diff options
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 111 |
1 files changed, 67 insertions, 44 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 8b2e413bf19c..3146710d4ac6 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -25,7 +25,6 @@ #include <linux/sched/task_stack.h> #include <linux/delay.h> -#include <linux/notifier.h> #include <linux/panic_notifier.h> #include <linux/ptrace.h> #include <linux/screen_info.h> @@ -37,6 +36,7 @@ #include <linux/dma-map-ops.h> #include <linux/pci.h> #include <clocksource/hyperv_timer.h> +#include <asm/mshyperv.h> #include "hyperv_vmbus.h" struct vmbus_dynid { @@ -68,53 +68,74 @@ static int hyperv_report_reg(void) return !sysctl_record_panic_msg || !hv_panic_page; } -static int hyperv_panic_event(struct notifier_block *nb, unsigned long val, +/* + * The panic notifier below is responsible solely for unloading the + * vmbus connection, which is necessary in a panic event. + * + * Notice an intrincate relation of this notifier with Hyper-V + * framebuffer panic notifier exists - we need vmbus connection alive + * there in order to succeed, so we need to order both with each other + * [see hvfb_on_panic()] - this is done using notifiers' priorities. + */ +static int hv_panic_vmbus_unload(struct notifier_block *nb, unsigned long val, void *args) { - struct pt_regs *regs; - vmbus_initiate_unload(true); - - /* - * Hyper-V should be notified only once about a panic. If we will be - * doing hv_kmsg_dump() with kmsg data later, don't do the notification - * here. - */ - if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE - && hyperv_report_reg()) { - regs = current_pt_regs(); - hyperv_report_panic(regs, val, false); - } return NOTIFY_DONE; } +static struct notifier_block hyperv_panic_vmbus_unload_block = { + .notifier_call = hv_panic_vmbus_unload, + .priority = INT_MIN + 1, /* almost the latest one to execute */ +}; + +static int hv_die_panic_notify_crash(struct notifier_block *self, + unsigned long val, void *args); + +static struct notifier_block hyperv_die_report_block = { + .notifier_call = hv_die_panic_notify_crash, +}; +static struct notifier_block hyperv_panic_report_block = { + .notifier_call = hv_die_panic_notify_crash, +}; -static int hyperv_die_event(struct notifier_block *nb, unsigned long val, - void *args) +/* + * The following callback works both as die and panic notifier; its + * goal is to provide panic information to the hypervisor unless the + * kmsg dumper is used [see hv_kmsg_dump()], which provides more + * information but isn't always available. + * + * Notice that both the panic/die report notifiers are registered only + * if we have the capability HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE set. + */ +static int hv_die_panic_notify_crash(struct notifier_block *self, + unsigned long val, void *args) { - struct die_args *die = args; - struct pt_regs *regs = die->regs; + struct pt_regs *regs; + bool is_die; + + /* Don't notify Hyper-V unless we have a die oops event or panic. */ + if (self == &hyperv_panic_report_block) { + is_die = false; + regs = current_pt_regs(); + } else { /* die event */ + if (val != DIE_OOPS) + return NOTIFY_DONE; - /* Don't notify Hyper-V if the die event is other than oops */ - if (val != DIE_OOPS) - return NOTIFY_DONE; + is_die = true; + regs = ((struct die_args *)args)->regs; + } /* - * Hyper-V should be notified only once about a panic. If we will be - * doing hv_kmsg_dump() with kmsg data later, don't do the notification - * here. + * Hyper-V should be notified only once about a panic/die. If we will + * be calling hv_kmsg_dump() later with kmsg data, don't do the + * notification here. */ if (hyperv_report_reg()) - hyperv_report_panic(regs, val, true); + hyperv_report_panic(regs, val, is_die); + return NOTIFY_DONE; } -static struct notifier_block hyperv_die_block = { - .notifier_call = hyperv_die_event, -}; -static struct notifier_block hyperv_panic_block = { - .notifier_call = hyperv_panic_event, -}; - static const char *fb_mmio_name = "fb_range"; static struct resource *fb_mmio; static struct resource *hyperv_mmio; @@ -1538,16 +1559,17 @@ static int vmbus_bus_init(void) if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) hv_kmsg_dump_register(); - register_die_notifier(&hyperv_die_block); + register_die_notifier(&hyperv_die_report_block); + atomic_notifier_chain_register(&panic_notifier_list, + &hyperv_panic_report_block); } /* - * Always register the panic notifier because we need to unload - * the VMbus channel connection to prevent any VMbus - * activity after the VM panics. + * Always register the vmbus unload panic notifier because we + * need to shut the VMbus channel connection on panic. */ atomic_notifier_chain_register(&panic_notifier_list, - &hyperv_panic_block); + &hyperv_panic_vmbus_unload_block); vmbus_request_offers(); @@ -2082,6 +2104,7 @@ int vmbus_device_register(struct hv_device *child_device_obj) ret = device_register(&child_device_obj->device); if (ret) { pr_err("Unable to register child device\n"); + put_device(&child_device_obj->device); return ret; } @@ -2239,7 +2262,7 @@ static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx) return AE_OK; } -static int vmbus_acpi_remove(struct acpi_device *device) +static void vmbus_acpi_remove(struct acpi_device *device) { struct resource *cur_res; struct resource *next_res; @@ -2256,8 +2279,6 @@ static int vmbus_acpi_remove(struct acpi_device *device) kfree(cur_res); } } - - return 0; } static void vmbus_reserve_fb(void) @@ -2799,15 +2820,17 @@ static void __exit vmbus_exit(void) if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { kmsg_dump_unregister(&hv_kmsg_dumper); - unregister_die_notifier(&hyperv_die_block); + unregister_die_notifier(&hyperv_die_report_block); + atomic_notifier_chain_unregister(&panic_notifier_list, + &hyperv_panic_report_block); } /* - * The panic notifier is always registered, hence we should + * The vmbus panic notifier is always registered, hence we should * also unconditionally unregister it here as well. */ atomic_notifier_chain_unregister(&panic_notifier_list, - &hyperv_panic_block); + &hyperv_panic_vmbus_unload_block); free_page((unsigned long)hv_panic_page); unregister_sysctl_table(hv_ctl_table_hdr); |