[PATCH v2 00/22] iommu: Refactoring domain allocation interface

[PATCH v2 00/22] iommu: Refactoring domain allocation interface

[Lu Baolu]

The IOMMU subsystem has undergone some changes, including the removal
of iommu_ops from the bus structure. Consequently, the existing domain
allocation interface, which relies on a bus type argument, is no longer
relevant:

    struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)

This series is designed to refactor the use of this interface. It
proposes two new interfaces to replace iommu_domain_alloc():

- iommu_user_domain_alloc(): This interface is intended for allocating
  iommu domains managed by userspace for device passthrough scenarios,
  such as those used by iommufd, vfio, and vdpa. It clearly indicates
  that the domain is for user-managed device DMA.

  If an IOMMU driver does not implement iommu_ops->domain_alloc_user,
  this interface will rollback to the generic paging domain allocation.

- iommu_paging_domain_alloc(): This interface is for allocating iommu
  domains managed by kernel drivers for kernel DMA purposes. It takes a
  device pointer as a parameter, which better reflects the current
  design of the IOMMU subsystem.

The majority of device drivers currently using iommu_domain_alloc() do
so to allocate a domain for a specific device and then attach that
domain to the device. These cases can be straightforwardly migrated to
the new interfaces.

The drm/tegra driver is a bit different in that the device pointer
passed to the helper, which allocates the iommu domain, is not the one
that will be used for the kernel DMA API. Move the existing logic in
iommu_domain_alloc() into the driver to ensure it works as intended.

Now that all consumers of iommu_domain_alloc() have switched to the new
interfaces, we can finally remove iommu_domain_alloc(). This removal
paves the way for the IOMMU subsystem to support multiple iommu drivers.
Additionally, the individual iommu driver implementation for domain
allocation could also be simplified, as there will always be a valid
device pointer passed along the path.

The whole series is also available on GitHub:
https://github.com/LuBaolu/intel-iommu/commits/iommu-domain-allocation-refactor-v2

Change log:

v2:
 - Drop the vt-d patches which implement paging domain support from this
   series. I will post them in a separate series later.
 - Convert all drivers that call iommu_domain_alloc() to use the new
   interface and remove iommu_domain_alloc() from the tree.
 - For the drm/msm driver, make the code compatible with the no-IOMMU
   case.
 - Various cleanups and refinements.

v1: https://lore.kernel.org/linux-iommu/20240529053250.91284-1-baolu.lu@linux.intel.com/

Lu Baolu (21):
  iommu: Add iommu_user_domain_alloc() interface
  iommufd: Use iommu_user_domain_alloc()
  vfio/type1: Use iommu_user_domain_alloc()
  vhost-vdpa: Use iommu_user_domain_alloc()
  iommu: Add iommu_paging_domain_alloc() interface
  drm/msm: Use iommu_paging_domain_alloc()
  drm/nouveau/tegra: Use iommu_paging_domain_alloc()
  gpu: host1x: Use iommu_paging_domain_alloc()
  media: nvidia: tegra: Use iommu_paging_domain_alloc()
  media: venus: firmware: Use iommu_paging_domain_alloc()
  ath10k: Use iommu_paging_domain_alloc()
  wifi: ath11k: Use iommu_paging_domain_alloc()
  remoteproc: Use iommu_paging_domain_alloc()
  soc/fsl/qbman: Use iommu_paging_domain_alloc()
  RDMA/usnic: Use iommu_paging_domain_alloc()
  iommu/vt-d: Add helper to allocate paging domain
  ARM: dma-mapping: Use iommu_paging_domain_alloc()
  drm/rockchip: Use iommu_paging_domain_alloc()
  drm/tegra: Remove call to iommu_domain_alloc()
  iommu: Remove iommu_present()
  iommu: Remove iommu_domain_alloc()

Robin Murphy (1):
  ARM: dma-mapping: Pass device to arm_iommu_create_mapping()

 include/linux/iommu.h                         |  18 +--
 arch/arm/include/asm/dma-iommu.h              |   2 +-
 arch/arm/mm/dma-mapping.c                     |  12 +-
 drivers/gpu/drm/exynos/exynos_drm_dma.c       |   2 +-
 drivers/gpu/drm/msm/msm_iommu.c               |   7 +-
 .../drm/nouveau/nvkm/engine/device/tegra.c    |   4 +-
 drivers/gpu/drm/rockchip/rockchip_drm_drv.c   |  10 +-
 drivers/gpu/drm/tegra/drm.c                   |  34 ++++--
 drivers/gpu/host1x/dev.c                      |   7 +-
 drivers/infiniband/hw/usnic/usnic_uiom.c      |   6 +-
 drivers/iommu/intel/iommu.c                   |  87 +++++++++++++--
 drivers/iommu/iommu.c                         | 103 +++++++++---------
 drivers/iommu/iommufd/hw_pagetable.c          |  20 +---
 drivers/iommu/ipmmu-vmsa.c                    |   3 +-
 drivers/iommu/mtk_iommu_v1.c                  |   3 +-
 .../media/platform/nvidia/tegra-vde/iommu.c   |   7 +-
 drivers/media/platform/qcom/venus/firmware.c  |   6 +-
 drivers/media/platform/ti/omap3isp/isp.c      |   2 +-
 drivers/net/wireless/ath/ath10k/snoc.c        |   6 +-
 drivers/net/wireless/ath/ath11k/ahb.c         |   6 +-
 drivers/remoteproc/remoteproc_core.c          |   6 +-
 drivers/soc/fsl/qbman/qman_portal.c           |   5 +-
 drivers/vfio/vfio_iommu_type1.c               |   7 +-
 drivers/vhost/vdpa.c                          |  14 +--
 24 files changed, 231 insertions(+), 146 deletions(-)

-- 
2.34.1

[PATCH v2 01/22] iommu: Add iommu_user_domain_alloc() interface

[Lu Baolu]

Commit <909f4abd1097> ("iommu: Add new iommu op to create domains owned
by userspace") added a dedicated iommu op to allocate a user domain.
While IOMMUFD has already made use of this callback, other frameworks
like vfio/type1 and vDPA still use the paging domain allocation interface.

Add a new interface named iommu_user_domain_alloc(), which indicates the
allocation of a domain for device DMA managed by user space driver. All
device passthrough frameworks could use this interface for their domain
allocation.

Although it is expected that all iommu drivers could implement their own
domain_alloc_user ops, most drivers haven't implemented it yet. Rollback
to the paging domain allocation interface if the iommu driver hasn't
implemented this op yet.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h |  6 ++++++
 drivers/iommu/iommu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 7bc8dff7cf6d..6648b2415474 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type *bus);
 extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
 extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
 extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);
+struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags);
 extern void iommu_domain_free(struct iommu_domain *domain);
 extern int iommu_attach_device(struct iommu_domain *domain,
 			       struct device *dev);
@@ -1086,6 +1087,11 @@ static inline struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus
 	return NULL;
 }
 
+static inline struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void iommu_domain_free(struct iommu_domain *domain)
 {
 }
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9df7cc75c1bc..f1416892ef8e 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2032,6 +2032,48 @@ struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
 }
 EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
+/**
+ * iommu_user_domain_alloc() - Allocate a user domain
+ * @dev: device for which the domain is allocated
+ * @flags: iommufd_hwpt_alloc_flags defined in uapi/linux/iommufd.h
+ *
+ * Allocate a user domain which will be managed by a userspace driver. Return
+ * allocated domain if successful, or a ERR pointer for failure.
+ */
+struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
+{
+	struct iommu_domain *domain;
+	const struct iommu_ops *ops;
+
+	if (!dev_has_iommu(dev))
+		return ERR_PTR(-ENODEV);
+
+	ops = dev_iommu_ops(dev);
+	if (ops->domain_alloc_user) {
+		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
+		if (IS_ERR(domain))
+			return domain;
+
+		domain->type = IOMMU_DOMAIN_UNMANAGED;
+		domain->owner = ops;
+		domain->pgsize_bitmap = ops->pgsize_bitmap;
+		domain->ops = ops->default_domain_ops;
+
+		return domain;
+	}
+
+	/*
+	 * The iommu driver doesn't support domain_alloc_user callback.
+	 * Rollback to a UNMANAGED paging domain which doesn't support
+	 * the allocation flags.
+	 */
+	if (flags)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	return __iommu_domain_alloc(ops, dev, IOMMU_DOMAIN_UNMANAGED);
+}
+EXPORT_SYMBOL_GPL(iommu_user_domain_alloc);
+
 void iommu_domain_free(struct iommu_domain *domain)
 {
 	if (domain->type == IOMMU_DOMAIN_SVA)
-- 
2.34.1

Re: [PATCH v2 01/22] iommu: Add iommu_user_domain_alloc() interface

[Yi Liu]

On 2024/6/4 09:51, Lu Baolu wrote:
> Commit <909f4abd1097> ("iommu: Add new iommu op to create domains owned
> by userspace") added a dedicated iommu op to allocate a user domain.
> While IOMMUFD has already made use of this callback, other frameworks
> like vfio/type1 and vDPA still use the paging domain allocation interface.
> 
> Add a new interface named iommu_user_domain_alloc(), which indicates the
> allocation of a domain for device DMA managed by user space driver. All
> device passthrough frameworks could use this interface for their domain
> allocation.
> 
> Although it is expected that all iommu drivers could implement their own
> domain_alloc_user ops, most drivers haven't implemented it yet. Rollback
> to the paging domain allocation interface if the iommu driver hasn't
> implemented this op yet.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>   include/linux/iommu.h |  6 ++++++
>   drivers/iommu/iommu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 48 insertions(+)
> 
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 7bc8dff7cf6d..6648b2415474 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type *bus);
>   extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
>   extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
>   extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);
> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags);
>   extern void iommu_domain_free(struct iommu_domain *domain);
>   extern int iommu_attach_device(struct iommu_domain *domain,
>   			       struct device *dev);
> @@ -1086,6 +1087,11 @@ static inline struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus
>   	return NULL;
>   }
>   
> +static inline struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
> +{
> +	return ERR_PTR(-ENODEV);
> +}
> +
>   static inline void iommu_domain_free(struct iommu_domain *domain)
>   {
>   }
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 9df7cc75c1bc..f1416892ef8e 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2032,6 +2032,48 @@ struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
>   }
>   EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>   
> +/**
> + * iommu_user_domain_alloc() - Allocate a user domain
> + * @dev: device for which the domain is allocated
> + * @flags: iommufd_hwpt_alloc_flags defined in uapi/linux/iommufd.h
> + *
> + * Allocate a user domain which will be managed by a userspace driver. Return
> + * allocated domain if successful, or a ERR pointer for failure.

do you want to mention that this is for paging domain allocation?

> + */
> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
> +{
> +	struct iommu_domain *domain;
> +	const struct iommu_ops *ops;
> +
> +	if (!dev_has_iommu(dev))
> +		return ERR_PTR(-ENODEV);
> +
> +	ops = dev_iommu_ops(dev);
> +	if (ops->domain_alloc_user) {
> +		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
> +		if (IS_ERR(domain))
> +			return domain;
> +
> +		domain->type = IOMMU_DOMAIN_UNMANAGED;
> +		domain->owner = ops;
> +		domain->pgsize_bitmap = ops->pgsize_bitmap;

this seems to break the iommufd selftest as the mock driver sets extra
bits in the domain->pgsize_bitmap in allocation. Override it may fail
something in the testing. you may need to check if domain->pgsize_bitmap
is set or use &=.

static struct iommu_domain *mock_domain_alloc_paging(struct device *dev)
{
	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
	struct mock_iommu_domain *mock;

	mock = kzalloc(sizeof(*mock), GFP_KERNEL);
	if (!mock)
		return NULL;
	mock->domain.geometry.aperture_start = MOCK_APERTURE_START;
	mock->domain.geometry.aperture_end = MOCK_APERTURE_LAST;
	mock->domain.pgsize_bitmap = MOCK_IO_PAGE_SIZE;
	if (dev && mdev->flags & MOCK_FLAGS_DEVICE_HUGE_IOVA)
		mock->domain.pgsize_bitmap |= MOCK_HUGE_PAGE_SIZE;
	mock->domain.ops = mock_ops.default_domain_ops;
	mock->domain.type = IOMMU_DOMAIN_UNMANAGED;
	xa_init(&mock->pfns);
	return &mock->domain;
}

> +		domain->ops = ops->default_domain_ops;
> +
> +		return domain;
> +	}
> +
> +	/*
> +	 * The iommu driver doesn't support domain_alloc_user callback.
> +	 * Rollback to a UNMANAGED paging domain which doesn't support
> +	 * the allocation flags.
> +	 */
> +	if (flags)
> +		return ERR_PTR(-EOPNOTSUPP);
> +
> +	return __iommu_domain_alloc(ops, dev, IOMMU_DOMAIN_UNMANAGED);
> +}
> +EXPORT_SYMBOL_GPL(iommu_user_domain_alloc);
> +
>   void iommu_domain_free(struct iommu_domain *domain)
>   {
>   	if (domain->type == IOMMU_DOMAIN_SVA)

-- 
Regards,
Yi Liu

Re: [PATCH v2 01/22] iommu: Add iommu_user_domain_alloc() interface

[Baolu Lu]

On 6/4/24 4:03 PM, Yi Liu wrote:
> On 2024/6/4 09:51, Lu Baolu wrote:
>> Commit <909f4abd1097> ("iommu: Add new iommu op to create domains owned
>> by userspace") added a dedicated iommu op to allocate a user domain.
>> While IOMMUFD has already made use of this callback, other frameworks
>> like vfio/type1 and vDPA still use the paging domain allocation 
>> interface.
>>
>> Add a new interface named iommu_user_domain_alloc(), which indicates the
>> allocation of a domain for device DMA managed by user space driver. All
>> device passthrough frameworks could use this interface for their domain
>> allocation.
>>
>> Although it is expected that all iommu drivers could implement their own
>> domain_alloc_user ops, most drivers haven't implemented it yet. Rollback
>> to the paging domain allocation interface if the iommu driver hasn't
>> implemented this op yet.
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>>   include/linux/iommu.h |  6 ++++++
>>   drivers/iommu/iommu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 48 insertions(+)
>>
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 7bc8dff7cf6d..6648b2415474 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type 
>> *bus);
>>   extern bool device_iommu_capable(struct device *dev, enum iommu_cap 
>> cap);
>>   extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
>>   extern struct iommu_domain *iommu_domain_alloc(const struct bus_type 
>> *bus);
>> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 
>> flags);
>>   extern void iommu_domain_free(struct iommu_domain *domain);
>>   extern int iommu_attach_device(struct iommu_domain *domain,
>>                      struct device *dev);
>> @@ -1086,6 +1087,11 @@ static inline struct iommu_domain 
>> *iommu_domain_alloc(const struct bus_type *bus
>>       return NULL;
>>   }
>> +static inline struct iommu_domain *iommu_user_domain_alloc(struct 
>> device *dev, u32 flags)
>> +{
>> +    return ERR_PTR(-ENODEV);
>> +}
>> +
>>   static inline void iommu_domain_free(struct iommu_domain *domain)
>>   {
>>   }
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index 9df7cc75c1bc..f1416892ef8e 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -2032,6 +2032,48 @@ struct iommu_domain *iommu_domain_alloc(const 
>> struct bus_type *bus)
>>   }
>>   EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>> +/**
>> + * iommu_user_domain_alloc() - Allocate a user domain
>> + * @dev: device for which the domain is allocated
>> + * @flags: iommufd_hwpt_alloc_flags defined in uapi/linux/iommufd.h
>> + *
>> + * Allocate a user domain which will be managed by a userspace 
>> driver. Return
>> + * allocated domain if successful, or a ERR pointer for failure.
> 
> do you want to mention that this is for paging domain allocation?

You are worrying about its confusion with nesting domain allocation,
right? My understanding is that if we want a common interface for
nesting domain allocation, we should make it in another interface. Here,
the user domain is a paging domain for GVA->HPA mapping, which is common
across iommufd, vfio, and vdpa.

> 
>> + */
>> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 
>> flags)
>> +{
>> +    struct iommu_domain *domain;
>> +    const struct iommu_ops *ops;
>> +
>> +    if (!dev_has_iommu(dev))
>> +        return ERR_PTR(-ENODEV);
>> +
>> +    ops = dev_iommu_ops(dev);
>> +    if (ops->domain_alloc_user) {
>> +        domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
>> +        if (IS_ERR(domain))
>> +            return domain;
>> +
>> +        domain->type = IOMMU_DOMAIN_UNMANAGED;
>> +        domain->owner = ops;
>> +        domain->pgsize_bitmap = ops->pgsize_bitmap;
> 
> this seems to break the iommufd selftest as the mock driver sets extra
> bits in the domain->pgsize_bitmap in allocation. Override it may fail
> something in the testing. you may need to check if domain->pgsize_bitmap
> is set or use &=.
> 
> static struct iommu_domain *mock_domain_alloc_paging(struct device *dev)
> {
>      struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
>      struct mock_iommu_domain *mock;
> 
>      mock = kzalloc(sizeof(*mock), GFP_KERNEL);
>      if (!mock)
>          return NULL;
>      mock->domain.geometry.aperture_start = MOCK_APERTURE_START;
>      mock->domain.geometry.aperture_end = MOCK_APERTURE_LAST;
>      mock->domain.pgsize_bitmap = MOCK_IO_PAGE_SIZE;
>      if (dev && mdev->flags & MOCK_FLAGS_DEVICE_HUGE_IOVA)
>          mock->domain.pgsize_bitmap |= MOCK_HUGE_PAGE_SIZE;
>      mock->domain.ops = mock_ops.default_domain_ops;
>      mock->domain.type = IOMMU_DOMAIN_UNMANAGED;
>      xa_init(&mock->pfns);
>      return &mock->domain;
> }

You are right. I should follow the code in __iommu_domain_alloc()

         /*
          * If not already set, assume all sizes by default; the driver
          * may override this later
          */
         if (!domain->pgsize_bitmap)
                 domain->pgsize_bitmap = ops->pgsize_bitmap;

Does it work?

Best regards,
baolu

Re: [PATCH v2 01/22] iommu: Add iommu_user_domain_alloc() interface

[Yi Liu]

On 2024/6/5 10:00, Baolu Lu wrote:
> On 6/4/24 4:03 PM, Yi Liu wrote:
>> On 2024/6/4 09:51, Lu Baolu wrote:
>>> Commit <909f4abd1097> ("iommu: Add new iommu op to create domains owned
>>> by userspace") added a dedicated iommu op to allocate a user domain.
>>> While IOMMUFD has already made use of this callback, other frameworks
>>> like vfio/type1 and vDPA still use the paging domain allocation interface.
>>>
>>> Add a new interface named iommu_user_domain_alloc(), which indicates the
>>> allocation of a domain for device DMA managed by user space driver. All
>>> device passthrough frameworks could use this interface for their domain
>>> allocation.
>>>
>>> Although it is expected that all iommu drivers could implement their own
>>> domain_alloc_user ops, most drivers haven't implemented it yet. Rollback
>>> to the paging domain allocation interface if the iommu driver hasn't
>>> implemented this op yet.
>>>
>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>> ---
>>>   include/linux/iommu.h |  6 ++++++
>>>   drivers/iommu/iommu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>>>   2 files changed, 48 insertions(+)
>>>
>>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>>> index 7bc8dff7cf6d..6648b2415474 100644
>>> --- a/include/linux/iommu.h
>>> +++ b/include/linux/iommu.h
>>> @@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type *bus);
>>>   extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
>>>   extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
>>>   extern struct iommu_domain *iommu_domain_alloc(const struct bus_type 
>>> *bus);
>>> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 
>>> flags);
>>>   extern void iommu_domain_free(struct iommu_domain *domain);
>>>   extern int iommu_attach_device(struct iommu_domain *domain,
>>>                      struct device *dev);
>>> @@ -1086,6 +1087,11 @@ static inline struct iommu_domain 
>>> *iommu_domain_alloc(const struct bus_type *bus
>>>       return NULL;
>>>   }
>>> +static inline struct iommu_domain *iommu_user_domain_alloc(struct 
>>> device *dev, u32 flags)
>>> +{
>>> +    return ERR_PTR(-ENODEV);
>>> +}
>>> +
>>>   static inline void iommu_domain_free(struct iommu_domain *domain)
>>>   {
>>>   }
>>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>>> index 9df7cc75c1bc..f1416892ef8e 100644
>>> --- a/drivers/iommu/iommu.c
>>> +++ b/drivers/iommu/iommu.c
>>> @@ -2032,6 +2032,48 @@ struct iommu_domain *iommu_domain_alloc(const 
>>> struct bus_type *bus)
>>>   }
>>>   EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>>> +/**
>>> + * iommu_user_domain_alloc() - Allocate a user domain
>>> + * @dev: device for which the domain is allocated
>>> + * @flags: iommufd_hwpt_alloc_flags defined in uapi/linux/iommufd.h
>>> + *
>>> + * Allocate a user domain which will be managed by a userspace driver. 
>>> Return
>>> + * allocated domain if successful, or a ERR pointer for failure.
>>
>> do you want to mention that this is for paging domain allocation?
> 
> You are worrying about its confusion with nesting domain allocation,
> right?

yes. As I replied in last version, user_domain is a bit confusing since
nested domain is also a user_domain. That's why we introduced the
alloc_domain_user op.

> My understanding is that if we want a common interface for
> nesting domain allocation, we should make it in another interface. Here,
> the user domain is a paging domain for GVA->HPA mapping, which is common
> across iommufd, vfio, and vdpa.

do you mean user_domain only includes paging domain?

>>
>>> + */
>>> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 
>>> flags)
>>> +{
>>> +    struct iommu_domain *domain;
>>> +    const struct iommu_ops *ops;
>>> +
>>> +    if (!dev_has_iommu(dev))
>>> +        return ERR_PTR(-ENODEV);
>>> +
>>> +    ops = dev_iommu_ops(dev);
>>> +    if (ops->domain_alloc_user) {
>>> +        domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
>>> +        if (IS_ERR(domain))
>>> +            return domain;
>>> +
>>> +        domain->type = IOMMU_DOMAIN_UNMANAGED;
>>> +        domain->owner = ops;
>>> +        domain->pgsize_bitmap = ops->pgsize_bitmap;
>>
>> this seems to break the iommufd selftest as the mock driver sets extra
>> bits in the domain->pgsize_bitmap in allocation. Override it may fail
>> something in the testing. you may need to check if domain->pgsize_bitmap
>> is set or use &=.
>>
>> static struct iommu_domain *mock_domain_alloc_paging(struct device *dev)
>> {
>>      struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
>>      struct mock_iommu_domain *mock;
>>
>>      mock = kzalloc(sizeof(*mock), GFP_KERNEL);
>>      if (!mock)
>>          return NULL;
>>      mock->domain.geometry.aperture_start = MOCK_APERTURE_START;
>>      mock->domain.geometry.aperture_end = MOCK_APERTURE_LAST;
>>      mock->domain.pgsize_bitmap = MOCK_IO_PAGE_SIZE;
>>      if (dev && mdev->flags & MOCK_FLAGS_DEVICE_HUGE_IOVA)
>>          mock->domain.pgsize_bitmap |= MOCK_HUGE_PAGE_SIZE;
>>      mock->domain.ops = mock_ops.default_domain_ops;
>>      mock->domain.type = IOMMU_DOMAIN_UNMANAGED;
>>      xa_init(&mock->pfns);
>>      return &mock->domain;
>> }
> 
> You are right. I should follow the code in __iommu_domain_alloc()
> 
>          /*
>           * If not already set, assume all sizes by default; the driver
>           * may override this later
>           */
>          if (!domain->pgsize_bitmap)
>                  domain->pgsize_bitmap = ops->pgsize_bitmap;
> 
> Does it work?

I think so. This should work.

-- 
Regards,
Yi Liu

Re: [PATCH v2 01/22] iommu: Add iommu_user_domain_alloc() interface

[Baolu Lu]

On 6/5/24 2:23 PM, Yi Liu wrote:
> On 2024/6/5 10:00, Baolu Lu wrote:
>> On 6/4/24 4:03 PM, Yi Liu wrote:
>>> On 2024/6/4 09:51, Lu Baolu wrote:
>>>> Commit <909f4abd1097> ("iommu: Add new iommu op to create domains owned
>>>> by userspace") added a dedicated iommu op to allocate a user domain.
>>>> While IOMMUFD has already made use of this callback, other frameworks
>>>> like vfio/type1 and vDPA still use the paging domain allocation 
>>>> interface.
>>>>
>>>> Add a new interface named iommu_user_domain_alloc(), which indicates 
>>>> the
>>>> allocation of a domain for device DMA managed by user space driver. All
>>>> device passthrough frameworks could use this interface for their domain
>>>> allocation.
>>>>
>>>> Although it is expected that all iommu drivers could implement their 
>>>> own
>>>> domain_alloc_user ops, most drivers haven't implemented it yet. 
>>>> Rollback
>>>> to the paging domain allocation interface if the iommu driver hasn't
>>>> implemented this op yet.
>>>>
>>>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>>>> ---
>>>>   include/linux/iommu.h |  6 ++++++
>>>>   drivers/iommu/iommu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>>>>   2 files changed, 48 insertions(+)
>>>>
>>>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>>>> index 7bc8dff7cf6d..6648b2415474 100644
>>>> --- a/include/linux/iommu.h
>>>> +++ b/include/linux/iommu.h
>>>> @@ -780,6 +780,7 @@ extern bool iommu_present(const struct bus_type 
>>>> *bus);
>>>>   extern bool device_iommu_capable(struct device *dev, enum 
>>>> iommu_cap cap);
>>>>   extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
>>>>   extern struct iommu_domain *iommu_domain_alloc(const struct 
>>>> bus_type *bus);
>>>> +struct iommu_domain *iommu_user_domain_alloc(struct device *dev, 
>>>> u32 flags);
>>>>   extern void iommu_domain_free(struct iommu_domain *domain);
>>>>   extern int iommu_attach_device(struct iommu_domain *domain,
>>>>                      struct device *dev);
>>>> @@ -1086,6 +1087,11 @@ static inline struct iommu_domain 
>>>> *iommu_domain_alloc(const struct bus_type *bus
>>>>       return NULL;
>>>>   }
>>>> +static inline struct iommu_domain *iommu_user_domain_alloc(struct 
>>>> device *dev, u32 flags)
>>>> +{
>>>> +    return ERR_PTR(-ENODEV);
>>>> +}
>>>> +
>>>>   static inline void iommu_domain_free(struct iommu_domain *domain)
>>>>   {
>>>>   }
>>>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>>>> index 9df7cc75c1bc..f1416892ef8e 100644
>>>> --- a/drivers/iommu/iommu.c
>>>> +++ b/drivers/iommu/iommu.c
>>>> @@ -2032,6 +2032,48 @@ struct iommu_domain *iommu_domain_alloc(const 
>>>> struct bus_type *bus)
>>>>   }
>>>>   EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>>>> +/**
>>>> + * iommu_user_domain_alloc() - Allocate a user domain
>>>> + * @dev: device for which the domain is allocated
>>>> + * @flags: iommufd_hwpt_alloc_flags defined in uapi/linux/iommufd.h
>>>> + *
>>>> + * Allocate a user domain which will be managed by a userspace 
>>>> driver. Return
>>>> + * allocated domain if successful, or a ERR pointer for failure.
>>>
>>> do you want to mention that this is for paging domain allocation?
>>
>> You are worrying about its confusion with nesting domain allocation,
>> right?
> 
> yes. As I replied in last version, user_domain is a bit confusing since
> nested domain is also a user_domain. That's why we introduced the
> alloc_domain_user op.

As I discussed with Jason in another reply, I will drop the
iommu_user_domain_alloc() interface as it is currently iommfd-specific
only and not generic for a common interface.

Best regards,
baolu

[PATCH v2 02/22] iommufd: Use iommu_user_domain_alloc()

[Lu Baolu]

Replace iommu_domain_alloc() with iommu_user_domain_alloc().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 33d142f8057d..ada05fccb36a 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -127,21 +127,11 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	hwpt_paging->ioas = ioas;
 	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
 
-	if (ops->domain_alloc_user) {
-		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
-						      user_data);
-		if (IS_ERR(hwpt->domain)) {
-			rc = PTR_ERR(hwpt->domain);
-			hwpt->domain = NULL;
-			goto out_abort;
-		}
-		hwpt->domain->owner = ops;
-	} else {
-		hwpt->domain = iommu_domain_alloc(idev->dev->bus);
-		if (!hwpt->domain) {
-			rc = -ENOMEM;
-			goto out_abort;
-		}
+	hwpt->domain = iommu_user_domain_alloc(idev->dev, flags);
+	if (IS_ERR(hwpt->domain)) {
+		rc = PTR_ERR(hwpt->domain);
+		hwpt->domain = NULL;
+		goto out_abort;
 	}
 
 	/*
-- 
2.34.1

Re: [PATCH v2 02/22] iommufd: Use iommu_user_domain_alloc()

[Jason Gunthorpe]

On Tue, Jun 04, 2024 at 09:51:14AM +0800, Lu Baolu wrote:
> Replace iommu_domain_alloc() with iommu_user_domain_alloc().
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/iommufd/hw_pagetable.c | 20 +++++---------------
>  1 file changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
> index 33d142f8057d..ada05fccb36a 100644
> --- a/drivers/iommu/iommufd/hw_pagetable.c
> +++ b/drivers/iommu/iommufd/hw_pagetable.c
> @@ -127,21 +127,11 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>  	hwpt_paging->ioas = ioas;
>  	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
>  
> -	if (ops->domain_alloc_user) {
> -		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
> -						      user_data);
                                                     ^^^^^^^^^^^^

> -		if (IS_ERR(hwpt->domain)) {
> -			rc = PTR_ERR(hwpt->domain);
> -			hwpt->domain = NULL;
> -			goto out_abort;
> -		}
> -		hwpt->domain->owner = ops;
> -	} else {
> -		hwpt->domain = iommu_domain_alloc(idev->dev->bus);
> -		if (!hwpt->domain) {
> -			rc = -ENOMEM;
> -			goto out_abort;
> -		}
> +	hwpt->domain = iommu_user_domain_alloc(idev->dev, flags);
> +	if (IS_ERR(hwpt->domain)) {

Where did the user_data go???

If you are going to wrapper the op function then all the args need to
be provided.

I'm not sure there is value in having vfio and vdpa call this
variation since they won't pass a user_data or flags?

Do you imagine there will ever be a difference between what
domain_alloc_user(dev, 0, NULL, NULL) returns from
domain_alloc_paging(dev) ?

That seems like questionable driver behavior to me.

Jason

Re: [PATCH v2 02/22] iommufd: Use iommu_user_domain_alloc()

[Baolu Lu]

On 6/5/24 12:51 AM, Jason Gunthorpe wrote:
> On Tue, Jun 04, 2024 at 09:51:14AM +0800, Lu Baolu wrote:
>> Replace iommu_domain_alloc() with iommu_user_domain_alloc().
>>
>> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
>> ---
>>   drivers/iommu/iommufd/hw_pagetable.c | 20 +++++---------------
>>   1 file changed, 5 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
>> index 33d142f8057d..ada05fccb36a 100644
>> --- a/drivers/iommu/iommufd/hw_pagetable.c
>> +++ b/drivers/iommu/iommufd/hw_pagetable.c
>> @@ -127,21 +127,11 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
>>   	hwpt_paging->ioas = ioas;
>>   	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
>>   
>> -	if (ops->domain_alloc_user) {
>> -		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
>> -						      user_data);
>                                                       ^^^^^^^^^^^^
> 
>> -		if (IS_ERR(hwpt->domain)) {
>> -			rc = PTR_ERR(hwpt->domain);
>> -			hwpt->domain = NULL;
>> -			goto out_abort;
>> -		}
>> -		hwpt->domain->owner = ops;
>> -	} else {
>> -		hwpt->domain = iommu_domain_alloc(idev->dev->bus);
>> -		if (!hwpt->domain) {
>> -			rc = -ENOMEM;
>> -			goto out_abort;
>> -		}
>> +	hwpt->domain = iommu_user_domain_alloc(idev->dev, flags);
>> +	if (IS_ERR(hwpt->domain)) {
> 
> Where did the user_data go???

The user_data is not used in allocating a paging user domain, so I
skipped it.

> 
> If you are going to wrapper the op function then all the args need to
> be provided.

Yes. Agreed.

> I'm not sure there is value in having vfio and vdpa call this
> variation since they won't pass a user_data or flags?
> 
> Do you imagine there will ever be a difference between what
> domain_alloc_user(dev, 0, NULL, NULL) returns from
> domain_alloc_paging(dev) ?

No.

> 
> That seems like questionable driver behavior to me.

In my first try, I simply replaced iommu_domain_alloc() with a new
paging domain allocation interface. On second thought, it occurred to me
why not use separate interfaces for different purposes? Even though from
an iommu perspective, they both use paging domains.

The @flags and @user_data are defined in uapi/linux/iommufd.h, which is
specific to iommufd. Wrapping them in a common interface for broader use
seems awkward.

So, perhaps we could return to my original idea? Let's just expose one
interface, iommu_paging_domain_alloc(), and replace iommu_domain_alloc()
with it everywhere?

Best regards,
baolu

Re: [PATCH v2 02/22] iommufd: Use iommu_user_domain_alloc()

[Jason Gunthorpe]

On Wed, Jun 05, 2024 at 10:17:07AM +0800, Baolu Lu wrote:
> On 6/5/24 12:51 AM, Jason Gunthorpe wrote:
> > On Tue, Jun 04, 2024 at 09:51:14AM +0800, Lu Baolu wrote:
> > > Replace iommu_domain_alloc() with iommu_user_domain_alloc().
> > > 
> > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> > > ---
> > >   drivers/iommu/iommufd/hw_pagetable.c | 20 +++++---------------
> > >   1 file changed, 5 insertions(+), 15 deletions(-)
> > > 
> > > diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
> > > index 33d142f8057d..ada05fccb36a 100644
> > > --- a/drivers/iommu/iommufd/hw_pagetable.c
> > > +++ b/drivers/iommu/iommufd/hw_pagetable.c
> > > @@ -127,21 +127,11 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
> > >   	hwpt_paging->ioas = ioas;
> > >   	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
> > > -	if (ops->domain_alloc_user) {
> > > -		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
> > > -						      user_data);
> >                                                       ^^^^^^^^^^^^
> > 
> > > -		if (IS_ERR(hwpt->domain)) {
> > > -			rc = PTR_ERR(hwpt->domain);
> > > -			hwpt->domain = NULL;
> > > -			goto out_abort;
> > > -		}
> > > -		hwpt->domain->owner = ops;
> > > -	} else {
> > > -		hwpt->domain = iommu_domain_alloc(idev->dev->bus);
> > > -		if (!hwpt->domain) {
> > > -			rc = -ENOMEM;
> > > -			goto out_abort;
> > > -		}
> > > +	hwpt->domain = iommu_user_domain_alloc(idev->dev, flags);
> > > +	if (IS_ERR(hwpt->domain)) {
> > 
> > Where did the user_data go???
> 
> The user_data is not used in allocating a paging user domain, so I
> skipped it.

That's not true.. We have no driver using it right now, but it is
definately part of the uAPI and a driver could start using it. That is
why it was hooked up in the first place.

> In my first try, I simply replaced iommu_domain_alloc() with a new
> paging domain allocation interface. On second thought, it occurred to me
> why not use separate interfaces for different purposes? Even though from
> an iommu perspective, they both use paging domains.

If we want to do that then it needs to forward all the args

> The @flags and @user_data are defined in uapi/linux/iommufd.h, which is
> specific to iommufd. Wrapping them in a common interface for broader use
> seems awkward.

Right, you'd have to forward declare the struct and just let it
be. Really nothing but iommufd could call this API.
 
> So, perhaps we could return to my original idea? Let's just expose one
> interface, iommu_paging_domain_alloc(), and replace iommu_domain_alloc()
> with it everywhere?

That's OK too, this above doesn't really need to be changed, some of
the concept here was that iommufd-only ops would just be directly
called by iommufd itself, to discourage future abuse.

Jason

[PATCH v2 03/22] vfio/type1: Use iommu_user_domain_alloc()

[Lu Baolu]

Replace iommu_domain_alloc() with iommu_user_domain_alloc().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/vfio/vfio_iommu_type1.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 3a0218171cfa..1d553f7f7c26 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2135,7 +2135,7 @@ static int vfio_iommu_domain_alloc(struct device *dev, void *data)
 {
 	struct iommu_domain **domain = data;
 
-	*domain = iommu_domain_alloc(dev->bus);
+	*domain = iommu_user_domain_alloc(dev, 0);
 	return 1; /* Don't iterate */
 }
 
@@ -2192,11 +2192,12 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	 * us a representative device for the IOMMU API call. We don't actually
 	 * want to iterate beyond the first device (if any).
 	 */
-	ret = -EIO;
 	iommu_group_for_each_dev(iommu_group, &domain->domain,
 				 vfio_iommu_domain_alloc);
-	if (!domain->domain)
+	if (IS_ERR(domain->domain)) {
+		ret = PTR_ERR(domain->domain);
 		goto out_free_domain;
+	}
 
 	if (iommu->nesting) {
 		ret = iommu_enable_nesting(domain->domain);
-- 
2.34.1

[PATCH v2 04/22] vhost-vdpa: Use iommu_user_domain_alloc()

[Lu Baolu]

Replace iommu_domain_alloc() with iommu_user_domain_alloc().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/vhost/vdpa.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 63a53680a85c..d15673cb05f2 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -1312,26 +1312,24 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
 	struct vdpa_device *vdpa = v->vdpa;
 	const struct vdpa_config_ops *ops = vdpa->config;
 	struct device *dma_dev = vdpa_get_dma_dev(vdpa);
-	const struct bus_type *bus;
 	int ret;
 
 	/* Device want to do DMA by itself */
 	if (ops->set_map || ops->dma_map)
 		return 0;
 
-	bus = dma_dev->bus;
-	if (!bus)
-		return -EFAULT;
-
 	if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) {
 		dev_warn_once(&v->dev,
 			      "Failed to allocate domain, device is not IOMMU cache coherent capable\n");
 		return -ENOTSUPP;
 	}
 
-	v->domain = iommu_domain_alloc(bus);
-	if (!v->domain)
-		return -EIO;
+	v->domain = iommu_user_domain_alloc(dma_dev, 0);
+	if (IS_ERR(v->domain)) {
+		ret = PTR_ERR(v->domain);
+		v->domain = NULL;
+		return ret;
+	}
 
 	ret = iommu_attach_device(v->domain, dma_dev);
 	if (ret)
-- 
2.34.1

[PATCH v2 05/22] iommu: Add iommu_paging_domain_alloc() interface

[Lu Baolu]

Commit <17de3f5fdd35> ("iommu: Retire bus ops") removes iommu ops from
bus. The iommu subsystem no longer relies on bus for operations. So the
bus parameter in iommu_domain_alloc() is no longer relevant.

Add a new interface named iommu_paging_domain_alloc(), which explicitly
indicates the allocation of a paging domain for DMA managed by a kernel
driver. The new interface takes a device pointer as its parameter, that
better aligns with the current iommu subsystem.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h |  6 ++++++
 drivers/iommu/iommu.c | 20 ++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6648b2415474..16401de7802d 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -781,6 +781,7 @@ extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
 extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
 extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);
 struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags);
+struct iommu_domain *iommu_paging_domain_alloc(struct device *dev);
 extern void iommu_domain_free(struct iommu_domain *domain);
 extern int iommu_attach_device(struct iommu_domain *domain,
 			       struct device *dev);
@@ -1092,6 +1093,11 @@ static inline struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u
 	return ERR_PTR(-ENODEV);
 }
 
+static inline struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void iommu_domain_free(struct iommu_domain *domain)
 {
 }
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f1416892ef8e..7df4a021b040 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2016,6 +2016,10 @@ static int __iommu_domain_alloc_dev(struct device *dev, void *data)
 	return 0;
 }
 
+/*
+ * The iommu ops in bus has been retired. Do not use this interface in
+ * new drivers.
+ */
 struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
 {
 	const struct iommu_ops *ops = NULL;
@@ -2074,6 +2078,22 @@ struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
 }
 EXPORT_SYMBOL_GPL(iommu_user_domain_alloc);
 
+/**
+ * iommu_paging_domain_alloc() - Allocate a paging domain
+ * @dev: device for which the domain is allocated
+ *
+ * Allocate a paging domain which will be managed by a kernel driver. Return
+ * allocated domain if successful, or a ERR pointer for failure.
+ */
+struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)
+{
+	if (!dev_has_iommu(dev))
+		return ERR_PTR(-ENODEV);
+
+	return __iommu_domain_alloc(dev_iommu_ops(dev), dev, IOMMU_DOMAIN_UNMANAGED);
+}
+EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc);
+
 void iommu_domain_free(struct iommu_domain *domain)
 {
 	if (domain->type == IOMMU_DOMAIN_SVA)
-- 
2.34.1

[PATCH v2 06/22] drm/msm: Use iommu_paging_domain_alloc()

[Lu Baolu]

The domain allocated in msm_iommu_new() is for the @dev. Replace
iommu_domain_alloc() with iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/gpu/drm/msm/msm_iommu.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index d5512037c38b..2a94e82316f9 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -407,10 +407,13 @@ struct msm_mmu *msm_iommu_new(struct device *dev, unsigned long quirks)
 	struct msm_iommu *iommu;
 	int ret;
 
-	domain = iommu_domain_alloc(dev->bus);
-	if (!domain)
+	if (!device_iommu_mapped(dev))
 		return NULL;
 
+	domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(domain))
+		return ERR_CAST(domain);
+
 	iommu_set_pgtable_quirks(domain, quirks);
 
 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
-- 
2.34.1

Re: [PATCH v2 06/22] drm/msm: Use iommu_paging_domain_alloc()

[Dmitry Baryshkov]

On Tue, Jun 04, 2024 at 09:51:18AM +0800, Lu Baolu wrote:
> The domain allocated in msm_iommu_new() is for the @dev. Replace
> iommu_domain_alloc() with iommu_paging_domain_alloc() to make it explicit.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/gpu/drm/msm/msm_iommu.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)

Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Thank you!

> 
> diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> index d5512037c38b..2a94e82316f9 100644
> --- a/drivers/gpu/drm/msm/msm_iommu.c
> +++ b/drivers/gpu/drm/msm/msm_iommu.c
> @@ -407,10 +407,13 @@ struct msm_mmu *msm_iommu_new(struct device *dev, unsigned long quirks)
>  	struct msm_iommu *iommu;
>  	int ret;
>  
> -	domain = iommu_domain_alloc(dev->bus);
> -	if (!domain)
> +	if (!device_iommu_mapped(dev))
>  		return NULL;
>  
> +	domain = iommu_paging_domain_alloc(dev);
> +	if (IS_ERR(domain))
> +		return ERR_CAST(domain);
> +
>  	iommu_set_pgtable_quirks(domain, quirks);
>  
>  	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry

[PATCH v2 07/22] drm/nouveau/tegra: Use iommu_paging_domain_alloc()

[Lu Baolu]

In nvkm_device_tegra_probe_iommu(), a paging domain is allocated for @dev
and attached to it on success. Use iommu_paging_domain_alloc() to make it
explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index 87caa4a72921..763c4c2925f9 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -120,8 +120,8 @@ nvkm_device_tegra_probe_iommu(struct nvkm_device_tegra *tdev)
 	mutex_init(&tdev->iommu.mutex);
 
 	if (device_iommu_mapped(dev)) {
-		tdev->iommu.domain = iommu_domain_alloc(&platform_bus_type);
-		if (!tdev->iommu.domain)
+		tdev->iommu.domain = iommu_paging_domain_alloc(dev);
+		if (IS_ERR(tdev->iommu.domain))
 			goto error;
 
 		/*
-- 
2.34.1

[PATCH v2 08/22] gpu: host1x: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in host1x_iommu_attach() and is attached to
host->dev. Use iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/gpu/host1x/dev.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 3a0aaa68ac8d..f86a6b12f24a 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -404,9 +404,10 @@ static struct iommu_domain *host1x_iommu_attach(struct host1x *host)
 		if (err < 0)
 			goto put_group;
 
-		host->domain = iommu_domain_alloc(&platform_bus_type);
-		if (!host->domain) {
-			err = -ENOMEM;
+		host->domain = iommu_paging_domain_alloc(host->dev);
+		if (IS_ERR(host->domain)) {
+			err = PTR_ERR(host->domain);
+			host->domain = NULL;
 			goto put_cache;
 		}
 
-- 
2.34.1

[PATCH v2 09/22] media: nvidia: tegra: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in tegra_vde_iommu_init() and is attached to
vde->dev. Use iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/media/platform/nvidia/tegra-vde/iommu.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/nvidia/tegra-vde/iommu.c b/drivers/media/platform/nvidia/tegra-vde/iommu.c
index 5521ed3e465f..b1d9d841d944 100644
--- a/drivers/media/platform/nvidia/tegra-vde/iommu.c
+++ b/drivers/media/platform/nvidia/tegra-vde/iommu.c
@@ -78,9 +78,10 @@ int tegra_vde_iommu_init(struct tegra_vde *vde)
 		arm_iommu_release_mapping(mapping);
 	}
 #endif
-	vde->domain = iommu_domain_alloc(&platform_bus_type);
-	if (!vde->domain) {
-		err = -ENOMEM;
+	vde->domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(vde->domain)) {
+		err = PTR_ERR(vde->domain);
+		vde->domain = NULL;
 		goto put_group;
 	}
 
-- 
2.34.1

[PATCH v2 10/22] media: venus: firmware: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in venus_firmware_init() and is attached to
core->fw.dev in the same function. Use iommu_paging_domain_alloc() to
make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/media/platform/qcom/venus/firmware.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
index fe7da2b30482..66a18830e66d 100644
--- a/drivers/media/platform/qcom/venus/firmware.c
+++ b/drivers/media/platform/qcom/venus/firmware.c
@@ -316,10 +316,10 @@ int venus_firmware_init(struct venus_core *core)
 
 	core->fw.dev = &pdev->dev;
 
-	iommu_dom = iommu_domain_alloc(&platform_bus_type);
-	if (!iommu_dom) {
+	iommu_dom = iommu_paging_domain_alloc(core->fw.dev);
+	if (IS_ERR(iommu_dom)) {
 		dev_err(core->fw.dev, "Failed to allocate iommu domain\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(iommu_dom);
 		goto err_unregister;
 	}
 
-- 
2.34.1

[PATCH v2 11/22] ath10k: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in ath10k_fw_init() and is attached to
ar_snoc->fw.dev in the same function. Use iommu_paging_domain_alloc() to
make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/net/wireless/ath/ath10k/snoc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
index 8530550cf5df..0fe47d51013c 100644
--- a/drivers/net/wireless/ath/ath10k/snoc.c
+++ b/drivers/net/wireless/ath/ath10k/snoc.c
@@ -1635,10 +1635,10 @@ static int ath10k_fw_init(struct ath10k *ar)
 
 	ar_snoc->fw.dev = &pdev->dev;
 
-	iommu_dom = iommu_domain_alloc(&platform_bus_type);
-	if (!iommu_dom) {
+	iommu_dom = iommu_paging_domain_alloc(ar_snoc->fw.dev);
+	if (IS_ERR(iommu_dom)) {
 		ath10k_err(ar, "failed to allocate iommu domain\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(iommu_dom);
 		goto err_unregister;
 	}
 
-- 
2.34.1

Re: [PATCH v2 11/22] ath10k: Use iommu_paging_domain_alloc()

[Jeff Johnson]

On 6/3/24 18:51, Lu Baolu wrote:
> An iommu domain is allocated in ath10k_fw_init() and is attached to
> ar_snoc->fw.dev in the same function. Use iommu_paging_domain_alloc() to
> make it explicit.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

nit: although the subject prefix you used probably matches the prefix in 
git history, subject prefix should now be "wifi: ath10k: "

with that addressed,
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>

Re: [PATCH v2 11/22] ath10k: Use iommu_paging_domain_alloc()

[Jeff Johnson]

+ath10k list for viibility

On 6/3/24 18:51, Lu Baolu wrote:
> An iommu domain is allocated in ath10k_fw_init() and is attached to
> ar_snoc->fw.dev in the same function. Use iommu_paging_domain_alloc() to
> make it explicit.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>   drivers/net/wireless/ath/ath10k/snoc.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
> index 8530550cf5df..0fe47d51013c 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -1635,10 +1635,10 @@ static int ath10k_fw_init(struct ath10k *ar)
>   
>   	ar_snoc->fw.dev = &pdev->dev;
>   
> -	iommu_dom = iommu_domain_alloc(&platform_bus_type);
> -	if (!iommu_dom) {
> +	iommu_dom = iommu_paging_domain_alloc(ar_snoc->fw.dev);
> +	if (IS_ERR(iommu_dom)) {
>   		ath10k_err(ar, "failed to allocate iommu domain\n");
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(iommu_dom);
>   		goto err_unregister;
>   	}
>   

[PATCH v2 12/22] wifi: ath11k: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in ath11k_ahb_fw_resources_init() and is
attached to ab_ahb->fw.dev in the same function.

Use iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/net/wireless/ath/ath11k/ahb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
index ca0f17ddebba..a469647719f9 100644
--- a/drivers/net/wireless/ath/ath11k/ahb.c
+++ b/drivers/net/wireless/ath/ath11k/ahb.c
@@ -1001,10 +1001,10 @@ static int ath11k_ahb_fw_resources_init(struct ath11k_base *ab)
 
 	ab_ahb->fw.dev = &pdev->dev;
 
-	iommu_dom = iommu_domain_alloc(&platform_bus_type);
-	if (!iommu_dom) {
+	iommu_dom = iommu_paging_domain_alloc(ab_ahb->fw.dev);
+	if (IS_ERR(iommu_dom)) {
 		ath11k_err(ab, "failed to allocate iommu domain\n");
-		ret = -ENOMEM;
+		ret = PTR_ERR(iommu_dom);
 		goto err_unregister;
 	}
 
-- 
2.34.1

Re: [PATCH v2 12/22] wifi: ath11k: Use iommu_paging_domain_alloc()

[Kalle Valo]

Lu Baolu <baolu.lu@linux.intel.com> writes:

> An iommu domain is allocated in ath11k_ahb_fw_resources_init() and is
> attached to ab_ahb->fw.dev in the same function.
>
> Use iommu_paging_domain_alloc() to make it explicit.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/net/wireless/ath/ath11k/ahb.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
> index ca0f17ddebba..a469647719f9 100644
> --- a/drivers/net/wireless/ath/ath11k/ahb.c
> +++ b/drivers/net/wireless/ath/ath11k/ahb.c
> @@ -1001,10 +1001,10 @@ static int ath11k_ahb_fw_resources_init(struct ath11k_base *ab)
>  
>  	ab_ahb->fw.dev = &pdev->dev;
>  
> -	iommu_dom = iommu_domain_alloc(&platform_bus_type);
> -	if (!iommu_dom) {
> +	iommu_dom = iommu_paging_domain_alloc(ab_ahb->fw.dev);
> +	if (IS_ERR(iommu_dom)) {
>  		ath11k_err(ab, "failed to allocate iommu domain\n");
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(iommu_dom);
>  		goto err_unregister;
>  	}

Adding Jeff and ath11k list so that they can review this as well.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH v2 12/22] wifi: ath11k: Use iommu_paging_domain_alloc()

[Jeff Johnson]

On 6/3/24 18:51, Lu Baolu wrote:
> An iommu domain is allocated in ath11k_ahb_fw_resources_init() and is
> attached to ab_ahb->fw.dev in the same function.
> 
> Use iommu_paging_domain_alloc() to make it explicit.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>

> ---
>   drivers/net/wireless/ath/ath11k/ahb.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/ahb.c b/drivers/net/wireless/ath/ath11k/ahb.c
> index ca0f17ddebba..a469647719f9 100644
> --- a/drivers/net/wireless/ath/ath11k/ahb.c
> +++ b/drivers/net/wireless/ath/ath11k/ahb.c
> @@ -1001,10 +1001,10 @@ static int ath11k_ahb_fw_resources_init(struct ath11k_base *ab)
>   
>   	ab_ahb->fw.dev = &pdev->dev;
>   
> -	iommu_dom = iommu_domain_alloc(&platform_bus_type);
> -	if (!iommu_dom) {
> +	iommu_dom = iommu_paging_domain_alloc(ab_ahb->fw.dev);
> +	if (IS_ERR(iommu_dom)) {
>   		ath11k_err(ab, "failed to allocate iommu domain\n");
> -		ret = -ENOMEM;
> +		ret = PTR_ERR(iommu_dom);
>   		goto err_unregister;
>   	}
>   

[PATCH v2 13/22] remoteproc: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in rproc_enable_iommu() and is attached to
rproc->dev.parent in the same function.

Use iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/remoteproc/remoteproc_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index f276956f2c5c..eb66f78ec8b7 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -109,10 +109,10 @@ static int rproc_enable_iommu(struct rproc *rproc)
 		return 0;
 	}
 
-	domain = iommu_domain_alloc(dev->bus);
-	if (!domain) {
+	domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(domain)) {
 		dev_err(dev, "can't alloc iommu domain\n");
-		return -ENOMEM;
+		return PTR_ERR(domain);
 	}
 
 	iommu_set_fault_handler(domain, rproc_iommu_fault, rproc);
-- 
2.34.1

[PATCH v2 14/22] soc/fsl/qbman: Use iommu_paging_domain_alloc()

[Lu Baolu]

An iommu domain is allocated in portal_set_cpu() and is attached to
pcfg->dev in the same function.

Use iommu_paging_domain_alloc() to make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/soc/fsl/qbman/qman_portal.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/fsl/qbman/qman_portal.c b/drivers/soc/fsl/qbman/qman_portal.c
index e23b60618c1a..456ef5d5c199 100644
--- a/drivers/soc/fsl/qbman/qman_portal.c
+++ b/drivers/soc/fsl/qbman/qman_portal.c
@@ -48,9 +48,10 @@ static void portal_set_cpu(struct qm_portal_config *pcfg, int cpu)
 	struct device *dev = pcfg->dev;
 	int ret;
 
-	pcfg->iommu_domain = iommu_domain_alloc(&platform_bus_type);
-	if (!pcfg->iommu_domain) {
+	pcfg->iommu_domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(pcfg->iommu_domain)) {
 		dev_err(dev, "%s(): iommu_domain_alloc() failed", __func__);
+		pcfg->iommu_domain = NULL;
 		goto no_iommu;
 	}
 	ret = fsl_pamu_configure_l1_stash(pcfg->iommu_domain, cpu);
-- 
2.34.1

[PATCH v2 15/22] RDMA/usnic: Use iommu_paging_domain_alloc()

[Lu Baolu]

usnic_uiom_alloc_pd() allocates a paging domain for a given device.
In this case, iommu_domain_alloc(dev->bus) is equivalent to 
iommu_paging_domain_alloc(dev). Replace it as iommu_domain_alloc()
has been deprecated.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/infiniband/hw/usnic/usnic_uiom.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 84e0f41e7dfa..f948b76f984d 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -443,11 +443,11 @@ struct usnic_uiom_pd *usnic_uiom_alloc_pd(struct device *dev)
 	if (!pd)
 		return ERR_PTR(-ENOMEM);
 
-	pd->domain = domain = iommu_domain_alloc(dev->bus);
-	if (!domain) {
+	pd->domain = domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(domain)) {
 		usnic_err("Failed to allocate IOMMU domain");
 		kfree(pd);
-		return ERR_PTR(-ENOMEM);
+		return ERR_CAST(domain);
 	}
 
 	iommu_set_fault_handler(pd->domain, usnic_uiom_dma_fault, NULL);
-- 
2.34.1

Re: [PATCH v2 15/22] RDMA/usnic: Use iommu_paging_domain_alloc()

[Jason Gunthorpe]

On Tue, Jun 04, 2024 at 09:51:27AM +0800, Lu Baolu wrote:
> usnic_uiom_alloc_pd() allocates a paging domain for a given device.
> In this case, iommu_domain_alloc(dev->bus) is equivalent to 
> iommu_paging_domain_alloc(dev). Replace it as iommu_domain_alloc()
> has been deprecated.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/infiniband/hw/usnic/usnic_uiom.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Acked-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

[PATCH v2 16/22] iommu/vt-d: Add helper to allocate paging domain

[Lu Baolu]

The domain_alloc_user operation is currently implemented by allocating a
paging domain using iommu_domain_alloc(). This is because it needs to fully
initialize the domain before return. Add a helper to do this to avoid using
iommu_domain_alloc().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 87 +++++++++++++++++++++++++++++++++----
 1 file changed, 78 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 2e9811bf2a4e..ccde5f5972e4 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3633,6 +3633,79 @@ static struct iommu_domain blocking_domain = {
 	}
 };
 
+static int iommu_superpage_capability(struct intel_iommu *iommu, bool first_stage)
+{
+	if (!intel_iommu_superpage)
+		return 0;
+
+	if (first_stage)
+		return cap_fl1gp_support(iommu->cap) ? 2 : 1;
+
+	return fls(cap_super_page_val(iommu->cap));
+}
+
+static struct dmar_domain *paging_domain_alloc(struct device *dev, bool first_stage)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct intel_iommu *iommu = info->iommu;
+	struct dmar_domain *domain;
+	int addr_width;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&domain->devices);
+	INIT_LIST_HEAD(&domain->dev_pasids);
+	INIT_LIST_HEAD(&domain->cache_tags);
+	spin_lock_init(&domain->lock);
+	spin_lock_init(&domain->cache_lock);
+	xa_init(&domain->iommu_array);
+
+	domain->nid = dev_to_node(dev);
+	domain->has_iotlb_device = info->ats_enabled;
+	domain->use_first_level = first_stage;
+
+	/* calculate the address width */
+	addr_width = agaw_to_width(iommu->agaw);
+	if (addr_width > cap_mgaw(iommu->cap))
+		addr_width = cap_mgaw(iommu->cap);
+	domain->gaw = addr_width;
+	domain->agaw = iommu->agaw;
+	domain->max_addr = __DOMAIN_MAX_ADDR(addr_width);
+
+	/* iommu memory access coherency */
+	domain->iommu_coherency = iommu_paging_structure_coherency(iommu);
+
+	/* pagesize bitmap */
+	domain->domain.pgsize_bitmap = SZ_4K;
+	domain->iommu_superpage = iommu_superpage_capability(iommu, first_stage);
+	domain->domain.pgsize_bitmap |= domain_super_pgsize_bitmap(domain);
+
+	/*
+	 * IOVA aperture: First-level translation restricts the input-address
+	 * to a canonical address (i.e., address bits 63:N have the same value
+	 * as address bit [N-1], where N is 48-bits with 4-level paging and
+	 * 57-bits with 5-level paging). Hence, skip bit [N-1].
+	 */
+	domain->domain.geometry.force_aperture = true;
+	domain->domain.geometry.aperture_start = 0;
+	if (first_stage)
+		domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw - 1);
+	else
+		domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw);
+
+	/* always allocate the top pgd */
+	domain->pgd = iommu_alloc_page_node(domain->nid, GFP_KERNEL);
+	if (!domain->pgd) {
+		kfree(domain);
+		return ERR_PTR(-ENOMEM);
+	}
+	domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
+
+	return domain;
+}
+
 static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
 {
 	struct dmar_domain *dmar_domain;
@@ -3695,15 +3768,11 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
 	if (user_data || (dirty_tracking && !ssads_supported(iommu)))
 		return ERR_PTR(-EOPNOTSUPP);
 
-	/*
-	 * domain_alloc_user op needs to fully initialize a domain before
-	 * return, so uses iommu_domain_alloc() here for simple.
-	 */
-	domain = iommu_domain_alloc(dev->bus);
-	if (!domain)
-		return ERR_PTR(-ENOMEM);
-
-	dmar_domain = to_dmar_domain(domain);
+	/* Do not use first stage for user domain translation. */
+	dmar_domain = paging_domain_alloc(dev, false);
+	if (IS_ERR(dmar_domain))
+		return ERR_CAST(dmar_domain);
+	domain = &dmar_domain->domain;
 
 	if (nested_parent) {
 		dmar_domain->nested_parent = true;
-- 
2.34.1

[PATCH v2 17/22] ARM: dma-mapping: Pass device to arm_iommu_create_mapping()

[Lu Baolu]

From: Robin Murphy <robin.murphy@arm.com>

All users of ARM IOMMU mappings create them for a particular device, so
change the interface to accept the device rather than forcing a vague
indirection through a bus type. This prepares for making a similar
change to iommu_domain_alloc() itself.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 arch/arm/include/asm/dma-iommu.h         | 2 +-
 arch/arm/mm/dma-mapping.c                | 8 ++++----
 drivers/gpu/drm/exynos/exynos_drm_dma.c  | 2 +-
 drivers/iommu/ipmmu-vmsa.c               | 3 +--
 drivers/iommu/mtk_iommu_v1.c             | 3 +--
 drivers/media/platform/ti/omap3isp/isp.c | 2 +-
 6 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h
index 82ec1ccf1fee..2ce4c5683e6d 100644
--- a/arch/arm/include/asm/dma-iommu.h
+++ b/arch/arm/include/asm/dma-iommu.h
@@ -24,7 +24,7 @@ struct dma_iommu_mapping {
 };
 
 struct dma_iommu_mapping *
-arm_iommu_create_mapping(const struct bus_type *bus, dma_addr_t base, u64 size);
+arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size);
 
 void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping);
 
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 5adf1769eee4..52f9c56cc3cb 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1532,7 +1532,7 @@ static const struct dma_map_ops iommu_ops = {
 
 /**
  * arm_iommu_create_mapping
- * @bus: pointer to the bus holding the client device (for IOMMU calls)
+ * @dev: pointer to the client device (for IOMMU calls)
  * @base: start address of the valid IO address space
  * @size: maximum size of the valid IO address space
  *
@@ -1544,7 +1544,7 @@ static const struct dma_map_ops iommu_ops = {
  * arm_iommu_attach_device function.
  */
 struct dma_iommu_mapping *
-arm_iommu_create_mapping(const struct bus_type *bus, dma_addr_t base, u64 size)
+arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size)
 {
 	unsigned int bits = size >> PAGE_SHIFT;
 	unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
@@ -1585,7 +1585,7 @@ arm_iommu_create_mapping(const struct bus_type *bus, dma_addr_t base, u64 size)
 
 	spin_lock_init(&mapping->lock);
 
-	mapping->domain = iommu_domain_alloc(bus);
+	mapping->domain = iommu_domain_alloc(dev->bus);
 	if (!mapping->domain)
 		goto err4;
 
@@ -1718,7 +1718,7 @@ static void arm_setup_iommu_dma_ops(struct device *dev)
 		dma_base = dma_range_map_min(dev->dma_range_map);
 		size = dma_range_map_max(dev->dma_range_map) - dma_base;
 	}
-	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
+	mapping = arm_iommu_create_mapping(dev, dma_base, size);
 	if (IS_ERR(mapping)) {
 		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
 				size, dev_name(dev));
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c
index e2c7373f20c6..6a6761935224 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dma.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c
@@ -110,7 +110,7 @@ int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
 		void *mapping = NULL;
 
 		if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
-			mapping = arm_iommu_create_mapping(&platform_bus_type,
+			mapping = arm_iommu_create_mapping(dev,
 				EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE);
 		else if (IS_ENABLED(CONFIG_IOMMU_DMA))
 			mapping = iommu_get_domain_for_dev(priv->dma_dev);
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index b657cc09605f..ff55b8c30712 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -804,8 +804,7 @@ static int ipmmu_init_arm_mapping(struct device *dev)
 	if (!mmu->mapping) {
 		struct dma_iommu_mapping *mapping;
 
-		mapping = arm_iommu_create_mapping(&platform_bus_type,
-						   SZ_1G, SZ_2G);
+		mapping = arm_iommu_create_mapping(dev, SZ_1G, SZ_2G);
 		if (IS_ERR(mapping)) {
 			dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
 			ret = PTR_ERR(mapping);
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index d6e4002200bd..da61df27582d 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -439,8 +439,7 @@ static int mtk_iommu_v1_create_mapping(struct device *dev,
 	mtk_mapping = data->mapping;
 	if (!mtk_mapping) {
 		/* MTK iommu support 4GB iova address space. */
-		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
-						0, 1ULL << 32);
+		mtk_mapping = arm_iommu_create_mapping(dev, 0, 1ULL << 32);
 		if (IS_ERR(mtk_mapping))
 			return PTR_ERR(mtk_mapping);
 
diff --git a/drivers/media/platform/ti/omap3isp/isp.c b/drivers/media/platform/ti/omap3isp/isp.c
index 1cda23244c7b..91101ba88ef0 100644
--- a/drivers/media/platform/ti/omap3isp/isp.c
+++ b/drivers/media/platform/ti/omap3isp/isp.c
@@ -1965,7 +1965,7 @@ static int isp_attach_iommu(struct isp_device *isp)
 	 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
 	 * VAs. This will allocate a corresponding IOMMU domain.
 	 */
-	mapping = arm_iommu_create_mapping(&platform_bus_type, SZ_1G, SZ_2G);
+	mapping = arm_iommu_create_mapping(isp->dev, SZ_1G, SZ_2G);
 	if (IS_ERR(mapping)) {
 		dev_err(isp->dev, "failed to create ARM IOMMU mapping\n");
 		return PTR_ERR(mapping);
-- 
2.34.1

[PATCH v2 18/22] ARM: dma-mapping: Use iommu_paging_domain_alloc()

[Lu Baolu]

Since arm_iommu_create_mapping() now accepts the device, let's replace
iommu_domain_alloc() with iommu_paging_domain_alloc() to retire the former.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 arch/arm/mm/dma-mapping.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 52f9c56cc3cb..88c2d68a69c9 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1585,9 +1585,11 @@ arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size)
 
 	spin_lock_init(&mapping->lock);
 
-	mapping->domain = iommu_domain_alloc(dev->bus);
-	if (!mapping->domain)
+	mapping->domain = iommu_paging_domain_alloc(dev);
+	if (IS_ERR(mapping->domain)) {
+		err = PTR_ERR(mapping->domain);
 		goto err4;
+	}
 
 	kref_init(&mapping->kref);
 	return mapping;
-- 
2.34.1

[PATCH v2 19/22] drm/rockchip: Use iommu_paging_domain_alloc()

[Lu Baolu]

Commit <421be3ee36a4> ("drm/rockchip: Refactor IOMMU initialisation") has
refactored rockchip_drm_init_iommu() to pass a device that the domain is
allocated for. Replace iommu_domain_alloc() with
iommu_paging_domain_alloc() to retire the former.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index ab55d7132550..52126ffb9280 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -103,13 +103,17 @@ static int rockchip_drm_init_iommu(struct drm_device *drm_dev)
 	struct rockchip_drm_private *private = drm_dev->dev_private;
 	struct iommu_domain_geometry *geometry;
 	u64 start, end;
+	int ret;
 
 	if (IS_ERR_OR_NULL(private->iommu_dev))
 		return 0;
 
-	private->domain = iommu_domain_alloc(private->iommu_dev->bus);
-	if (!private->domain)
-		return -ENOMEM;
+	private->domain = iommu_paging_domain_alloc(private->iommu_dev);
+	if (IS_ERR(private->domain)) {
+		ret = PTR_ERR(private->domain);
+		private->domain = NULL;
+		return ret;
+	}
 
 	geometry = &private->domain->geometry;
 	start = geometry->aperture_start;
-- 
2.34.1

[PATCH v2 20/22] drm/tegra: Remove call to iommu_domain_alloc()

[Lu Baolu]

Commit <17de3f5fdd35> ("iommu: Retire bus ops") removes iommu ops from
the bus structure. The iommu subsystem no longer relies on bus for
operations. So iommu_domain_alloc() interface is no longer relevant.

Normally, iommu_paging_domain_alloc() could be a replacement for
iommu_domain_alloc() if the caller has the right device for IOMMU API
use. Unfortunately, this is not the case for this driver.

Iterate the devices on the platform bus and find a suitable device
whose device DMA is translated by an IOMMU. Then use this device to
allocate an iommu domain. The iommu subsystem prevents domains
allocated by one iommu driver from being attached to devices managed
by any different iommu driver.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/gpu/drm/tegra/drm.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 03d1c76aec2d..ee391f859992 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -1133,6 +1133,17 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
 	return domain != NULL;
 }
 
+static int iommu_mapped_device(struct device *dev, void *data)
+{
+	struct device **iommu_dev = data;
+
+	if (!device_iommu_mapped(dev))
+		return 0;
+
+	*iommu_dev = dev;
+	return 1;
+}
+
 static int host1x_drm_probe(struct host1x_device *dev)
 {
 	struct tegra_drm *tegra;
@@ -1149,16 +1160,21 @@ static int host1x_drm_probe(struct host1x_device *dev)
 		goto put;
 	}
 
-	if (host1x_drm_wants_iommu(dev) && iommu_present(&platform_bus_type)) {
-		tegra->domain = iommu_domain_alloc(&platform_bus_type);
-		if (!tegra->domain) {
-			err = -ENOMEM;
-			goto free;
+	if (host1x_drm_wants_iommu(dev)) {
+		struct device *iommu_dev = NULL;
+
+		bus_for_each_dev(&platform_bus_type, NULL, &iommu_dev, iommu_mapped_device);
+		if (iommu_dev) {
+			tegra->domain = iommu_paging_domain_alloc(iommu_dev);
+			if (IS_ERR(tegra->domain)) {
+				err = PTR_ERR(tegra->domain);
+				goto free;
+			}
+
+			err = iova_cache_get();
+			if (err < 0)
+				goto domain;
 		}
-
-		err = iova_cache_get();
-		if (err < 0)
-			goto domain;
 	}
 
 	mutex_init(&tegra->clients_lock);
-- 
2.34.1

[PATCH v2 21/22] iommu: Remove iommu_present()

[Lu Baolu]

The iommu_present() interface is no longer used in the tree anymore.
Remove it to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h |  6 ------
 drivers/iommu/iommu.c | 25 -------------------------
 2 files changed, 31 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 16401de7802d..b0bd16a7768e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -776,7 +776,6 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather)
 }
 
 extern int bus_iommu_probe(const struct bus_type *bus);
-extern bool iommu_present(const struct bus_type *bus);
 extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
 extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
 extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);
@@ -1073,11 +1072,6 @@ struct iommu_iotlb_gather {};
 struct iommu_dirty_bitmap {};
 struct iommu_dirty_ops {};
 
-static inline bool iommu_present(const struct bus_type *bus)
-{
-	return false;
-}
-
 static inline bool device_iommu_capable(struct device *dev, enum iommu_cap cap)
 {
 	return false;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7df4a021b040..3e4195c28e85 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1846,31 +1846,6 @@ int bus_iommu_probe(const struct bus_type *bus)
 	return 0;
 }
 
-/**
- * iommu_present() - make platform-specific assumptions about an IOMMU
- * @bus: bus to check
- *
- * Do not use this function. You want device_iommu_mapped() instead.
- *
- * Return: true if some IOMMU is present and aware of devices on the given bus;
- * in general it may not be the only IOMMU, and it may not have anything to do
- * with whatever device you are ultimately interested in.
- */
-bool iommu_present(const struct bus_type *bus)
-{
-	bool ret = false;
-
-	for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) {
-		if (iommu_buses[i] == bus) {
-			spin_lock(&iommu_device_lock);
-			ret = !list_empty(&iommu_device_list);
-			spin_unlock(&iommu_device_lock);
-		}
-	}
-	return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_present);
-
 /**
  * device_iommu_capable() - check for a general IOMMU capability
  * @dev: device to which the capability would be relevant, if available
-- 
2.34.1

[PATCH v2 22/22] iommu: Remove iommu_domain_alloc()

[Lu Baolu]

The iommu_domain_alloc() interface is no longer used in the tree anymore.
Remove it to avoid dead code.

There is increasing demand for supporting multiple IOMMU drivers, and this
is the last bus-based thing standing in the way of that.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h |  6 ------
 drivers/iommu/iommu.c | 36 ------------------------------------
 2 files changed, 42 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b0bd16a7768e..8b4ce7aa16ac 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -778,7 +778,6 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather)
 extern int bus_iommu_probe(const struct bus_type *bus);
 extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap);
 extern bool iommu_group_has_isolated_msi(struct iommu_group *group);
-extern struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus);
 struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags);
 struct iommu_domain *iommu_paging_domain_alloc(struct device *dev);
 extern void iommu_domain_free(struct iommu_domain *domain);
@@ -1077,11 +1076,6 @@ static inline bool device_iommu_capable(struct device *dev, enum iommu_cap cap)
 	return false;
 }
 
-static inline struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
-{
-	return NULL;
-}
-
 static inline struct iommu_domain *iommu_user_domain_alloc(struct device *dev, u32 flags)
 {
 	return ERR_PTR(-ENODEV);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3e4195c28e85..9ce8bc18485b 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1975,42 +1975,6 @@ __iommu_group_domain_alloc(struct iommu_group *group, unsigned int type)
 	return __iommu_domain_alloc(dev_iommu_ops(dev), dev, type);
 }
 
-static int __iommu_domain_alloc_dev(struct device *dev, void *data)
-{
-	const struct iommu_ops **ops = data;
-
-	if (!dev_has_iommu(dev))
-		return 0;
-
-	if (WARN_ONCE(*ops && *ops != dev_iommu_ops(dev),
-		      "Multiple IOMMU drivers present for bus %s, which the public IOMMU API can't fully support yet. You will still need to disable one or more for this to work, sorry!\n",
-		      dev_bus_name(dev)))
-		return -EBUSY;
-
-	*ops = dev_iommu_ops(dev);
-	return 0;
-}
-
-/*
- * The iommu ops in bus has been retired. Do not use this interface in
- * new drivers.
- */
-struct iommu_domain *iommu_domain_alloc(const struct bus_type *bus)
-{
-	const struct iommu_ops *ops = NULL;
-	int err = bus_for_each_dev(bus, NULL, &ops, __iommu_domain_alloc_dev);
-	struct iommu_domain *domain;
-
-	if (err || !ops)
-		return NULL;
-
-	domain = __iommu_domain_alloc(ops, NULL, IOMMU_DOMAIN_UNMANAGED);
-	if (IS_ERR(domain))
-		return NULL;
-	return domain;
-}
-EXPORT_SYMBOL_GPL(iommu_domain_alloc);
-
 /**
  * iommu_user_domain_alloc() - Allocate a user domain
  * @dev: device for which the domain is allocated
-- 
2.34.1