[PATCH] pv-ops: register xen pci notifier

[PATCH] pv-ops: register xen pci notifier

[Weidong Han]

Register the notifier to handle hot-plug devices and SR-IOV devices
for Xen hypervisor. When a device is hot added or removed, it adds
or removes it to Xen via hypercalls.

Signed-off-by: Weidong Han <weidong.han@intel.com>
---
 drivers/xen/Makefile            |    5 +-
 drivers/xen/pci.c               |  105 +++++++++++++++++++++++++++++++++++++++
 include/xen/interface/physdev.h |   21 ++++++++
 3 files changed, 129 insertions(+), 2 deletions(-)
 create mode 100644 drivers/xen/pci.c

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 007aa99..fd5c88c 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -1,12 +1,13 @@
 obj-y	+= grant-table.o features.o events.o manage.o biomerge.o
 obj-y	+= xenbus/
 
+obj-$(CONFIG_PCI)			+= pci.o
 obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
 obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
 obj-$(CONFIG_XEN_BALLOON)		+= balloon.o
 obj-$(CONFIG_XEN_DEV_EVTCHN)		+= evtchn.o
-obj-$(CONFIG_XEN_GNTDEV)	+= gntdev.o
+obj-$(CONFIG_XEN_GNTDEV)		+= gntdev.o
 obj-$(CONFIG_XEN_BLKDEV_BACKEND)	+= blkback/
 obj-$(CONFIG_XEN_NETDEV_BACKEND)	+= netback/
 obj-$(CONFIG_XENFS)			+= xenfs/
-obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
\ No newline at end of file
+obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
new file mode 100644
index 0000000..b1261d4
--- /dev/null
+++ b/drivers/xen/pci.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * Author: Weidong Han <weidong.han@intel.com>
+ */
+
+#include <linux/pci.h>
+#include <xen/interface/physdev.h>
+#include <asm/xen/hypercall.h>
+#include "../pci/pci.h"
+
+static int xen_add_device(struct device *dev)
+{
+	int r;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct physdev_manage_pci manage_pci;
+	struct physdev_manage_pci_ext manage_pci_ext;
+
+#ifdef CONFIG_PCI_IOV
+	if (pci_dev->is_virtfn) {
+		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
+		manage_pci_ext.bus = pci_dev->bus->number;
+		manage_pci_ext.devfn = pci_dev->devfn;
+		manage_pci_ext.is_virtfn = 1;
+		manage_pci_ext.physfn.bus = pci_dev->physfn->bus->number;
+		manage_pci_ext.physfn.devfn = pci_dev->physfn->devfn;
+		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
+					  &manage_pci_ext);
+	} else
+#endif
+	if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
+		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
+		manage_pci_ext.bus = pci_dev->bus->number;
+		manage_pci_ext.devfn = pci_dev->devfn;
+		manage_pci_ext.is_extfn = 1;
+		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
+					  &manage_pci_ext);
+	} else {
+		manage_pci.bus = pci_dev->bus->number;
+		manage_pci.devfn = pci_dev->devfn;
+		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
+					  &manage_pci);
+	}
+
+	return r;
+}
+
+static int xen_remove_device(struct device *dev)
+{
+	int r;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct physdev_manage_pci manage_pci;
+
+	manage_pci.bus = pci_dev->bus->number;
+	manage_pci.devfn = pci_dev->devfn;
+
+	r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
+				  &manage_pci);
+
+	return r;
+}
+
+static int xen_pci_notifier(struct notifier_block *nb,
+			    unsigned long action, void *data)
+{
+	struct device *dev = data;
+	int r = 0;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		r = xen_add_device(dev);
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		r = xen_remove_device(dev);
+		break;
+	default:
+		break;
+	}
+
+	return r;
+}
+
+struct notifier_block device_nb = {
+	.notifier_call = xen_pci_notifier,
+};
+
+void __init register_xen_pci_notifier(void)
+{
+	bus_register_notifier(&pci_bus_type, &device_nb);
+}
+
+fs_initcall(register_xen_pci_notifier);
diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
index cd69391..dcae970 100644
--- a/include/xen/interface/physdev.h
+++ b/include/xen/interface/physdev.h
@@ -106,6 +106,27 @@ struct physdev_irq {
 	uint32_t vector;
 };
 
+#define PHYSDEVOP_manage_pci_add         15
+#define PHYSDEVOP_manage_pci_remove      16
+struct physdev_manage_pci {
+	/* IN */
+	uint8_t bus;
+	uint8_t devfn;
+};
+
+#define PHYSDEVOP_manage_pci_add_ext     20
+struct physdev_manage_pci_ext {
+	/* IN */
+	uint8_t bus;
+	uint8_t devfn;
+	unsigned is_extfn;
+	unsigned is_virtfn;
+	struct {
+		uint8_t bus;
+		uint8_t devfn;
+	} physfn;
+};
+
 /*
  * Argument to physdev_op_compat() hypercall. Superceded by new physdev_op()
  * hypercall since 0x00030202.
-- 
1.6.0.4

Re: [PATCH] pv-ops: register xen pci notifier

[Jesse Barnes]

On Mon, 27 Jul 2009 09:56:48 +0800
Weidong Han <weidong.han@intel.com> wrote:

> Register the notifier to handle hot-plug devices and SR-IOV devices
> for Xen hypervisor. When a device is hot added or removed, it adds
> or removes it to Xen via hypercalls.
> 
> Signed-off-by: Weidong Han <weidong.han@intel.com>
> ---
>  drivers/xen/Makefile            |    5 +-
>  drivers/xen/pci.c               |  105
> +++++++++++++++++++++++++++++++++++++++
> include/xen/interface/physdev.h |   21 ++++++++ 3 files changed, 129
> insertions(+), 2 deletions(-) create mode 100644 drivers/xen/pci.c

Did you want this to come through the PCI tree?  Or do you just want
some extra review on it before pushing it through the Xen tree?

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center

Re: [PATCH] pv-ops: register xen pci notifier

[Jeremy Fitzhardinge]

On 07/28/09 09:27, Jesse Barnes wrote:
> On Mon, 27 Jul 2009 09:56:48 +0800
> Weidong Han <weidong.han@intel.com> wrote:
>
>   
>> Register the notifier to handle hot-plug devices and SR-IOV devices
>> for Xen hypervisor. When a device is hot added or removed, it adds
>> or removes it to Xen via hypercalls.
>>
>> Signed-off-by: Weidong Han <weidong.han@intel.com>
>> ---
>>  drivers/xen/Makefile            |    5 +-
>>  drivers/xen/pci.c               |  105
>> +++++++++++++++++++++++++++++++++++++++
>> include/xen/interface/physdev.h |   21 ++++++++ 3 files changed, 129
>> insertions(+), 2 deletions(-) create mode 100644 drivers/xen/pci.c
>>     
>
> Did you want this to come through the PCI tree?  Or do you just want
> some extra review on it before pushing it through the Xen tree?
>   

I'll put it through the Xen tree, since I don't think it makes much
sense standalone.  Are you happy to Ack/Reviewed-by it?

    J

Re: [PATCH] pv-ops: register xen pci notifier

[Jeremy Fitzhardinge]

On 07/26/09 18:56, Weidong Han wrote:
> Register the notifier to handle hot-plug devices and SR-IOV devices
> for Xen hypervisor. When a device is hot added or removed, it adds
> or removes it to Xen via hypercalls.
>   

Looks pretty good.  A few small comments below.

    J

> Signed-off-by: Weidong Han <weidong.han@intel.com>
> ---
>  drivers/xen/Makefile            |    5 +-
>  drivers/xen/pci.c               |  105 +++++++++++++++++++++++++++++++++++++++
>  include/xen/interface/physdev.h |   21 ++++++++
>  3 files changed, 129 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/xen/pci.c
>
> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> index 007aa99..fd5c88c 100644
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -1,12 +1,13 @@
>  obj-y	+= grant-table.o features.o events.o manage.o biomerge.o
>  obj-y	+= xenbus/
>  
> +obj-$(CONFIG_PCI)			+= pci.o
>  obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
>  obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
>  obj-$(CONFIG_XEN_BALLOON)		+= balloon.o
>  obj-$(CONFIG_XEN_DEV_EVTCHN)		+= evtchn.o
> -obj-$(CONFIG_XEN_GNTDEV)	+= gntdev.o
> +obj-$(CONFIG_XEN_GNTDEV)		+= gntdev.o
>  obj-$(CONFIG_XEN_BLKDEV_BACKEND)	+= blkback/
>  obj-$(CONFIG_XEN_NETDEV_BACKEND)	+= netback/
>  obj-$(CONFIG_XENFS)			+= xenfs/
> -obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
> \ No newline at end of file
> +obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
> new file mode 100644
> index 0000000..b1261d4
> --- /dev/null
> +++ b/drivers/xen/pci.c
> @@ -0,0 +1,105 @@
> +/*
> + * Copyright (c) 2009, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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.
> + *
> + * Author: Weidong Han <weidong.han@intel.com>
> + */
> +
> +#include <linux/pci.h>
> +#include <xen/interface/physdev.h>
> +#include <asm/xen/hypercall.h>
> +#include "../pci/pci.h"
> +
> +static int xen_add_device(struct device *dev)
> +{
> +	int r;
> +	struct pci_dev *pci_dev = to_pci_dev(dev);
> +	struct physdev_manage_pci manage_pci;
> +	struct physdev_manage_pci_ext manage_pci_ext;
> +
> +#ifdef CONFIG_PCI_IOV
> +	if (pci_dev->is_virtfn) {
>   

Perhaps something like:

(earlier in the file)

#ifdef CONFIG_PCI_IOV
#define HANDLE_PCI_IOV	1
#else
#define HANDLE_PCI_IOV	0
#endif

(or is there already something we can use as a compile-time constant for this?)

and then:

	if (HANDLE_PCI_IOV && pci_dev->is_virtfn) {
		...
	} else if (pci_ari_enabled( ... )) {
		...
	} else {
		...
	}

That removes the inline #ifdef and the awkward dangling else/#endif
construction.


> +		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
>   
Rather than doing this, move the variable decl into this scope and use
an initializer to assign the elements:

		struct physdev_manage_pci_ext manage_pci_ext = {
			.bus = pci_dev->bus->number,
			.devfn = pci_dev->devfn,
			...
		};

(ditto for the others)

> +		manage_pci_ext.bus = pci_dev->bus->number;
> +		manage_pci_ext.devfn = pci_dev->devfn;
> +		manage_pci_ext.is_virtfn = 1;
> +		manage_pci_ext.physfn.bus = pci_dev->physfn->bus->number;
> +		manage_pci_ext.physfn.devfn = pci_dev->physfn->devfn;
> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
> +					  &manage_pci_ext);
> +	} else
> +#endif
>   


> +	if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
> +		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
> +		manage_pci_ext.bus = pci_dev->bus->number;
> +		manage_pci_ext.devfn = pci_dev->devfn;
> +		manage_pci_ext.is_extfn = 1;
> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
> +					  &manage_pci_ext);
> +	} else {
> +		manage_pci.bus = pci_dev->bus->number;
> +		manage_pci.devfn = pci_dev->devfn;
> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
> +					  &manage_pci);
> +	}
> +
>   
> +	return r;
> +}
> +
> +static int xen_remove_device(struct device *dev)
> +{
> +	int r;
> +	struct pci_dev *pci_dev = to_pci_dev(dev);
> +	struct physdev_manage_pci manage_pci;
> +
> +	manage_pci.bus = pci_dev->bus->number;
> +	manage_pci.devfn = pci_dev->devfn;
> +
> +	r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
> +				  &manage_pci);
> +
> +	return r;
> +}
> +
> +static int xen_pci_notifier(struct notifier_block *nb,
> +			    unsigned long action, void *data)
> +{
> +	struct device *dev = data;
> +	int r = 0;
> +
> +	switch (action) {
> +	case BUS_NOTIFY_ADD_DEVICE:
> +		r = xen_add_device(dev);
> +		break;
> +	case BUS_NOTIFY_DEL_DEVICE:
> +		r = xen_remove_device(dev);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return r;
> +}
> +
> +struct notifier_block device_nb = {
> +	.notifier_call = xen_pci_notifier,
> +};
> +
> +void __init register_xen_pci_notifier(void)
> +{
> +	bus_register_notifier(&pci_bus_type, &device_nb);
> +}
> +
> +fs_initcall(register_xen_pci_notifier);
>   

Why fs_initcall?  Is that the conventional initcall for registering
these kinds of notifiers?

Thanks,
    J

RE: [PATCH] pv-ops: register xen pci notifier

[Han, Weidong]

Jeremy Fitzhardinge wrote:
> On 07/26/09 18:56, Weidong Han wrote:
>> Register the notifier to handle hot-plug devices and SR-IOV devices
>> for Xen hypervisor. When a device is hot added or removed, it adds
>> or removes it to Xen via hypercalls.
>> 
> 
> Looks pretty good.  A few small comments below.
> 
>     J
> 
>> Signed-off-by: Weidong Han <weidong.han@intel.com>
>> ---
>>  drivers/xen/Makefile            |    5 +-
>>  drivers/xen/pci.c               |  105
>>  +++++++++++++++++++++++++++++++++++++++
>>  include/xen/interface/physdev.h |   21 ++++++++ 3 files changed,
>>  129 insertions(+), 2 deletions(-) create mode 100644
>> drivers/xen/pci.c 
>> 
>> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
>> index 007aa99..fd5c88c 100644
>> --- a/drivers/xen/Makefile
>> +++ b/drivers/xen/Makefile
>> @@ -1,12 +1,13 @@
>>  obj-y	+= grant-table.o features.o events.o manage.o biomerge.o 
>> obj-y	+= xenbus/ 
>> 
>> +obj-$(CONFIG_PCI)			+= pci.o
>>  obj-$(CONFIG_HOTPLUG_CPU)		+= cpu_hotplug.o
>>  obj-$(CONFIG_XEN_XENCOMM)		+= xencomm.o
>>  obj-$(CONFIG_XEN_BALLOON)		+= balloon.o
>>  obj-$(CONFIG_XEN_DEV_EVTCHN)		+= evtchn.o
>> -obj-$(CONFIG_XEN_GNTDEV)	+= gntdev.o
>> +obj-$(CONFIG_XEN_GNTDEV)		+= gntdev.o
>>  obj-$(CONFIG_XEN_BLKDEV_BACKEND)	+= blkback/
>>  obj-$(CONFIG_XEN_NETDEV_BACKEND)	+= netback/
>>  obj-$(CONFIG_XENFS)			+= xenfs/
>> -obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o \ No newline
>> at end of file +obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
>> diff --git a/drivers/xen/pci.c b/drivers/xen/pci.c
>> new file mode 100644
>> index 0000000..b1261d4
>> --- /dev/null
>> +++ b/drivers/xen/pci.c
>> @@ -0,0 +1,105 @@
>> +/*
>> + * Copyright (c) 2009, Intel Corporation.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> modify it + * under the terms and conditions of the GNU General
>> Public License, + * version 2, as published by the Free Software
>> Foundation. + * + * This program is distributed in the hope 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. + *
>> + * Author: Weidong Han <weidong.han@intel.com>
>> + */
>> +
>> +#include <linux/pci.h>
>> +#include <xen/interface/physdev.h>
>> +#include <asm/xen/hypercall.h>
>> +#include "../pci/pci.h"
>> +
>> +static int xen_add_device(struct device *dev)
>> +{
>> +	int r;
>> +	struct pci_dev *pci_dev = to_pci_dev(dev);
>> +	struct physdev_manage_pci manage_pci;
>> +	struct physdev_manage_pci_ext manage_pci_ext;
>> +
>> +#ifdef CONFIG_PCI_IOV
>> +	if (pci_dev->is_virtfn) {
>> 
> 
> Perhaps something like:
> 
> (earlier in the file)
> 
> #ifdef CONFIG_PCI_IOV
> #define HANDLE_PCI_IOV	1
> #else
> #define HANDLE_PCI_IOV	0
> #endif
> 
> (or is there already something we can use as a compile-time constant
> for this?) 
> 
> and then:
> 
> 	if (HANDLE_PCI_IOV && pci_dev->is_virtfn) {
> 		...
> 	} else if (pci_ari_enabled( ... )) {
> 		...
> 	} else {
> 		...
> 	}
> 
> That removes the inline #ifdef and the awkward dangling else/#endif
> construction.
> 

Ok.

> 
>> +		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
>> 
> Rather than doing this, move the variable decl into this scope and use
> an initializer to assign the elements:
> 
> 		struct physdev_manage_pci_ext manage_pci_ext = {
> 			.bus = pci_dev->bus->number,
> 			.devfn = pci_dev->devfn,
> 			...
> 		};
> 
> (ditto for the others)
> 

Ok. will use the variable declaration to initialize it.

>> +		manage_pci_ext.bus = pci_dev->bus->number;
>> +		manage_pci_ext.devfn = pci_dev->devfn;
>> +		manage_pci_ext.is_virtfn = 1;
>> +		manage_pci_ext.physfn.bus = pci_dev->physfn->bus->number;
>> +		manage_pci_ext.physfn.devfn = pci_dev->physfn->devfn;
>> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext, +					 
>> &manage_pci_ext); +	} else
>> +#endif
>> 
> 
> 
>> +	if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
>> +		memset(&manage_pci_ext, 0, sizeof(manage_pci_ext));
>> +		manage_pci_ext.bus = pci_dev->bus->number;
>> +		manage_pci_ext.devfn = pci_dev->devfn;
>> +		manage_pci_ext.is_extfn = 1;
>> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext, +					 
>> &manage_pci_ext); +	} else {
>> +		manage_pci.bus = pci_dev->bus->number;
>> +		manage_pci.devfn = pci_dev->devfn;
>> +		r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add, +					 
>> &manage_pci); +	}
>> +
>> 
>> +	return r;
>> +}
>> +
>> +static int xen_remove_device(struct device *dev)
>> +{
>> +	int r;
>> +	struct pci_dev *pci_dev = to_pci_dev(dev);
>> +	struct physdev_manage_pci manage_pci;
>> +
>> +	manage_pci.bus = pci_dev->bus->number;
>> +	manage_pci.devfn = pci_dev->devfn;
>> +
>> +	r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove, +				 
>> &manage_pci); +
>> +	return r;
>> +}
>> +
>> +static int xen_pci_notifier(struct notifier_block *nb,
>> +			    unsigned long action, void *data)
>> +{
>> +	struct device *dev = data;
>> +	int r = 0;
>> +
>> +	switch (action) {
>> +	case BUS_NOTIFY_ADD_DEVICE:
>> +		r = xen_add_device(dev);
>> +		break;
>> +	case BUS_NOTIFY_DEL_DEVICE:
>> +		r = xen_remove_device(dev);
>> +		break;
>> +	default:
>> +		break;
>> +	}
>> +
>> +	return r;
>> +}
>> +
>> +struct notifier_block device_nb = {
>> +	.notifier_call = xen_pci_notifier,
>> +};
>> +
>> +void __init register_xen_pci_notifier(void)
>> +{
>> +	bus_register_notifier(&pci_bus_type, &device_nb); +}
>> +
>> +fs_initcall(register_xen_pci_notifier);
>> 
> 
> Why fs_initcall?  Is that the conventional initcall for registering
> these kinds of notifiers?
> 

register_xen_pci_notifier must be executed after PCI subsystem. I think fs_initcall is the suitable initcall achieve it. 

Regards,
Weidong

Re: [PATCH] pv-ops: register xen pci notifier

[Jeremy Fitzhardinge]

On 07/28/09 18:33, Han, Weidong wrote:
> register_xen_pci_notifier must be executed after PCI subsystem. I think fs_initcall is the suitable initcall achieve it. 
>   

Yes, that's a bit awkward.  It requires pci_bus_type to have been
registered/initialized with bus_register() before you can register a
notifier on it.  Its a pity it couldn't be rearranged so that you can
register the notifier at any time.

    J

RE: [PATCH] pv-ops: register xen pci notifier

[Jiang, Yunhong]

yes, the pci_iommu_init() is also fs_initcall().

--jyh

Jeremy Fitzhardinge wrote:
> On 07/28/09 18:33, Han, Weidong wrote:
>> register_xen_pci_notifier must be executed after PCI
> subsystem. I think fs_initcall is the suitable initcall achieve it.
>> 
> 
> Yes, that's a bit awkward.  It requires pci_bus_type to have been
> registered/initialized with bus_register() before you can register a
> notifier on it.  Its a pity it couldn't be rearranged so that you can
> register the notifier at any time.
> 
>    J