Rather than an errno, return a pointer to the opaque vfio_device to allow the bus driver to call into vfio-core without additional lookups and references. Note that bus drivers are still required to use vfio_del_group_dev() to teardown the vfio_device. Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 6 ++++-- drivers/vfio/mdev/vfio_mdev.c | 5 ++++- drivers/vfio/pci/vfio_pci.c | 7 +++++-- drivers/vfio/platform/vfio_platform_common.c | 7 +++++-- drivers/vfio/vfio.c | 23 ++++++++++------------- include/linux/vfio.h | 6 +++--- 6 files changed, 31 insertions(+), 23 deletions(-) diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index f27e25112c40..a4c2d0b9cd51 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -592,6 +592,7 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev) struct iommu_group *group; struct vfio_fsl_mc_device *vdev; struct device *dev = &mc_dev->dev; + struct vfio_device *device; int ret; group = vfio_iommu_group_get(dev); @@ -608,8 +609,9 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev) vdev->mc_dev = mc_dev; - ret = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev); - if (ret) { + device = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev); + if (IS_ERR(device)) { + ret = PTR_ERR(device); dev_err(dev, "VFIO_FSL_MC: Failed to add to vfio group\n"); goto out_group_put; } diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c index b52eea128549..32901b265864 100644 --- a/drivers/vfio/mdev/vfio_mdev.c +++ b/drivers/vfio/mdev/vfio_mdev.c @@ -124,8 +124,11 @@ static const struct vfio_device_ops vfio_mdev_dev_ops = { static int vfio_mdev_probe(struct device *dev) { struct mdev_device *mdev = to_mdev_device(dev); + struct vfio_device *device; - return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev); + device = vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev); + + return IS_ERR(device) ? PTR_ERR(device) : 0; } static void vfio_mdev_remove(struct device *dev) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 65e7e6b44578..f0a1d05f0137 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1926,6 +1926,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct vfio_pci_device *vdev; struct iommu_group *group; + struct vfio_device *device; int ret; if (vfio_pci_is_denylisted(pdev)) @@ -1968,9 +1969,11 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) INIT_LIST_HEAD(&vdev->vma_list); init_rwsem(&vdev->memory_lock); - ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); - if (ret) + device = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev); + if (IS_ERR(device)) { + ret = PTR_ERR(device); goto out_free; + } ret = vfio_pci_reflck_attach(vdev); if (ret) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index fb4b385191f2..ff41fe0b758e 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -657,6 +657,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, struct device *dev) { struct iommu_group *group; + struct vfio_device *device; int ret; if (!vdev) @@ -685,9 +686,11 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, goto put_reset; } - ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); - if (ret) + device = vfio_add_group_dev(dev, &vfio_platform_ops, vdev); + if (IS_ERR(device)) { + ret = PTR_ERR(device); goto put_iommu; + } mutex_init(&vdev->igate); diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 464caef97aff..067cd843961c 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -848,8 +848,9 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, /** * VFIO driver API */ -int vfio_add_group_dev(struct device *dev, - const struct vfio_device_ops *ops, void *device_data) +struct vfio_device *vfio_add_group_dev(struct device *dev, + const struct vfio_device_ops *ops, + void *device_data) { struct iommu_group *iommu_group; struct vfio_group *group; @@ -857,14 +858,14 @@ int vfio_add_group_dev(struct device *dev, iommu_group = iommu_group_get(dev); if (!iommu_group) - return -EINVAL; + return ERR_PTR(-EINVAL); group = vfio_group_get_from_iommu(iommu_group); if (!group) { group = vfio_create_group(iommu_group); if (IS_ERR(group)) { iommu_group_put(iommu_group); - return PTR_ERR(group); + return (struct vfio_device *)group; } } else { /* @@ -880,23 +881,19 @@ int vfio_add_group_dev(struct device *dev, iommu_group_id(iommu_group)); vfio_device_put(device); vfio_group_put(group); - return -EBUSY; + return ERR_PTR(-EBUSY); } device = vfio_group_create_device(group, dev, ops, device_data); - if (IS_ERR(device)) { - vfio_group_put(group); - return PTR_ERR(device); - } /* - * Drop all but the vfio_device reference. The vfio_device holds - * a reference to the vfio_group, which holds a reference to the - * iommu_group. + * Drop all but the vfio_device reference. The vfio_device, if + * !IS_ERR() holds a reference to the vfio_group, which holds a + * reference to the iommu_group. */ vfio_group_put(group); - return 0; + return device; } EXPORT_SYMBOL_GPL(vfio_add_group_dev); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index b7e18bde5aa8..b784463000d4 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -48,9 +48,9 @@ struct vfio_device_ops { extern struct iommu_group *vfio_iommu_group_get(struct device *dev); extern void vfio_iommu_group_put(struct iommu_group *group, struct device *dev); -extern int vfio_add_group_dev(struct device *dev, - const struct vfio_device_ops *ops, - void *device_data); +extern struct vfio_device *vfio_add_group_dev(struct device *dev, + const struct vfio_device_ops *ops, + void *device_data); extern void *vfio_del_group_dev(struct device *dev); extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);