Introduce a pair of new ioctls to set/unset a per-viommu virtual device id that should be linked to a physical device id via an idev pointer.
Continue the support IOMMU_VIOMMU_TYPE_DEFAULT for a core-managed viommu. Provide a lookup function for drivers to load device pointer by a virtual device id.
Add a rw_semaphore protection around the vdev_id list. Any future ioctl handlers that potentially access the list must grab the lock too.
Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- drivers/iommu/iommufd/device.c | 12 +++ drivers/iommu/iommufd/iommufd_private.h | 21 ++++ drivers/iommu/iommufd/main.c | 6 ++ drivers/iommu/iommufd/viommu.c | 121 ++++++++++++++++++++++++ include/uapi/linux/iommufd.h | 40 ++++++++ 5 files changed, 200 insertions(+)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 5fd3dd420290..3ad759971b32 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -136,6 +136,18 @@ void iommufd_device_destroy(struct iommufd_object *obj) struct iommufd_device *idev = container_of(obj, struct iommufd_device, obj);
+ /* Unlocked since there should be no race in a destroy() */ + if (idev->vdev_id) { + struct iommufd_vdev_id *vdev_id = idev->vdev_id; + struct iommufd_viommu *viommu = vdev_id->viommu; + struct iommufd_vdev_id *old; + + old = xa_cmpxchg(&viommu->vdev_ids, vdev_id->id, vdev_id, NULL, + GFP_KERNEL); + WARN_ON(old != vdev_id); + kfree(vdev_id); + idev->vdev_id = NULL; + } iommu_device_release_dma_owner(idev->dev); iommufd_put_group(idev->igroup); if (!iommufd_selftest_is_mock_dev(idev->dev)) diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 1f2a1c133b9a..2c6e168c5300 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -416,6 +416,7 @@ struct iommufd_device { struct iommufd_object obj; struct iommufd_ctx *ictx; struct iommufd_group *igroup; + struct iommufd_vdev_id *vdev_id; struct list_head group_item; /* always the physical device */ struct device *dev; @@ -533,11 +534,31 @@ struct iommufd_viommu { struct iommufd_ctx *ictx; struct iommufd_hwpt_paging *hwpt;
+ /* The locking order is vdev_ids_rwsem -> igroup::lock */ + struct rw_semaphore vdev_ids_rwsem; + struct xarray vdev_ids; + unsigned int type; };
+struct iommufd_vdev_id { + struct iommufd_viommu *viommu; + struct iommufd_device *idev; + u64 id; +}; + +static inline struct iommufd_viommu * +iommufd_get_viommu(struct iommufd_ucmd *ucmd, u32 id) +{ + return container_of(iommufd_get_object(ucmd->ictx, id, + IOMMUFD_OBJ_VIOMMU), + struct iommufd_viommu, obj); +} + int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd); void iommufd_viommu_destroy(struct iommufd_object *obj); +int iommufd_viommu_set_vdev_id(struct iommufd_ucmd *ucmd); +int iommufd_viommu_unset_vdev_id(struct iommufd_ucmd *ucmd);
#ifdef CONFIG_IOMMUFD_TEST int iommufd_test(struct iommufd_ucmd *ucmd); diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 288ee51b6829..199ad90fa36b 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -334,6 +334,8 @@ union ucmd_buffer { struct iommu_option option; struct iommu_vfio_ioas vfio_ioas; struct iommu_viommu_alloc viommu; + struct iommu_viommu_set_vdev_id set_vdev_id; + struct iommu_viommu_unset_vdev_id unset_vdev_id; #ifdef CONFIG_IOMMUFD_TEST struct iommu_test_cmd test; #endif @@ -387,6 +389,10 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { __reserved), IOCTL_OP(IOMMU_VIOMMU_ALLOC, iommufd_viommu_alloc_ioctl, struct iommu_viommu_alloc, out_viommu_id), + IOCTL_OP(IOMMU_VIOMMU_SET_VDEV_ID, iommufd_viommu_set_vdev_id, + struct iommu_viommu_set_vdev_id, vdev_id), + IOCTL_OP(IOMMU_VIOMMU_UNSET_VDEV_ID, iommufd_viommu_unset_vdev_id, + struct iommu_viommu_unset_vdev_id, vdev_id), #ifdef CONFIG_IOMMUFD_TEST IOCTL_OP(IOMMU_TEST_CMD, iommufd_test, struct iommu_test_cmd, last), #endif diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index 200653a4bf57..8ffcd72b16b8 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -8,6 +8,15 @@ void iommufd_viommu_destroy(struct iommufd_object *obj) { struct iommufd_viommu *viommu = container_of(obj, struct iommufd_viommu, obj); + struct iommufd_vdev_id *vdev_id; + unsigned long index; + + xa_for_each(&viommu->vdev_ids, index, vdev_id) { + /* Unlocked since there should be no race in a destroy() */ + vdev_id->idev->vdev_id = NULL; + kfree(vdev_id); + } + xa_destroy(&viommu->vdev_ids);
refcount_dec(&viommu->hwpt->common.obj.users); } @@ -53,6 +62,9 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) viommu->ictx = ucmd->ictx; viommu->hwpt = hwpt_paging;
+ xa_init(&viommu->vdev_ids); + init_rwsem(&viommu->vdev_ids_rwsem); + refcount_inc(&viommu->hwpt->common.obj.users);
cmd->out_viommu_id = viommu->obj.id; @@ -70,3 +82,112 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd) iommufd_put_object(ucmd->ictx, &idev->obj); return rc; } + +int iommufd_viommu_set_vdev_id(struct iommufd_ucmd *ucmd) +{ + struct iommu_viommu_set_vdev_id *cmd = ucmd->cmd; + struct iommufd_vdev_id *vdev_id, *curr; + struct iommufd_viommu *viommu; + struct iommufd_device *idev; + int rc = 0; + + if (cmd->vdev_id > ULONG_MAX) + return -EINVAL; + + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id); + if (IS_ERR(viommu)) + return PTR_ERR(viommu); + + idev = iommufd_get_device(ucmd, cmd->dev_id); + if (IS_ERR(idev)) { + rc = PTR_ERR(idev); + goto out_put_viommu; + } + + down_write(&viommu->vdev_ids_rwsem); + mutex_lock(&idev->igroup->lock); + if (idev->vdev_id) { + rc = -EEXIST; + goto out_unlock_igroup; + } + + vdev_id = kzalloc(sizeof(*vdev_id), GFP_KERNEL); + if (!vdev_id) { + rc = -ENOMEM; + goto out_unlock_igroup; + } + + vdev_id->idev = idev; + vdev_id->viommu = viommu; + vdev_id->id = cmd->vdev_id; + + curr = xa_cmpxchg(&viommu->vdev_ids, cmd->vdev_id, NULL, vdev_id, + GFP_KERNEL); + if (curr) { + rc = xa_err(curr) ? : -EBUSY; + goto out_free; + } + + idev->vdev_id = vdev_id; + goto out_unlock_igroup; + +out_free: + kfree(vdev_id); +out_unlock_igroup: + mutex_unlock(&idev->igroup->lock); + up_write(&viommu->vdev_ids_rwsem); + iommufd_put_object(ucmd->ictx, &idev->obj); +out_put_viommu: + iommufd_put_object(ucmd->ictx, &viommu->obj); + return rc; +} + +int iommufd_viommu_unset_vdev_id(struct iommufd_ucmd *ucmd) +{ + struct iommu_viommu_unset_vdev_id *cmd = ucmd->cmd; + struct iommufd_viommu *viommu; + struct iommufd_vdev_id *old; + struct iommufd_device *idev; + int rc = 0; + + if (cmd->vdev_id > ULONG_MAX) + return -EINVAL; + + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id); + if (IS_ERR(viommu)) + return PTR_ERR(viommu); + + idev = iommufd_get_device(ucmd, cmd->dev_id); + if (IS_ERR(idev)) { + rc = PTR_ERR(idev); + goto out_put_viommu; + } + + down_write(&viommu->vdev_ids_rwsem); + mutex_lock(&idev->igroup->lock); + if (!idev->vdev_id) { + rc = -ENOENT; + goto out_unlock_igroup; + } + if (idev->vdev_id->id != cmd->vdev_id) { + rc = -EINVAL; + goto out_unlock_igroup; + } + + old = xa_cmpxchg(&viommu->vdev_ids, idev->vdev_id->id, + idev->vdev_id, NULL, GFP_KERNEL); + if (xa_is_err(old)) { + rc = xa_err(old); + goto out_unlock_igroup; + } + kfree(old); + idev->vdev_id = NULL; + +out_unlock_igroup: + mutex_unlock(&idev->igroup->lock); + up_write(&viommu->vdev_ids_rwsem); + iommufd_put_object(ucmd->ictx, &idev->obj); +out_put_viommu: + iommufd_put_object(ucmd->ictx, &viommu->obj); + return rc; +} diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 51ce6a019c34..1816e89c922d 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -52,6 +52,8 @@ enum { IOMMUFD_CMD_HWPT_INVALIDATE = 0x8d, IOMMUFD_CMD_FAULT_QUEUE_ALLOC = 0x8e, IOMMUFD_CMD_VIOMMU_ALLOC = 0x8f, + IOMMUFD_CMD_VIOMMU_SET_VDEV_ID = 0x90, + IOMMUFD_CMD_VIOMMU_UNSET_VDEV_ID = 0x91, };
/** @@ -882,4 +884,42 @@ struct iommu_viommu_alloc { __u32 out_viommu_id; }; #define IOMMU_VIOMMU_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_ALLOC) + +/** + * struct iommu_viommu_set_vdev_id - ioctl(IOMMU_VIOMMU_SET_VDEV_ID) + * @size: sizeof(struct iommu_viommu_set_vdev_id) + * @viommu_id: viommu ID to associate with the device to store its virtual ID + * @dev_id: device ID to set its virtual ID + * @__reserved: Must be 0 + * @vdev_id: Virtual device ID + * + * Set a viommu-specific virtual ID of a device + */ +struct iommu_viommu_set_vdev_id { + __u32 size; + __u32 viommu_id; + __u32 dev_id; + __u32 __reserved; + __aligned_u64 vdev_id; +}; +#define IOMMU_VIOMMU_SET_VDEV_ID _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_SET_VDEV_ID) + +/** + * struct iommu_viommu_unset_vdev_id - ioctl(IOMMU_VIOMMU_UNSET_VDEV_ID) + * @size: sizeof(struct iommu_viommu_unset_vdev_id) + * @viommu_id: viommu ID associated with the device to delete its virtual ID + * @dev_id: device ID to unset its virtual ID + * @__reserved: Must be 0 + * @vdev_id: Virtual device ID (for verification) + * + * Unset a viommu-specific virtual ID of a device + */ +struct iommu_viommu_unset_vdev_id { + __u32 size; + __u32 viommu_id; + __u32 dev_id; + __u32 __reserved; + __aligned_u64 vdev_id; +}; +#define IOMMU_VIOMMU_UNSET_VDEV_ID _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_UNSET_VDEV_ID) #endif