Include port number with virtio serial devices

To ensure that the device addressing scheme is stable across
hotplug/unplug, all virtio serial channels needs to have an
associated port number in their address. This is then specified
to QEMU using the nr=NNN parameter

* src/conf/domain_conf.c, src/conf/domain_conf.h: Parsing
  for port number in vioserial address types.
* src/qemu/qemu_conf.c: Set 'nr=NNN' parameter with virtio
  serial port number
* tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args,
  tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml: Expand
  data set to ensure coverage of port addressing

src/conf/domain_conf.c

@@ -1055,9 +1055,10 @@ static int virDomainDeviceInfoFormat(virBufferPtr buf,
         break;
 
     case VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_SERIAL:
-        virBufferVSprintf(buf, " controller='%d' bus='%d'",
+        virBufferVSprintf(buf, " controller='%d' bus='%d' port='%d'",
                           info->addr.vioserial.controller,
-                          info->addr.vioserial.bus);
+                          info->addr.vioserial.bus,
+                          info->addr.vioserial.port);
         break;
 
     default:
@@ -1190,13 +1191,14 @@ virDomainDeviceVirtioSerialAddressParseXML(
     virDomainDeviceVirtioSerialAddressPtr addr
 )
 {
-    char *controller, *bus;
+    char *controller, *bus, *port;
     int ret = -1;
 
     memset(addr, 0, sizeof(*addr));
 
     controller = virXMLPropString(node, "controller");
     bus = virXMLPropString(node, "bus");
+    port = virXMLPropString(node, "port");
 
     if (controller &&
         virStrToLong_ui(controller, NULL, 10, &addr->controller) < 0) {
@@ -1212,6 +1214,13 @@ virDomainDeviceVirtioSerialAddressParseXML(
         goto cleanup;
     }
 
+    if (port &&
+        virStrToLong_ui(port, NULL, 10, &addr->port) < 0) {
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                             _("Cannot parse <address> 'port' attribute"));
+        goto cleanup;
+    }
+
     if (!virDomainDeviceVirtioSerialAddressIsValid(addr)) {
         virDomainReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                              _("Insufficient specification for "
@@ -4375,6 +4384,21 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
             goto error;
 
         def->channels[def->nchannels++] = chr;
+
+        if (chr->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_SERIAL &&
+            chr->info.addr.vioserial.port == 0) {
+            int maxport = -1;
+            int j;
+            for (j = 0 ; j < i ; j++) {
+                virDomainChrDefPtr thischr = def->channels[j];
+                if (thischr->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_VIRTIO_SERIAL &&
+                    thischr->info.addr.vioserial.controller == chr->info.addr.vioserial.controller &&
+                    thischr->info.addr.vioserial.bus == chr->info.addr.vioserial.bus &&
+                    (int)thischr->info.addr.vioserial.port > maxport)
+                    maxport = thischr->info.addr.vioserial.port;
+            }
+            chr->info.addr.vioserial.port = maxport + 1;
+        }
     }
     VIR_FREE(nodes);
 

src/conf/domain_conf.h

@@ -98,6 +98,7 @@ typedef virDomainDeviceVirtioSerialAddress *virDomainDeviceVirtioSerialAddressPt
 struct _virDomainDeviceVirtioSerialAddress {
     unsigned int controller;
     unsigned int bus;
+    unsigned int port;
 };
 
 typedef struct _virDomainDeviceInfo virDomainDeviceInfo;

src/qemu/qemu_conf.c

@@ -3239,6 +3239,9 @@ qemuBuildVirtioSerialPortDevStr(virDomainChrDefPtr dev)
                           ",bus=" QEMU_VIRTIO_SERIAL_PREFIX "%d.%d",
                           dev->info.addr.vioserial.controller,
                           dev->info.addr.vioserial.bus);
+        virBufferVSprintf(&buf,
+                          ",nr=%d",
+                          dev->info.addr.vioserial.port);
     }
 
     virBufferVSprintf(&buf, ",chardev=%s", dev->info.alias);

tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args

@@ -1 +1 @@
-LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefaults -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -device virtio-serial-pci,id=virtio-serial0,max_ports=16,vectors=4,bus=pci.0,addr=0x4 -device virtio-serial-pci,id=virtio-serial1,bus=pci.0,addr=0xa -hda /dev/HostVG/QEMUGuest1 -chardev pty,id=channel0 -device virtserialport,chardev=channel0,name=org.linux-kvm.port.0 -chardev pty,id=channel1 -device virtserialport,bus=virtio-serial1.0,chardev=channel1,name=org.linux-kvm.port.1 -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -nodefaults -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -device virtio-serial-pci,id=virtio-serial0,max_ports=16,vectors=4,bus=pci.0,addr=0x4 -device virtio-serial-pci,id=virtio-serial1,bus=pci.0,addr=0xa -hda /dev/HostVG/QEMUGuest1 -chardev pty,id=channel0 -device virtserialport,chardev=channel0,name=org.linux-kvm.port.0 -chardev pty,id=channel1 -device virtserialport,bus=virtio-serial1.0,nr=0,chardev=channel1,name=org.linux-kvm.port.foo -chardev pty,id=channel2 -device virtserialport,bus=virtio-serial1.0,nr=3,chardev=channel2,name=org.linux-kvm.port.bar -chardev pty,id=channel3 -device virtserialport,bus=virtio-serial0.0,nr=0,chardev=channel3,name=org.linux-kvm.port.wizz -chardev pty,id=channel4 -device virtserialport,bus=virtio-serial1.0,nr=4,chardev=channel4,name=org.linux-kvm.port.ooh -usb -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.xml

@@ -28,7 +28,19 @@
       <target type='virtio' name='org.linux-kvm.port.0'/>
     </channel>
     <channel type='pty'>
-      <target type='virtio' name='org.linux-kvm.port.1'/>
+      <target type='virtio' name='org.linux-kvm.port.foo'/>
+      <address type='virtio-serial' controller='1' bus='0'/>
+    </channel>
+    <channel type='pty'>
+      <target type='virtio' name='org.linux-kvm.port.bar'/>
+      <address type='virtio-serial' controller='1' bus='0' port='3'/>
+    </channel>
+    <channel type='pty'>
+      <target type='virtio' name='org.linux-kvm.port.wizz'/>
+      <address type='virtio-serial' controller='0' bus='0'/>
+    </channel>
+    <channel type='pty'>
+      <target type='virtio' name='org.linux-kvm.port.ooh'/>
       <address type='virtio-serial' controller='1' bus='0'/>
     </channel>
   </devices>