[PATCH 16/17] nodedev: add optional device address of channel device to css device

[Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>]

Add the new introduced sysfs attribute dev_busid which provides the address
of the device in the subchannel independent from the bound device driver.
It is added if available in the sysfs as optional channel_dev_addr element into
the css device capabilty providing the ccw deivce address attributes cssid,
ssid and devno.

Signed-off-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>
---
 src/conf/node_device_conf.c        | 26 ++++++++++++++++++++++++++
 src/conf/node_device_conf.h        |  2 ++
 src/conf/schemas/nodedev.rng       |  5 +++++
 src/node_device/node_device_udev.c |  8 ++++++++
 4 files changed, 41 insertions(+)

diff --git a/src/conf/node_device_conf.c b/src/conf/node_device_conf.c
index 5aafcbb838..d5ee8da3ee 100644
--- a/src/conf/node_device_conf.c
+++ b/src/conf/node_device_conf.c
@@ -645,6 +645,17 @@ virNodeDeviceCapCSSDefFormat(virBuffer *buf,
 
     virNodeDeviceCapCCWDefFormat(buf, data);
 
+    if (ccw_dev.channel_dev_addr) {
+        virCCWDeviceAddress *ccw = ccw_dev.channel_dev_addr;
+        virBufferAddLit(buf, "<channel_dev_addr>\n");
+        virBufferAdjustIndent(buf, 2);
+        virBufferAsprintf(buf, "<cssid>0x%x</cssid>\n", ccw->cssid);
+        virBufferAsprintf(buf, "<ssid>0x%x</ssid>\n", ccw->ssid);
+        virBufferAsprintf(buf, "<devno>0x%04x</devno>\n", ccw->devno);
+        virBufferAdjustIndent(buf, -2);
+        virBufferAddLit(buf, "</channel_dev_addr>\n");
+    }
+
     if (ccw_dev.flags & VIR_NODE_DEV_CAP_FLAG_CSS_MDEV)
         virNodeDeviceCapMdevTypesFormat(buf,
                                         ccw_dev.mdev_types,
@@ -1257,6 +1268,8 @@ virNodeDevCapCSSParseXML(xmlXPathContextPtr ctxt,
     g_autofree xmlNodePtr *nodes = NULL;
     int n = 0;
     size_t i = 0;
+    xmlNodePtr channel_ddno = NULL;
+    g_autofree virCCWDeviceAddress *channel_dev = NULL;
 
     ctxt->node = node;
 
@@ -1271,6 +1284,19 @@ virNodeDevCapCSSParseXML(xmlXPathContextPtr ctxt,
             return -1;
     }
 
+    // channel_dev_addr is optional
+    if ((channel_ddno = virXPathNode("./channel_dev_addr[1]", ctxt))) {
+        channel_dev = g_new0(virCCWDeviceAddress, 1);
+
+        if (virNodeDevCCWDeviceAddressParseXML(ctxt,
+                                               channel_ddno,
+                                               def->name,
+                                               channel_dev) < 0)
+            return -1;
+
+        ccw_dev->channel_dev_addr = g_steal_pointer(&channel_dev);
+    }
+
     return 0;
 }
 
diff --git a/src/conf/node_device_conf.h b/src/conf/node_device_conf.h
index e4d1f67d53..d1751ed874 100644
--- a/src/conf/node_device_conf.h
+++ b/src/conf/node_device_conf.h
@@ -24,6 +24,7 @@
 
 #include "internal.h"
 #include "virbitmap.h"
+#include "virccw.h"
 #include "virpcivpd.h"
 #include "virscsihost.h"
 #include "virpci.h"
@@ -279,6 +280,7 @@ struct _virNodeDevCapCCW {
     unsigned int flags; /* enum virNodeDevCCWCapFlags */
     virMediatedDeviceType **mdev_types;
     size_t nmdev_types;
+    virCCWDeviceAddress *channel_dev_addr;
 };
 
 typedef struct _virNodeDevCapVDPA virNodeDevCapVDPA;
diff --git a/src/conf/schemas/nodedev.rng b/src/conf/schemas/nodedev.rng
index a9f83e048c..e40243e257 100644
--- a/src/conf/schemas/nodedev.rng
+++ b/src/conf/schemas/nodedev.rng
@@ -682,6 +682,11 @@
       <value>css</value>
     </attribute>
     <ref name="capccwaddress"/>
+    <optional>
+      <element name="channel_dev_addr">
+        <ref name="capccwaddress"/>
+      </element>
+    </optional>
     <optional>
       <ref name="mdev_types"/>
     </optional>
diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 4bb841c66b..16314627ca 100644
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -1124,6 +1124,8 @@ static int
 udevProcessCSS(struct udev_device *device,
                virNodeDeviceDef *def)
 {
+    char *dev_busid;
+
     /* only process IO subchannel and vfio-ccw devices to keep the list sane */
     if (!def->driver ||
         (STRNEQ(def->driver, "io_subchannel") &&
@@ -1135,6 +1137,12 @@ udevProcessCSS(struct udev_device *device,
 
     udevGenerateDeviceName(device, def, NULL);
 
+    /* process optional channel devices information */
+    udevGetStringSysfsAttr(device, "dev_busid", &dev_busid);
+
+    if (dev_busid != NULL)
+        def->caps->data.ccw_dev.channel_dev_addr = virCCWDeviceAddressFromString(dev_busid);
+
     if (virNodeDeviceGetCSSDynamicCaps(def->sysfs_path, &def->caps->data.ccw_dev) < 0)
         return -1;
 
-- 
2.33.1