qemu: add capabilities bit for device "pxb-pcie"

The pxb device is a PCIe expander bus that can be added to any
    Q35-based machinetype. A single PCIe port (*not* hotpluggable) is
    provided; if more than one device is desired, or if hotplug
    support is needed, either a pcie-root-port, or some combination of
    pcie-switch-upstream-port and pcie-swith-downstream-ports must be
    added to it. It can have a NUMA node number associated with it, as
    well as a bus number.

src/qemu/qemu_capabilities.c

@@ -323,6 +323,8 @@ VIR_ENUM_IMPL(virQEMUCaps, QEMU_CAPS_LAST,
               "debug-threads",
               "secret",
               "pxb",
+
+              "pxb-pcie", /* 220 */
     );
 
 
@@ -1579,6 +1581,7 @@ struct virQEMUCapsStringFlags virQEMUCapsObjectTypes[] = {
     { "mptsas1068", QEMU_CAPS_SCSI_MPTSAS1068 },
     { "secret", QEMU_CAPS_OBJECT_SECRET },
     { "pxb", QEMU_CAPS_DEVICE_PXB },
+    { "pxb-pcie", QEMU_CAPS_DEVICE_PXB_PCIE },
 };
 
 static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsVirtioBalloon[] = {

src/qemu/qemu_capabilities.h

@@ -354,6 +354,9 @@ typedef enum {
     QEMU_CAPS_OBJECT_SECRET, /* -object secret */
     QEMU_CAPS_DEVICE_PXB, /* -device pxb */
 
+    /* 220 */
+    QEMU_CAPS_DEVICE_PXB_PCIE, /* -device pxb-pcie */
+
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
 

tests/qemucapabilitiesdata/caps_2.6.0-1.caps

@@ -180,4 +180,5 @@
     <flag name='debug-threads'/>
     <flag name='secret'/>
     <flag name='pxb'/>
+    <flag name='pxb-pcie'/>
   </qemuCaps>

tests/qemucapabilitiesdata/caps_2.6.0-1.replies

@@ -1322,6 +1322,9 @@
     {
       "name": "pxb"
     },
+    {
+      "name": "pxb-pcie"
+    },
     {
       "name": "kvm64-x86_64-cpu"
     },