node_device: detecting mdev_types capability on CSS devices

Add detection of mdev_types capability to channel subsystem devices.

Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.ibm.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

docs/drvnodedev.html.in

@@ -139,7 +139,7 @@
 
     <h3><a id="MDEVCap">MDEV capability</a></h3>
     <p>
-      A PCI device capable of creating mediated devices will include a nested
+      A device capable of creating mediated devices will include a nested
       capability <code>mdev_types</code> which enumerates all supported mdev
       types on the physical device, along with the type attributes available
       through sysfs. A detailed description of the XML format for the

docs/formatnode.html.in

@@ -405,6 +405,21 @@
               <dd>The subchannel-set identifier.</dd>
               <dt><code>devno</code></dt>
               <dd>The device number.</dd>
+              <dt><code>capability</code></dt>
+              <dd>
+                This optional element can occur multiple times. If it
+                exists, it has a mandatory <code>type</code> attribute
+                which will be set to:
+                <dl>
+                  <dt><code><a id="MDEVTypesCapCSS">mdev_types</a></code></dt>
+                  <dd>
+                    <span class="since">Since 6.10.0</span>
+                    This device is capable of creating mediated devices.
+                    The sub-elements are summarized in
+                    <a href="#MDevTypesCap">mdev_types capability</a>.
+                  </dd>
+                </dl>
+              </dd>
             </dl>
           </dd>
           <dt><code>vdpa</code></dt>
@@ -423,10 +438,10 @@
     <h3><a id="MDEVTypesCap">mdev_types capability</a></h3>
 
     <p>
-      <a href="#MDEVTypesCapPCI">PCI</a> devices can be capable of
+      <a href="#MDEVTypesCapPCI">PCI</a> and <a href="#MDEVTypesCapCSS">CSS</a>
-      creating mediated devices. If they indeed are capable,
+      devices can be capable of creating mediated devices.
-      then the parent <code>capability</code> element for
+      If they indeed are capable, then the parent <code>capability</code>
-      <code>mdev_types</code> type will contain a list of
+      element for <code>mdev_types</code> type will contain a list of
       <code>type</code> elements, which list all mdev types supported
       on the physical device. <span class="since">Since 3.4.0</span>
       Each <code>type</code> element has a single <code>id</code>

docs/schemas/nodedev.rng

@@ -654,6 +654,9 @@
     <element name="devno">
       <ref name="ccwDevnoRange"/>
     </element>
+    <optional>
+      <ref name="mdev_types"/>
+    </optional>
   </define>
 
   <define name="capvdpa">
@@ -702,6 +705,7 @@
           <element name="deviceAPI">
             <choice>
               <value>vfio-pci</value>
+              <value>vfio-ccw</value>
             </choice>
           </element>
           <element name="availableInstances">

src/conf/node_device_conf.c

@@ -552,6 +552,10 @@ virNodeDeviceCapCCWDefFormat(virBufferPtr buf,
                       data->ccw_dev.ssid);
     virBufferAsprintf(buf, "<devno>0x%04x</devno>\n",
                       data->ccw_dev.devno);
+    if (data->ccw_dev.flags & VIR_NODE_DEV_CAP_FLAG_CSS_MDEV)
+        virNodeDeviceCapMdevTypesFormat(buf,
+                                        data->ccw_dev.mdev_types,
+                                        data->ccw_dev.nmdev_types);
 }
 
 
@@ -843,6 +847,33 @@ virNodeDevCapMdevTypesParseXML(xmlXPathContextPtr ctxt,
 }
 
 
+static int
+virNodeDevCSSCapabilityParseXML(xmlXPathContextPtr ctxt,
+                                xmlNodePtr node,
+                                virNodeDevCapCCWPtr ccw_dev)
+{
+    g_autofree char *type = virXMLPropString(node, "type");
+    VIR_XPATH_NODE_AUTORESTORE(ctxt)
+
+    ctxt->node = node;
+
+    if (!type) {
+        virReportError(VIR_ERR_XML_ERROR, "%s", _("Missing capability type"));
+        return -1;
+    }
+
+    if (STREQ(type, "mdev_types")) {
+        if (virNodeDevCapMdevTypesParseXML(ctxt,
+                                           &ccw_dev->mdev_types,
+                                           &ccw_dev->nmdev_types) < 0)
+            return -1;
+        ccw_dev->flags |= VIR_NODE_DEV_CAP_FLAG_CSS_MDEV;
+    }
+
+    return 0;
+}
+
+
 static int
 virNodeDevCapCCWParseXML(xmlXPathContextPtr ctxt,
                          virNodeDeviceDefPtr def,
@@ -850,6 +881,9 @@ virNodeDevCapCCWParseXML(xmlXPathContextPtr ctxt,
                          virNodeDevCapCCWPtr ccw_dev)
 {
     VIR_XPATH_NODE_AUTORESTORE(ctxt)
+    g_autofree xmlNodePtr *nodes = NULL;
+    int n = 0;
+    size_t i = 0;
     g_autofree char *cssid = NULL;
     g_autofree char *ssid = NULL;
     g_autofree char *devno = NULL;
@@ -895,6 +929,14 @@ virNodeDevCapCCWParseXML(xmlXPathContextPtr ctxt,
         return -1;
     }
 
+    if ((n = virXPathNodeSet("./capability", ctxt, &nodes)) < 0)
+        return -1;
+
+    for (i = 0; i < n; i++) {
+        if (virNodeDevCSSCapabilityParseXML(ctxt, nodes[i], ccw_dev) < 0)
+            return -1;
+    }
+
     return 0;
 }
 
@@ -2253,12 +2295,16 @@ virNodeDevCapsDefFree(virNodeDevCapsDefPtr caps)
             virMediatedDeviceAttrFree(data->mdev.attributes[i]);
         VIR_FREE(data->mdev.attributes);
         break;
+    case VIR_NODE_DEV_CAP_CSS_DEV:
+        for (i = 0; i < data->ccw_dev.nmdev_types; i++)
+            virMediatedDeviceTypeFree(data->ccw_dev.mdev_types[i]);
+        VIR_FREE(data->ccw_dev.mdev_types);
+        break;
     case VIR_NODE_DEV_CAP_MDEV_TYPES:
     case VIR_NODE_DEV_CAP_DRM:
     case VIR_NODE_DEV_CAP_FC_HOST:
     case VIR_NODE_DEV_CAP_VPORTS:
     case VIR_NODE_DEV_CAP_CCW_DEV:
-    case VIR_NODE_DEV_CAP_CSS_DEV:
     case VIR_NODE_DEV_CAP_VDPA:
     case VIR_NODE_DEV_CAP_LAST:
         /* This case is here to shutup the compiler */
@@ -2297,6 +2343,11 @@ virNodeDeviceUpdateCaps(virNodeDeviceDefPtr def)
                                                &cap->data.pci_dev) < 0)
                 return -1;
             break;
+        case VIR_NODE_DEV_CAP_CSS_DEV:
+            if (virNodeDeviceGetCSSDynamicCaps(def->sysfs_path,
+                                               &cap->data.ccw_dev) < 0)
+                return -1;
+            break;
 
             /* all types that (supposedly) don't require any updates
              * relative to what's in the cache.
@@ -2313,7 +2364,6 @@ virNodeDeviceUpdateCaps(virNodeDeviceDefPtr def)
         case VIR_NODE_DEV_CAP_MDEV_TYPES:
         case VIR_NODE_DEV_CAP_MDEV:
         case VIR_NODE_DEV_CAP_CCW_DEV:
-        case VIR_NODE_DEV_CAP_CSS_DEV:
         case VIR_NODE_DEV_CAP_VDPA:
         case VIR_NODE_DEV_CAP_LAST:
             break;
@@ -2388,6 +2438,15 @@ virNodeDeviceCapsListExport(virNodeDeviceDefPtr def,
                 ncaps++;
             }
         }
+
+        if (caps->data.type == VIR_NODE_DEV_CAP_CSS_DEV) {
+            flags = caps->data.ccw_dev.flags;
+
+            if (flags & VIR_NODE_DEV_CAP_FLAG_CSS_MDEV) {
+                MAYBE_ADD_CAP(VIR_NODE_DEV_CAP_MDEV_TYPES);
+                ncaps++;
+            }
+        }
     }
 
 #undef MAYBE_ADD_CAP
@@ -2653,6 +2712,28 @@ virNodeDeviceGetPCIDynamicCaps(const char *sysfsPath,
     return 0;
 }
 
+
+/* virNodeDeviceGetCSSDynamicCaps() get info that is stored in sysfs
+ * about devices related to this device, i.e. things that can change
+ * without this device itself changing. These must be refreshed
+ * anytime full XML of the device is requested, because they can
+ * change with no corresponding notification from the kernel/udev.
+ */
+int
+virNodeDeviceGetCSSDynamicCaps(const char *sysfsPath,
+                               virNodeDevCapCCWPtr ccw_dev)
+{
+    ccw_dev->flags &= ~VIR_NODE_DEV_CAP_FLAG_CSS_MDEV;
+    if (virNodeDeviceGetMdevTypesCaps(sysfsPath,
+                                      &ccw_dev->mdev_types,
+                                      &ccw_dev->nmdev_types) < 0)
+        return -1;
+    if (ccw_dev->nmdev_types > 0)
+        ccw_dev->flags |= VIR_NODE_DEV_CAP_FLAG_CSS_MDEV;
+
+    return 0;
+}
+
 #else
 
 int
@@ -2675,4 +2756,11 @@ int virNodeDeviceGetSCSITargetCaps(const char *sysfsPath G_GNUC_UNUSED,
     return -1;
 }
 
+int
+virNodeDeviceGetCSSDynamicCaps(const char *sysfsPath G_GNUC_UNUSED,
+                               virNodeDevCapCCWPtr ccw_dev G_GNUC_UNUSED)
+{
+    return -1;
+}
+
 #endif /* __linux__ */

src/conf/node_device_conf.h

@@ -102,6 +102,10 @@ typedef enum {
     VIR_NODE_DEV_CAP_FLAG_PCI_MDEV                  = (1 << 3),
 } virNodeDevPCICapFlags;
 
+typedef enum {
+    VIR_NODE_DEV_CAP_FLAG_CSS_MDEV                  = (1 << 0),
+} virNodeDevCCWCapFlags;
+
 typedef enum {
     /* Keep in sync with VIR_ENUM_IMPL in node_device_conf.c */
     VIR_NODE_DEV_DRM_PRIMARY,
@@ -274,6 +278,9 @@ struct _virNodeDevCapCCW {
     unsigned int cssid;
     unsigned int ssid;
     unsigned int devno;
+    unsigned int flags; /* enum virNodeDevCCWCapFlags */
+    virMediatedDeviceTypePtr *mdev_types;
+    size_t nmdev_types;
 };
 
 typedef struct _virNodeDevCapVDPA virNodeDevCapVDPA;
@@ -391,6 +398,10 @@ int
 virNodeDeviceGetPCIDynamicCaps(const char *sysfsPath,
                                virNodeDevCapPCIDevPtr pci_dev);
 
+int
+virNodeDeviceGetCSSDynamicCaps(const char *sysfsPath,
+                               virNodeDevCapCCWPtr ccw_dev);
+
 int
 virNodeDeviceUpdateCaps(virNodeDeviceDefPtr def);
 

src/conf/virnodedeviceobj.c

@@ -696,6 +696,12 @@ virNodeDeviceObjHasCap(const virNodeDeviceObj *obj,
                 return true;
             break;
 
+        case VIR_NODE_DEV_CAP_CSS_DEV:
+            if (type == VIR_NODE_DEV_CAP_MDEV_TYPES &&
+                (cap->data.ccw_dev.flags & VIR_NODE_DEV_CAP_FLAG_CSS_MDEV))
+                return true;
+            break;
+
         case VIR_NODE_DEV_CAP_SYSTEM:
         case VIR_NODE_DEV_CAP_USB_DEV:
         case VIR_NODE_DEV_CAP_USB_INTERFACE:
@@ -710,7 +716,6 @@ virNodeDeviceObjHasCap(const virNodeDeviceObj *obj,
         case VIR_NODE_DEV_CAP_MDEV_TYPES:
         case VIR_NODE_DEV_CAP_MDEV:
         case VIR_NODE_DEV_CAP_CCW_DEV:
-        case VIR_NODE_DEV_CAP_CSS_DEV:
         case VIR_NODE_DEV_CAP_VDPA:
         case VIR_NODE_DEV_CAP_LAST:
             break;

src/libvirt_private.syms

@@ -824,6 +824,7 @@ virNodeDeviceDefFree;
 virNodeDeviceDefParseFile;
 virNodeDeviceDefParseNode;
 virNodeDeviceDefParseString;
+virNodeDeviceGetCSSDynamicCaps;
 virNodeDeviceGetPCIDynamicCaps;
 virNodeDeviceGetSCSIHostCaps;
 virNodeDeviceGetSCSITargetCaps;

src/node_device/node_device_udev.c

@@ -1139,6 +1139,9 @@ udevProcessCSS(struct udev_device *device,
     if (udevGenerateDeviceName(device, def, NULL) != 0)
         return -1;
 
+    if (virNodeDeviceGetCSSDynamicCaps(def->sysfs_path, &def->caps->data.ccw_dev) < 0)
+        return -1;
+
     return 0;
 }
 

tests/nodedevschemadata/css_0_0_fffe_mdev_types.xml

@@ -0,0 +1,17 @@
+<device>
+  <name>css_0_0_fffe</name>
+  <path>/sys/devices/css0/0.0.fffe</path>
+  <parent>computer</parent>
+  <capability type='css'>
+    <cssid>0x0</cssid>
+    <ssid>0x0</ssid>
+    <devno>0xfffe</devno>
+    <capability type='mdev_types'>
+      <type id='vfio_ccw-io'>
+        <name>I/O subchannel (Non-QDIO)</name>
+        <deviceAPI>vfio-ccw</deviceAPI>
+        <availableInstances>1</availableInstances>
+      </type>
+    </capability>
+  </capability>
+</device>

tests/nodedevxml2xmltest.c

@@ -124,6 +124,7 @@ mymain(void)
     DO_TEST("mdev_3627463d_b7f0_4fea_b468_f1da537d301b");
     DO_TEST("ccw_0_0_ffff");
     DO_TEST("css_0_0_ffff");
+    DO_TEST("css_0_0_fffe_mdev_types");
 
     return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }