| Message ID | 20190715123710.1780-4-paul.durrant@citrix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iommu groups + cleanup | expand |
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 <paul.durrant@citrix.com> LGTM, just two comments below. > --- > Cc: Jan Beulich <jbeulich@suse.com> > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > Cc: George Dunlap <George.Dunlap@eu.citrix.com> > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > Cc: Julien Grall <julien.grall@arm.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: Stefano Stabellini <sstabellini@kernel.org> > Cc: Tim Deegan <tim@xen.org> > Cc: Wei Liu <wl@xen.org> > > 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 0000000000..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 <xen/iommu.h> > +#include <xen/radix-tree.h> > + > +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.
> -----Original Message----- > From: Roger Pau Monne <roger.pau@citrix.com> > Sent: 15 July 2019 16:35 > To: Paul Durrant <Paul.Durrant@citrix.com> > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini <sstabellini@kernel.org>; Wei Liu <wl@xen.org>; > Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; George Dunlap <George.Dunlap@citrix.com>; Andrew > Cooper <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim (Xen.org) <tim@xen.org>; > Julien Grall <julien.grall@arm.com>; Jan Beulich <jbeulich@suse.com> > 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 <paul.durrant@citrix.com> > > LGTM, just two comments below. > > > --- > > Cc: Jan Beulich <jbeulich@suse.com> > > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > > Cc: George Dunlap <George.Dunlap@eu.citrix.com> > > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > > Cc: Julien Grall <julien.grall@arm.com> > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > Cc: Stefano Stabellini <sstabellini@kernel.org> > > Cc: Tim Deegan <tim@xen.org> > > Cc: Wei Liu <wl@xen.org> > > > > 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 0000000000..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 <xen/iommu.h> > > +#include <xen/radix-tree.h> > > + > > +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. It needs to be there because it needs to conform to the all device iterator function callback prototype. It is indeed unused though. > > > +{ > > + 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. That's a good catch. It's tested for < 0 below so it does need to be signed at this point. Paul > > Thanks, Roger.
On Mon, Jul 15, 2019 at 05:41:27PM +0200, Paul Durrant wrote: > > -----Original Message----- > > From: Roger Pau Monne <roger.pau@citrix.com> > > Sent: 15 July 2019 16:35 > > To: Paul Durrant <Paul.Durrant@citrix.com> > > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini <sstabellini@kernel.org>; Wei Liu <wl@xen.org>; > > Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; George Dunlap <George.Dunlap@citrix.com>; Andrew > > Cooper <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim (Xen.org) <tim@xen.org>; > > Julien Grall <julien.grall@arm.com>; Jan Beulich <jbeulich@suse.com> > > 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 <paul.durrant@citrix.com> > > > > LGTM, just two comments below. > > > > > --- > > > Cc: Jan Beulich <jbeulich@suse.com> > > > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > > > Cc: George Dunlap <George.Dunlap@eu.citrix.com> > > > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > > > Cc: Julien Grall <julien.grall@arm.com> > > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > > Cc: Stefano Stabellini <sstabellini@kernel.org> > > > Cc: Tim Deegan <tim@xen.org> > > > Cc: Wei Liu <wl@xen.org> > > > > > > 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 0000000000..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 <xen/iommu.h> > > > +#include <xen/radix-tree.h> > > > + > > > +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. > > It needs to be there because it needs to conform to the all device iterator function callback prototype. It is indeed unused though. Oh right, sorry for the noise. > > > > > +{ > > > + 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. > > That's a good catch. It's tested for < 0 below so it does need to be signed at this point. With that you can add my: Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Thanks, Roger.
> -----Original Message----- > From: Roger Pau Monne <roger.pau@citrix.com> > Sent: 16 July 2019 09:57 > To: Paul Durrant <Paul.Durrant@citrix.com> > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini <sstabellini@kernel.org>; Wei Liu <wl@xen.org>; > Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; George Dunlap <George.Dunlap@citrix.com>; Andrew > Cooper <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim (Xen.org) <tim@xen.org>; > Julien Grall <julien.grall@arm.com>; Jan Beulich <jbeulich@suse.com> > 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 <roger.pau@citrix.com> > > > Sent: 15 July 2019 16:35 > > > To: Paul Durrant <Paul.Durrant@citrix.com> > > > Cc: xen-devel@lists.xenproject.org; Stefano Stabellini <sstabellini@kernel.org>; Wei Liu > <wl@xen.org>; > > > Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>; George Dunlap <George.Dunlap@citrix.com>; Andrew > > > Cooper <Andrew.Cooper3@citrix.com>; Ian Jackson <Ian.Jackson@citrix.com>; Tim (Xen.org) > <tim@xen.org>; > > > Julien Grall <julien.grall@arm.com>; Jan Beulich <jbeulich@suse.com> > > > 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 <paul.durrant@citrix.com> > > > > > > LGTM, just two comments below. > > > > > > > --- > > > > Cc: Jan Beulich <jbeulich@suse.com> > > > > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > > > > Cc: George Dunlap <George.Dunlap@eu.citrix.com> > > > > Cc: Ian Jackson <ian.jackson@eu.citrix.com> > > > > Cc: Julien Grall <julien.grall@arm.com> > > > > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > > > Cc: Stefano Stabellini <sstabellini@kernel.org> > > > > Cc: Tim Deegan <tim@xen.org> > > > > Cc: Wei Liu <wl@xen.org> > > > > > > > > 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 0000000000..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 <xen/iommu.h> > > > > +#include <xen/radix-tree.h> > > > > + > > > > +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. > > > > It needs to be there because it needs to conform to the all device iterator function callback > prototype. It is indeed unused though. > > Oh right, sorry for the noise. > > > > > > > > +{ > > > > + 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. > > > > That's a good catch. It's tested for < 0 below so it does need to be signed at this point. > > With that you can add my: > > Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Thanks :-) Paul > > Thanks, Roger.
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 0000000000..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 <xen/iommu.h> +#include <xen/radix-tree.h> + +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_assign, NULL); } int iommu_enable_x2apic(void) diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h index 48f87480a7..c93f580fdc 100644 --- a/xen/include/xen/iommu.h +++ b/xen/include/xen/iommu.h @@ -317,6 +317,13 @@ DECLARE_PER_CPU(bool_t, iommu_dont_flush_iotlb); extern struct spinlock iommu_pt_cleanup_lock; extern struct page_list_head iommu_pt_cleanup_list; +#ifdef CONFIG_HAS_PCI + +void iommu_groups_init(void); +int iommu_group_assign(struct pci_dev *pdev, void *arg); + +#endif /* CONFIG_HAS_PCI */ + #endif /* _IOMMU_H_ */ /* diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h index 79eb25417b..e1f887af1c 100644 --- a/xen/include/xen/pci.h +++ b/xen/include/xen/pci.h @@ -79,6 +79,8 @@ struct pci_dev { struct list_head alldevs_list; struct list_head domain_list; + struct iommu_group *grp; + struct list_head msi_list; struct arch_msix *msix;
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 <paul.durrant@citrix.com> --- Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: George Dunlap <George.Dunlap@eu.citrix.com> Cc: Ian Jackson <ian.jackson@eu.citrix.com> Cc: Julien Grall <julien.grall@arm.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Tim Deegan <tim@xen.org> Cc: Wei Liu <wl@xen.org> 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