s390/pci: Fix zpci_bus_is_isolated_vf() for non-VFs

commit 8691abd3afaadd816a298503ec1a759df1305d2e upstream.

For non-VFs, zpci_bus_is_isolated_vf() should return false because they
aren't VFs. While zpci_iov_find_parent_pf() specifically checks if
a function is a VF, it then simply returns that there is no parent. The
simplistic check for a parent then leads to these functions being
confused with isolated VFs and isolating them on their own domain even
if sibling PFs should share the domain.

Fix this by explicitly checking if a function is not a VF. Note also
that at this point the case where RIDs are ignored is already handled
and in this case all PCI functions get isolated by being detected in
zpci_bus_is_multifunction_root().

Cc: stable@vger.kernel.org
Fixes: 2844ddbd540f ("s390/pci: Fix handling of isolated VFs")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index 39a481ec4a402dbcd7e4c757fe77115c0ed5e81c..983d9239feb411387ac4ad7fafc58f4698faa614 100644 (file)
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -335,6 +335,9 @@ static bool zpci_bus_is_isolated_vf(struct zpci_bus *zbus, struct zpci_dev *zdev
 {
        struct pci_dev *pdev;
 
+       if (!zdev->vfn)
+               return false;
+
        pdev = zpci_iov_find_parent_pf(zbus, zdev);
        if (!pdev)
                return true;