From: Lu Baolu baolu.lu@linux.intel.com
mainline inclusion from mainline-v6.11-rc1 commit 34765cbc679c59ea5d952d738d2d16bf4aadc497 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB4WDJ CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 hwpt->fault is non NULL. Attaching, detaching, or replacing an iopf-capable hwpt to an RID or PASID will differ from those that are not iopf-capable.
Link: https://lore.kernel.org/r/20240702063444.105814-9-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Kevin Tian kevin.tian@intel.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com --- drivers/iommu/iommufd/fault.c | 17 +++++++++++ drivers/iommu/iommufd/hw_pagetable.c | 38 +++++++++++++++++++------ drivers/iommu/iommufd/iommufd_private.h | 9 ++++++ include/uapi/linux/iommufd.h | 8 ++++++ 4 files changed, 64 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index 4934ae572638..54d6cd20a673 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -414,3 +414,20 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd)
return rc; } + +int iommufd_fault_iopf_handler(struct iopf_group *group) +{ + struct iommufd_hw_pagetable *hwpt; + struct iommufd_fault *fault; + + hwpt = group->attach_handle->domain->fault_data; + 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 5fc233ae6ba4..5118335f1b94 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) + refcount_dec(&hwpt->fault->obj.users); +} + 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); }
@@ -216,7 +221,8 @@ 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); @@ -230,7 +236,8 @@ 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, + flags & ~IOMMU_HWPT_FAULT_ID_VALID, parent->common.domain, user_data); if (IS_ERR(hwpt->domain)) { rc = PTR_ERR(hwpt->domain); @@ -312,6 +319,21 @@ 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; + refcount_inc(&fault->obj.users); + iommufd_put_object(ucmd->ictx, &fault->obj); + } + 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 aa4c26c87cb9..92efe30a8f0d 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -458,8 +458,17 @@ struct iommufd_attach_handle { /* Convert an iommu attach handle to iommufd handle. */ #define to_iommufd_handle(hdl) container_of(hdl, struct iommufd_attach_handle, handle)
+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);
int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev); diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 70b8a38fcd46..ede2b464a761 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, };
/** @@ -412,6 +415,9 @@ enum iommu_hwpt_data_type { * @data_type: One of enum iommu_hwpt_data_type * @data_len: Length of the type specific data * @data_uptr: User pointer to 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. + * @__reserved2: Padding to 64-bit alignment. Must be 0. * * Explicitly allocate a hardware page table object. This is the same object * type that is returned by iommufd_device_attach() and represents the @@ -442,6 +448,8 @@ struct iommu_hwpt_alloc { __u32 data_type; __u32 data_len; __aligned_u64 data_uptr; + __u32 fault_id; + __u32 __reserved2; }; #define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)