diff --git a/Documentation/s390/pci.rst b/Documentation/s390/pci.rst
index 492850bff316..8157f0cddbc2 100644
--- a/Documentation/s390/pci.rst
+++ b/Documentation/s390/pci.rst
@@ -50,7 +50,8 @@ Entries specific to zPCI functions and entries that hold zPCI information.
 * /sys/bus/pci/slots/XXXXXXXX
 
   The slot entries are set up using the function identifier (FID) of the
-  PCI function.
+  PCI function. The format depicted as XXXXXXXX above is 8 hexadecimal digits
+  with 0 padding and lower case hexadecimal digitis.
 
   - /sys/bus/pci/slots/XXXXXXXX/power
 
@@ -88,8 +89,15 @@ Entries specific to zPCI functions and entries that hold zPCI information.
     is attached to.
 
   - uid
-    The unique identifier (UID) is defined when configuring an LPAR and is
-    unique in the LPAR.
+    The user identifier (UID) may be defined as part of the machine
+    configuration or the z/VM or KVM guest configuration. If the accompanying
+    uid_is_unique attribute is 1 the platform guarantees that the UID is unique
+    within that instance and no devices with the same UID can be attached
+    during the lifetime of the system.
+
+  - uid_is_unique
+    Indicates whether the user identifier (UID) is guaranteed to be and remain
+    unique within this Linux instance.
 
   - pfip/segmentX
     The segments determine the isolation of a function.
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index 5c028bee91b9..e14d346dafd6 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -131,6 +131,13 @@ static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
 }
 static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
 
+static ssize_t uid_is_unique_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
+}
+static DEVICE_ATTR_RO(uid_is_unique);
+
 static struct bin_attribute *zpci_bin_attrs[] = {
 	&bin_attr_util_string,
 	&bin_attr_report_error,
@@ -148,8 +155,10 @@ static struct attribute *zpci_dev_attrs[] = {
 	&dev_attr_uid.attr,
 	&dev_attr_recover.attr,
 	&dev_attr_mio_enabled.attr,
+	&dev_attr_uid_is_unique.attr,
 	NULL,
 };
+
 static struct attribute_group zpci_attr_group = {
 	.attrs = zpci_dev_attrs,
 	.bin_attrs = zpci_bin_attrs,