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iommufd: Associate fault object with iommufd_hw_pgtable

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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>
This commit is contained in:
Lu Baolu 2024-07-02 14:34:42 +08:00 committed by Jason Gunthorpe
parent b7d8833677
commit 34765cbc67
4 changed files with 64 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/iommu/iommufd/fault.c
View File

@ -414,3 +414,20 @@ out_abort:
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;
}

38
drivers/iommu/iommufd/hw_pagetable.c
View File

@ -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);
}
@ -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 +233,8 @@ 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);
@ -308,6 +315,21 @@ 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)

9
drivers/iommu/iommufd/iommufd_private.h
View File

@ -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);

8
include/uapi/linux/iommufd.h
View File

@ -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)