[PATCH v10 11/22] vfio-iommufd: Split bind/attach into two steps

Yi Liu
2023-04-26T15:04:53Z

to align 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>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/group.c | 18 ++++++++++++++----
drivers/vfio/iommufd.c | 37 ++++++++++++++++++-------------------
drivers/vfio/vfio.h | 9 +++++++++
3 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 7955f7513eaf..fe84d09e4c61 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -200,9 +200,14 @@ static int vfio_device_group_open(struct vfio_device_file *df)
}

ret = vfio_device_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;
}

/*
@@ -211,12 +216,17 @@ static int vfio_device_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_device_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 b0d0024b2980..cee81f5910d4 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -30,36 +30,35 @@ int vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,

int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
{
- u32 ioas_id;
u32 device_id;
- int ret;

lockdep_assert_held(&vdev->dev_set->lock);

if (vdev->noiommu)
return vfio_iommufd_emulated_bind(vdev, ictx, &device_id);

- ret = vdev->ops->bind_iommufd(vdev, ictx, &device_id);
- if (ret)
- return ret;
+ /* 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);
+
+ /* compat noiommu does not need to do ioas attach */
+ if (vdev->noiommu)
+ 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 c1a4f3920cc5..b84fbcdd00aa 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -239,6 +239,8 @@ int vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,
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 int
vfio_iommufd_compat_probe_noiommu(struct vfio_device *device,
@@ -256,6 +258,13 @@ 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