Split the actual noiommu group creation from vfio_iommu_group_get into a
new helper, and open code the rest of vfio_iommu_group_get in its only
caller. This creates an entirely separate and clear code path for the
noiommu group creation.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/vfio/vfio.c | 101 ++++++++++++++++++++++----------------------
1 file changed, 51 insertions(+), 50 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 852fe22125520d..109d3ef57665b0 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -169,50 +169,6 @@ static void vfio_release_device_set(struct vfio_device *device)
xa_unlock(&vfio_device_set_xa);
}
-static struct iommu_group *vfio_iommu_group_get(struct device *dev)
-{
- struct iommu_group *group;
- int __maybe_unused ret;
-
- group = iommu_group_get(dev);
-
-#ifdef CONFIG_VFIO_NOIOMMU
- /*
- * With noiommu enabled, an IOMMU group will be created for a device
- * that doesn't already have one and doesn't have an iommu_ops on their
- * bus. We set iommudata simply to be able to identify these groups
- * as special use and for reclamation later.
- */
- if (group || !noiommu || iommu_present(dev->bus))
- return group;
-
- group = iommu_group_alloc();
- if (IS_ERR(group))
- return NULL;
-
- iommu_group_set_name(group, "vfio-noiommu");
- iommu_group_set_iommudata(group, &noiommu, NULL);
- ret = iommu_group_add_device(group, dev);
- if (ret) {
- iommu_group_put(group);
- return NULL;
- }
-
- /*
- * Where to taint? At this point we've added an IOMMU group for a
- * device that is not backed by iommu_ops, therefore any iommu_
- * callback using iommu_ops can legitimately Oops. So, while we may
- * be about to give a DMA capable device to a user without IOMMU
- * protection, which is clearly taint-worthy, let's go ahead and do
- * it here.
- */
- add_taint(TAINT_USER, LOCKDEP_STILL_OK);
- dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
-#endif
-
- return group;
-}
-
#ifdef CONFIG_VFIO_NOIOMMU
static void *vfio_noiommu_open(unsigned long arg)
{
@@ -823,12 +779,61 @@ void vfio_uninit_group_dev(struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
-struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
+#ifdef CONFIG_VFIO_NOIOMMU
+static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
+ int ret;
+
+ iommu_group = iommu_group_alloc();
+ if (IS_ERR(iommu_group))
+ return ERR_CAST(iommu_group);
- iommu_group = vfio_iommu_group_get(dev);
+ iommu_group_set_name(iommu_group, "vfio-noiommu");
+ iommu_group_set_iommudata(iommu_group, &noiommu, NULL);
+ ret = iommu_group_add_device(iommu_group, dev);
+ if (ret)
+ goto out_put_group;
+
+ group = vfio_create_group(iommu_group);
+ if (IS_ERR(group)) {
+ ret = PTR_ERR(group);
+ goto out_remove_device;
+ }
+
+ return group;
+
+out_remove_device:
+ iommu_group_remove_device(dev);
+out_put_group:
+ iommu_group_put(iommu_group);
+ return ERR_PTR(ret);
+}
+#endif
+
+static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
+{
+ struct iommu_group *iommu_group;
+ struct vfio_group *group;
+
+ iommu_group = iommu_group_get(dev);
+#ifdef CONFIG_VFIO_NOIOMMU
+ if (!iommu_group && noiommu && !iommu_present(dev->bus)) {
+ /*
+ * With noiommu enabled, create an IOMMU group for devices that
+ * don't already have one and don't have an iommu_ops on their
+ * bus. Taint the kernel because we're about to give a DMA
+ * capable device to a user without IOMMU protection.
+ */
+ group = vfio_noiommu_group_alloc(dev);
+ if (group) {
+ add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+ dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
+ }
+ return group;
+ }
+#endif
if (!iommu_group)
return ERR_PTR(-EINVAL);
@@ -844,10 +849,6 @@ struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
return group;
out_put:
-#ifdef CONFIG_VFIO_NOIOMMU
- if (iommu_group_get_iommudata(iommu_group) == &noiommu)
- iommu_group_remove_device(dev);
-#endif
iommu_group_put(iommu_group);
return group;
}
--
2.30.2
