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iommufd: Associate fault object with iommufd_hw_pgtable

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.

Lu Baolu committed 2 years ago

Commit 34765cb1 parent b7d88334 files · +64 −8Browse files

Unified · Split

4 files
  1. drivers/iommu/iommufd/fault.c +17 −0
  2. drivers/iommu/iommufd/hw_pagetable.c +30 −8
  3. drivers/iommu/iommufd/iommufd_private.h +9 −0
  4. include/uapi/linux/iommufd.h +8 −0
drivers/iommu/iommufd/fault.c+17−0
@@ -414,3 +414,20 @@ out_abort: · 413 unmodified lines
414 414
415 return rc;415 return rc;
416}416}
417
418int iommufd_fault_iopf_handler(struct iopf_group *group)
419{
420 struct iommufd_hw_pagetable *hwpt;
421 struct iommufd_fault *fault;
422
423 hwpt = group->attach_handle->domain->fault_data;
424 fault = hwpt->fault;
425
426 mutex_lock(&fault->mutex);
427 list_add_tail(&group->node, &fault->deliver);
428 mutex_unlock(&fault->mutex);
429
430 wake_up_interruptible(&fault->wait_queue);
431
432 return 0;
433}
drivers/iommu/iommufd/hw_pagetable.c+30−8
@@ -8,6 +8,15 @@ · 7 unmodified lines
8#include "../iommu-priv.h"8#include "../iommu-priv.h"
9#include "iommufd_private.h"9#include "iommufd_private.h"
10 10
11static void __iommufd_hwpt_destroy(struct iommufd_hw_pagetable *hwpt)
12{
13 if (hwpt->domain)
14 iommu_domain_free(hwpt->domain);
15
16 if (hwpt->fault)
17 refcount_dec(&hwpt->fault->obj.users);
18}
19
11void iommufd_hwpt_paging_destroy(struct iommufd_object *obj)20void iommufd_hwpt_paging_destroy(struct iommufd_object *obj)
12{21{
13 struct iommufd_hwpt_paging *hwpt_paging =22 struct iommufd_hwpt_paging *hwpt_paging =
@@ -22,9 +31,7 @@ void iommufd_hwpt_paging_destroy(struct iommufd_object *obj) · 8 unmodified lines
22 hwpt_paging->common.domain);31 hwpt_paging->common.domain);
23 }32 }
24 33
25 if (hwpt_paging->common.domain)34 __iommufd_hwpt_destroy(&hwpt_paging->common);
26 iommu_domain_free(hwpt_paging->common.domain);
27
28 refcount_dec(&hwpt_paging->ioas->obj.users);35 refcount_dec(&hwpt_paging->ioas->obj.users);
29}36}
30 37
@@ -49,9 +56,7 @@ void iommufd_hwpt_nested_destroy(struct iommufd_object *obj) · 18 unmodified lines
49 struct iommufd_hwpt_nested *hwpt_nested =56 struct iommufd_hwpt_nested *hwpt_nested =
50 container_of(obj, struct iommufd_hwpt_nested, common.obj);57 container_of(obj, struct iommufd_hwpt_nested, common.obj);
51 58
52 if (hwpt_nested->common.domain)59 __iommufd_hwpt_destroy(&hwpt_nested->common);
53 iommu_domain_free(hwpt_nested->common.domain);
54
55 refcount_dec(&hwpt_nested->parent->common.obj.users);60 refcount_dec(&hwpt_nested->parent->common.obj.users);
56}61}
57 62
@@ -213,7 +218,8 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, · 155 unmodified lines
213 struct iommufd_hw_pagetable *hwpt;218 struct iommufd_hw_pagetable *hwpt;
214 int rc;219 int rc;
215 220
216 if (flags || !user_data->len || !ops->domain_alloc_user)221 if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) ||
222 !user_data->len || !ops->domain_alloc_user)
217 return ERR_PTR(-EOPNOTSUPP);223 return ERR_PTR(-EOPNOTSUPP);
218 if (parent->auto_domain || !parent->nest_parent)224 if (parent->auto_domain || !parent->nest_parent)
219 return ERR_PTR(-EINVAL);225 return ERR_PTR(-EINVAL);
@@ -227,7 +233,8 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, · 7 unmodified lines
227 refcount_inc(&parent->common.obj.users);233 refcount_inc(&parent->common.obj.users);
228 hwpt_nested->parent = parent;234 hwpt_nested->parent = parent;
229 235
230 hwpt->domain = ops->domain_alloc_user(idev->dev, flags,236 hwpt->domain = ops->domain_alloc_user(idev->dev,
237 flags & ~IOMMU_HWPT_FAULT_ID_VALID,
231 parent->common.domain, user_data);238 parent->common.domain, user_data);
232 if (IS_ERR(hwpt->domain)) {239 if (IS_ERR(hwpt->domain)) {
233 rc = PTR_ERR(hwpt->domain);240 rc = PTR_ERR(hwpt->domain);
@@ -308,6 +315,21 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) · 74 unmodified lines
308 goto out_put_pt;315 goto out_put_pt;
309 }316 }
310 317
318 if (cmd->flags & IOMMU_HWPT_FAULT_ID_VALID) {
319 struct iommufd_fault *fault;
320
321 fault = iommufd_get_fault(ucmd, cmd->fault_id);
322 if (IS_ERR(fault)) {
323 rc = PTR_ERR(fault);
324 goto out_hwpt;
325 }
326 hwpt->fault = fault;
327 hwpt->domain->iopf_handler = iommufd_fault_iopf_handler;
328 hwpt->domain->fault_data = hwpt;
329 refcount_inc(&fault->obj.users);
330 iommufd_put_object(ucmd->ictx, &fault->obj);
331 }
332
311 cmd->out_hwpt_id = hwpt->obj.id;333 cmd->out_hwpt_id = hwpt->obj.id;
312 rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));334 rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
313 if (rc)335 if (rc)
drivers/iommu/iommufd/iommufd_private.h+9−0
@@ -458,8 +458,17 @@ struct iommufd_attach_handle { · 457 unmodified lines
458/* Convert an iommu attach handle to iommufd handle. */458/* Convert an iommu attach handle to iommufd handle. */
459#define to_iommufd_handle(hdl) container_of(hdl, struct iommufd_attach_handle, handle)459#define to_iommufd_handle(hdl) container_of(hdl, struct iommufd_attach_handle, handle)
460 460
461static inline struct iommufd_fault *
462iommufd_get_fault(struct iommufd_ucmd *ucmd, u32 id)
463{
464 return container_of(iommufd_get_object(ucmd->ictx, id,
465 IOMMUFD_OBJ_FAULT),
466 struct iommufd_fault, obj);
467}
468
461int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);469int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);
462void iommufd_fault_destroy(struct iommufd_object *obj);470void iommufd_fault_destroy(struct iommufd_object *obj);
471int iommufd_fault_iopf_handler(struct iopf_group *group);
463 472
464int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,473int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,
465 struct iommufd_device *idev);474 struct iommufd_device *idev);
include/uapi/linux/iommufd.h+8−0
@@ -357,10 +357,13 @@ struct iommu_vfio_ioas { · 356 unmodified lines
357 * the parent HWPT in a nesting configuration.357 * the parent HWPT in a nesting configuration.
358 * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is358 * @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is
359 * enforced on device attachment359 * enforced on device attachment
360 * @IOMMU_HWPT_FAULT_ID_VALID: The fault_id field of hwpt allocation data is
361 * valid.
360 */362 */
361enum iommufd_hwpt_alloc_flags {363enum iommufd_hwpt_alloc_flags {
362 IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0,364 IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0,
363 IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1,365 IOMMU_HWPT_ALLOC_DIRTY_TRACKING = 1 << 1,
366 IOMMU_HWPT_FAULT_ID_VALID = 1 << 2,
364};367};
365 368
366/**369/**
@@ -412,6 +415,9 @@ enum iommu_hwpt_data_type { · 45 unmodified lines
412 * @data_type: One of enum iommu_hwpt_data_type415 * @data_type: One of enum iommu_hwpt_data_type
413 * @data_len: Length of the type specific data416 * @data_len: Length of the type specific data
414 * @data_uptr: User pointer to the type specific data417 * @data_uptr: User pointer to the type specific data
418 * @fault_id: The ID of IOMMUFD_FAULT object. Valid only if flags field of
419 * IOMMU_HWPT_FAULT_ID_VALID is set.
420 * @__reserved2: Padding to 64-bit alignment. Must be 0.
415 *421 *
416 * Explicitly allocate a hardware page table object. This is the same object422 * Explicitly allocate a hardware page table object. This is the same object
417 * type that is returned by iommufd_device_attach() and represents the423 * type that is returned by iommufd_device_attach() and represents the
@@ -442,6 +448,8 @@ struct iommu_hwpt_alloc { · 24 unmodified lines
442 __u32 data_type;448 __u32 data_type;
443 __u32 data_len;449 __u32 data_len;
444 __aligned_u64 data_uptr;450 __aligned_u64 data_uptr;
451 __u32 fault_id;
452 __u32 __reserved2;
445};453};
446#define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)454#define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)
447 455