--- /dev/null
+What: /sys/devices/pci0000:00/*/QEMU0001:00/capability
+Date: Jan 2021
+Contact: zhenwei pi <pizhenwei@bytedance.com>
+Description:
+ Read-only attribute. Capabilities of pvpanic device which
+ are supported by QEMU.
+
+ Format: %x.
+
+ Detailed bit definition refers to section <Bit Definition>
+ from pvpanic device specification:
+ https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/specs/pvpanic.txt
#include <uapi/misc/pvpanic.h>
static void __iomem *base;
+static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED;
+
+static ssize_t capability_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%x", capability);
+}
+static DEVICE_ATTR_RO(capability);
+
+static struct attribute *pvpanic_dev_attrs[] = {
+ &dev_attr_capability.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(pvpanic_dev);
MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
MODULE_DESCRIPTION("pvpanic device driver");
static void
pvpanic_send_event(unsigned int event)
{
- iowrite8(event, base);
+ if (event & capability)
+ iowrite8(event, base);
}
static int
return -EINVAL;
}
- atomic_notifier_chain_register(&panic_notifier_list,
- &pvpanic_panic_nb);
+ /* initlize capability by RDPT */
+ capability &= ioread8(base);
+
+ if (capability)
+ 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);
+ if (capability)
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &pvpanic_panic_nb);
return 0;
}
.name = "pvpanic-mmio",
.of_match_table = pvpanic_mmio_match,
.acpi_match_table = pvpanic_device_ids,
+ .dev_groups = pvpanic_dev_groups,
},
.probe = pvpanic_mmio_probe,
.remove = pvpanic_mmio_remove,