vfio-iommufd: Split bind/attach into two steps

This aligns the bind/attach logic with the coming vfio device cdev support.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-12-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index b8b77da..41a09a2 100644 (file)
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -207,9 +207,13 @@ static int vfio_df_group_open(struct vfio_device_file *df)
        }
 
        ret = vfio_df_open(df);
-       if (ret) {
-               df->iommufd = NULL;
+       if (ret)
                goto out_put_kvm;
+
+       if (df->iommufd && device->open_count == 1) {
+               ret = vfio_iommufd_compat_attach_ioas(device, df->iommufd);
+               if (ret)
+                       goto out_close_device;
        }
 
        /*
@@ -218,12 +222,17 @@ static int vfio_df_group_open(struct vfio_device_file *df)
         */
        smp_store_release(&df->access_granted, true);
 
+       mutex_unlock(&device->dev_set->lock);
+       mutex_unlock(&device->group->group_lock);
+       return 0;
+
+out_close_device:
+       vfio_df_close(df);
 out_put_kvm:
+       df->iommufd = NULL;
        if (device->open_count == 0)
                vfio_device_put_kvm(device);
-
        mutex_unlock(&device->dev_set->lock);
-
 out_unlock:
        mutex_unlock(&device->group->group_lock);
        return ret;

diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 36f838d..91fdae6 100644 (file)
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -20,33 +20,32 @@ bool vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
 
 int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
 {
-       u32 ioas_id;
        u32 device_id;
+
+       lockdep_assert_held(&vdev->dev_set->lock);
+
+       /* The legacy path has no way to return the device id */
+       return vdev->ops->bind_iommufd(vdev, ictx, &device_id);
+}
+
+int vfio_iommufd_compat_attach_ioas(struct vfio_device *vdev,
+                                   struct iommufd_ctx *ictx)
+{
+       u32 ioas_id;
        int ret;
 
        lockdep_assert_held(&vdev->dev_set->lock);
 
-       ret = vdev->ops->bind_iommufd(vdev, ictx, &device_id);
-       if (ret)
-               return ret;
+       /* compat noiommu does not need to do ioas attach */
+       if (vfio_device_is_noiommu(vdev))
+               return 0;
 
        ret = iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
        if (ret)
-               goto err_unbind;
-       ret = vdev->ops->attach_ioas(vdev, &ioas_id);
-       if (ret)
-               goto err_unbind;
-
-       /*
-        * The legacy path has no way to return the device id or the selected
-        * pt_id
-        */
-       return 0;
+               return ret;
 
-err_unbind:
-       if (vdev->ops->unbind_iommufd)
-               vdev->ops->unbind_iommufd(vdev);
-       return ret;
+       /* The legacy path has no way to return the selected pt_id */
+       return vdev->ops->attach_ioas(vdev, &ioas_id);
 }
 
 void vfio_iommufd_unbind(struct vfio_device *vdev)

diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 300cab0..0475537 100644 (file)
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -238,6 +238,8 @@ bool vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
                                         struct iommufd_ctx *ictx);
 int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
 void vfio_iommufd_unbind(struct vfio_device *device);
+int vfio_iommufd_compat_attach_ioas(struct vfio_device *device,
+                                   struct iommufd_ctx *ictx);
 #else
 static inline bool
 vfio_iommufd_device_has_compat_ioas(struct vfio_device *vdev,
@@ -255,6 +257,13 @@ static inline int vfio_iommufd_bind(struct vfio_device *device,
 static inline void vfio_iommufd_unbind(struct vfio_device *device)
 {
 }
+
+static inline int
+vfio_iommufd_compat_attach_ioas(struct vfio_device *device,
+                               struct iommufd_ctx *ictx)
+{
+       return -EOPNOTSUPP;
+}
 #endif
 
 #if IS_ENABLED(CONFIG_VFIO_VIRQFD)