Merge tag 'vfio-v4.19-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - mark switch fall-through cases (Gustavo A. R. Silva)

 - disable binding SR-IOV enabled PFs (Alex Williamson)

* tag 'vfio-v4.19-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Disable binding to PFs with SR-IOV enabled
  vfio: Mark expected switch fall-throughs

2 files changed, 15 insertions, 1 deletions

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 3b1083fdb898..cddb453a1ba5 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -789,7 +789,7 @@ static long vfio_pci_ioctl(void *device_data,
                 case VFIO_PCI_ERR_IRQ_INDEX:
                         if (pci_is_pcie(vdev->pdev))
                                 break;
-                /* pass thru to return error */
+                /* fall through */
                 default:
                         return -EINVAL;
                 }
@@ -1192,6 +1192,19 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
         if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
                 return -EINVAL;
 
+        /*
+         * Prevent binding to PFs with VFs enabled, this too easily allows
+         * userspace instance with VFs and PFs from the same device, which
+         * cannot work.  Disabling SR-IOV here would initiate removing the
+         * VFs, which would unbind the driver, which is prone to blocking
+         * if that VF is also in use by vfio-pci.  Just reject these PFs
+         * and let the user sort it out.
+         */
+        if (pci_num_vf(pdev)) {
+                pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
+                return -EBUSY;
+        }
+
         group = vfio_iommu_group_get(&pdev->dev);
         if (!group)
                 return -EINVAL;
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 3e5b17710a4f..d9fd3188615d 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1601,6 +1601,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
                 break;
         case VFIO_TYPE1_NESTING_IOMMU:
                 iommu->nesting = true;
+                /* fall through */
         case VFIO_TYPE1v2_IOMMU:
                 iommu->v2 = true;
                 break;