[Qemu-devel] [PATCH] pvevent: pvevent device driver

[Qemu-devel] [PATCH] pvevent: pvevent device driver

[Hu Tao]

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

ref: http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02293.html

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
---
 drivers/platform/x86/Kconfig   |   7 +++
 drivers/platform/x86/Makefile  |   2 +
 drivers/platform/x86/pvevent.c | 115 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 drivers/platform/x86/pvevent.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 7ab0b2f..369135e 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -768,4 +768,11 @@ config APPLE_GMUX
 	  graphics as well as the backlight. Currently only backlight
 	  control is supported by the driver.
 
+config PVEVENT
+	tristate "pvevent device support"
+	depends on ACPI
+	---help---
+	  This driver provides support for pvevent 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 bf7e4f9..8779396 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -50,3 +50,5 @@ obj-$(CONFIG_INTEL_MID_POWER_BUTTON)	+= intel_mid_powerbtn.o
 obj-$(CONFIG_INTEL_OAKTRAIL)	+= intel_oaktrail.o
 obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
 obj-$(CONFIG_APPLE_GMUX)	+= apple-gmux.o
+
+obj-$(CONFIG_PVEVENT)           += pvevent.o
diff --git a/drivers/platform/x86/pvevent.c b/drivers/platform/x86/pvevent.c
new file mode 100644
index 0000000..00ef7f4
--- /dev/null
+++ b/drivers/platform/x86/pvevent.c
@@ -0,0 +1,115 @@
+/*
+ *  pvevent.c - pvevent 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 <hutao@cn.fujitsu.com>");
+MODULE_DESCRIPTION("pvevent device driver");
+MODULE_LICENSE("GPL");
+
+static int pvevent_add(struct acpi_device *device);
+static int pvevent_remove(struct acpi_device *device);
+
+static const struct acpi_device_id pvevent_device_ids[] = {
+	{ "MSFT0001", 0},
+	{ "", 0},
+};
+MODULE_DEVICE_TABLE(acpi, pvevent_device_ids);
+
+#define PVEVENT_PANICKED	(1 << 0)
+
+static acpi_handle handle;
+
+static struct acpi_driver pvevent_driver = {
+	.name =		"pvevent",
+	.class =	"QEMU",
+	.ids =		pvevent_device_ids,
+	.ops =		{
+				.add =		pvevent_add,
+				.remove =	pvevent_remove,
+			},
+	.owner =	THIS_MODULE,
+};
+
+static void
+pvevent_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
+pvevent_panic_notify(struct notifier_block *nb, unsigned long code,
+		     void *unused)
+{
+	pvevent_send_event(PVEVENT_PANICKED);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block pvevent_panic_nb = {
+	.notifier_call = pvevent_panic_notify,
+};
+
+static int pvevent_add(struct acpi_device *device)
+{
+	acpi_status status;
+	u64 ret;
+
+	status = acpi_evaluate_integer(device->handle, "_STA", NULL,
+				       &ret);
+
+	if (ACPI_FAILURE(status) || !ret)
+		return -ENODEV;
+
+	handle = device->handle;
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &pvevent_panic_nb);
+
+	return 0;
+}
+
+static int pvevent_remove(struct acpi_device *device)
+{
+
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &pvevent_panic_nb);
+	handle = NULL;
+	return 0;
+}
+
+module_acpi_driver(pvevent_driver);
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Gleb Natapov]

On Thu, Mar 14, 2013 at 04:51:13PM +0800, Hu Tao wrote:
> pvevent device is a qemu simulated device through which guest panic
> event is sent to host.
> 
> ref: http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02293.html
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  drivers/platform/x86/Kconfig   |   7 +++
>  drivers/platform/x86/Makefile  |   2 +
>  drivers/platform/x86/pvevent.c | 115 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 124 insertions(+)
>  create mode 100644 drivers/platform/x86/pvevent.c
> 
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 7ab0b2f..369135e 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -768,4 +768,11 @@ config APPLE_GMUX
>  	  graphics as well as the backlight. Currently only backlight
>  	  control is supported by the driver.
>  
> +config PVEVENT
> +	tristate "pvevent device support"
> +	depends on ACPI
May be adding something like "default y if PARAVIRT_GUEST"?

--
			Gleb.

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Matthew Garrett]

On Thu, 2013-03-14 at 16:51 +0800, Hu Tao wrote:

> +	{ "MSFT0001", 0},

This seems wrong, and it looks like qemu agrees. Can you resubmit when
there's agreement on the name?

> +	acpi_evaluate_object(handle, "WRPT", &arg_list, NULL);

Is there a spec for this?

Is the only reason for this to allow guests to notify the host that
they've panicked? It seems like making use of pstore to push the crash
dump to the host as well would be a useful thing to do.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Blue Swirl]

On Thu, Mar 14, 2013 at 8:51 AM, Hu Tao <hutao@cn.fujitsu.com> wrote:
> pvevent device is a qemu simulated device through which guest panic
> event is sent to host.
>
> ref: http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02293.html
>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  drivers/platform/x86/Kconfig   |   7 +++
>  drivers/platform/x86/Makefile  |   2 +
>  drivers/platform/x86/pvevent.c | 115 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 124 insertions(+)
>  create mode 100644 drivers/platform/x86/pvevent.c
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 7ab0b2f..369135e 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -768,4 +768,11 @@ config APPLE_GMUX
>           graphics as well as the backlight. Currently only backlight
>           control is supported by the driver.
>
> +config PVEVENT
> +       tristate "pvevent device support"
> +       depends on ACPI
> +       ---help---
> +         This driver provides support for pvevent 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 bf7e4f9..8779396 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -50,3 +50,5 @@ obj-$(CONFIG_INTEL_MID_POWER_BUTTON)  += intel_mid_powerbtn.o
>  obj-$(CONFIG_INTEL_OAKTRAIL)   += intel_oaktrail.o
>  obj-$(CONFIG_SAMSUNG_Q10)      += samsung-q10.o
>  obj-$(CONFIG_APPLE_GMUX)       += apple-gmux.o
> +
> +obj-$(CONFIG_PVEVENT)           += pvevent.o
> diff --git a/drivers/platform/x86/pvevent.c b/drivers/platform/x86/pvevent.c
> new file mode 100644
> index 0000000..00ef7f4
> --- /dev/null
> +++ b/drivers/platform/x86/pvevent.c
> @@ -0,0 +1,115 @@
> +/*
> + *  pvevent.c - pvevent 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Current address of FSF is:

51 Franklin Street, Fifth Floor
Boston, MA 02110-1301
USA

I'd use the web version recommended by FSF.

> + */
> +
> +#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 <hutao@cn.fujitsu.com>");
> +MODULE_DESCRIPTION("pvevent device driver");
> +MODULE_LICENSE("GPL");
> +
> +static int pvevent_add(struct acpi_device *device);
> +static int pvevent_remove(struct acpi_device *device);
> +
> +static const struct acpi_device_id pvevent_device_ids[] = {
> +       { "MSFT0001", 0},
> +       { "", 0},
> +};
> +MODULE_DEVICE_TABLE(acpi, pvevent_device_ids);
> +
> +#define PVEVENT_PANICKED       (1 << 0)
> +
> +static acpi_handle handle;
> +
> +static struct acpi_driver pvevent_driver = {
> +       .name =         "pvevent",
> +       .class =        "QEMU",
> +       .ids =          pvevent_device_ids,
> +       .ops =          {
> +                               .add =          pvevent_add,
> +                               .remove =       pvevent_remove,
> +                       },
> +       .owner =        THIS_MODULE,
> +};
> +
> +static void
> +pvevent_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
> +pvevent_panic_notify(struct notifier_block *nb, unsigned long code,
> +                    void *unused)
> +{
> +       pvevent_send_event(PVEVENT_PANICKED);
> +       return NOTIFY_DONE;
> +}
> +
> +static struct notifier_block pvevent_panic_nb = {
> +       .notifier_call = pvevent_panic_notify,
> +};
> +
> +static int pvevent_add(struct acpi_device *device)
> +{
> +       acpi_status status;
> +       u64 ret;
> +
> +       status = acpi_evaluate_integer(device->handle, "_STA", NULL,
> +                                      &ret);
> +
> +       if (ACPI_FAILURE(status) || !ret)
> +               return -ENODEV;
> +
> +       handle = device->handle;
> +       atomic_notifier_chain_register(&panic_notifier_list,
> +                                      &pvevent_panic_nb);
> +
> +       return 0;
> +}
> +
> +static int pvevent_remove(struct acpi_device *device)
> +{
> +
> +       atomic_notifier_chain_unregister(&panic_notifier_list,
> +                                        &pvevent_panic_nb);
> +       handle = NULL;
> +       return 0;
> +}
> +
> +module_acpi_driver(pvevent_driver);
> --
> 1.8.1.4
>

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Paolo Bonzini]

Il 15/03/2013 20:35, Matthew Garrett ha scritto:
> On Thu, 2013-03-14 at 16:51 +0800, Hu Tao wrote:
> 
>> +	{ "MSFT0001", 0},
> 
> This seems wrong, and it looks like qemu agrees. Can you resubmit when
> there's agreement on the name?
> 
>> +	acpi_evaluate_object(handle, "WRPT", &arg_list, NULL);
> 
> Is there a spec for this?

Not yet.  Hu, in the next version of your QEMU patches you probably will
not need anymore usage information in docs/pvevent.txt.  Instead, please
add a spec for both the ISA and ACPI interfaces in docs/spec/pvevent.txt.

> Is the only reason for this to allow guests to notify the host that
> they've panicked? It seems like making use of pstore to push the crash
> dump to the host. as well would be a useful thing to do.

Since we try to limit the amount of VM-specific interfaces we have
(yeah, I know this is one), that would mean implementing APEI in QEMU, I
guess.  It is definitely a useful thing to have, but a bit wider in
scope than a simple device to distinguish idle and crashed VMs.

Paolo

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Hu Tao]

On Sun, Mar 17, 2013 at 07:12:09PM +0000, Blue Swirl wrote:
> On Thu, Mar 14, 2013 at 8:51 AM, Hu Tao <hutao@cn.fujitsu.com> wrote:
> > pvevent device is a qemu simulated device through which guest panic
> > event is sent to host.
> >
> > ref: http://lists.nongnu.org/archive/html/qemu-devel/2013-03/msg02293.html
> >
> > Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> > ---
> >  drivers/platform/x86/Kconfig   |   7 +++
> >  drivers/platform/x86/Makefile  |   2 +
> >  drivers/platform/x86/pvevent.c | 115 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 124 insertions(+)
> >  create mode 100644 drivers/platform/x86/pvevent.c
> >
> > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > index 7ab0b2f..369135e 100644
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -768,4 +768,11 @@ config APPLE_GMUX
> >           graphics as well as the backlight. Currently only backlight
> >           control is supported by the driver.
> >
> > +config PVEVENT
> > +       tristate "pvevent device support"
> > +       depends on ACPI
> > +       ---help---
> > +         This driver provides support for pvevent 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 bf7e4f9..8779396 100644
> > --- a/drivers/platform/x86/Makefile
> > +++ b/drivers/platform/x86/Makefile
> > @@ -50,3 +50,5 @@ obj-$(CONFIG_INTEL_MID_POWER_BUTTON)  += intel_mid_powerbtn.o
> >  obj-$(CONFIG_INTEL_OAKTRAIL)   += intel_oaktrail.o
> >  obj-$(CONFIG_SAMSUNG_Q10)      += samsung-q10.o
> >  obj-$(CONFIG_APPLE_GMUX)       += apple-gmux.o
> > +
> > +obj-$(CONFIG_PVEVENT)           += pvevent.o
> > diff --git a/drivers/platform/x86/pvevent.c b/drivers/platform/x86/pvevent.c
> > new file mode 100644
> > index 0000000..00ef7f4
> > --- /dev/null
> > +++ b/drivers/platform/x86/pvevent.c
> > @@ -0,0 +1,115 @@
> > +/*
> > + *  pvevent.c - pvevent 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
> 
> Current address of FSF is:
> 
> 51 Franklin Street, Fifth Floor
> Boston, MA 02110-1301
> USA
> 
> I'd use the web version recommended by FSF.

Thanks, I'll update it in the next version.

-- 
Regards,
Hu Tao

Re: [Qemu-devel] [PATCH] pvevent: pvevent device driver

[Hu Tao]

On Fri, Mar 15, 2013 at 07:35:12PM +0000, Matthew Garrett wrote:
> On Thu, 2013-03-14 at 16:51 +0800, Hu Tao wrote:
> 
> > +	{ "MSFT0001", 0},
> 
> This seems wrong, and it looks like qemu agrees. Can you resubmit when
> there's agreement on the name?

My fault. The name should be "QEMU". I'll send an updated version.

-- 
Regards,
Hu Tao