qemu: Allow panic device for pSeries guests

The guest firmware provides the same functionality as the pvpanic
device, which is not available in QEMU on pSeries, so the domain
XML should be allowed to contain the <panic> element.

On the other hand, unlike the pvpanic device, the guest firmware
can't be configured, so report an error if an address has been
provided in the XML.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1182388

docs/formatdomain.html.in

@@ -5960,7 +5960,8 @@ qemu-kvm -net nic,model=? /dev/null
     <dd>
       <p>
         address of panic. The default ioport is 0x505. Most users
-        don't need to specify an address.
+        don't need to specify an address, and doing so is forbidden
+        altogether for pSeries guests.
       </p>
     </dd>
   </dl>

src/qemu/qemu_command.c

@@ -10821,25 +10821,41 @@ qemuBuildCommandLine(virConnectPtr conn,
     }
 
     if (def->panic) {
-        if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_PANIC)) {
-            if (def->panic->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_ISA) {
+        if (ARCH_IS_PPC64(def->os.arch) && STRPREFIX(def->os.machine, "pseries")) {
+            /* For pSeries guests, the firmware provides the same
+             * functionality as the pvpanic device. The address
+             * cannot be configured by the user */
+            if (def->panic->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("setting the panic device address is not "
+                                 "supported for pSeries guests"));
+                goto error;
+            }
+        } else {
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_PANIC)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("the QEMU binary does not support the "
+                                 "panic device"));
+                goto error;
+            }
+
+            switch (def->panic->info.type) {
+            case VIR_DOMAIN_DEVICE_ADDRESS_TYPE_ISA:
                 virCommandAddArg(cmd, "-device");
                 virCommandAddArgFormat(cmd, "pvpanic,ioport=%d",
                                        def->panic->info.addr.isa.iobase);
-            } else if (def->panic->info.type ==
-                       VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
+                break;
+
+            case VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE:
                 virCommandAddArgList(cmd, "-device", "pvpanic", NULL);
-            } else {
+                break;
+
+            default:
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                                _("panic is supported only "
                                  "with ISA address type"));
                 goto error;
             }
-        } else {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                           _("the QEMU binary does not support the "
-                             "panic device"));
-            goto error;
         }
     }
 

tests/qemuxml2argvdata/qemuxml2argv-pseries-panic-address.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>1ccfd97d-5eb4-478a-bbe6-88d254c16db7</uuid>
+  <memory unit='KiB'>524288</memory>
+  <currentMemory unit='KiB'>524288</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='ppc64' machine='pseries'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-ppc64</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <serial type='pty'>
+      <target port='0'/>
+      <address type='spapr-vio'/>
+    </serial>
+    <console type='pty'>
+      <target type='serial' port='0'/>
+      <address type='spapr-vio'/>
+    </console>
+    <memballoon model='none'/>
+    <panic>
+        <address type='isa' iobase='0x505'/>
+    </panic>
+  </devices>
+</domain>

tests/qemuxml2argvdata/qemuxml2argv-pseries-panic-no-address.args

+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-ppc64 -S -M pseries -m 512 -smp 1 -nographic \
+-nodefconfig -nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/test-monitor,server,nowait \
+-mon chardev=charmonitor,id=monitor,mode=readline -no-acpi -boot c -usb \
+-chardev pty,id=charserial0 \
+-device spapr-vty,chardev=charserial0,reg=0x30000000

tests/qemuxml2argvdata/qemuxml2argv-pseries-panic-no-address.xml

+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>1ccfd97d-5eb4-478a-bbe6-88d254c16db7</uuid>
+  <memory unit='KiB'>524288</memory>
+  <currentMemory unit='KiB'>524288</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='ppc64' machine='pseries'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-ppc64</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <serial type='pty'>
+      <target port='0'/>
+      <address type='spapr-vio'/>
+    </serial>
+    <console type='pty'>
+      <target type='serial' port='0'/>
+      <address type='spapr-vio'/>
+    </console>
+    <memballoon model='none'/>
+    <panic/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1365,6 +1365,10 @@ mymain(void)
             QEMU_CAPS_CHARDEV, QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
     DO_TEST("pseries-cpu-le",  QEMU_CAPS_KVM, QEMU_CAPS_CPU_HOST,
             QEMU_CAPS_CHARDEV, QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
+    DO_TEST("pseries-panic-no-address",
+            QEMU_CAPS_CHARDEV, QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
+    DO_TEST_FAILURE("pseries-panic-address",
+                    QEMU_CAPS_CHARDEV, QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG);
     DO_TEST("disk-ide-drive-split",
             QEMU_CAPS_DRIVE, QEMU_CAPS_DEVICE, QEMU_CAPS_NODEFCONFIG,
             QEMU_CAPS_IDE_CD);

tests/qemuxml2xmltest.c

@@ -537,6 +537,7 @@ mymain(void)
     DO_TEST("virtio-rng-egd");
 
     DO_TEST("pseries-nvram");
+    DO_TEST("pseries-panic-no-address");
 
     /* These tests generate different XML */
     DO_TEST_DIFFERENT("balloon-device-auto");