This adds ioctl for userspace to attach device cdev fd to and detach from IOAS/hw_pagetable managed by iommufd. VFIO_DEVICE_ATTACH_IOMMUFD_PT: attach vfio device to IOAS, hw_pagetable managed by iommufd. Attach can be undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close. VFIO_DEVICE_DETACH_IOMMUFD_PT: detach vfio device from the current attached IOAS or hw_pagetable managed by iommufd. Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx> --- drivers/vfio/device_cdev.c | 76 ++++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 16 ++++++++ drivers/vfio/vfio_main.c | 8 ++++ include/uapi/linux/vfio.h | 52 ++++++++++++++++++++++++++ 4 files changed, 152 insertions(+) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index be62f0a5687e..6870e42944ba 100644 --- a/drivers/vfio/device_cdev.c +++ b/drivers/vfio/device_cdev.c @@ -182,6 +182,82 @@ long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, return ret; } +int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_attach_iommufd_pt attach; + unsigned long minsz; + int ret; + + minsz = offsetofend(struct vfio_device_attach_iommufd_pt, pt_id); + + if (copy_from_user(&attach, (void __user *)arg, minsz)) + return -EFAULT; + + if (attach.argsz < minsz || attach.flags || + attach.pt_id == IOMMUFD_INVALID_ID) + return -EINVAL; + + if (!device->ops->bind_iommufd) + return -ENODEV; + + mutex_lock(&device->dev_set->lock); + if (df->noiommu) { + ret = -EINVAL; + goto out_unlock; + } + + ret = device->ops->attach_ioas(device, &attach.pt_id); + if (ret) + goto out_unlock; + + ret = copy_to_user((void __user *)arg + + offsetofend(struct vfio_device_attach_iommufd_pt, flags), + &attach.pt_id, + sizeof(attach.pt_id)) ? -EFAULT : 0; + if (ret) + goto out_detach; + mutex_unlock(&device->dev_set->lock); + + return 0; + +out_detach: + device->ops->detach_ioas(device); +out_unlock: + mutex_unlock(&device->dev_set->lock); + return ret; +} + +int vfio_ioctl_device_detach(struct vfio_device_file *df, + void __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_detach_iommufd_pt detach; + unsigned long minsz; + + minsz = offsetofend(struct vfio_device_detach_iommufd_pt, flags); + + if (copy_from_user(&detach, (void __user *)arg, minsz)) + return -EFAULT; + + if (detach.argsz < minsz || detach.flags) + return -EINVAL; + + if (!device->ops->bind_iommufd) + return -ENODEV; + + mutex_lock(&device->dev_set->lock); + if (df->noiommu) { + mutex_unlock(&device->dev_set->lock); + return -EINVAL; + } + device->ops->detach_ioas(device); + mutex_unlock(&device->dev_set->lock); + + return 0; +} + static char *vfio_device_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev)); diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index 40b54b0ce993..1cba2baafb08 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -264,6 +264,10 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep); void vfio_device_cdev_close(struct vfio_device_file *df); long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, unsigned long arg); +int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg); +int vfio_ioctl_device_detach(struct vfio_device_file *df, + void __user *arg); int vfio_cdev_init(struct class *device_class); void vfio_cdev_cleanup(void); #else @@ -297,6 +301,18 @@ static inline long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, return -EOPNOTSUPP; } +static inline int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg) +{ + return -EOPNOTSUPP; +} + +static inline int vfio_ioctl_device_detach(struct vfio_device_file *df, + void __user *arg) +{ + return -EOPNOTSUPP; +} + static inline int vfio_cdev_init(struct class *device_class) { return 0; diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 5e9a4fd800be..af03ea97844e 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -1157,6 +1157,14 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, ret = vfio_ioctl_device_feature(device, (void __user *)arg); break; + case VFIO_DEVICE_ATTACH_IOMMUFD_PT: + ret = vfio_ioctl_device_attach(df, (void __user *)arg); + break; + + case VFIO_DEVICE_DETACH_IOMMUFD_PT: + ret = vfio_ioctl_device_detach(df, (void __user *)arg); + break; + default: if (unlikely(!device->ops->ioctl)) ret = -EINVAL; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 1fe69173e739..026af52cf22e 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -228,6 +228,58 @@ struct vfio_device_bind_iommufd { #define VFIO_DEVICE_BIND_IOMMUFD _IO(VFIO_TYPE, VFIO_BASE + 19) +/* + * VFIO_DEVICE_ATTACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 20, + * struct vfio_device_attach_iommufd_pt) + * + * Attach a vfio device to an iommufd address space specified by IOAS + * id or hw_pagetable (hwpt) id. + * + * Available only after a device has been bound to iommufd via + * VFIO_DEVICE_BIND_IOMMUFD + * + * Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close. + * + * @argsz: user filled size of this data. + * @flags: must be 0. + * @pt_id: Input the target id which can represent an ioas or a hwpt + * allocated via iommufd subsystem. + * Output the attached hwpt id which could be the specified + * hwpt itself or a hwpt automatically created for the + * specified ioas by kernel during the attachment. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_attach_iommufd_pt { + __u32 argsz; + __u32 flags; + __u32 pt_id; +}; + +#define VFIO_DEVICE_ATTACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 20) + +/* + * VFIO_DEVICE_DETACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 21, + * struct vfio_device_detach_iommufd_pt) + * + * Detach a vfio device from the iommufd address space it has been + * attached to. After it, device should be in a blocking DMA state. + * + * Available only after a device has been bound to iommufd via + * VFIO_DEVICE_BIND_IOMMUFD + * + * @argsz: user filled size of this data. + * @flags: must be 0. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_detach_iommufd_pt { + __u32 argsz; + __u32 flags; +}; + +#define VFIO_DEVICE_DETACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 21) + /** * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7, * struct vfio_device_info) -- 2.34.1