Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups

2019-07-16 Thread Paul Durrant 
> -Original Message-
> From: Roger Pau Monne 
> Sent: 16 July 2019 09:57
> To: Paul Durrant 
> Cc: xen-devel@lists.xenproject.org; Stefano Stabellini 
> ; Wei Liu ;
> Konrad Rzeszutek Wilk ; George Dunlap 
> ; Andrew
> Cooper ; Ian Jackson ; Tim 
> (Xen.org) ;
> Julien Grall ; Jan Beulich 
> Subject: Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups
> 
> On Mon, Jul 15, 2019 at 05:41:27PM +0200, Paul Durrant wrote:
> > > -Original Message-
> > > From: Roger Pau Monne 
> > > Sent: 15 July 2019 16:35
> > > To: Paul Durrant 
> > > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini 
> > > ; Wei Liu
> ;
> > > Konrad Rzeszutek Wilk ; George Dunlap 
> > > ; Andrew
> > > Cooper ; Ian Jackson ; 
> > > Tim (Xen.org)
> ;
> > > Julien Grall ; Jan Beulich 
> > > Subject: Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups
> > >
> > > On Mon, Jul 15, 2019 at 01:37:09PM +0100, Paul Durrant wrote:
> > > > Some devices may share a single PCIe initiator id, e.g. if they are 
> > > > actually
> > > > legacy PCI devices behind a bridge, and hence DMA from such devices will
> > > > be subject to the same address translation in the IOMMU. Hence these 
> > > > devices
> > > > should be treated as a unit for the purposes of assignment. There are 
> > > > also
> > > > other reasons why multiple devices should be treated as a unit, e.g. 
> > > > those
> > > > subject to a shared RMRR or those downstream of a bridge that does not
> > > > support ACS.
> > > >
> > > > This patch introduces a new struct iommu_group to act as a container for
> > > > devices that should be treated as a unit, and builds a list of them as
> > > > PCI devices are scanned. The iommu_ops already implement a method,
> > > > get_device_group_id(), that is seemingly intended to return the 
> > > > initiator
> > > > id for a given SBDF so use this as the mechanism for group assignment in
> > > > the first instance. Assignment based on shared RMRR or lack of ACS will 
> > > > be
> > > > dealt with in subsequent patches, as will modifications to the device
> > > > assignment code.
> > > >
> > > > Signed-off-by: Paul Durrant 
> > >
> > > LGTM, just two comments below.
> > >
> > > > ---
> > > > Cc: Jan Beulich 
> > > > Cc: Andrew Cooper 
> > > > Cc: George Dunlap 
> > > > Cc: Ian Jackson 
> > > > Cc: Julien Grall 
> > > > Cc: Konrad Rzeszutek Wilk 
> > > > Cc: Stefano Stabellini 
> > > > Cc: Tim Deegan 
> > > > Cc: Wei Liu 
> > > >
> > > > v2:
> > > >  - Move code into new drivers/passthrough/groups.c
> > > >  - Drop the group index.
> > > >  - Handle failure to get group id.
> > > >  - Drop the group devs list.
> > > > ---
> > > >  xen/drivers/passthrough/Makefile|  1 +
> > > >  xen/drivers/passthrough/groups.c| 91 
> > > > +
> > > >  xen/drivers/passthrough/x86/iommu.c |  8 +++-
> > > >  xen/include/xen/iommu.h |  7 +++
> > > >  xen/include/xen/pci.h   |  2 +
> > > >  5 files changed, 108 insertions(+), 1 deletion(-)
> > > >  create mode 100644 xen/drivers/passthrough/groups.c
> > > >
> > > > diff --git a/xen/drivers/passthrough/Makefile 
> > > > b/xen/drivers/passthrough/Makefile
> > > > index d50ab188c8..8a77110179 100644
> > > > --- a/xen/drivers/passthrough/Makefile
> > > > +++ b/xen/drivers/passthrough/Makefile
> > > > @@ -4,6 +4,7 @@ subdir-$(CONFIG_X86) += x86
> > > >  subdir-$(CONFIG_ARM) += arm
> > > >
> > > >  obj-y += iommu.o
> > > > +obj-$(CONFIG_HAS_PCI) += groups.o
> > > >  obj-$(CONFIG_HAS_PCI) += pci.o
> > > >  obj-$(CONFIG_HAS_DEVICE_TREE) += device_tree.o
> > > >
> > > > diff --git a/xen/drivers/passthrough/groups.c 
> > > > b/xen/drivers/passthrough/groups.c
> > > > new file mode 100644
> > > > index 00..1a2f461c87
> > > > --- /dev/null
> > > > +++ b/xen/drivers/passthrough/groups.c
> > > > @@ -0,0 +1,91 @@
> > > > +/*
> > > > + * Copyright (c) 2019 Citrix Systems Inc.
> > >

Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups

2019-07-16 Thread Roger Pau Monné 
On Mon, Jul 15, 2019 at 05:41:27PM +0200, Paul Durrant wrote:
> > -Original Message-
> > From: Roger Pau Monne 
> > Sent: 15 July 2019 16:35
> > To: Paul Durrant 
> > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini 
> > ; Wei Liu ;
> > Konrad Rzeszutek Wilk ; George Dunlap 
> > ; Andrew
> > Cooper ; Ian Jackson ; 
> > Tim (Xen.org) ;
> > Julien Grall ; Jan Beulich 
> > Subject: Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups
> > 
> > On Mon, Jul 15, 2019 at 01:37:09PM +0100, Paul Durrant wrote:
> > > Some devices may share a single PCIe initiator id, e.g. if they are 
> > > actually
> > > legacy PCI devices behind a bridge, and hence DMA from such devices will
> > > be subject to the same address translation in the IOMMU. Hence these 
> > > devices
> > > should be treated as a unit for the purposes of assignment. There are also
> > > other reasons why multiple devices should be treated as a unit, e.g. those
> > > subject to a shared RMRR or those downstream of a bridge that does not
> > > support ACS.
> > >
> > > This patch introduces a new struct iommu_group to act as a container for
> > > devices that should be treated as a unit, and builds a list of them as
> > > PCI devices are scanned. The iommu_ops already implement a method,
> > > get_device_group_id(), that is seemingly intended to return the initiator
> > > id for a given SBDF so use this as the mechanism for group assignment in
> > > the first instance. Assignment based on shared RMRR or lack of ACS will be
> > > dealt with in subsequent patches, as will modifications to the device
> > > assignment code.
> > >
> > > Signed-off-by: Paul Durrant 
> > 
> > LGTM, just two comments below.
> > 
> > > ---
> > > Cc: Jan Beulich 
> > > Cc: Andrew Cooper 
> > > Cc: George Dunlap 
> > > Cc: Ian Jackson 
> > > Cc: Julien Grall 
> > > Cc: Konrad Rzeszutek Wilk 
> > > Cc: Stefano Stabellini 
> > > Cc: Tim Deegan 
> > > Cc: Wei Liu 
> > >
> > > v2:
> > >  - Move code into new drivers/passthrough/groups.c
> > >  - Drop the group index.
> > >  - Handle failure to get group id.
> > >  - Drop the group devs list.
> > > ---
> > >  xen/drivers/passthrough/Makefile|  1 +
> > >  xen/drivers/passthrough/groups.c| 91 
> > > +
> > >  xen/drivers/passthrough/x86/iommu.c |  8 +++-
> > >  xen/include/xen/iommu.h |  7 +++
> > >  xen/include/xen/pci.h   |  2 +
> > >  5 files changed, 108 insertions(+), 1 deletion(-)
> > >  create mode 100644 xen/drivers/passthrough/groups.c
> > >
> > > diff --git a/xen/drivers/passthrough/Makefile 
> > > b/xen/drivers/passthrough/Makefile
> > > index d50ab188c8..8a77110179 100644
> > > --- a/xen/drivers/passthrough/Makefile
> > > +++ b/xen/drivers/passthrough/Makefile
> > > @@ -4,6 +4,7 @@ subdir-$(CONFIG_X86) += x86
> > >  subdir-$(CONFIG_ARM) += arm
> > >
> > >  obj-y += iommu.o
> > > +obj-$(CONFIG_HAS_PCI) += groups.o
> > >  obj-$(CONFIG_HAS_PCI) += pci.o
> > >  obj-$(CONFIG_HAS_DEVICE_TREE) += device_tree.o
> > >
> > > diff --git a/xen/drivers/passthrough/groups.c 
> > > b/xen/drivers/passthrough/groups.c
> > > new file mode 100644
> > > index 00..1a2f461c87
> > > --- /dev/null
> > > +++ b/xen/drivers/passthrough/groups.c
> > > @@ -0,0 +1,91 @@
> > > +/*
> > > + * Copyright (c) 2019 Citrix Systems Inc.
> > > + *
> > > + * 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.
> > > + */
> > > +
> > > +#include 
> > > +#include 
> > > +
> > > +struct iommu_group {
> > > +unsigned int id;
> > > +};
> > > +
> > > +static struct radix_tree_root iommu_groups;
> > &

Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups

2019-07-15 Thread Paul Durrant 
> -Original Message-
> From: Roger Pau Monne 
> Sent: 15 July 2019 16:35
> To: Paul Durrant 
> Cc: xen-devel@lists.xenproject.org; Stefano Stabellini 
> ; Wei Liu ;
> Konrad Rzeszutek Wilk ; George Dunlap 
> ; Andrew
> Cooper ; Ian Jackson ; Tim 
> (Xen.org) ;
> Julien Grall ; Jan Beulich 
> Subject: Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups
> 
> On Mon, Jul 15, 2019 at 01:37:09PM +0100, Paul Durrant wrote:
> > Some devices may share a single PCIe initiator id, e.g. if they are actually
> > legacy PCI devices behind a bridge, and hence DMA from such devices will
> > be subject to the same address translation in the IOMMU. Hence these devices
> > should be treated as a unit for the purposes of assignment. There are also
> > other reasons why multiple devices should be treated as a unit, e.g. those
> > subject to a shared RMRR or those downstream of a bridge that does not
> > support ACS.
> >
> > This patch introduces a new struct iommu_group to act as a container for
> > devices that should be treated as a unit, and builds a list of them as
> > PCI devices are scanned. The iommu_ops already implement a method,
> > get_device_group_id(), that is seemingly intended to return the initiator
> > id for a given SBDF so use this as the mechanism for group assignment in
> > the first instance. Assignment based on shared RMRR or lack of ACS will be
> > dealt with in subsequent patches, as will modifications to the device
> > assignment code.
> >
> > Signed-off-by: Paul Durrant 
> 
> LGTM, just two comments below.
> 
> > ---
> > Cc: Jan Beulich 
> > Cc: Andrew Cooper 
> > Cc: George Dunlap 
> > Cc: Ian Jackson 
> > Cc: Julien Grall 
> > Cc: Konrad Rzeszutek Wilk 
> > Cc: Stefano Stabellini 
> > Cc: Tim Deegan 
> > Cc: Wei Liu 
> >
> > v2:
> >  - Move code into new drivers/passthrough/groups.c
> >  - Drop the group index.
> >  - Handle failure to get group id.
> >  - Drop the group devs list.
> > ---
> >  xen/drivers/passthrough/Makefile|  1 +
> >  xen/drivers/passthrough/groups.c| 91 
> > +
> >  xen/drivers/passthrough/x86/iommu.c |  8 +++-
> >  xen/include/xen/iommu.h |  7 +++
> >  xen/include/xen/pci.h   |  2 +
> >  5 files changed, 108 insertions(+), 1 deletion(-)
> >  create mode 100644 xen/drivers/passthrough/groups.c
> >
> > diff --git a/xen/drivers/passthrough/Makefile 
> > b/xen/drivers/passthrough/Makefile
> > index d50ab188c8..8a77110179 100644
> > --- a/xen/drivers/passthrough/Makefile
> > +++ b/xen/drivers/passthrough/Makefile
> > @@ -4,6 +4,7 @@ subdir-$(CONFIG_X86) += x86
> >  subdir-$(CONFIG_ARM) += arm
> >
> >  obj-y += iommu.o
> > +obj-$(CONFIG_HAS_PCI) += groups.o
> >  obj-$(CONFIG_HAS_PCI) += pci.o
> >  obj-$(CONFIG_HAS_DEVICE_TREE) += device_tree.o
> >
> > diff --git a/xen/drivers/passthrough/groups.c 
> > b/xen/drivers/passthrough/groups.c
> > new file mode 100644
> > index 00..1a2f461c87
> > --- /dev/null
> > +++ b/xen/drivers/passthrough/groups.c
> > @@ -0,0 +1,91 @@
> > +/*
> > + * Copyright (c) 2019 Citrix Systems Inc.
> > + *
> > + * 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.
> > + */
> > +
> > +#include 
> > +#include 
> > +
> > +struct iommu_group {
> > +unsigned int id;
> > +};
> > +
> > +static struct radix_tree_root iommu_groups;
> > +
> > +void __init iommu_groups_init(void)
> > +{
> > +radix_tree_init(&iommu_groups);
> > +}
> > +
> > +static struct iommu_group *alloc_iommu_group(unsigned int id)
> > +{
> > +struct iommu_group *grp = xzalloc(struct iommu_group);
> > +
> > +if ( !grp )
> > +return NULL;
> > +
> > +grp->id = id;
> > +
> > +if ( radix_tree_insert(&iommu_groups, id, grp) )
> > +{
> > +xfree(grp);
> > +grp = NULL;
> > +}
> > +
> > +

Re: [Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups

2019-07-15 Thread Roger Pau Monné 
On Mon, Jul 15, 2019 at 01:37:09PM +0100, Paul Durrant wrote:
> Some devices may share a single PCIe initiator id, e.g. if they are actually
> legacy PCI devices behind a bridge, and hence DMA from such devices will
> be subject to the same address translation in the IOMMU. Hence these devices
> should be treated as a unit for the purposes of assignment. There are also
> other reasons why multiple devices should be treated as a unit, e.g. those
> subject to a shared RMRR or those downstream of a bridge that does not
> support ACS.
> 
> This patch introduces a new struct iommu_group to act as a container for
> devices that should be treated as a unit, and builds a list of them as
> PCI devices are scanned. The iommu_ops already implement a method,
> get_device_group_id(), that is seemingly intended to return the initiator
> id for a given SBDF so use this as the mechanism for group assignment in
> the first instance. Assignment based on shared RMRR or lack of ACS will be
> dealt with in subsequent patches, as will modifications to the device
> assignment code.
> 
> Signed-off-by: Paul Durrant 

LGTM, just two comments below.

> ---
> Cc: Jan Beulich 
> Cc: Andrew Cooper 
> Cc: George Dunlap 
> Cc: Ian Jackson 
> Cc: Julien Grall 
> Cc: Konrad Rzeszutek Wilk 
> Cc: Stefano Stabellini 
> Cc: Tim Deegan 
> Cc: Wei Liu 
> 
> v2:
>  - Move code into new drivers/passthrough/groups.c
>  - Drop the group index.
>  - Handle failure to get group id.
>  - Drop the group devs list.
> ---
>  xen/drivers/passthrough/Makefile|  1 +
>  xen/drivers/passthrough/groups.c| 91 
> +
>  xen/drivers/passthrough/x86/iommu.c |  8 +++-
>  xen/include/xen/iommu.h |  7 +++
>  xen/include/xen/pci.h   |  2 +
>  5 files changed, 108 insertions(+), 1 deletion(-)
>  create mode 100644 xen/drivers/passthrough/groups.c
> 
> diff --git a/xen/drivers/passthrough/Makefile 
> b/xen/drivers/passthrough/Makefile
> index d50ab188c8..8a77110179 100644
> --- a/xen/drivers/passthrough/Makefile
> +++ b/xen/drivers/passthrough/Makefile
> @@ -4,6 +4,7 @@ subdir-$(CONFIG_X86) += x86
>  subdir-$(CONFIG_ARM) += arm
>  
>  obj-y += iommu.o
> +obj-$(CONFIG_HAS_PCI) += groups.o
>  obj-$(CONFIG_HAS_PCI) += pci.o
>  obj-$(CONFIG_HAS_DEVICE_TREE) += device_tree.o
>  
> diff --git a/xen/drivers/passthrough/groups.c 
> b/xen/drivers/passthrough/groups.c
> new file mode 100644
> index 00..1a2f461c87
> --- /dev/null
> +++ b/xen/drivers/passthrough/groups.c
> @@ -0,0 +1,91 @@
> +/*
> + * Copyright (c) 2019 Citrix Systems Inc.
> + *
> + * 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.
> + */
> +
> +#include 
> +#include 
> +
> +struct iommu_group {
> +unsigned int id;
> +};
> +
> +static struct radix_tree_root iommu_groups;
> +
> +void __init iommu_groups_init(void)
> +{
> +radix_tree_init(&iommu_groups);
> +}
> +
> +static struct iommu_group *alloc_iommu_group(unsigned int id)
> +{
> +struct iommu_group *grp = xzalloc(struct iommu_group);
> +
> +if ( !grp )
> +return NULL;
> +
> +grp->id = id;
> +
> +if ( radix_tree_insert(&iommu_groups, id, grp) )
> +{
> +xfree(grp);
> +grp = NULL;
> +}
> +
> +return grp;
> +}
> +
> +static struct iommu_group *get_iommu_group(unsigned int id)
> +{
> +struct iommu_group *grp = radix_tree_lookup(&iommu_groups, id);
> +
> +if ( !grp )
> +grp = alloc_iommu_group(id);
> +
> +return grp;
> +}
> +
> +int iommu_group_assign(struct pci_dev *pdev, void *arg)

I'm not sure I see the point of the arg parameter, AFAICT it's
completely unused.

> +{
> +const struct iommu_ops *ops = iommu_get_ops();
> +unsigned int id;
> +struct iommu_group *grp;
> +
> +if ( !ops->get_device_group_id )
> +return 0;
> +
> +id = ops->get_device_group_id(pdev->seg, pdev->bus, pdev->devfn);

I think I would prefer id to be of signed type here, then when you
pass it to get_iommu_group it's already made unsigned.

Thanks, Roger.

___
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

[Xen-devel] [PATCH v2 3/4] iommu: introduce iommu_groups

2019-07-15 Thread Paul Durrant 
Some devices may share a single PCIe initiator id, e.g. if they are actually
legacy PCI devices behind a bridge, and hence DMA from such devices will
be subject to the same address translation in the IOMMU. Hence these devices
should be treated as a unit for the purposes of assignment. There are also
other reasons why multiple devices should be treated as a unit, e.g. those
subject to a shared RMRR or those downstream of a bridge that does not
support ACS.

This patch introduces a new struct iommu_group to act as a container for
devices that should be treated as a unit, and builds a list of them as
PCI devices are scanned. The iommu_ops already implement a method,
get_device_group_id(), that is seemingly intended to return the initiator
id for a given SBDF so use this as the mechanism for group assignment in
the first instance. Assignment based on shared RMRR or lack of ACS will be
dealt with in subsequent patches, as will modifications to the device
assignment code.

Signed-off-by: Paul Durrant 
---
Cc: Jan Beulich 
Cc: Andrew Cooper 
Cc: George Dunlap 
Cc: Ian Jackson 
Cc: Julien Grall 
Cc: Konrad Rzeszutek Wilk 
Cc: Stefano Stabellini 
Cc: Tim Deegan 
Cc: Wei Liu 

v2:
 - Move code into new drivers/passthrough/groups.c
 - Drop the group index.
 - Handle failure to get group id.
 - Drop the group devs list.
---
 xen/drivers/passthrough/Makefile|  1 +
 xen/drivers/passthrough/groups.c| 91 +
 xen/drivers/passthrough/x86/iommu.c |  8 +++-
 xen/include/xen/iommu.h |  7 +++
 xen/include/xen/pci.h   |  2 +
 5 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 xen/drivers/passthrough/groups.c

diff --git a/xen/drivers/passthrough/Makefile b/xen/drivers/passthrough/Makefile
index d50ab188c8..8a77110179 100644
--- a/xen/drivers/passthrough/Makefile
+++ b/xen/drivers/passthrough/Makefile
@@ -4,6 +4,7 @@ subdir-$(CONFIG_X86) += x86
 subdir-$(CONFIG_ARM) += arm
 
 obj-y += iommu.o
+obj-$(CONFIG_HAS_PCI) += groups.o
 obj-$(CONFIG_HAS_PCI) += pci.o
 obj-$(CONFIG_HAS_DEVICE_TREE) += device_tree.o
 
diff --git a/xen/drivers/passthrough/groups.c b/xen/drivers/passthrough/groups.c
new file mode 100644
index 00..1a2f461c87
--- /dev/null
+++ b/xen/drivers/passthrough/groups.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2019 Citrix Systems Inc.
+ *
+ * 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.
+ */
+
+#include 
+#include 
+
+struct iommu_group {
+unsigned int id;
+};
+
+static struct radix_tree_root iommu_groups;
+
+void __init iommu_groups_init(void)
+{
+radix_tree_init(&iommu_groups);
+}
+
+static struct iommu_group *alloc_iommu_group(unsigned int id)
+{
+struct iommu_group *grp = xzalloc(struct iommu_group);
+
+if ( !grp )
+return NULL;
+
+grp->id = id;
+
+if ( radix_tree_insert(&iommu_groups, id, grp) )
+{
+xfree(grp);
+grp = NULL;
+}
+
+return grp;
+}
+
+static struct iommu_group *get_iommu_group(unsigned int id)
+{
+struct iommu_group *grp = radix_tree_lookup(&iommu_groups, id);
+
+if ( !grp )
+grp = alloc_iommu_group(id);
+
+return grp;
+}
+
+int iommu_group_assign(struct pci_dev *pdev, void *arg)
+{
+const struct iommu_ops *ops = iommu_get_ops();
+unsigned int id;
+struct iommu_group *grp;
+
+if ( !ops->get_device_group_id )
+return 0;
+
+id = ops->get_device_group_id(pdev->seg, pdev->bus, pdev->devfn);
+if ( id < 0 )
+return -ENODATA;
+
+grp = get_iommu_group(id);
+if ( !grp )
+return -ENOMEM;
+
+if ( iommu_verbose )
+printk(XENLOG_INFO "Assign %04x:%02x:%02x.%u -> IOMMU group %x\n",
+   pdev->seg, pdev->bus, PCI_SLOT(pdev->devfn),
+   PCI_FUNC(pdev->devfn), grp->id);
+
+pdev->grp = grp;
+
+return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/drivers/passthrough/x86/iommu.c 
b/xen/drivers/passthrough/x86/iommu.c
index a7438c9c25..90fc750456 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -43,7 +43,13 @@ int __init iommu_hardware_setup(void)
 /* x2apic setup may have previously initialised the struct. */
 ASSERT(iommu_ops.init == iommu_init_ops->ops->init);
 
-return iommu_init_ops->setup();
+rc = iommu_init_ops->setup();
+if ( rc )
+return rc;
+
+iommu_groups_init();
+
+return pci_pdevs_iterate(iommu_group_ass