[Intel-gfx] [PATCH v6 19/24] vfio-iommufd: Add detach_ioas support for emulated VFIO devices

[Yi Liu]

this prepares for adding DETACH ioctl for emulated VFIO devices.

Signed-off-by: Yi Liu <yi.l....@intel.com>
Reviewed-by: Kevin Tian <kevin.t...@intel.com>
Tested-by: Terrence Xu <terrence...@intel.com>
Tested-by: Nicolin Chen <nicol...@nvidia.com>
Tested-by: Matthew Rosato <mjros...@linux.ibm.com>
---
 drivers/gpu/drm/i915/gvt/kvmgt.c  |  1 +
 drivers/s390/cio/vfio_ccw_ops.c   |  1 +
 drivers/s390/crypto/vfio_ap_ops.c |  1 +
 drivers/vfio/iommufd.c            | 14 +++++++++++++-
 include/linux/vfio.h              |  3 +++
 5 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index de675d799c7d..9cd9e9da60dd 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1474,6 +1474,7 @@ static const struct vfio_device_ops intel_vgpu_dev_ops = {
        .bind_iommufd   = vfio_iommufd_emulated_bind,
        .unbind_iommufd = vfio_iommufd_emulated_unbind,
        .attach_ioas    = vfio_iommufd_emulated_attach_ioas,
+       .detach_ioas    = vfio_iommufd_emulated_detach_ioas,
 };
 
 static int intel_vgpu_probe(struct mdev_device *mdev)
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 5b53b94f13c7..cba4971618ff 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -632,6 +632,7 @@ static const struct vfio_device_ops vfio_ccw_dev_ops = {
        .bind_iommufd = vfio_iommufd_emulated_bind,
        .unbind_iommufd = vfio_iommufd_emulated_unbind,
        .attach_ioas = vfio_iommufd_emulated_attach_ioas,
+       .detach_ioas = vfio_iommufd_emulated_detach_ioas,
 };
 
 struct mdev_driver vfio_ccw_mdev_driver = {
diff --git a/drivers/s390/crypto/vfio_ap_ops.c 
b/drivers/s390/crypto/vfio_ap_ops.c
index 72e10abb103a..9902e62e7a17 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1844,6 +1844,7 @@ static const struct vfio_device_ops 
vfio_ap_matrix_dev_ops = {
        .bind_iommufd = vfio_iommufd_emulated_bind,
        .unbind_iommufd = vfio_iommufd_emulated_unbind,
        .attach_ioas = vfio_iommufd_emulated_attach_ioas,
+       .detach_ioas = vfio_iommufd_emulated_detach_ioas,
 };
 
 static struct mdev_driver vfio_ap_matrix_driver = {
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index c06494e322f9..8a9457d0a33c 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -218,8 +218,20 @@ int vfio_iommufd_emulated_attach_ioas(struct vfio_device 
*vdev, u32 *pt_id)
 {
        lockdep_assert_held(&vdev->dev_set->lock);
 
-       if (!vdev->iommufd_access)
+       if (WARN_ON(!vdev->iommufd_access))
                return -ENOENT;
        return iommufd_access_set_ioas(vdev->iommufd_access, *pt_id);
 }
 EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);
+
+void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev)
+{
+       lockdep_assert_held(&vdev->dev_set->lock);
+
+       if (WARN_ON(!vdev->iommufd_access))
+               return;
+
+       iommufd_access_destroy(vdev->iommufd_access);
+       vdev->iommufd_access = NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_detach_ioas);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 8982e48a30e2..5a1c5b6f1a63 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -126,6 +126,7 @@ int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
                               struct iommufd_ctx *ictx, u32 *out_device_id);
 void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
 int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
+void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev);
 #else
 #define vfio_iommufd_physical_bind                                      \
        ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
@@ -145,6 +146,8 @@ int vfio_iommufd_emulated_attach_ioas(struct vfio_device 
*vdev, u32 *pt_id);
        ((void (*)(struct vfio_device *vdev)) NULL)
 #define vfio_iommufd_emulated_attach_ioas \
        ((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
+#define vfio_iommufd_emulated_detach_ioas \
+       ((void (*)(struct vfio_device *vdev)) NULL)
 #endif
 
 /**
-- 
2.34.1