qemu: switch s390/s390x default console back to serial

Now that <serial> and <console> on s390/s390x behave a bit more like the
other architectures, remove this extra differentation, and use sclp
console by default for new guests.  New virtio consoles can still be
added, and it is actually needed because of the limited number of
instances for sclp and sclplm.

This reverts commit b1c88c1476, whose
reasons are not totally clear.

Signed-off-by: Pino Toscano <ptoscano@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>

src/qemu/qemu_domain.c

@@ -4259,13 +4259,6 @@ qemuDomainChrDefPostParse(virDomainChrDefPtr chr,
                           virQEMUDriverPtr driver,
                           unsigned int parseFlags)
 {
-    /* set the default console type for S390 arches */
-    if (chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CONSOLE &&
-        chr->targetType == VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_NONE &&
-        ARCH_IS_S390(def->os.arch)) {
-        chr->targetType = VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_VIRTIO;
-    }
-
     /* Historically, isa-serial and the default matched, so in order to
      * maintain backwards compatibility we map them here. The actual default
      * will be picked below based on the architecture and machine type. */

tests/qemuxml2argvdata/qemuxml2argv-s390-serial-console.args

@@ -18,8 +18,5 @@ QEMU_AUDIO_DRV=none \
 server,nowait \
 -mon chardev=charmonitor,id=monitor,mode=readline \
 -boot c \
--device virtio-serial-ccw,id=virtio-serial0,devno=fe.0.0000 \
 -chardev pty,id=charserial0 \
--device sclpconsole,chardev=charserial0,id=serial0 \
--chardev pty,id=charconsole1 \
--device virtconsole,chardev=charconsole1,id=console1
+-device sclpconsole,chardev=charserial0,id=serial0

tests/qemuxml2xmloutdata/qemuxml2xmlout-s390-defaultconsole.xml

@@ -14,9 +14,13 @@
   <on_crash>destroy</on_crash>
   <devices>
     <emulator>/usr/bin/qemu-system-s390x</emulator>
-    <controller type='virtio-serial' index='0'/>
+    <serial type='pty'>
+      <target type='sclp-serial' port='0'>
+        <model name='sclpconsole'/>
+      </target>
+    </serial>
     <console type='pty'>
-      <target type='virtio' port='0'/>
+      <target type='serial' port='0'/>
     </console>
     <memballoon model='none'/>
     <panic model='s390'/>

tests/qemuxml2xmloutdata/qemuxml2xmlout-s390-serial-console.xml

@@ -14,9 +14,6 @@
   <on_crash>destroy</on_crash>
   <devices>
     <emulator>/usr/bin/qemu-system-s390x</emulator>
-    <controller type='virtio-serial' index='0'>
-      <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
-    </controller>
     <serial type='pty'>
       <target type='sclp-serial' port='0'>
         <model name='sclpconsole'/>
@@ -25,9 +22,6 @@
     <console type='pty'>
       <target type='serial' port='0'/>
     </console>
-    <console type='pty'>
-      <target type='virtio' port='0'/>
-    </console>
     <memballoon model='none'/>
     <panic model='s390'/>
   </devices>