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

drivers/iommu/iommufd/fault.c +17 −0
drivers/iommu/iommufd/hw_pagetable.c +30 −8
drivers/iommu/iommufd/iommufd_private.h +9 −0
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	415	return rc;
416	416	}
	417	+
	418	+int 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	8	#include "../iommu-priv.h"
9	9	#include "iommufd_private.h"
10	10
	11	+static 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	+
11	20	void iommufd_hwpt_paging_destroy(struct iommufd_object *obj)
12	21	{
13	22	struct iommufd_hwpt_paging *hwpt_paging =
@@ -22,9 +31,7 @@ void iommufd_hwpt_paging_destroy(struct iommufd_object *obj) · 8 unmodified lines
22	31	hwpt_paging->common.domain);
23	32	}
24	33
25		− if (hwpt_paging->common.domain)
26		− iommu_domain_free(hwpt_paging->common.domain);
27		−
	34	+ __iommufd_hwpt_destroy(&hwpt_paging->common);
28	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	56	struct iommufd_hwpt_nested *hwpt_nested =
50	57	container_of(obj, struct iommufd_hwpt_nested, common.obj);
51	58
52		− if (hwpt_nested->common.domain)
53		− iommu_domain_free(hwpt_nested->common.domain);
54		−
	59	+ __iommufd_hwpt_destroy(&hwpt_nested->common);
55	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	218	struct iommufd_hw_pagetable *hwpt;
214	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	223	return ERR_PTR(-EOPNOTSUPP);
218	224	if (parent->auto_domain \|\| !parent->nest_parent)
219	225	return ERR_PTR(-EINVAL);
@@ -227,7 +233,8 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, · 7 unmodified lines
227	233	refcount_inc(&parent->common.obj.users);
228	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	238	parent->common.domain, user_data);
232	239	if (IS_ERR(hwpt->domain)) {
233	240	rc = PTR_ERR(hwpt->domain);
@@ -308,6 +315,21 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) · 74 unmodified lines
308	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	333	cmd->out_hwpt_id = hwpt->obj.id;
312	334	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
313	335	if (rc)

drivers/iommu/iommufd/iommufd_private.h+9−0

@@ -458,8 +458,17 @@ struct iommufd_attach_handle { · 457 unmodified lines
458	458	/* Convert an iommu attach handle to iommufd handle. */
459	459	#define to_iommufd_handle(hdl) container_of(hdl, struct iommufd_attach_handle, handle)
460	460
	461	+static inline struct iommufd_fault *
	462	+iommufd_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	+
461	469	int iommufd_fault_alloc(struct iommufd_ucmd *ucmd);
462	470	void iommufd_fault_destroy(struct iommufd_object *obj);
	471	+int iommufd_fault_iopf_handler(struct iopf_group *group);
463	472
464	473	int iommufd_fault_domain_attach_dev(struct iommufd_hw_pagetable *hwpt,
465	474	struct iommufd_device *idev);

include/uapi/linux/iommufd.h+8−0

@@ -357,10 +357,13 @@ struct iommu_vfio_ioas { · 356 unmodified lines
357	357	* the parent HWPT in a nesting configuration.
358	358	* @IOMMU_HWPT_ALLOC_DIRTY_TRACKING: Dirty tracking support for device IOMMU is
359	359	* enforced on device attachment
	360	+ * @IOMMU_HWPT_FAULT_ID_VALID: The fault_id field of hwpt allocation data is
	361	+ * valid.
360	362	*/
361	363	enum iommufd_hwpt_alloc_flags {
362	364	IOMMU_HWPT_ALLOC_NEST_PARENT = 1 << 0,
363	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	415	* @data_type: One of enum iommu_hwpt_data_type
413	416	* @data_len: Length of the type specific data
414	417	* @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	422	* Explicitly allocate a hardware page table object. This is the same object
417	423	* type that is returned by iommufd_device_attach() and represents the
@@ -442,6 +448,8 @@ struct iommu_hwpt_alloc { · 24 unmodified lines
442	448	__u32 data_type;
443	449	__u32 data_len;
444	450	__aligned_u64 data_uptr;
	451	+ __u32 fault_id;
	452	+ __u32 __reserved2;
445	453	};
446	454	#define IOMMU_HWPT_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_ALLOC)
447	455