s390/pci: track whether util_str is valid in the zpci_dev

We'll need to keep track of whether or not the byte string in util_str is
valid and thus needs to be passed to a vfio-pci passthrough device.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

arch/s390/include/asm/pci.h

@@ -132,7 +132,8 @@ struct zpci_dev {
 	u8		rid_available	: 1;
 	u8		has_hp_slot	: 1;
 	u8		is_physfn	: 1;
-	u8		reserved	: 5;
+	u8		util_str_avail	: 1;
+	u8		reserved	: 4;
 	unsigned int	devfn;		/* DEVFN part of the RID*/
 
 	struct mutex lock;

arch/s390/pci/pci_clp.c

@@ -168,6 +168,7 @@ static int clp_store_query_pci_fn(struct zpci_dev *zdev,
 	if (response->util_str_avail) {
 		memcpy(zdev->util_str, response->util_str,
 		       sizeof(zdev->util_str));
+		zdev->util_str_avail = 1;
 	}
 	zdev->mio_capable = response->mio_addr_avail;
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {