Nested translation has stage-1 and stage-2 page tables. A stage-1 page table is managed by user space, and it needs to work with a stage-2 page table, which is a parent hwpt for the stage-1 hwpt.
iommu core already supports accepting parent iommu_domain and user_data to allocate an iommu_domain. This makes iommufd_hw_pagetable_alloc() to accept the parent hwpt and user_data, and relays them to iommu core, to prepare for supporting hw_pagetable allocation with user_data.
Also, add a parent pointer in struct iommufd_hw_pagetable for taking and releasing its refcount.
Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommufd/device.c | 2 +- drivers/iommu/iommufd/hw_pagetable.c | 28 ++++++++++++++++++++++--- drivers/iommu/iommufd/iommufd_private.h | 5 ++++- 3 files changed, 30 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 5c352807d946..19cd6df46c6a 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -558,7 +558,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev, }
hwpt = iommufd_hw_pagetable_alloc(idev->ictx, ioas, idev, - immediate_attach); + NULL, NULL, immediate_attach); if (IS_ERR(hwpt)) { destroy_hwpt = ERR_CAST(hwpt); goto out_unlock; diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 84b4a11e62f8..16e92a1c150b 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -24,6 +24,8 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) if (hwpt->domain) iommu_domain_free(hwpt->domain);
+ if (hwpt->parent) + refcount_dec(&hwpt->parent->obj.users); refcount_dec(&hwpt->ioas->obj.users); }
@@ -46,6 +48,8 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) * @ictx: iommufd context * @ioas: IOAS to associate the domain with * @idev: Device to get an iommu_domain for + * @parent: Optional parent HWPT to associate with the domain with + * @user_data: Optional user_data pointer * @immediate_attach: True if idev should be attached to the hwpt * * Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT @@ -54,14 +58,20 @@ int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt) */ struct iommufd_hw_pagetable * iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, - struct iommufd_device *idev, bool immediate_attach) + struct iommufd_device *idev, + struct iommufd_hw_pagetable *parent, + void *user_data, bool immediate_attach) { const struct iommu_ops *ops = dev_iommu_ops(idev->dev); + struct iommu_domain *parent_domain = NULL; struct iommufd_hw_pagetable *hwpt; int rc;
lockdep_assert_held(&ioas->mutex);
+ if (parent && !ops->domain_alloc_user) + return ERR_PTR(-EOPNOTSUPP); + hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE); if (IS_ERR(hwpt)) return hwpt; @@ -70,9 +80,15 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, /* Pairs with iommufd_hw_pagetable_destroy() */ refcount_inc(&ioas->obj.users); hwpt->ioas = ioas; + if (parent) { + hwpt->parent = parent; + parent_domain = parent->domain; + refcount_inc(&parent->obj.users); + }
if (ops->domain_alloc_user) - hwpt->domain = ops->domain_alloc_user(idev->dev, NULL, NULL); + hwpt->domain = ops->domain_alloc_user(idev->dev, + parent_domain, user_data); else hwpt->domain = iommu_domain_alloc(idev->dev->bus); if (!hwpt->domain) { @@ -80,6 +96,11 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, goto out_abort; }
+ /* It must be either NESTED or UNMANAGED, depending on parent_domain */ + if ((parent_domain && hwpt->domain->type != IOMMU_DOMAIN_NESTED) || + (!parent_domain && hwpt->domain->type != IOMMU_DOMAIN_UNMANAGED)) + goto out_abort; + /* * Set the coherency mode before we do iopt_table_add_domain() as some * iommus have a per-PTE bit that controls it and need to decide before @@ -150,7 +171,8 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) }
mutex_lock(&ioas->mutex); - hwpt = iommufd_hw_pagetable_alloc(ucmd->ictx, ioas, idev, false); + hwpt = iommufd_hw_pagetable_alloc(ucmd->ictx, ioas, idev, + NULL, NULL, false); mutex_unlock(&ioas->mutex); if (IS_ERR(hwpt)) { rc = PTR_ERR(hwpt); diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 05b5ad66f716..182c074eecdc 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -243,6 +243,7 @@ int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd); */ struct iommufd_hw_pagetable { struct iommufd_object obj; + struct iommufd_hw_pagetable *parent; struct iommufd_ioas *ioas; struct iommu_domain *domain; bool auto_domain : 1; @@ -254,7 +255,9 @@ struct iommufd_hw_pagetable {
struct iommufd_hw_pagetable * iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, - struct iommufd_device *idev, bool immediate_attach); + struct iommufd_device *idev, + struct iommufd_hw_pagetable *parent, + void *user_data, bool immediate_attach); int iommufd_hw_pagetable_enforce_cc(struct iommufd_hw_pagetable *hwpt); int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt, struct iommufd_device *idev);