Re: [PATCH kernel v11 18/34] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
On Fri, May 29, 2015 at 06:44:42PM +1000, Alexey Kardashevskiy wrote: > This adds tce_iommu_take_ownership() and tce_iommu_release_ownership > which call in a loop iommu_take_ownership()/iommu_release_ownership() > for every table on the group. As there is just one now, no change in > behaviour is expected. > > At the moment the iommu_table struct has a set_bypass() which enables/ > disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code > which calls this callback when external IOMMU users such as VFIO are > about to get over a PHB. > > The set_bypass() callback is not really an iommu_table function but > IOMMU/PE function. This introduces a iommu_table_group_ops struct and > adds take_ownership()/release_ownership() callbacks to it which are > called when an external user takes/releases control over the IOMMU. > > This replaces set_bypass() with ownership callbacks as it is not > necessarily just bypass enabling, it can be something else/more > so let's give it more generic name. > > The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, > IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. > The following patches will replace iommu_take_ownership/ > iommu_release_ownership calls in IODA2 with full IOMMU table release/ > create. > > As we here and touching bypass control, this removes > pnv_pci_ioda2_setup_bypass_pe() as it does not do much > more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base > initialization to pnv_pci_ioda2_setup_dma_pe. > > Signed-off-by: Alexey Kardashevskiy > [aw: for the vfio related changes] > Acked-by: Alex Williamson > Reviewed-by: Gavin Shan Reviewed-by: David Gibson -- David Gibson| I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson pgpWtQcYMBMIE.pgp Description: PGP signature
Re: [PATCH kernel v11 18/34] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
On Fri, May 29, 2015 at 06:44:42PM +1000, Alexey Kardashevskiy wrote: This adds tce_iommu_take_ownership() and tce_iommu_release_ownership which call in a loop iommu_take_ownership()/iommu_release_ownership() for every table on the group. As there is just one now, no change in behaviour is expected. At the moment the iommu_table struct has a set_bypass() which enables/ disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code which calls this callback when external IOMMU users such as VFIO are about to get over a PHB. The set_bypass() callback is not really an iommu_table function but IOMMU/PE function. This introduces a iommu_table_group_ops struct and adds take_ownership()/release_ownership() callbacks to it which are called when an external user takes/releases control over the IOMMU. This replaces set_bypass() with ownership callbacks as it is not necessarily just bypass enabling, it can be something else/more so let's give it more generic name. The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. The following patches will replace iommu_take_ownership/ iommu_release_ownership calls in IODA2 with full IOMMU table release/ create. As we here and touching bypass control, this removes pnv_pci_ioda2_setup_bypass_pe() as it does not do much more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base initialization to pnv_pci_ioda2_setup_dma_pe. Signed-off-by: Alexey Kardashevskiy a...@ozlabs.ru [aw: for the vfio related changes] Acked-by: Alex Williamson alex.william...@redhat.com Reviewed-by: Gavin Shan gws...@linux.vnet.ibm.com Reviewed-by: David Gibson da...@gibson.dropbear.id.au -- David Gibson| I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson pgpWtQcYMBMIE.pgp Description: PGP signature
[PATCH kernel v11 18/34] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
This adds tce_iommu_take_ownership() and tce_iommu_release_ownership
which call in a loop iommu_take_ownership()/iommu_release_ownership()
for every table on the group. As there is just one now, no change in
behaviour is expected.
At the moment the iommu_table struct has a set_bypass() which enables/
disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code
which calls this callback when external IOMMU users such as VFIO are
about to get over a PHB.
The set_bypass() callback is not really an iommu_table function but
IOMMU/PE function. This introduces a iommu_table_group_ops struct and
adds take_ownership()/release_ownership() callbacks to it which are
called when an external user takes/releases control over the IOMMU.
This replaces set_bypass() with ownership callbacks as it is not
necessarily just bypass enabling, it can be something else/more
so let's give it more generic name.
The callbacks is implemented for IODA2 only. Other platforms (P5IOC2,
IODA1) will use the old iommu_take_ownership/iommu_release_ownership API.
The following patches will replace iommu_take_ownership/
iommu_release_ownership calls in IODA2 with full IOMMU table release/
create.
As we here and touching bypass control, this removes
pnv_pci_ioda2_setup_bypass_pe() as it does not do much
more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base
initialization to pnv_pci_ioda2_setup_dma_pe.
Signed-off-by: Alexey Kardashevskiy
[aw: for the vfio related changes]
Acked-by: Alex Williamson
Reviewed-by: Gavin Shan
---
Changes:
v10:
* fixed comments around take_ownership/release_ownership in
iommu_table_group_ops
v9:
* squashed "vfio: powerpc/spapr: powerpc/iommu: Rework IOMMU ownership control"
and "vfio: powerpc/spapr: powerpc/powernv/ioda2: Rework IOMMU ownership control"
into a single patch
* moved helpers with a loop through tables in a group
to vfio_iommu_spapr_tce.c to keep the platform code free of IOMMU table
groups as much as possible
* added missing tce_iommu_clear() to tce_iommu_release_ownership()
* replaced the set_ownership(enable) callback with take_ownership() and
release_ownership()
---
arch/powerpc/include/asm/iommu.h | 11 -
arch/powerpc/kernel/iommu.c | 12 -
arch/powerpc/platforms/powernv/pci-ioda.c | 73 ++-
drivers/vfio/vfio_iommu_spapr_tce.c | 70 ++---
4 files changed, 118 insertions(+), 48 deletions(-)
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 44a20cc..489133c 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -93,7 +93,6 @@ struct iommu_table {
unsigned long it_page_shift;/* table iommu page size */
struct list_head it_group_list;/* List of iommu_table_group_link */
struct iommu_table_ops *it_ops;
- void (*set_bypass)(struct iommu_table *tbl, bool enable);
};
/* Pure 2^n version of get_order */
@@ -126,6 +125,15 @@ extern struct iommu_table *iommu_init_table(struct
iommu_table * tbl,
int nid);
#define IOMMU_TABLE_GROUP_MAX_TABLES 1
+struct iommu_table_group;
+
+struct iommu_table_group_ops {
+ /* Switch ownership from platform code to external user (e.g. VFIO) */
+ void (*take_ownership)(struct iommu_table_group *table_group);
+ /* Switch ownership from external user (e.g. VFIO) back to core */
+ void (*release_ownership)(struct iommu_table_group *table_group);
+};
+
struct iommu_table_group_link {
struct list_head next;
struct rcu_head rcu;
@@ -135,6 +143,7 @@ struct iommu_table_group_link {
struct iommu_table_group {
struct iommu_group *group;
struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
+ struct iommu_table_group_ops *ops;
};
#ifdef CONFIG_IOMMU_API
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index e305a8f..b6a397a 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1047,14 +1047,6 @@ int iommu_take_ownership(struct iommu_table *tbl)
memset(tbl->it_map, 0xff, sz);
- /*
-* Disable iommu bypass, otherwise the user can DMA to all of
-* our physical memory via the bypass window instead of just
-* the pages that has been explicitly mapped into the iommu
-*/
- if (tbl->set_bypass)
- tbl->set_bypass(tbl, false);
-
return 0;
}
EXPORT_SYMBOL_GPL(iommu_take_ownership);
@@ -1068,10 +1060,6 @@ void iommu_release_ownership(struct iommu_table *tbl)
/* Restore bit#0 set by iommu_init_table() */
if (tbl->it_offset == 0)
set_bit(0, tbl->it_map);
-
- /* The kernel owns the device now, we can restore the iommu bypass */
- if (tbl->set_bypass)
- tbl->set_bypass(tbl, true);
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);
diff --git
[PATCH kernel v11 18/34] vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
This adds tce_iommu_take_ownership() and tce_iommu_release_ownership
which call in a loop iommu_take_ownership()/iommu_release_ownership()
for every table on the group. As there is just one now, no change in
behaviour is expected.
At the moment the iommu_table struct has a set_bypass() which enables/
disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code
which calls this callback when external IOMMU users such as VFIO are
about to get over a PHB.
The set_bypass() callback is not really an iommu_table function but
IOMMU/PE function. This introduces a iommu_table_group_ops struct and
adds take_ownership()/release_ownership() callbacks to it which are
called when an external user takes/releases control over the IOMMU.
This replaces set_bypass() with ownership callbacks as it is not
necessarily just bypass enabling, it can be something else/more
so let's give it more generic name.
The callbacks is implemented for IODA2 only. Other platforms (P5IOC2,
IODA1) will use the old iommu_take_ownership/iommu_release_ownership API.
The following patches will replace iommu_take_ownership/
iommu_release_ownership calls in IODA2 with full IOMMU table release/
create.
As we here and touching bypass control, this removes
pnv_pci_ioda2_setup_bypass_pe() as it does not do much
more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base
initialization to pnv_pci_ioda2_setup_dma_pe.
Signed-off-by: Alexey Kardashevskiy a...@ozlabs.ru
[aw: for the vfio related changes]
Acked-by: Alex Williamson alex.william...@redhat.com
Reviewed-by: Gavin Shan gws...@linux.vnet.ibm.com
---
Changes:
v10:
* fixed comments around take_ownership/release_ownership in
iommu_table_group_ops
v9:
* squashed vfio: powerpc/spapr: powerpc/iommu: Rework IOMMU ownership control
and vfio: powerpc/spapr: powerpc/powernv/ioda2: Rework IOMMU ownership control
into a single patch
* moved helpers with a loop through tables in a group
to vfio_iommu_spapr_tce.c to keep the platform code free of IOMMU table
groups as much as possible
* added missing tce_iommu_clear() to tce_iommu_release_ownership()
* replaced the set_ownership(enable) callback with take_ownership() and
release_ownership()
---
arch/powerpc/include/asm/iommu.h | 11 -
arch/powerpc/kernel/iommu.c | 12 -
arch/powerpc/platforms/powernv/pci-ioda.c | 73 ++-
drivers/vfio/vfio_iommu_spapr_tce.c | 70 ++---
4 files changed, 118 insertions(+), 48 deletions(-)
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 44a20cc..489133c 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -93,7 +93,6 @@ struct iommu_table {
unsigned long it_page_shift;/* table iommu page size */
struct list_head it_group_list;/* List of iommu_table_group_link */
struct iommu_table_ops *it_ops;
- void (*set_bypass)(struct iommu_table *tbl, bool enable);
};
/* Pure 2^n version of get_order */
@@ -126,6 +125,15 @@ extern struct iommu_table *iommu_init_table(struct
iommu_table * tbl,
int nid);
#define IOMMU_TABLE_GROUP_MAX_TABLES 1
+struct iommu_table_group;
+
+struct iommu_table_group_ops {
+ /* Switch ownership from platform code to external user (e.g. VFIO) */
+ void (*take_ownership)(struct iommu_table_group *table_group);
+ /* Switch ownership from external user (e.g. VFIO) back to core */
+ void (*release_ownership)(struct iommu_table_group *table_group);
+};
+
struct iommu_table_group_link {
struct list_head next;
struct rcu_head rcu;
@@ -135,6 +143,7 @@ struct iommu_table_group_link {
struct iommu_table_group {
struct iommu_group *group;
struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
+ struct iommu_table_group_ops *ops;
};
#ifdef CONFIG_IOMMU_API
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index e305a8f..b6a397a 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1047,14 +1047,6 @@ int iommu_take_ownership(struct iommu_table *tbl)
memset(tbl-it_map, 0xff, sz);
- /*
-* Disable iommu bypass, otherwise the user can DMA to all of
-* our physical memory via the bypass window instead of just
-* the pages that has been explicitly mapped into the iommu
-*/
- if (tbl-set_bypass)
- tbl-set_bypass(tbl, false);
-
return 0;
}
EXPORT_SYMBOL_GPL(iommu_take_ownership);
@@ -1068,10 +1060,6 @@ void iommu_release_ownership(struct iommu_table *tbl)
/* Restore bit#0 set by iommu_init_table() */
if (tbl-it_offset == 0)
set_bit(0, tbl-it_map);
-
- /* The kernel owns the device now, we can restore the iommu bypass */
- if (tbl-set_bypass)
- tbl-set_bypass(tbl, true);
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);
