linux/drivers/misc/pvpanic.c
zhenwei pi 191941692a misc: pvpanic: add crash loaded event
Some users prefer kdump tools to generate guest kernel dumpfile,
at the same time, need a out-of-band kernel panic event.

Currently if booting guest kernel with 'crash_kexec_post_notifiers',
QEMU will receive PVPANIC_PANICKED event and stop VM. If booting
guest kernel without 'crash_kexec_post_notifiers', guest will not
call notifier chain.

Add PVPANIC_CRASH_LOADED bit for pvpanic event, it means that guest
kernel actually hit a kernel panic, but the guest kernel wants to
handle by itself.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Link: https://lore.kernel.org/r/20200102023513.318836-3-pizhenwei@bytedance.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 15:07:37 +01:00

203 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Pvpanic Device Support
*
* Copyright (C) 2013 Fujitsu.
* Copyright (C) 2018 ZTE.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <uapi/misc/pvpanic.h>
static void __iomem *base;
MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
MODULE_DESCRIPTION("pvpanic device driver");
MODULE_LICENSE("GPL");
static void
pvpanic_send_event(unsigned int event)
{
iowrite8(event, base);
}
static int
pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
void *unused)
{
unsigned int event = PVPANIC_PANICKED;
if (kexec_crash_loaded())
event = PVPANIC_CRASH_LOADED;
pvpanic_send_event(event);
return NOTIFY_DONE;
}
static struct notifier_block pvpanic_panic_nb = {
.notifier_call = pvpanic_panic_notify,
.priority = 1, /* let this called before broken drm_fb_helper */
};
#ifdef CONFIG_ACPI
static int pvpanic_add(struct acpi_device *device);
static int pvpanic_remove(struct acpi_device *device);
static const struct acpi_device_id pvpanic_device_ids[] = {
{ "QEMU0001", 0 },
{ "", 0 }
};
MODULE_DEVICE_TABLE(acpi, pvpanic_device_ids);
static struct acpi_driver pvpanic_driver = {
.name = "pvpanic",
.class = "QEMU",
.ids = pvpanic_device_ids,
.ops = {
.add = pvpanic_add,
.remove = pvpanic_remove,
},
.owner = THIS_MODULE,
};
static acpi_status
pvpanic_walk_resources(struct acpi_resource *res, void *context)
{
struct resource r;
if (acpi_dev_resource_io(res, &r)) {
#ifdef CONFIG_HAS_IOPORT_MAP
base = ioport_map(r.start, resource_size(&r));
return AE_OK;
#else
return AE_ERROR;
#endif
} else if (acpi_dev_resource_memory(res, &r)) {
base = ioremap(r.start, resource_size(&r));
return AE_OK;
}
return AE_ERROR;
}
static int pvpanic_add(struct acpi_device *device)
{
int ret;
ret = acpi_bus_get_status(device);
if (ret < 0)
return ret;
if (!device->status.enabled || !device->status.functional)
return -ENODEV;
acpi_walk_resources(device->handle, METHOD_NAME__CRS,
pvpanic_walk_resources, NULL);
if (!base)
return -ENODEV;
atomic_notifier_chain_register(&panic_notifier_list,
&pvpanic_panic_nb);
return 0;
}
static int pvpanic_remove(struct acpi_device *device)
{
atomic_notifier_chain_unregister(&panic_notifier_list,
&pvpanic_panic_nb);
iounmap(base);
return 0;
}
static int pvpanic_register_acpi_driver(void)
{
return acpi_bus_register_driver(&pvpanic_driver);
}
static void pvpanic_unregister_acpi_driver(void)
{
acpi_bus_unregister_driver(&pvpanic_driver);
}
#else
static int pvpanic_register_acpi_driver(void)
{
return -ENODEV;
}
static void pvpanic_unregister_acpi_driver(void) {}
#endif
static int pvpanic_mmio_probe(struct platform_device *pdev)
{
struct resource *mem;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem)
return -EINVAL;
base = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(base))
return PTR_ERR(base);
atomic_notifier_chain_register(&panic_notifier_list,
&pvpanic_panic_nb);
return 0;
}
static int pvpanic_mmio_remove(struct platform_device *pdev)
{
atomic_notifier_chain_unregister(&panic_notifier_list,
&pvpanic_panic_nb);
return 0;
}
static const struct of_device_id pvpanic_mmio_match[] = {
{ .compatible = "qemu,pvpanic-mmio", },
{}
};
static struct platform_driver pvpanic_mmio_driver = {
.driver = {
.name = "pvpanic-mmio",
.of_match_table = pvpanic_mmio_match,
},
.probe = pvpanic_mmio_probe,
.remove = pvpanic_mmio_remove,
};
static int __init pvpanic_mmio_init(void)
{
if (acpi_disabled)
return platform_driver_register(&pvpanic_mmio_driver);
else
return pvpanic_register_acpi_driver();
}
static void __exit pvpanic_mmio_exit(void)
{
if (acpi_disabled)
platform_driver_unregister(&pvpanic_mmio_driver);
else
pvpanic_unregister_acpi_driver();
}
module_init(pvpanic_mmio_init);
module_exit(pvpanic_mmio_exit);