Add a new ioctl for user space to do a vIOMMU allocation. It must be based on a nesting parent HWPT, so take its refcount.
As an initial version, define an IOMMU_VIOMMU_TYPE_DEFAULT type. Using it, the object will be allocated by the iommufd core. If an IOMMU driver supports a driver-managed vIOMMU object, it must define its own IOMMU_VIOMMU_TYPE_ in the uAPI header and implement a viommu_alloc op in its iommu_ops. Signed-off-by: Nicolin Chen <nicol...@nvidia.com> --- drivers/iommu/iommufd/Makefile | 3 +- drivers/iommu/iommufd/iommufd_private.h | 3 + include/uapi/linux/iommufd.h | 40 +++++++++++ drivers/iommu/iommufd/main.c | 6 ++ drivers/iommu/iommufd/viommu.c | 91 +++++++++++++++++++++++++ 5 files changed, 142 insertions(+), 1 deletion(-) create mode 100644 drivers/iommu/iommufd/viommu.c diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index 93daedd7e5c8..288ef3e895e3 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -7,7 +7,8 @@ iommufd-y := \ ioas.o \ main.o \ pages.o \ - vfio_compat.o + vfio_compat.o \ + viommu.o iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 6a364073f699..4aefac6af23f 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -521,6 +521,9 @@ static inline int iommufd_hwpt_replace_device(struct iommufd_device *idev, return iommu_group_replace_domain(idev->igroup->group, hwpt->domain); } +int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd); +void iommufd_viommu_destroy(struct iommufd_object *obj); + #ifdef CONFIG_IOMMUFD_TEST int iommufd_test(struct iommufd_ucmd *ucmd); void iommufd_selftest_destroy(struct iommufd_object *obj); diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index cd4920886ad0..db9008a4eeef 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -51,6 +51,7 @@ enum { IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP = 0x8c, IOMMUFD_CMD_HWPT_INVALIDATE = 0x8d, IOMMUFD_CMD_FAULT_QUEUE_ALLOC = 0x8e, + IOMMUFD_CMD_VIOMMU_ALLOC = 0x8f, }; /** @@ -852,4 +853,43 @@ struct iommu_fault_alloc { __u32 out_fault_fd; }; #define IOMMU_FAULT_QUEUE_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_FAULT_QUEUE_ALLOC) + +/** + * enum iommu_viommu_type - Virtual IOMMU Type + * @IOMMU_VIOMMU_TYPE_DEFAULT: Core-managed virtual IOMMU type + */ +enum iommu_viommu_type { + IOMMU_VIOMMU_TYPE_DEFAULT = 0, +}; + +/** + * 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 + * @out_viommu_id: Output virtual IOMMU ID for the allocated object + * + * Allocate a virtual IOMMU object that represents the underlying physical + * IOMMU's virtualization support. The vIOMMU object is a security-isolated + * slice of the physical IOMMU HW that is unique to a specific VM. Operations + * global to the IOMMU are connected to the vIOMMU, such as: + * - Security namespace for guest owned ID, e.g. guest-controlled cache tags + * - Access to a sharable nesting parent pagetable across physical IOMMUs + * - Virtualization of various platforms IDs, e.g. RIDs and others + * - Delivery of paravirtualized invalidation + * - Direct assigned invalidation queues + * - Direct assigned interrupts + * - Non-affiliated event reporting + */ +struct iommu_viommu_alloc { + __u32 size; + __u32 flags; + __u32 type; + __u32 dev_id; + __u32 hwpt_id; + __u32 out_viommu_id; +}; +#define IOMMU_VIOMMU_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_ALLOC) #endif diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 92bd075108e5..cbd0a80b2d67 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -301,6 +301,7 @@ union ucmd_buffer { struct iommu_ioas_unmap unmap; struct iommu_option option; struct iommu_vfio_ioas vfio_ioas; + struct iommu_viommu_alloc viommu; #ifdef CONFIG_IOMMUFD_TEST struct iommu_test_cmd test; #endif @@ -352,6 +353,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { val64), IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas, __reserved), + IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl, + struct iommu_viommu_alloc, out_viommu_id), #ifdef CONFIG_IOMMUFD_TEST IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last), #endif @@ -487,6 +490,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = { [IOMMUFD_OBJ_FAULT] = { .destroy = iommufd_fault_destroy, }, + [IOMMUFD_OBJ_VIOMMU] = { + .destroy = iommufd_viommu_destroy, + }, #ifdef CONFIG_IOMMUFD_TEST [IOMMUFD_OBJ_SELFTEST] = { .destroy = iommufd_selftest_destroy, diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c new file mode 100644 index 000000000000..3a903baeee6a --- /dev/null +++ b/drivers/iommu/iommufd/viommu.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES + */ + +#include "iommufd_private.h" + +void iommufd_viommu_destroy(struct iommufd_object *obj) +{ + struct iommufd_viommu *viommu = + container_of(obj, struct iommufd_viommu, obj); + + if (viommu->ops && viommu->ops->free) + viommu->ops->free(viommu); + refcount_dec(&viommu->hwpt->common.obj.users); +} + +int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) +{ + struct iommu_viommu_alloc *cmd = ucmd->cmd; + struct iommufd_hwpt_paging *hwpt_paging; + struct iommufd_viommu *viommu; + struct iommufd_device *idev; + const struct iommu_ops *ops; + int rc; + + if (cmd->flags) + return -EOPNOTSUPP; + + idev = iommufd_get_device(ucmd, cmd->dev_id); + if (IS_ERR(idev)) + return PTR_ERR(idev); + ops = dev_iommu_ops(idev->dev); + + 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 (cmd->type == IOMMU_VIOMMU_TYPE_DEFAULT) { + viommu = __iommufd_viommu_alloc(ucmd->ictx, sizeof(*viommu), + NULL); + } else { + if (!ops->viommu_alloc) { + rc = -EOPNOTSUPP; + goto out_put_hwpt; + } + + viommu = ops->viommu_alloc(idev->dev->iommu->iommu_dev, + hwpt_paging->common.domain, + ucmd->ictx, cmd->type); + } + if (IS_ERR(viommu)) { + rc = PTR_ERR(viommu); + goto out_put_hwpt; + } + + viommu->type = cmd->type; + viommu->ictx = ucmd->ictx; + viommu->hwpt = hwpt_paging; + + /* + * A real physical IOMMU instance would unlikely get unplugged, so the + * life cycle of this iommu_dev is guaranteed to stay alive, mostly. A + * pluggable IOMMU instance (if exists) is responsible for refcounting + * on its own. + */ + viommu->iommu_dev = idev->dev->iommu->iommu_dev; + + refcount_inc(&viommu->hwpt->common.obj.users); + + cmd->out_viommu_id = viommu->obj.id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_abort; + iommufd_object_finalize(ucmd->ictx, &viommu->obj); + goto out_put_hwpt; + +out_abort: + iommufd_object_abort_and_destroy(ucmd->ictx, &viommu->obj); +out_put_hwpt: + iommufd_put_object(ucmd->ictx, &hwpt_paging->common.obj); +out_put_idev: + iommufd_put_object(ucmd->ictx, &idev->obj); + return rc; +} -- 2.43.0