On Thu, Sep 21, 2023 at 12:51:24AM -0700, Yi Liu wrote:
From: Nicolin Chen nicolinc@nvidia.com
The struct iommufd_hw_pagetable has been representing a kernel-managed HWPT, yet soon will be reused to represent a user-managed HWPT. These two types of HWPTs has the same IOMMUFD object type and an iommu_domain object, but have quite different attributes/members.
Add a union in struct iommufd_hw_pagetable and group all the existing kernel-managed members. One of the following patches will add another struct for user-managed members.
Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com
drivers/iommu/iommufd/iommufd_private.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 3064997a0181..947a797536e3 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -231,13 +231,18 @@ int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd); */ struct iommufd_hw_pagetable { struct iommufd_object obj;
- struct iommufd_ioas *ioas; struct iommu_domain *domain;
- bool auto_domain : 1;
- bool enforce_cache_coherency : 1;
- bool msi_cookie : 1;
- /* Head at iommufd_ioas::hwpt_list */
- struct list_head hwpt_item;
- union {
struct { /* kernel-managed */struct iommufd_ioas *ioas;bool auto_domain : 1;
Will iommufd_hw_pagetable_put() also be called on non-kernel-managed domain? If yes, hwpt->user_managed needs to be checked in iommufd_hw_pagetable_put(), (e.g. as below). Otherwise, this union will lead to hwpt->ioas and hwpt->auto_domain still being accessible though invalid.
static inline void iommufd_hw_pagetable_put(struct iommufd_ctx *ictx, struct iommufd_hw_pagetable *hwpt) { - lockdep_assert_not_held(&hwpt->ioas->mutex); - if (hwpt->auto_domain) + if (!hwpt->user_managed) + lockdep_assert_not_held(&hwpt->ioas->mutex); + + if (!hwpt->user_managed && hwpt->auto_domain) iommufd_object_deref_user(ictx, &hwpt->obj); else refcount_dec(&hwpt->obj.users); }
bool enforce_cache_coherency : 1;bool msi_cookie : 1;/* Head at iommufd_ioas::hwpt_list */struct list_head hwpt_item;};- };
}; struct iommufd_hw_pagetable * -- 2.34.1