[Intel-gfx] [PATCH v12 11/24] vfio-iommufd: Split bind/attach into two steps

Yi Liu
2023-06-02T12:17:13Z

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

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/group.c | 17 +++++++++++++----
drivers/vfio/iommufd.c | 35 +++++++++++++++++------------------
drivers/vfio/vfio.h | 9 +++++++++
3 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index b8b77daf7aa6..41a09a2df690 100644
--- 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 21237f5d0ffc..b30f9aaae6e7 100644
--- 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 76181d208bc1..bb7a375315bb 100644
--- 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)
--
2.34.1