Merge tag 'vfio-v5.19-rc7' of https://github.com/awilliam/linux-vfio

Pull VFIO fix from Alex Williamson:

 - Move IOMMU test to unbreak no-iommu support (Jason Gunthorpe)

* tag 'vfio-v5.19-rc7' of https://github.com/awilliam/linux-vfio:
  vfio: Move IOMMU_CAP_CACHE_COHERENCY test to after we know we have a group

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 61e71c1..e60b06f 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -549,6 +549,16 @@ static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
        if (!iommu_group)
                return ERR_PTR(-EINVAL);
 
+       /*
+        * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
+        * restore cache coherency. It has to be checked here because it is only
+        * valid for cases where we are using iommu groups.
+        */
+       if (!iommu_capable(dev->bus, IOMMU_CAP_CACHE_COHERENCY)) {
+               iommu_group_put(iommu_group);
+               return ERR_PTR(-EINVAL);
+       }
+
        group = vfio_group_get_from_iommu(iommu_group);
        if (!group)
                group = vfio_create_group(iommu_group, VFIO_IOMMU);
@@ -601,13 +611,6 @@ static int __vfio_register_dev(struct vfio_device *device,
 
 int vfio_register_group_dev(struct vfio_device *device)
 {
-       /*
-        * VFIO always sets IOMMU_CACHE because we offer no way for userspace to
-        * restore cache coherency.
-        */
-       if (!iommu_capable(device->dev->bus, IOMMU_CAP_CACHE_COHERENCY))
-               return -EINVAL;
-
        return __vfio_register_dev(device,
                vfio_group_find_or_alloc(device->dev));
 }