[SRU][F][PATCH 10/12] s390/pci: Do not disable PF when VFs exist

[frank.heimes at canonical.com]

From: Pierre Morel <pmorel at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1874056

The Physical function should not be disabled until no virtual
functions depends on it.
Let's force the user to first use echo 0 > sriov_numfs before
allowing to disable the PF with echo 0 > power.

Signed-off-by: Pierre Morel <pmorel at linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle at linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor at linux.ibm.com>
(backported from commit 53dd462ac4dc3fc61ee90ad03d96202e17589156)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
 drivers/pci/hotplug/s390_pci_hpc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/hotplug/s390_pci_hpc.c b/drivers/pci/hotplug/s390_pci_hpc.c
index 1579ba895edf..b59f84918fe0 100644
--- a/drivers/pci/hotplug/s390_pci_hpc.c
+++ b/drivers/pci/hotplug/s390_pci_hpc.c
@@ -91,6 +91,9 @@ static int disable_slot(struct hotplug_slot *hotplug_slot)
 
 	pdev = pci_get_slot(zbus->bus, zdev->devfn);
 	if (pdev) {
+		if (pci_num_vf(pdev))
+			return -EBUSY;
+
 		pci_stop_and_remove_bus_device_locked(pdev);
 		pci_dev_put(pdev);
 	}
-- 
2.25.1