diff mbox series

[2/2] iommu: Fix the domain type checks when default_domain is set

Message ID 170618452753.3805.4425669653666211728.stgit@ltcd48-lp2.aus.stglab.ibm.com
State New
Headers
Series powerpc: iommu: Fix the vfio-pci bind and unbind issues |

Commit Message

Shivaprasad G Bhat Jan. 25, 2024, 12:08 p.m. UTC 
  On PPC64, the iommu_ops.def_domain_type() is not defined and
CONFIG_IOMMU_DMA not enabled. With commit 0f6a90436a57 ("iommu: Do not
use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled"), the
iommu_get_default_domain_type() return IOMMU_DOMAIN_IDENTITY. With
commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove
set_platform_dma_ops"), the defaule_domain is set wih the type being
PLATFORM. With these two changes, iommu_group_alloc_default_domain()
ends up returning the NULL(with recent changes, ERR_PTR(-EINVAL))
leading to iommu_probe_device() failure and the device has no
iommu_group set in effect. Subsequently, the bind to vfio(VFIO_IOMMU)
fail as the iommu_group is not set for the device.

Make the iommu_get_default_domain_type() to take default_domain->type
into consideration along with default_domain_type() and fix
iommu_group_alloc_default_domain() to not error out if the requested
type is same as default domain type.

Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
Fixes: 0f6a90436a57 ("iommu: Do not use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled")
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
---
 drivers/iommu/iommu.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Comments

Jason Gunthorpe Jan. 25, 2024, 3:52 p.m. UTC | #1 
On Thu, Jan 25, 2024 at 06:08:52AM -0600, Shivaprasad G Bhat wrote:
> On PPC64, the iommu_ops.def_domain_type() is not defined and
> CONFIG_IOMMU_DMA not enabled. With commit 0f6a90436a57 ("iommu: Do not
> use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled"), the
> iommu_get_default_domain_type() return IOMMU_DOMAIN_IDENTITY. With
> commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove
> set_platform_dma_ops"), the defaule_domain is set wih the type being
> PLATFORM. With these two changes, iommu_group_alloc_default_domain()
> ends up returning the NULL(with recent changes, ERR_PTR(-EINVAL))
> leading to iommu_probe_device() failure and the device has no
> iommu_group set in effect. Subsequently, the bind to vfio(VFIO_IOMMU)
> fail as the iommu_group is not set for the device.
> 
> Make the iommu_get_default_domain_type() to take default_domain->type
> into consideration along with default_domain_type() and fix
> iommu_group_alloc_default_domain() to not error out if the requested
> type is same as default domain type.
> 
> Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
> Fixes: 0f6a90436a57 ("iommu: Do not use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled")
> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---
>  drivers/iommu/iommu.c |   14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)

Are you OK with this version?

https://lore.kernel.org/linux-iommu/20240123174905.GS50608@ziepe.ca/

?

I think it does the same thing

Jason
Shivaprasad G Bhat Jan. 26, 2024, 3:19 p.m. UTC | #2 
On 1/25/24 21:22, Jason Gunthorpe wrote:
> On Thu, Jan 25, 2024 at 06:08:52AM -0600, Shivaprasad G Bhat wrote:
>> On PPC64, the iommu_ops.def_domain_type() is not defined and
>> CONFIG_IOMMU_DMA not enabled. With commit 0f6a90436a57 ("iommu: Do not
>> use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled"), the
>> iommu_get_default_domain_type() return IOMMU_DOMAIN_IDENTITY. With
>> commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove
>> set_platform_dma_ops"), the defaule_domain is set wih the type being
>> PLATFORM. With these two changes, iommu_group_alloc_default_domain()
>> ends up returning the NULL(with recent changes, ERR_PTR(-EINVAL))
>> leading to iommu_probe_device() failure and the device has no
>> iommu_group set in effect. Subsequently, the bind to vfio(VFIO_IOMMU)
>> fail as the iommu_group is not set for the device.
>>
>> Make the iommu_get_default_domain_type() to take default_domain->type
>> into consideration along with default_domain_type() and fix
>> iommu_group_alloc_default_domain() to not error out if the requested
>> type is same as default domain type.
>>
>> Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
>> Fixes: 0f6a90436a57 ("iommu: Do not use IOMMU_DOMAIN_DMA if CONFIG_IOMMU_DMA is not enabled")
>> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
>> ---
>>   drivers/iommu/iommu.c |   14 ++++++++++----
>>   1 file changed, 10 insertions(+), 4 deletions(-)
> Are you OK with this version?
>
> https://lore.kernel.org/linux-iommu/20240123174905.GS50608@ziepe.ca/
>
> ?
>
> I think it does the same thing

Yes, This works. I see a very minor difference of default_domain->type 
is given

precedence over def_domain_type(). Please keep me CC when you post this 
fix, I'll

test it with any(?) other changes if coming along with it.


Thanks,

Shivaprasad

> Jason
diff mbox series

Patch

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 68e648b55767..04083a1d9f7e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -135,6 +135,8 @@  static struct group_device *iommu_group_alloc_device(struct iommu_group *group,
 						     struct device *dev);
 static void __iommu_group_free_device(struct iommu_group *group,
 				      struct group_device *grp_dev);
+static int iommu_get_def_domain_type(struct iommu_group *group,
+				     struct device *dev, int cur_type);
 
 #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)		\
 struct iommu_group_attribute iommu_group_attr_##_name =		\
@@ -1788,7 +1790,8 @@  __iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
 static struct iommu_domain *
 iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
 {
-	const struct iommu_ops *ops = dev_iommu_ops(iommu_group_first_dev(group));
+	struct device *dev = iommu_group_first_dev(group);
+	const struct iommu_ops *ops = dev_iommu_ops(dev);
 	struct iommu_domain *dom;
 
 	lockdep_assert_held(&group->mutex);
@@ -1799,7 +1802,7 @@  iommu_group_alloc_default_domain(struct iommu_group *group, int req_type)
 	 * domain. Do not use in new drivers.
 	 */
 	if (ops->default_domain) {
-		if (req_type)
+		if (iommu_get_def_domain_type(group, dev, req_type) != req_type)
 			return ERR_PTR(-EINVAL);
 		return ops->default_domain;
 	}
@@ -1871,10 +1874,13 @@  static int iommu_get_def_domain_type(struct iommu_group *group,
 	const struct iommu_ops *ops = dev_iommu_ops(dev);
 	int type;
 
-	if (!ops->def_domain_type)
+	if (ops->def_domain_type)
+		type = ops->def_domain_type(dev);
+	else if (group->default_domain)
+		type = group->default_domain->type;
+	else
 		return cur_type;
 
-	type = ops->def_domain_type(dev);
 	if (!type || cur_type == type)
 		return cur_type;
 	if (!cur_type)