From: Lu Baolu baolu.lu@linux.intel.com
When allocating a user iommufd_hw_pagetable, the user space is allowed to associate a fault object with the hw_pagetable by specifying the fault object ID in the page table allocation data and setting the IOMMU_HWPT_FAULT_ID_VALID flag bit.
On a successful return of hwpt allocation, the user can retrieve and respond to page faults by reading and writing the file interface of the fault object.
Once a fault object has been associated with a hwpt, the hwpt is iopf-capable, indicated by fault_capable set to true. Attaching, detaching, or replacing an iopf-capable hwpt to an RID or PASID will differ from those that are not iopf-capable. The implementation of these will be introduced in the next patch.
Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- drivers/iommu/iommufd/fault.c | 14 ++++++++++ drivers/iommu/iommufd/hw_pagetable.c | 36 +++++++++++++++++++------ drivers/iommu/iommufd/iommufd_private.h | 11 ++++++++ include/uapi/linux/iommufd.h | 6 +++++ 4 files changed, 59 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index 9844a85feeb2..e752d1c49dde 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -253,3 +253,17 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
return rc; } + +int iommufd_fault_iopf_handler(struct iopf_group *group) +{ + struct iommufd_hw_pagetable *hwpt = group->cookie->domain->fault_data; + struct iommufd_fault *fault = hwpt->fault; + + mutex_lock(&fault->mutex); + list_add_tail(&group->node, &fault->deliver); + mutex_unlock(&fault->mutex); + + wake_up_interruptible(&fault->wait_queue); + + return 0; +} diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 33d142f8057d..95ea943f5be5 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -8,6 +8,15 @@ #include "../iommu-priv.h" #include "iommufd_private.h"
+static void __iommufd_hwpt_destroy(struct iommufd_hw_pagetable *hwpt) +{ + if (hwpt->domain) + iommu_domain_free(hwpt->domain); + + if (hwpt->fault) + iommufd_put_object(hwpt->fault->ictx, &hwpt->fault->obj); +} + void iommufd_hwpt_paging_destroy(struct iommufd_object *obj) { struct iommufd_hwpt_paging *hwpt_paging = @@ -22,9 +31,7 @@ void iommufd_hwpt_paging_destroy(struct iommufd_object *obj) hwpt_paging->common.domain); }
- if (hwpt_paging->common.domain) - iommu_domain_free(hwpt_paging->common.domain); - + __iommufd_hwpt_destroy(&hwpt_paging->common); refcount_dec(&hwpt_paging->ioas->obj.users); }
@@ -49,9 +56,7 @@ void iommufd_hwpt_nested_destroy(struct iommufd_object *obj) struct iommufd_hwpt_nested *hwpt_nested = container_of(obj, struct iommufd_hwpt_nested, common.obj);
- if (hwpt_nested->common.domain) - iommu_domain_free(hwpt_nested->common.domain); - + __iommufd_hwpt_destroy(&hwpt_nested->common); refcount_dec(&hwpt_nested->parent->common.obj.users); }
@@ -213,7 +218,8 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, struct iommufd_hw_pagetable *hwpt; int rc;
- if (flags || !user_data->len || !ops->domain_alloc_user) + if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) || + !user_data->len || !ops->domain_alloc_user) return ERR_PTR(-EOPNOTSUPP); if (parent->auto_domain || !parent->nest_parent) return ERR_PTR(-EINVAL); @@ -227,7 +233,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, refcount_inc(&parent->common.obj.users); hwpt_nested->parent = parent;
- hwpt->domain = ops->domain_alloc_user(idev->dev, flags, + hwpt->domain = ops->domain_alloc_user(idev->dev, 0, parent->common.domain, user_data); if (IS_ERR(hwpt->domain)) { rc = PTR_ERR(hwpt->domain); @@ -308,6 +314,20 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) goto out_put_pt; }
+ if (cmd->flags & IOMMU_HWPT_FAULT_ID_VALID) { + struct iommufd_fault *fault; + + fault = iommufd_get_fault(ucmd, cmd->fault_id); + if (IS_ERR(fault)) { + rc = PTR_ERR(fault); + goto out_hwpt; + } + hwpt->fault = fault; + hwpt->domain->iopf_handler = iommufd_fault_iopf_handler; + hwpt->domain->fault_data = hwpt; + hwpt->fault_capable = true; + } + cmd->out_hwpt_id = hwpt->obj.id; rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); if (rc) diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 52d83e888bd0..2780bed0c6b1 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -293,6 +293,8 @@ int iommufd_check_iova_range(struct io_pagetable *iopt, struct iommufd_hw_pagetable { struct iommufd_object obj; struct iommu_domain *domain; + struct iommufd_fault *fault; + bool fault_capable : 1; };
struct iommufd_hwpt_paging { @@ -446,8 +448,17 @@ struct iommufd_fault { struct wait_queue_head wait_queue; };
+static inline struct iommufd_fault * +iommufd_get_fault(struct iommufd_ucmd *ucmd, u32 id) +{ + return container_of(iommufd_get_object(ucmd->ictx, id, + IOMMUFD_OBJ_FAULT), + struct iommufd_fault, obj); +} + int iommufd_fault_alloc(struct iommufd_ucmd *ucmd); void iommufd_fault_destroy(struct iommufd_object *obj); +int iommufd_fault_iopf_handler(struct iopf_group *group);
#ifdef CONFIG_IOMMUFD_TEST int iommufd_test(struct iommufd_ucmd *ucmd); diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index c32d62b02306..7481cdd57027 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -357,10 +357,13 @@ struct iommu_vfio_ioas { * the parent HWPT in a nesting configuration. * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is * enforced on device attachment + * @IOMMU_HWPT_FAULT_ID_VALID: The fault_id field of hwpt allocation data is + * valid. */ enum iommufd_hwpt_alloc_flags { IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0, IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1, + IOMMU_HWPT_FAULT_ID_VALID = 1 << 2, };
/** @@ -411,6 +414,8 @@ enum iommu_hwpt_data_type { * @__reserved: Must be 0 * @data_type: One of enum iommu_hwpt_data_type * @data_len: Length of the type specific data + * @fault_id: The ID of IOMMUFD_FAULT object. Valid only if flags field of + * IOMMU_HWPT_FAULT_ID_VALID is set. * @data_uptr: User pointer to the type specific data * * Explicitly allocate a hardware page table object. This is the same object @@ -441,6 +446,7 @@ struct iommu_hwpt_alloc { __u32 __reserved; __u32 data_type; __u32 data_len; + __u32 fault_id; __aligned_u64 data_uptr; }; #define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)