From 14678219cf4093e897ab353fd78eab7994d1be7d Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 2 Jul 2024 14:34:35 +0800 Subject: iommu: Introduce domain attachment handle Currently, when attaching a domain to a device or its PASID, domain is stored within the iommu group. It could be retrieved for use during the window between attachment and detachment. With new features introduced, there's a need to store more information than just a domain pointer. This information essentially represents the association between a domain and a device. For example, the SVA code already has a custom struct iommu_sva which represents a bond between sva domain and a PASID of a device. Looking forward, the IOMMUFD needs a place to store the iommufd_device pointer in the core, so that the device object ID could be quickly retrieved in the critical fault handling path. Introduce domain attachment handle that explicitly represents the attachment relationship between a domain and a device or its PASID. Co-developed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240702063444.105814-2-baolu.lu@linux.intel.com Signed-off-by: Will Deacon --- include/linux/iommu.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 17b3f36ad843..afc5af0069bb 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -989,12 +989,22 @@ struct iommu_fwspec { /* ATS is supported */ #define IOMMU_FWSPEC_PCI_RC_ATS (1 << 0) +/* + * An iommu attach handle represents a relationship between an iommu domain + * and a PASID or RID of a device. It is allocated and managed by the component + * that manages the domain and is stored in the iommu group during the time the + * domain is attached. + */ +struct iommu_attach_handle { + struct iommu_domain *domain; +}; + /** * struct iommu_sva - handle to a device-mm bond */ struct iommu_sva { + struct iommu_attach_handle handle; struct device *dev; - struct iommu_domain *domain; struct list_head handle_item; refcount_t users; }; @@ -1052,7 +1062,8 @@ int iommu_device_claim_dma_owner(struct device *dev, void *owner); void iommu_device_release_dma_owner(struct device *dev); int iommu_attach_device_pasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid); + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); struct iommu_domain * @@ -1388,7 +1399,8 @@ static inline int iommu_device_claim_dma_owner(struct device *dev, void *owner) } static inline int iommu_attach_device_pasid(struct iommu_domain *domain, - struct device *dev, ioasid_t pasid) + struct device *dev, ioasid_t pasid, + struct iommu_attach_handle *handle) { return -ENODEV; } -- cgit v1.2.3 From 3e7f57d1ef3f5fbed58974fae38d35e430f57d35 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 2 Jul 2024 14:34:36 +0800 Subject: iommu: Remove sva handle list The struct sva_iommu represents an association between an SVA domain and a PASID of a device. It's stored in the iommu group's pasid array and also tracked by a list in the per-mm data structure. Removes duplicate tracking of sva_iommu by eliminating the list. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240702063444.105814-3-baolu.lu@linux.intel.com Signed-off-by: Will Deacon --- include/linux/iommu.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index afc5af0069bb..87ebcc29020e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1005,14 +1005,12 @@ struct iommu_attach_handle { struct iommu_sva { struct iommu_attach_handle handle; struct device *dev; - struct list_head handle_item; refcount_t users; }; struct iommu_mm_data { u32 pasid; struct list_head sva_domains; - struct list_head sva_handles; }; int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, -- cgit v1.2.3 From 06cdcc32d65759d42c6340700796e2906045b6a5 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 2 Jul 2024 14:34:37 +0800 Subject: iommu: Add attach handle to struct iopf_group Previously, the domain that a page fault targets is stored in an iopf_group, which represents a minimal set of page faults. With the introduction of attach handle, replace the domain with the handle so that the fault handler can obtain more information as needed when handling the faults. iommu_report_device_fault() is currently used for SVA page faults, which handles the page fault in an internal cycle. The domain is retrieved with iommu_get_domain_for_dev_pasid() if the pasid in the fault message is valid. This doesn't work in IOMMUFD case, where if the pasid table of a device is wholly managed by user space, there is no domain attached to the PASID of the device, and all page faults are forwarded through a NESTING domain attaching to RID. Add a static flag in iommu ops, which indicates if the IOMMU driver supports user-managed PASID tables. In the iopf deliver path, if no attach handle found for the iopf PASID, roll back to RID domain when the IOMMU driver supports this capability. iommu_get_domain_for_dev_pasid() is no longer used and can be removed. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240702063444.105814-4-baolu.lu@linux.intel.com Signed-off-by: Will Deacon --- include/linux/iommu.h | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 87ebcc29020e..910aec80886e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -127,7 +127,7 @@ struct iopf_group { /* list node for iommu_fault_param::faults */ struct list_head pending_node; struct work_struct work; - struct iommu_domain *domain; + struct iommu_attach_handle *attach_handle; /* The device's fault data parameter. */ struct iommu_fault_param *fault_param; }; @@ -547,6 +547,10 @@ static inline int __iommu_copy_struct_from_user_array( * @default_domain: If not NULL this will always be set as the default domain. * This should be an IDENTITY/BLOCKED/PLATFORM domain. * Do not use in new drivers. + * @user_pasid_table: IOMMU driver supports user-managed PASID table. There is + * no user domain for each PASID and the I/O page faults are + * forwarded through the user domain attached to the device + * RID. */ struct iommu_ops { bool (*capable)(struct device *dev, enum iommu_cap); @@ -590,6 +594,7 @@ struct iommu_ops { struct iommu_domain *blocked_domain; struct iommu_domain *release_domain; struct iommu_domain *default_domain; + u8 user_pasid_table:1; }; /** @@ -1064,9 +1069,6 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, struct iommu_attach_handle *handle); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); -struct iommu_domain * -iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid, - unsigned int type); ioasid_t iommu_alloc_global_pasid(struct device *dev); void iommu_free_global_pasid(ioasid_t pasid); #else /* CONFIG_IOMMU_API */ @@ -1408,13 +1410,6 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain, { } -static inline struct iommu_domain * -iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid, - unsigned int type) -{ - return NULL; -} - static inline ioasid_t iommu_alloc_global_pasid(struct device *dev) { return IOMMU_PASID_INVALID; -- cgit v1.2.3 From 07838f7fd529c8a6de44b601d4b7057e6c8d36ed Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 2 Jul 2024 14:34:40 +0800 Subject: iommufd: Add iommufd fault object An iommufd fault object provides an interface for delivering I/O page faults to user space. These objects are created and destroyed by user space, and they can be associated with or dissociated from hardware page table objects during page table allocation or destruction. User space interacts with the fault object through a file interface. This interface offers a straightforward and efficient way for user space to handle page faults. It allows user space to read fault messages sequentially and respond to them by writing to the same file. The file interface supports reading messages in poll mode, so it's recommended that user space applications use io_uring to enhance read and write efficiency. A fault object can be associated with any iopf-capable iommufd_hw_pgtable during the pgtable's allocation. All I/O page faults triggered by devices when accessing the I/O addresses of an iommufd_hw_pgtable are routed through the fault object to user space. Similarly, user space's responses to these page faults are routed back to the iommu device driver through the same fault object. Link: https://lore.kernel.org/r/20240702063444.105814-7-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe --- include/linux/iommu.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 910aec80886e..73bc3aee95a1 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -124,12 +124,16 @@ struct iopf_fault { struct iopf_group { struct iopf_fault last_fault; struct list_head faults; + size_t fault_count; /* list node for iommu_fault_param::faults */ struct list_head pending_node; struct work_struct work; struct iommu_attach_handle *attach_handle; /* The device's fault data parameter. */ struct iommu_fault_param *fault_param; + /* Used by handler provider to hook the group on its own lists. */ + struct list_head node; + u32 cookie; }; /** -- cgit v1.2.3