[Qemu-devel] [PATCH v17] pvpanic: pvpanic device driver

[Hu Tao]

pvpanic device is a qemu simulated device through which guest panic
event is sent to host.

Signed-off-by: Hu Tao <address@hidden>
---

ref: http://lists.nongnu.org/archive/html/qemu-devel/2013-04/msg01028.html

 drivers/platform/x86/Kconfig   |   7 +++
 drivers/platform/x86/Makefile  |   2 +
 drivers/platform/x86/pvpanic.c | 115 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 drivers/platform/x86/pvpanic.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 3338437..527ed04 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -781,4 +781,11 @@ config APPLE_GMUX
          graphics as well as the backlight. Currently only backlight
          control is supported by the driver.
 
+config PVPANIC
+       tristate "pvpanic device support"
+       depends on ACPI
+       ---help---
+         This driver provides support for pvpanic device, which is a qemu
+         simulated device through which guest panic event is sent to host.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index ace2b38..ef0ec74 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -51,3 +51,5 @@ obj-$(CONFIG_INTEL_OAKTRAIL)  += intel_oaktrail.o
 obj-$(CONFIG_SAMSUNG_Q10)      += samsung-q10.o
 obj-$(CONFIG_APPLE_GMUX)       += apple-gmux.o
 obj-$(CONFIG_CHROMEOS_LAPTOP)  += chromeos_laptop.o
+
+obj-$(CONFIG_PVPANIC)           += pvpanic.o
diff --git a/drivers/platform/x86/pvpanic.c b/drivers/platform/x86/pvpanic.c
new file mode 100644
index 0000000..81c95ec
--- /dev/null
+++ b/drivers/platform/x86/pvpanic.c
@@ -0,0 +1,115 @@
+/*
+ *  pvpanic.c - pvpanic Device Support
+ *
+ *  Copyright (C) 2013 Fujitsu.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  
USA
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+MODULE_AUTHOR("Hu Tao <address@hidden>");
+MODULE_DESCRIPTION("pvpanic device driver");
+MODULE_LICENSE("GPL");
+
+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);
+
+#define PVPANIC_PANICKED       (1 << 0)
+
+static acpi_handle handle;
+
+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 void
+pvpanic_send_event(unsigned int event)
+{
+       union acpi_object arg;
+       struct acpi_object_list arg_list;
+
+       if (!handle)
+               return;
+
+       arg.type = ACPI_TYPE_INTEGER;
+       arg.integer.value = event;
+
+       arg_list.count = 1;
+       arg_list.pointer = &arg;
+
+       acpi_evaluate_object(handle, "WRPT", &arg_list, NULL);
+}
+
+static int
+pvpanic_panic_notify(struct notifier_block *nb, unsigned long code,
+                    void *unused)
+{
+       pvpanic_send_event(PVPANIC_PANICKED);
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block pvpanic_panic_nb = {
+       .notifier_call = pvpanic_panic_notify,
+};
+
+static int pvpanic_add(struct acpi_device *device)
+{
+       acpi_status status;
+       u64 ret;
+
+       status = acpi_evaluate_integer(device->handle, "_STA", NULL,
+                                      &ret);
+
+       if (ACPI_FAILURE(status) || (ret & 0x0B) != 0x0B)
+               return -ENODEV;
+
+       handle = device->handle;
+       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);
+       handle = NULL;
+       return 0;
+}
+
+module_acpi_driver(pvpanic_driver);
-- 
1.8.1.4