Add IOMMU_VIOMMU_TYPE_HYPERVISOR with a file-based VM partition reference. This represents a hypervisor-backed per-VM IOMMU object used to bind and organize vDEVICEs for a guest VM partition, with or without a guest vIOMMU.
This type has no nesting-parent HWPT. Teach the vIOMMU core to pass a NULL parent domain to the driver callback. Signed-off-by: Jacob Pan <[email protected]> Assisted-by: GPT-5.6 Sol --- drivers/iommu/amd/iommufd.c | 10 ++++++++- drivers/iommu/iommufd/viommu.c | 37 +++++++++++++++++++++++----------- include/linux/iommu.h | 8 +++++--- include/uapi/linux/iommufd.h | 25 ++++++++++++++++++++++- 4 files changed, 63 insertions(+), 17 deletions(-) diff --git a/drivers/iommu/amd/iommufd.c b/drivers/iommu/amd/iommufd.c index 52300b867c1f..8fcd5228c547 100644 --- a/drivers/iommu/amd/iommufd.c +++ b/drivers/iommu/amd/iommufd.c @@ -34,6 +34,10 @@ void *amd_iommufd_hw_info(struct device *dev, u32 *length, enum iommu_hw_info_ty size_t amd_iommufd_get_viommu_size(struct device *dev, enum iommu_viommu_type viommu_type) { + /* AMD vIOMMUs require a nesting parent; hypervisor vIOMMUs are parentless. */ + if (viommu_type == IOMMU_VIOMMU_TYPE_HYPERVISOR) + return 0; + return VIOMMU_STRUCT_SIZE(struct amd_iommu_viommu, core); } @@ -41,9 +45,13 @@ int amd_iommufd_viommu_init(struct iommufd_viommu *viommu, struct iommu_domain * const struct iommu_user_data *user_data) { unsigned long flags; - struct protection_domain *pdom = to_pdomain(parent); + struct protection_domain *pdom; struct amd_iommu_viommu *aviommu = container_of(viommu, struct amd_iommu_viommu, core); + if (!parent) + return -EOPNOTSUPP; + + pdom = to_pdomain(parent); xa_init_flags(&aviommu->gdomid_array, XA_FLAGS_ALLOC1); aviommu->parent = pdom; diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index f7951057a1e5..73a06c1a2ada 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -10,7 +10,8 @@ void iommufd_viommu_destroy(struct iommufd_object *obj) if (viommu->ops && viommu->ops->destroy) viommu->ops->destroy(viommu); - refcount_dec(&viommu->hwpt->common.obj.users); + if (viommu->hwpt) + refcount_dec(&viommu->hwpt->common.obj.users); xa_destroy(&viommu->vdevs); } @@ -63,15 +64,19 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) goto out_put_idev; } - hwpt_paging = iommufd_get_hwpt_paging(ucmd, cmd->hwpt_id); - if (IS_ERR(hwpt_paging)) { - rc = PTR_ERR(hwpt_paging); - goto out_put_idev; - } + if (cmd->type == IOMMU_VIOMMU_TYPE_HYPERVISOR) { + hwpt_paging = NULL; + } else { + hwpt_paging = iommufd_get_hwpt_paging(ucmd, cmd->hwpt_id); + if (IS_ERR(hwpt_paging)) { + rc = PTR_ERR(hwpt_paging); + goto out_put_idev; + } - if (!hwpt_paging->nest_parent) { - rc = -EINVAL; - goto out_put_hwpt; + if (!hwpt_paging->nest_parent) { + rc = -EINVAL; + goto out_put_hwpt; + } } viommu = (struct iommufd_viommu *)_iommufd_object_alloc_ucmd( @@ -85,7 +90,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) viommu->type = cmd->type; viommu->ictx = ucmd->ictx; viommu->hwpt = hwpt_paging; - refcount_inc(&viommu->hwpt->common.obj.users); + if (viommu->hwpt) + refcount_inc(&viommu->hwpt->common.obj.users); INIT_LIST_HEAD(&viommu->veventqs); init_rwsem(&viommu->veventqs_rwsem); /* @@ -95,7 +101,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) */ viommu->iommu_dev = iommu_dev; - rc = ops->viommu_init(viommu, hwpt_paging->common.domain, + rc = ops->viommu_init(viommu, + hwpt_paging ? hwpt_paging->common.domain : NULL, user_data.len ? &user_data : NULL); if (rc) goto out_put_hwpt; @@ -110,7 +117,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); out_put_hwpt: - iommufd_put_object(ucmd->ictx, &hwpt_paging->common.obj); + if (hwpt_paging) + iommufd_put_object(ucmd->ictx, &hwpt_paging->common.obj); out_put_idev: iommufd_put_object(ucmd->ictx, &idev->obj); return rc; @@ -394,6 +402,11 @@ int iommufd_hw_queue_alloc_ioctl(struct iommufd_ucmd *ucmd) if (IS_ERR(viommu)) return PTR_ERR(viommu); + if (!viommu->hwpt) { + rc = -EOPNOTSUPP; + goto out_put_viommu; + } + if (!viommu->ops || !viommu->ops->get_hw_queue_size || !viommu->ops->hw_queue_init_phys) { rc = -EOPNOTSUPP; diff --git a/include/linux/iommu.h b/include/linux/iommu.h index ede77b90f0fd..95211e95ea5d 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -685,9 +685,11 @@ __iommu_copy_struct_to_user(const struct iommu_user_data *dst_data, * driver-level vIOMMU structure related to the core one * @viommu_init: Init the driver-level struct of an iommufd_viommu on a physical * IOMMU instance @viommu->iommu_dev, as the set of virtualization - * resources shared/passed to user space IOMMU instance. Associate - * it with a nesting @parent_domain. It is required for driver to - * set @viommu->ops pointing to its own viommu_ops + * resources shared/passed to user space IOMMU instance. + * @parent_domain may be NULL for a parentless vIOMMU type; a + * driver advertising such a type through @get_viommu_size must + * accept a NULL parent. It is required for driver to set + * @viommu->ops pointing to its own viommu_ops * @owner: Driver module providing these ops * @identity_domain: An always available, always attachable identity * translation. diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 206fa667c782..bffa25c5267e 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -1095,6 +1095,11 @@ struct iommu_fault_alloc { * @IOMMU_VIOMMU_TYPE_ARM_SMMUV3: ARM SMMUv3 driver specific type * @IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV: NVIDIA Tegra241 CMDQV (extension for ARM * SMMUv3) enabled ARM SMMUv3 type + * @IOMMU_VIOMMU_TYPE_HYPERVISOR: Hypervisor-backed per-VM IOMMU object + * tracks a file-based VM partition + * reference; also used to bind and organize + * vDEVICEs for a guest VM partition, with or + * without a guest vIOMMU. */ enum iommu_viommu_type { IOMMU_VIOMMU_TYPE_DEFAULT = 0, @@ -1105,6 +1110,7 @@ enum iommu_viommu_type { * VMM must wire the HYP_OWN bit to 0 in guest VINTF_CONFIG register */ IOMMU_VIOMMU_TYPE_TEGRA241_CMDQV = 2, + IOMMU_VIOMMU_TYPE_HYPERVISOR = 3, }; /** @@ -1123,13 +1129,29 @@ struct iommu_viommu_tegra241_cmdqv { __aligned_u64 out_vintf_mmap_length; }; +/** + * struct iommu_viommu_hypervisor - Hypervisor-backed virtual IOMMU + * (IOMMU_VIOMMU_TYPE_HYPERVISOR) + * @vm_fd: Hypervisor VM/partition file descriptor + * @flags: Must be 0 for now. Future flags may indicate the presence of a guest + * virtual IOMMU, allowing hypervisor pvIOMMU drivers to enable + * PASID/ATS and prepare for nested translation as appropriate. + * @__reserved: Must be 0 + */ +struct iommu_viommu_hypervisor { + __s32 vm_fd; + __u32 flags; + __aligned_u64 __reserved; +}; + /** * struct iommu_viommu_alloc - ioctl(IOMMU_VIOMMU_ALLOC) * @size: sizeof(struct iommu_viommu_alloc) * @flags: Must be 0 * @type: Type of the virtual IOMMU. Must be defined in enum iommu_viommu_type * @dev_id: The device's physical IOMMU will be used to back the virtual IOMMU - * @hwpt_id: ID of a nesting parent HWPT to associate to + * @hwpt_id: ID of a nesting parent HWPT to associate to. This field is + * ignored if the vIOMMU type does not use a nesting parent * @out_viommu_id: Output virtual IOMMU ID for the allocated object * @data_len: Length of the type specific data * @__reserved: Must be 0 @@ -1146,6 +1168,7 @@ struct iommu_viommu_tegra241_cmdqv { * - Delivery of paravirtualized invalidation * - Direct assigned invalidation queues * - Direct assigned interrupts + * - Hypervisor controlled translation, e.g. for Type-1 Bare-metal hypervisors */ struct iommu_viommu_alloc { __u32 size; -- 2.43.0
