is resuming in a new domain. + */ + si->cancelled = HYPERVISOR_suspend(xen_pv_domain() + ? virt_to_mfn(xen_start_info) + : 0); + + xen_arch_post_suspend(si->cancelled); + gnttab_resume(); + + if (!si->cancelled) { + xen_irq_resume(); + xen_timer_resume(); + } + + syscore_resume(); + + return 0; +} + +static void do_suspend(void) +{ + int err; + struct suspend_info si; + + shutting_down = SHUTDOWN_SUSPEND; + + err = freeze_processes(); + if (err) { + pr_err("%s: freeze processes failed %d\n", __func__, err); + goto out; + } + + err = freeze_kernel_threads(); + if (err) { + pr_err("%s: freeze kernel threads failed %d\n", __func__, err); + goto out_thaw; + } + + err = dpm_suspend_start(PMSG_FREEZE); + if (err) { + pr_err("%s: dpm_suspend_start %d\n", __func__, err); + goto out_thaw; + } + + printk(KERN_DEBUG "suspending xenstore...\n"); + xs_suspend(); + + err = dpm_suspend_end(PMSG_FREEZE); + if (err) { + pr_err("dpm_suspend_end failed: %d\n", err); + si.cancelled = 0; + goto out_resume; + } + + xen_arch_suspend(); + + si.cancelled = 1; + + err = stop_machine(xen_suspend, &si, cpumask_of(0)); + + /* Resume console as early as possible. */ + if (!si.cancelled) + xen_console_resume(); + + raw_notifier_call_chain(&xen_resume_notifier, 0, NULL); + + dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE); + + if (err) { + pr_err("failed to start xen_suspend: %d\n", err); + si.cancelled = 1; + } + + xen_arch_resume(); + +out_resume: + if (!si.cancelled) + xs_resume(); + else + xs_suspend_cancel(); + + dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); + +out_thaw: + thaw_processes(); +out: + shutting_down = SHUTDOWN_INVALID; +} +#endif /* CONFIG_HIBERNATE_CALLBACKS */ + +struct shutdown_handler { + const char *command; + void (*cb)(void); +}; + +static int poweroff_nb(struct notifier_block *cb, unsigned long code, void *unused) +{ + switch (code) { + case SYS_DOWN: + case SYS_HALT: + case SYS_POWER_OFF: + shutting_down = SHUTDOWN_POWEROFF; + default: + break; + } + return NOTIFY_DONE; +} +static void do_poweroff(void) +{ + switch (system_state) { + case SYSTEM_BOOTING: + orderly_poweroff(true); + break; + case SYSTEM_RUNNING: + orderly_poweroff(false); + break; + default: + /* Don't do it when we are halting/rebooting. */ + pr_info("Ignoring Xen toolstack shutdown.\n"); + break; + } +} + +static void do_reboot(void) +{ + shutting_down = SHUTDOWN_POWEROFF; /* ? */ + ctrl_alt_del(); +} + +static void shutdown_handler(struct xenbus_watch *watch, + const char **vec, unsigned int len) +{ + char *str; + struct xenbus_transaction xbt; + int err; + static struct shutdown_handler handlers[] = { + { "poweroff", do_poweroff }, + { "halt", do_poweroff }, + { "reboot", do_reboot }, +#ifdef CONFIG_HIBERNATE_CALLBACKS + { "suspend", do_suspend }, +#endif + {NULL, NULL}, + }; + static struct shutdown_handler *handler; + + 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; + } + + for (handler = &handlers[0]; handler->command; handler++) { + if (strcmp(str, handler->command) == 0) + break; + } + + /* Only acknowledge commands which we are prepared to handle. */ + if (handler->cb) + xenbus_write(xbt, "control", "shutdown", ""); + + err = xenbus_transaction_end(xbt, 0); + if (err == -EAGAIN) { + kfree(str); + goto again; + } + + if (handler->cb) { + handler->cb(); + } else { + pr_info("Ignoring shutdown request: %s\n", str); + shutting_down = SHUTDOWN_INVALID; + } + + kfree(str); +} + +#ifdef CONFIG_MAGIC_SYSRQ +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)) { + pr_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); +} + +static struct xenbus_watch sysrq_watch = { + .node = "control/sysrq", + .callback = sysrq_handler +}; +#endif + +static struct xenbus_watch shutdown_watch = { + .node = "control/shutdown", + .callback = shutdown_handler +}; + +static struct notifier_block xen_reboot_nb = { + .notifier_call = poweroff_nb, +}; + +static int setup_shutdown_watcher(void) +{ + int err; + + err = register_xenbus_watch(&shutdown_watch); + if (err) { + pr_err("Failed to set shutdown watcher\n"); + return err; + } + + +#ifdef CONFIG_MAGIC_SYSRQ + err = register_xenbus_watch(&sysrq_watch); + if (err) { + pr_err("Failed to set sysrq watcher\n"); + return err; + } +#endif + + return 0; +} + +static int shutdown_event(struct notifier_block *notifier, + unsigned long event, + void *data) +{ + setup_shutdown_watcher(); + return NOTIFY_DONE; +} + +int xen_setup_shutdown_event(void) +{ + static struct notifier_block xenstore_notifier = { + .notifier_call = shutdown_event + }; + + if (!xen_domain()) + return -ENODEV; + register_xenstore_notifier(&xenstore_notifier); + register_reboot_notifier(&xen_reboot_nb); + + return 0; +} +EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); + +subsys_initcall(xen_setup_shutdown_event);