Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
iommufd/device: Replace device_list with device_array
igroup->attach->device_list is used to track attached device of a group
in the RID path. Such tracking is also needed in the PASID path in order
to share path with the RID path.
While there is only one list_head in the iommufd_device. It cannot work
if the device has been attached in both RID path and PASID path. To solve
it, replacing the device_list with an xarray. The attached iommufd_device
is stored in the entry indexed by the idev->obj.id.
Link: https://patch.msgid.link/r/20250321171940.7213-9-yi.l.liu@intel.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
authored by
Yi Liu
and committed by
Jason Gunthorpe
831b40f8
75f990ae
+39
-19
+39
-19
drivers/iommu/iommufd/device.c
+39
-19
drivers/iommu/iommufd/device.c
···
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struct iommufd_attach {
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struct iommufd_hw_pagetable *hwpt;
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-
struct list_head device_list;
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+
struct xarray device_array;
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};
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static void iommufd_group_release(struct kref *kref)
···
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}
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EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, "IOMMUFD");
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+
static unsigned int iommufd_group_device_num(struct iommufd_group *igroup)
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{
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struct iommufd_device *idev;
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unsigned int count = 0;
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unsigned long index;
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+
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lockdep_assert_held(&igroup->lock);
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+
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if (igroup->attach)
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xa_for_each(&igroup->attach->device_array, index, idev)
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count++;
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return count;
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}
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+
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#ifdef CONFIG_IRQ_MSI_IOMMU
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static int iommufd_group_setup_msi(struct iommufd_group *igroup,
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struct iommufd_hwpt_paging *hwpt_paging)
···
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/* Check if idev is attached to igroup->hwpt */
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static bool iommufd_device_is_attached(struct iommufd_device *idev)
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{
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struct iommufd_device *cur;
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list_for_each_entry(cur, &idev->igroup->attach->device_list, group_item)
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if (cur == idev)
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return true;
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return false;
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return xa_load(&idev->igroup->attach->device_array, idev->obj.id);
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}
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static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
···
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rc = -ENOMEM;
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goto err_unlock;
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}
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-
INIT_LIST_HEAD(&attach->device_list);
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xa_init(&attach->device_array);
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}
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old_hwpt = attach->hwpt;
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+
rc = xa_insert(&attach->device_array, idev->obj.id, XA_ZERO_ENTRY,
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GFP_KERNEL);
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if (rc) {
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WARN_ON(rc == -EBUSY && !old_hwpt);
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goto err_free_attach;
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}
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+
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if (old_hwpt && old_hwpt != hwpt) {
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rc = -EINVAL;
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-
goto err_free_attach;
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+
goto err_release_devid;
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}
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if (attach_resv) {
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rc = iommufd_device_attach_reserved_iova(idev, hwpt_paging);
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if (rc)
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-
goto err_free_attach;
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+
goto err_release_devid;
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}
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/*
···
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igroup->attach = attach;
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}
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refcount_inc(&hwpt->obj.users);
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-
list_add_tail(&idev->group_item, &attach->device_list);
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WARN_ON(xa_is_err(xa_store(&attach->device_array, idev->obj.id,
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idev, GFP_KERNEL)));
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mutex_unlock(&igroup->lock);
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return 0;
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err_unresv:
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if (attach_resv)
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iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
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+
err_release_devid:
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xa_release(&attach->device_array, idev->obj.id);
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err_free_attach:
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if (iommufd_group_first_attach(igroup, pasid))
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kfree(attach);
···
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hwpt = attach->hwpt;
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hwpt_paging = find_hwpt_paging(hwpt);
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-
list_del(&idev->group_item);
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-
if (list_empty(&attach->device_list)) {
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xa_erase(&attach->device_array, idev->obj.id);
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+
if (xa_empty(&attach->device_array)) {
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iommufd_hwpt_detach_device(hwpt, idev, pasid);
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igroup->attach = NULL;
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kfree(attach);
···
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struct iommufd_hwpt_paging *hwpt_paging)
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{
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struct iommufd_device *cur;
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+
unsigned long index;
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lockdep_assert_held(&igroup->lock);
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-
list_for_each_entry(cur, &igroup->attach->device_list, group_item)
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xa_for_each(&igroup->attach->device_array, index, cur)
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iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, cur->dev);
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}
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···
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{
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struct iommufd_hwpt_paging *old_hwpt_paging;
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struct iommufd_device *cur;
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+
unsigned long index;
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int rc;
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lockdep_assert_held(&igroup->lock);
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old_hwpt_paging = find_hwpt_paging(igroup->attach->hwpt);
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if (!old_hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas) {
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-
list_for_each_entry(cur,
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&igroup->attach->device_list, group_item) {
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+
xa_for_each(&igroup->attach->device_array, index, cur) {
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rc = iopt_table_enforce_dev_resv_regions(
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&hwpt_paging->ioas->iopt, cur->dev, NULL);
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if (rc)
···
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old_hwpt = attach->hwpt;
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-
WARN_ON(!old_hwpt || list_empty(&attach->device_list));
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+
WARN_ON(!old_hwpt || xa_empty(&attach->device_array));
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if (!iommufd_device_is_attached(idev)) {
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rc = -EINVAL;
···
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attach->hwpt = hwpt;
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-
num_devices = list_count_nodes(&attach->device_list);
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+
num_devices = iommufd_group_device_num(igroup);
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/*
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-
* Move the refcounts held by the device_list to the new hwpt. Retain a
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+
* Move the refcounts held by the device_array to the new hwpt. Retain a
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* refcount for this thread as the caller will free it.
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*/
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refcount_add(num_devices, &hwpt->obj.users);