[PATCH 04/10] vfio/fsl-mc: Use vfio_init/register/unregister_group_dev

From: Jason Gunthorpe <jgg@nvidia.com>
To: Alex Williamson <alex.williamson@redhat.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Diana Craciun <diana.craciun@oss.nxp.com>,
	kvm@vger.kernel.org
Cc: "Raj, Ashok" <ashok.raj@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Daniel Vetter <daniel@ffwll.ch>, Christoph Hellwig <hch@lst.de>,
	Leon Romanovsky <leonro@nvidia.com>,
	Max Gurtovoy <mgurtovoy@nvidia.com>,
	Tarun Gupta <targupta@nvidia.com>
Subject: [PATCH 04/10] vfio/fsl-mc: Use vfio_init/register/unregister_group_dev
Date: Tue,  9 Mar 2021 17:38:46 -0400	[thread overview]
Message-ID: <4-v1-7355d38b9344+17481-vfio1_jgg@nvidia.com> (raw)
In-Reply-To: <0-v1-7355d38b9344+17481-vfio1_jgg@nvidia.com>

fsl-mc already allocates a struct vfio_fsl_mc_device with exactly the same
lifetime as vfio_device, switch to the new API and embed vfio_device in
vfio_fsl_mc_device. While here remove the devm usage for the vdev, this
code is clean and doesn't need devm.

Add a note the probe ordering is racy.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c         | 30 +++++++++++++----------
 drivers/vfio/fsl-mc/vfio_fsl_mc_private.h |  1 +
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index f27e25112c4037..ddee6ed20c4523 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -600,20 +600,28 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 		return -EINVAL;
 	}
 
-	vdev = devm_kzalloc(dev, sizeof(*vdev), GFP_KERNEL);
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
 	if (!vdev) {
 		ret = -ENOMEM;
 		goto out_group_put;
 	}
 
+	vfio_init_group_dev(&vdev->vdev, dev, &vfio_fsl_mc_ops, vdev);
+	mutex_init(&vdev->igate);
 	vdev->mc_dev = mc_dev;
 
-	ret = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev);
+	ret = vfio_register_group_dev(&vdev->vdev);
 	if (ret) {
 		dev_err(dev, "VFIO_FSL_MC: Failed to add to vfio group\n");
-		goto out_group_put;
+		goto out_kfree;
 	}
+	dev_set_drvdata(dev, vdev);
 
+	/*
+	 * FIXME: vfio_register_group_dev() allows VFIO_GROUP_GET_DEVICE_FD to
+	 * immediately return the device to userspace, but we haven't finished
+	 * setting it up yet.
+	 */
 	ret = vfio_fsl_mc_reflck_attach(vdev);
 	if (ret)
 		goto out_group_dev;
@@ -621,15 +629,14 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 	ret = vfio_fsl_mc_init_device(vdev);
 	if (ret)
 		goto out_reflck;
-
-	mutex_init(&vdev->igate);
-
 	return 0;
 
 out_reflck:
 	vfio_fsl_mc_reflck_put(vdev->reflck);
 out_group_dev:
-	vfio_del_group_dev(dev);
+	vfio_unregister_group_dev(&vdev->vdev);
+out_kfree:
+	kfree(vdev);
 out_group_put:
 	vfio_iommu_group_put(group, dev);
 	return ret;
@@ -637,13 +644,10 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 
 static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
 {
-	struct vfio_fsl_mc_device *vdev;
 	struct device *dev = &mc_dev->dev;
+	struct vfio_fsl_mc_device *vdev = dev_get_drvdata(dev);
 
-	vdev = vfio_del_group_dev(dev);
-	if (!vdev)
-		return -EINVAL;
-
+	vfio_unregister_group_dev(&vdev->vdev);
 	mutex_destroy(&vdev->igate);
 
 	vfio_fsl_mc_reflck_put(vdev->reflck);
@@ -656,8 +660,8 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
 	if (vdev->nb.notifier_call)
 		bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
 
+	kfree(vdev);
 	vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
-
 	return 0;
 }
 
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
index a97ee691ed47ec..89700e00e77d10 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_private.h
@@ -36,6 +36,7 @@ struct vfio_fsl_mc_region {
 };
 
 struct vfio_fsl_mc_device {
+	struct vfio_device		vdev;
 	struct fsl_mc_device		*mc_dev;
 	struct notifier_block        nb;
 	int				refcnt;
-- 
2.30.1

