Now a vIOMMU holds a shareable nesting parent HWPT. So, it can act like that nesting parent HWPT to allocate a nested HWPT.
Support that in the IOMMU_HWPT_ALLOC ioctl handler, and update its kdoc.
Also, add an iommufd_viommu_alloc_hwpt_nested helper to allocate a nested HWPT for a vIOMMU object. Since a vIOMMU object holds the parent hwpt's refcount already, increase the refcount of the vIOMMU only.
Reviewed-by: Kevin Tian kevin.tian@intel.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- drivers/iommu/iommufd/iommufd_private.h | 1 + include/uapi/linux/iommufd.h | 14 ++--- drivers/iommu/iommufd/hw_pagetable.c | 72 ++++++++++++++++++++++++- 3 files changed, 80 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index a8104d9d4cef..e8f5ef550cc9 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -290,6 +290,7 @@ struct iommufd_hwpt_paging { struct iommufd_hwpt_nested { struct iommufd_hw_pagetable common; struct iommufd_hwpt_paging *parent; + struct iommufd_viommu *viommu; };
static inline bool hwpt_is_paging(struct iommufd_hw_pagetable *hwpt) diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 302844136b02..a498d4838f9a 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -435,7 +435,7 @@ enum iommu_hwpt_data_type { * @size: sizeof(struct iommu_hwpt_alloc) * @flags: Combination of enum iommufd_hwpt_alloc_flags * @dev_id: The device to allocate this HWPT for - * @pt_id: The IOAS or HWPT to connect this HWPT to + * @pt_id: The IOAS or HWPT or vIOMMU to connect this HWPT to * @out_hwpt_id: The ID of the new HWPT * @__reserved: Must be 0 * @data_type: One of enum iommu_hwpt_data_type @@ -454,11 +454,13 @@ enum iommu_hwpt_data_type { * IOMMU_HWPT_DATA_NONE. The HWPT can be allocated as a parent HWPT for a * nesting configuration by passing IOMMU_HWPT_ALLOC_NEST_PARENT via @flags. * - * A user-managed nested HWPT will be created from a given parent HWPT via - * @pt_id, in which the parent HWPT must be allocated previously via the - * same ioctl from a given IOAS (@pt_id). In this case, the @data_type - * must be set to a pre-defined type corresponding to an I/O page table - * type supported by the underlying IOMMU hardware. + * A user-managed nested HWPT will be created from a given vIOMMU (wrapping a + * parent HWPT) or a parent HWPT via @pt_id, in which the parent HWPT must be + * allocated previously via the same ioctl from a given IOAS (@pt_id). In this + * case, the @data_type must be set to a pre-defined type corresponding to an + * I/O page table type supported by the underlying IOMMU hardware. The device + * via @dev_id and the vIOMMU via @pt_id must be associated to the same IOMMU + * instance. * * If the @data_type is set to IOMMU_HWPT_DATA_NONE, @data_len and * @data_uptr should be zero. Otherwise, both @data_len and @data_uptr diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index d06bf6e6c19f..384afa374d25 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -57,7 +57,10 @@ void iommufd_hwpt_nested_destroy(struct iommufd_object *obj) container_of(obj, struct iommufd_hwpt_nested, common.obj);
__iommufd_hwpt_destroy(&hwpt_nested->common); - refcount_dec(&hwpt_nested->parent->common.obj.users); + if (hwpt_nested->viommu) + refcount_dec(&hwpt_nested->viommu->obj.users); + else + refcount_dec(&hwpt_nested->parent->common.obj.users); }
void iommufd_hwpt_nested_abort(struct iommufd_object *obj) @@ -260,6 +263,57 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, return ERR_PTR(rc); }
+/** + * iommufd_viommu_alloc_hwpt_nested() - Get a hwpt_nested for a vIOMMU + * @viommu: vIOMMU ojbect to associate the hwpt_nested/domain with + * @user_data: user_data pointer. Must be valid + * + * Allocate a new IOMMU_DOMAIN_NESTED for a vIOMMU and return it as a NESTED + * hw_pagetable. + */ +static struct iommufd_hwpt_nested * +iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags, + const struct iommu_user_data *user_data) +{ + struct iommufd_hwpt_nested *hwpt_nested; + struct iommufd_hw_pagetable *hwpt; + int rc; + + if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) || !user_data->len) + return ERR_PTR(-EOPNOTSUPP); + if (!viommu->ops || !viommu->ops->alloc_domain_nested) + return ERR_PTR(-EOPNOTSUPP); + + hwpt_nested = __iommufd_object_alloc( + viommu->ictx, hwpt_nested, IOMMUFD_OBJ_HWPT_NESTED, common.obj); + if (IS_ERR(hwpt_nested)) + return ERR_CAST(hwpt_nested); + hwpt = &hwpt_nested->common; + + hwpt_nested->viommu = viommu; + refcount_inc(&viommu->obj.users); + hwpt_nested->parent = viommu->hwpt; + + hwpt->domain = + viommu->ops->alloc_domain_nested(viommu, flags, user_data); + if (IS_ERR(hwpt->domain)) { + rc = PTR_ERR(hwpt->domain); + hwpt->domain = NULL; + goto out_abort; + } + hwpt->domain->owner = viommu->iommu_dev->ops; + + if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) { + rc = -EINVAL; + goto out_abort; + } + return hwpt_nested; + +out_abort: + iommufd_object_abort_and_destroy(viommu->ictx, &hwpt->obj); + return ERR_PTR(rc); +} + int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) { struct iommu_hwpt_alloc *cmd = ucmd->cmd; @@ -316,6 +370,22 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) goto out_unlock; } hwpt = &hwpt_nested->common; + } else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) { + struct iommufd_hwpt_nested *hwpt_nested; + struct iommufd_viommu *viommu; + + viommu = container_of(pt_obj, struct iommufd_viommu, obj); + if (viommu->iommu_dev != __iommu_get_iommu_dev(idev->dev)) { + rc = -EINVAL; + goto out_unlock; + } + hwpt_nested = iommufd_viommu_alloc_hwpt_nested( + viommu, cmd->flags, &user_data); + if (IS_ERR(hwpt_nested)) { + rc = PTR_ERR(hwpt_nested); + goto out_unlock; + } + hwpt = &hwpt_nested->common; } else { rc = -EINVAL; goto out_put_pt;