From 7b51b13733214b0491e935ff6ffc64a5730caa2a Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Fri, 12 Apr 2024 08:26:40 +0200 Subject: misc/pvpanic: add support for normal shutdowns MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Shutdown requests are normally hardware dependent. By extending pvpanic to also handle shutdown requests, guests can submit such requests with an easily implementable and cross-platform mechanism. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20240412-pvpanic-shutdown-v3-1-c214e9873b3f@weissschuh.net Signed-off-by: Greg Kroah-Hartman --- drivers/misc/pvpanic/pvpanic.c | 43 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c index df3457ce1cb1..17c0eb549463 100644 --- a/drivers/misc/pvpanic/pvpanic.c +++ b/drivers/misc/pvpanic/pvpanic.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -35,6 +36,7 @@ struct pvpanic_instance { void __iomem *base; unsigned int capability; unsigned int events; + struct sys_off_handler *sys_off; struct list_head list; }; @@ -78,6 +80,39 @@ static struct notifier_block pvpanic_panic_nb = { .priority = INT_MAX, }; +static int pvpanic_sys_off(struct sys_off_data *data) +{ + pvpanic_send_event(PVPANIC_SHUTDOWN); + + return NOTIFY_DONE; +} + +static void pvpanic_synchronize_sys_off_handler(struct device *dev, struct pvpanic_instance *pi) +{ + /* The kernel core has logic to fall back to system halt if no + * sys_off_handler is registered. + * When the pvpanic sys_off_handler is disabled via sysfs the kernel + * should use that fallback logic, so the handler needs to be unregistered. + */ + + struct sys_off_handler *sys_off; + + if (!(pi->events & PVPANIC_SHUTDOWN) == !pi->sys_off) + return; + + if (!pi->sys_off) { + sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_LOW, + pvpanic_sys_off, NULL); + if (IS_ERR(sys_off)) + dev_warn(dev, "Could not register sys_off_handler: %pe\n", sys_off); + else + pi->sys_off = sys_off; + } else { + unregister_sys_off_handler(pi->sys_off); + pi->sys_off = NULL; + } +} + static void pvpanic_remove(void *param) { struct pvpanic_instance *pi_cur, *pi_next; @@ -91,6 +126,8 @@ static void pvpanic_remove(void *param) } } spin_unlock(&pvpanic_lock); + + unregister_sys_off_handler(pi->sys_off); } static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -123,6 +160,7 @@ static ssize_t events_store(struct device *dev, struct device_attribute *attr, return -EINVAL; pi->events = tmp; + pvpanic_synchronize_sys_off_handler(dev, pi); return count; } @@ -156,12 +194,15 @@ int devm_pvpanic_probe(struct device *dev, void __iomem *base) return -ENOMEM; pi->base = base; - pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; + pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED | PVPANIC_SHUTDOWN; /* initlize capability by RDPT */ pi->capability &= ioread8(base); pi->events = pi->capability; + pi->sys_off = NULL; + pvpanic_synchronize_sys_off_handler(dev, pi); + spin_lock(&pvpanic_lock); list_add(&pi->list, &pvpanic_list); spin_unlock(&pvpanic_lock); -- cgit v1.2.3