summaryrefslogtreecommitdiffstats
path: root/drivers/vfio
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2021-09-24 17:56:55 +0200
committerAlex Williamson <alex.williamson@redhat.com>2021-09-30 12:46:44 -0600
commit3af917713230c8a6c3431e60601f0c7ad72eceb6 (patch)
treef71757ebfa998dab528b30982aea8b762d52576b /drivers/vfio
parent1362591f15233bdc3d1fbf27e266068bd16a4e92 (diff)
downloadlinux-3af917713230c8a6c3431e60601f0c7ad72eceb6.tar.bz2
vfio: refactor noiommu group creation
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@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20210924155705.4258-6-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio.c104
1 files changed, 52 insertions, 52 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 2b2679c7126f..b1ed156adccd 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 (!IS_ERR(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);
@@ -840,14 +845,9 @@ struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
/* a newly created vfio_group keeps the reference. */
group = vfio_create_group(iommu_group);
if (IS_ERR(group))
- goto out_remove;
+ goto out_put;
return group;
-out_remove:
-#ifdef CONFIG_VFIO_NOIOMMU
- if (iommu_group_get_iommudata(iommu_group) == &noiommu)
- iommu_group_remove_device(dev);
-#endif
out_put:
iommu_group_put(iommu_group);
return group;