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iommufd/device: Wrap igroup->hwpt and igroup->device_list into attach struct

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The igroup->hwpt and igroup->device_list are used to track the hwpt attach
of a group in the RID path. While the coming PASID path also needs such
tracking. To be prepared, wrap igroup->hwpt and igroup->device_list into
attach struct which is allocated per attaching the first device of the
group and freed per detaching the last device of the group.

Link: https://patch.msgid.link/r/20250321171940.7213-8-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Nicolin Chen <nicolinc@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>
This commit is contained in:
Yi Liu 2025-03-21 10:19:29 -07:00 committed by Jason Gunthorpe
parent ba1de6cd41
commit 75f990aef3
2 changed files with 58 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
drivers/iommu/iommufd/device.c
View File

@ -17,12 +17,17 @@ MODULE_PARM_DESC(
"Allow IOMMUFD to bind to devices even if the platform cannot isolate "
"the MSI interrupt window. Enabling this is a security weakness.");
struct iommufd_attach {
struct iommufd_hw_pagetable *hwpt;
struct list_head device_list;
};
static void iommufd_group_release(struct kref *kref)
{
struct iommufd_group *igroup =
container_of(kref, struct iommufd_group, ref);
WARN_ON(igroup->hwpt || !list_empty(&igroup->device_list));
WARN_ON(igroup->attach);
xa_cmpxchg(&igroup->ictx->groups, iommu_group_id(igroup->group), igroup,
NULL, GFP_KERNEL);
@ -89,7 +94,6 @@ static struct iommufd_group *iommufd_get_group(struct iommufd_ctx *ictx,
kref_init(&new_igroup->ref);
mutex_init(&new_igroup->lock);
INIT_LIST_HEAD(&new_igroup->device_list);
new_igroup->sw_msi_start = PHYS_ADDR_MAX;
/* group reference moves into new_igroup */
new_igroup->group = group;
@ -333,7 +337,7 @@ static bool
iommufd_group_first_attach(struct iommufd_group *igroup, ioasid_t pasid)
{
lockdep_assert_held(&igroup->lock);
return !igroup->hwpt;
return !igroup->attach;
}
static int
@ -369,7 +373,7 @@ static bool iommufd_device_is_attached(struct iommufd_device *idev)
{
struct iommufd_device *cur;
list_for_each_entry(cur, &idev->igroup->device_list, group_item)
list_for_each_entry(cur, &idev->igroup->attach->device_list, group_item)
if (cur == idev)
return true;
return false;
@ -493,19 +497,33 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt);
bool attach_resv = hwpt_paging && pasid == IOMMU_NO_PASID;
struct iommufd_group *igroup = idev->igroup;
struct iommufd_hw_pagetable *old_hwpt;
struct iommufd_attach *attach;
int rc;
mutex_lock(&igroup->lock);
if (igroup->hwpt && igroup->hwpt != hwpt) {
attach = igroup->attach;
if (!attach) {
attach = kzalloc(sizeof(*attach), GFP_KERNEL);
if (!attach) {
rc = -ENOMEM;
goto err_unlock;
}
INIT_LIST_HEAD(&attach->device_list);
}
old_hwpt = attach->hwpt;
if (old_hwpt && old_hwpt != hwpt) {
rc = -EINVAL;
goto err_unlock;
goto err_free_attach;
}
if (attach_resv) {
rc = iommufd_device_attach_reserved_iova(idev, hwpt_paging);
if (rc)
goto err_unlock;
goto err_free_attach;
}
/*
@ -519,15 +537,19 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
rc = iommufd_hwpt_attach_device(hwpt, idev, pasid);
if (rc)
goto err_unresv;
igroup->hwpt = hwpt;
attach->hwpt = hwpt;
igroup->attach = attach;
}
refcount_inc(&hwpt->obj.users);
list_add_tail(&idev->group_item, &igroup->device_list);
list_add_tail(&idev->group_item, &attach->device_list);
mutex_unlock(&igroup->lock);
return 0;
err_unresv:
if (attach_resv)
iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
err_free_attach:
if (iommufd_group_first_attach(igroup, pasid))
kfree(attach);
err_unlock:
mutex_unlock(&igroup->lock);
return rc;
@ -537,14 +559,20 @@ struct iommufd_hw_pagetable *
iommufd_hw_pagetable_detach(struct iommufd_device *idev, ioasid_t pasid)
{
struct iommufd_group *igroup = idev->igroup;
struct iommufd_hw_pagetable *hwpt = igroup->hwpt;
struct iommufd_hwpt_paging *hwpt_paging = find_hwpt_paging(hwpt);
struct iommufd_hwpt_paging *hwpt_paging;
struct iommufd_hw_pagetable *hwpt;
struct iommufd_attach *attach;
mutex_lock(&igroup->lock);
attach = igroup->attach;
hwpt = attach->hwpt;
hwpt_paging = find_hwpt_paging(hwpt);
list_del(&idev->group_item);
if (list_empty(&igroup->device_list)) {
if (list_empty(&attach->device_list)) {
iommufd_hwpt_detach_device(hwpt, idev, pasid);
igroup->hwpt = NULL;
igroup->attach = NULL;
kfree(attach);
}
if (hwpt_paging && pasid == IOMMU_NO_PASID)
iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, idev->dev);
@ -574,7 +602,7 @@ iommufd_group_remove_reserved_iova(struct iommufd_group *igroup,
lockdep_assert_held(&igroup->lock);
list_for_each_entry(cur, &igroup->device_list, group_item)
list_for_each_entry(cur, &igroup->attach->device_list, group_item)
iopt_remove_reserved_iova(&hwpt_paging->ioas->iopt, cur->dev);
}
@ -588,9 +616,10 @@ iommufd_group_do_replace_reserved_iova(struct iommufd_group *igroup,
lockdep_assert_held(&igroup->lock);
old_hwpt_paging = find_hwpt_paging(igroup->hwpt);
old_hwpt_paging = find_hwpt_paging(igroup->attach->hwpt);
if (!old_hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas) {
list_for_each_entry(cur, &igroup->device_list, group_item) {
list_for_each_entry(cur,
&igroup->attach->device_list, group_item) {
rc = iopt_table_enforce_dev_resv_regions(
&hwpt_paging->ioas->iopt, cur->dev, NULL);
if (rc)
@ -617,27 +646,32 @@ iommufd_device_do_replace(struct iommufd_device *idev, ioasid_t pasid,
struct iommufd_hwpt_paging *old_hwpt_paging;
struct iommufd_group *igroup = idev->igroup;
struct iommufd_hw_pagetable *old_hwpt;
struct iommufd_attach *attach;
unsigned int num_devices;
int rc;
mutex_lock(&igroup->lock);
if (igroup->hwpt == NULL) {
attach = igroup->attach;
if (!attach) {
rc = -EINVAL;
goto err_unlock;
}
old_hwpt = attach->hwpt;
WARN_ON(!old_hwpt || list_empty(&attach->device_list));
if (!iommufd_device_is_attached(idev)) {
rc = -EINVAL;
goto err_unlock;
}
if (hwpt == igroup->hwpt) {
if (hwpt == old_hwpt) {
mutex_unlock(&igroup->lock);
return NULL;
}
old_hwpt = igroup->hwpt;
if (attach_resv) {
rc = iommufd_group_do_replace_reserved_iova(igroup, hwpt_paging);
if (rc)
@ -653,9 +687,9 @@ iommufd_device_do_replace(struct iommufd_device *idev, ioasid_t pasid,
(!hwpt_paging || hwpt_paging->ioas != old_hwpt_paging->ioas))
iommufd_group_remove_reserved_iova(igroup, old_hwpt_paging);
igroup->hwpt = hwpt;
attach->hwpt = hwpt;
num_devices = list_count_nodes(&igroup->device_list);
num_devices = list_count_nodes(&attach->device_list);
/*
* Move the refcounts held by the device_list to the new hwpt. Retain a
* refcount for this thread as the caller will free it.

5
drivers/iommu/iommufd/iommufd_private.h
View File

@ -399,13 +399,14 @@ static inline void iommufd_hw_pagetable_put(struct iommufd_ctx *ictx,
refcount_dec(&hwpt->obj.users);
}
struct iommufd_attach;
struct iommufd_group {
struct kref ref;
struct mutex lock;
struct iommufd_ctx *ictx;
struct iommu_group *group;
struct iommufd_hw_pagetable *hwpt;
struct list_head device_list;
struct iommufd_attach *attach;
struct iommufd_sw_msi_maps required_sw_msi;
phys_addr_t sw_msi_start;
};