For the device fd opened from cdev, userspace needs to bind it to an iommufd and attach it to IOAS managed by iommufd. With such operations, userspace can set up a secure DMA context and hence access device.
This changes the existing vfio_iommufd_bind() to accept a pt_id pointer as an optional input, and also an dev_id pointer to selectively return the dev_id to prepare for adding bind_iommufd ioctl, which does the bind first and then attach IOAS. Signed-off-by: Yi Liu <yi.l....@intel.com> Reviewed-by: Kevin Tian <kevin.t...@intel.com> --- drivers/vfio/group.c | 17 ++++++++++++++--- drivers/vfio/iommufd.c | 21 +++++++++------------ drivers/vfio/vfio.h | 9 ++++++--- drivers/vfio/vfio_main.c | 10 ++++++---- 4 files changed, 35 insertions(+), 22 deletions(-) diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index 2abf55c69281..9f3f6f0e4942 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -169,6 +169,7 @@ static void vfio_device_group_get_kvm_safe(struct vfio_device *device) static int vfio_device_group_open(struct vfio_device_file *df) { struct vfio_device *device = df->device; + u32 ioas_id; int ret; mutex_lock(&device->group->group_lock); @@ -177,6 +178,13 @@ static int vfio_device_group_open(struct vfio_device_file *df) goto out_unlock; } + if (device->group->iommufd) { + ret = iommufd_vfio_compat_ioas_id(device->group->iommufd, + &ioas_id); + if (ret) + goto out_unlock; + } + mutex_lock(&device->dev_set->lock); /* @@ -188,9 +196,12 @@ static int vfio_device_group_open(struct vfio_device_file *df) if (device->open_count == 0) vfio_device_group_get_kvm_safe(device); - df->iommufd = device->group->iommufd; - - ret = vfio_device_open(df); + if (device->group->iommufd) { + df->iommufd = device->group->iommufd; + ret = vfio_device_open(df, NULL, &ioas_id); + } else { + ret = vfio_device_open(df, NULL, NULL); + } if (ret) df->iommufd = NULL; diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c index 4f82a6fa7c6c..beef6ca21107 100644 --- a/drivers/vfio/iommufd.c +++ b/drivers/vfio/iommufd.c @@ -10,9 +10,9 @@ MODULE_IMPORT_NS(IOMMUFD); MODULE_IMPORT_NS(IOMMUFD_VFIO); -int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx) +int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx, + u32 *dev_id, u32 *pt_id) { - u32 ioas_id; u32 device_id; int ret; @@ -29,17 +29,14 @@ int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx) if (ret) return ret; - ret = iommufd_vfio_compat_ioas_id(ictx, &ioas_id); - if (ret) - goto err_unbind; - ret = vdev->ops->attach_ioas(vdev, &ioas_id); - if (ret) - goto err_unbind; + if (pt_id) { + ret = vdev->ops->attach_ioas(vdev, pt_id); + if (ret) + goto err_unbind; + } - /* - * The legacy path has no way to return the device id or the selected - * pt_id - */ + if (dev_id) + *dev_id = device_id; return 0; err_unbind: diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index d56cdb114024..6f063e31d08a 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -26,7 +26,8 @@ struct vfio_device_file { void vfio_device_put_registration(struct vfio_device *device); bool vfio_device_try_get_registration(struct vfio_device *device); -int vfio_device_open(struct vfio_device_file *df); +int vfio_device_open(struct vfio_device_file *df, + u32 *dev_id, u32 *pt_id); void vfio_device_close(struct vfio_device_file *df); struct vfio_device_file * vfio_allocate_device_file(struct vfio_device *device); @@ -224,11 +225,13 @@ static inline void vfio_container_cleanup(void) #endif #if IS_ENABLED(CONFIG_IOMMUFD) -int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx); +int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx, + u32 *dev_id, u32 *pt_id); void vfio_iommufd_unbind(struct vfio_device *device); #else static inline int vfio_iommufd_bind(struct vfio_device *device, - struct iommufd_ctx *ictx) + struct iommufd_ctx *ictx, + u32 *dev_id, u32 *pt_id) { return -EOPNOTSUPP; } diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 2267057240bd..b40c2d95f693 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -411,7 +411,8 @@ vfio_allocate_device_file(struct vfio_device *device) return df; } -static int vfio_device_first_open(struct vfio_device_file *df) +static int vfio_device_first_open(struct vfio_device_file *df, + u32 *dev_id, u32 *pt_id) { struct vfio_device *device = df->device; struct iommufd_ctx *iommufd = df->iommufd; @@ -423,7 +424,7 @@ static int vfio_device_first_open(struct vfio_device_file *df) return -ENODEV; if (iommufd) - ret = vfio_iommufd_bind(device, iommufd); + ret = vfio_iommufd_bind(device, iommufd, dev_id, pt_id); else ret = vfio_device_group_use_iommu(device); if (ret) @@ -462,7 +463,8 @@ static void vfio_device_last_close(struct vfio_device_file *df) module_put(device->dev->driver->owner); } -int vfio_device_open(struct vfio_device_file *df) +int vfio_device_open(struct vfio_device_file *df, + u32 *dev_id, u32 *pt_id) { struct vfio_device *device = df->device; int ret = 0; @@ -471,7 +473,7 @@ int vfio_device_open(struct vfio_device_file *df) device->open_count++; if (device->open_count == 1) { - ret = vfio_device_first_open(df); + ret = vfio_device_first_open(df, dev_id, pt_id); if (ret) device->open_count--; } -- 2.34.1