spicevmc: support new qemu chardev

Inspired by https://bugzilla.redhat.com/show_bug.cgi?id=615757

Add a new character device backend for virtio serial channels that
activates the QEMU spice agent on the main channel using the vdagent
spicevmc connection.  The <target> must be type='virtio', and supports
an optional name that specifies how the guest will see the channel
(for now, name must be com.redhat.spice.0).

<channel type='spicevmc'>
  <target type='virtio'/>
  <address type='virtio-serial' controller='1' bus='0' port='3'/>
</channel>

* docs/schemas/domain.rng: Support new XML.
* docs/formatdomain.html.in: Document it.
* src/conf/domain_conf.h (virDomainChrType): New enum value.
* src/conf/domain_conf.c (virDomainChr): Add spicevmc.
(virDomainChrDefParseXML, virDomainChrSourceDefParseXML)
(virDomainChrDefParseTargetXML): Parse and enforce proper use.
(virDomainChrSourceDefFormat, virDomainChrDefFormat): Format.
* src/qemu/qemu_command.c (qemuBuildChrChardevStr)
(qemuBuildCommandLine): Add qemu support.
* tests/qemuxml2argvtest.c (domain): New test.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.xml: New
file.
* tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.args:
Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>

docs/formatdomain.html.in

@@ -1734,6 +1734,9 @@ qemu-kvm -net nic,model=? /dev/null
     <channel type='pty'>
       <target type='virtio' name='arbitrary.virtio.serial.port.name'/>
     </channel>
+    <channel type='spicevmc'>
+      <target type='virtio' name='com.redhat.spice.0'/>
+    </channel>
   </devices>
   ...</pre>
 
@@ -1759,6 +1762,20 @@ qemu-kvm -net nic,model=? /dev/null
         optional element <code>address</code> can tie the channel to a
         particular <code>type='virtio-serial'</code> controller.
         <span class="since">Since 0.7.7</span></dd>
+
+      <dt><code>spicevmc</code></dt>
+      <dd>Paravirtualized SPICE channel. The domain must also have a
+        SPICE server as a <a href="#elementsGraphics">graphics
+        device</a>, at which point the host piggy-backs messages
+        across the <code>main</code> channel.  The <code>target</code>
+        element must be present, with
+        attribute <code>type='virtio'</code>; an optional
+        attribute <code>name</code> controls how the guest will have
+        access to the channel, and defaults
+        to <code>name='com.redhat.spice.0'</code>.  The
+        optional <code>address</code> element can tie the channel to a
+        particular <code>type='virtio-serial'</code> controller.
+        <span class="since">Since 0.8.8</span></dd>
     </dl>
 
     <h5><a name="elementsCharHostInterface">Host interface</a></h5>

docs/schemas/domain.rng

@@ -1475,6 +1475,7 @@
         <value>stdio</value>
         <value>vc</value>
         <value>pty</value>
+        <value>spicevmc</value>
       </choice>
     </attribute>
   </define>
@@ -1611,7 +1612,7 @@
   <define name="virtioTarget">
     <element name="target">
       <attribute name="type">
-          <value>virtio</value>
+        <value>virtio</value>
       </attribute>
       <optional>
         <attribute name="name"/>

src/conf/domain_conf.c

@@ -226,7 +226,8 @@ VIR_ENUM_IMPL(virDomainChr, VIR_DOMAIN_CHR_TYPE_LAST,
               "stdio",
               "udp",
               "tcp",
-              "unix")
+              "unix",
+              "spicevmc")
 
 VIR_ENUM_IMPL(virDomainChrTcpProtocol, VIR_DOMAIN_CHR_TCP_PROTOCOL_LAST,
               "raw",
@@ -3065,6 +3066,7 @@ virDomainChrSourceDefParseXML(virDomainChrSourceDefPtr def,
         break;
 
     case VIR_DOMAIN_CHR_TYPE_STDIO:
+    case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
         /* Nada */
         break;
 
@@ -3254,6 +3256,13 @@ virDomainChrDefParseXML(virCapsPtr caps,
         }
     }
 
+    if (def->source.type == VIR_DOMAIN_CHR_TYPE_SPICEVMC &&
+        def->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO) {
+        virDomainReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                             _("spicevmc device type only supports virtio"));
+        goto error;
+    }
+
     if (virDomainDeviceInfoParseXML(node, &def->info, flags) < 0)
         goto error;
 
@@ -3361,6 +3370,12 @@ virDomainSmartcardDefParseXML(xmlNodePtr node,
         cur = node->children;
         if (virDomainChrSourceDefParseXML(&def->data.passthru, cur) < 0)
             goto error;
+
+        if (def->data.passthru.type == VIR_DOMAIN_CHR_TYPE_SPICEVMC) {
+            virDomainReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                                 _("smartcard spicevmc device not supported"));
+            goto error;
+        }
         break;
 
     default:
@@ -6843,6 +6858,7 @@ virDomainChrSourceDefFormat(virBufferPtr buf,
     case VIR_DOMAIN_CHR_TYPE_NULL:
     case VIR_DOMAIN_CHR_TYPE_VC:
     case VIR_DOMAIN_CHR_TYPE_STDIO:
+    case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
         /* nada */
         break;
 

src/conf/domain_conf.h

@@ -413,6 +413,7 @@ enum virDomainChrType {
     VIR_DOMAIN_CHR_TYPE_UDP,
     VIR_DOMAIN_CHR_TYPE_TCP,
     VIR_DOMAIN_CHR_TYPE_UNIX,
+    VIR_DOMAIN_CHR_TYPE_SPICEVMC,
 
     VIR_DOMAIN_CHR_TYPE_LAST,
 };
@@ -432,6 +433,7 @@ typedef virDomainChrSourceDef *virDomainChrSourceDefPtr;
 struct _virDomainChrSourceDef {
     int type; /* virDomainChrType */
     union {
+        /* no <source> for null, vc, stdio, spicevmc */
         struct {
             char *path;
         } file; /* pty, file, pipe, or device */

src/qemu/qemu_command.c

@@ -2006,7 +2006,8 @@ qemuBuildUSBHostdevUsbDevStr(virDomainHostdevDefPtr dev)
 /* This function outputs a -chardev command line option which describes only the
  * host side of the character device */
 static char *
-qemuBuildChrChardevStr(virDomainChrSourceDefPtr dev, const char *alias)
+qemuBuildChrChardevStr(virDomainChrSourceDefPtr dev, const char *alias,
+                       unsigned long long qemuCmdFlags)
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
     bool telnet;
@@ -2072,6 +2073,21 @@ qemuBuildChrChardevStr(virDomainChrSourceDefPtr dev, const char *alias)
                           dev->data.nix.path,
                           dev->data.nix.listen ? ",server,nowait" : "");
         break;
+
+    case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
+        if (!(qemuCmdFlags & QEMUD_CMD_FLAG_CHARDEV_SPICEVMC)) {
+            qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                            _("spicevmc not supported in this QEMU binary"));
+            goto error;
+        }
+        virBufferVSprintf(&buf, "spicevmc,id=char%s,name=vdagent", alias);
+        break;
+
+    default:
+        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                        _("unsupported chardev '%s'"),
+                        virDomainChrTypeToString(dev->type));
+        goto error;
     }
 
     if (virBufferError(&buf)) {
@@ -2196,6 +2212,14 @@ qemuBuildVirtioSerialPortDevStr(virDomainChrDefPtr dev)
 
     virBufferVSprintf(&buf, ",chardev=char%s,id=%s",
                       dev->info.alias, dev->info.alias);
+    if (dev->source.type == VIR_DOMAIN_CHR_TYPE_SPICEVMC &&
+        dev->target.name &&
+        STRNEQ(dev->target.name, "com.redhat.spice.0")) {
+        qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                        _("Unsupported spicevmc target name '%s'"),
+                        dev->target.name);
+        goto error;
+    }
     if (dev->target.name) {
         virBufferVSprintf(&buf, ",name=%s", dev->target.name);
     }
@@ -2825,7 +2849,8 @@ qemuBuildCommandLine(virConnectPtr conn,
         if (qemuCmdFlags & QEMUD_CMD_FLAG_CHARDEV) {
 
             virCommandAddArg(cmd, "-chardev");
-            if (!(chrdev = qemuBuildChrChardevStr(monitor_chr, "monitor")))
+            if (!(chrdev = qemuBuildChrChardevStr(monitor_chr, "monitor",
+                                                  qemuCmdFlags)))
                 goto error;
             virCommandAddArg(cmd, chrdev);
             VIR_FREE(chrdev);
@@ -3523,7 +3548,8 @@ qemuBuildCommandLine(virConnectPtr conn,
 
             virCommandAddArg(cmd, "-chardev");
             if (!(devstr = qemuBuildChrChardevStr(&smartcard->data.passthru,
-                                                  smartcard->info.alias))) {
+                                                  smartcard->info.alias,
+                                                  qemuCmdFlags))) {
                 virBufferFreeAndReset(&opt);
                 goto error;
             }
@@ -3560,7 +3586,8 @@ qemuBuildCommandLine(virConnectPtr conn,
                 (qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE)) {
                 virCommandAddArg(cmd, "-chardev");
                 if (!(devstr = qemuBuildChrChardevStr(&serial->source,
-                                                      serial->info.alias)))
+                                                      serial->info.alias,
+                                                      qemuCmdFlags)))
                     goto error;
                 virCommandAddArg(cmd, devstr);
                 VIR_FREE(devstr);
@@ -3592,7 +3619,8 @@ qemuBuildCommandLine(virConnectPtr conn,
                 (qemuCmdFlags & QEMUD_CMD_FLAG_DEVICE)) {
                 virCommandAddArg(cmd, "-chardev");
                 if (!(devstr = qemuBuildChrChardevStr(&parallel->source,
-                                                      parallel->info.alias)))
+                                                      parallel->info.alias,
+                                                      qemuCmdFlags)))
                     goto error;
                 virCommandAddArg(cmd, devstr);
                 VIR_FREE(devstr);
@@ -3626,7 +3654,8 @@ qemuBuildCommandLine(virConnectPtr conn,
 
             virCommandAddArg(cmd, "-chardev");
             if (!(devstr = qemuBuildChrChardevStr(&channel->source,
-                                                  channel->info.alias)))
+                                                  channel->info.alias,
+                                                  qemuCmdFlags)))
                 goto error;
             virCommandAddArg(cmd, devstr);
             VIR_FREE(devstr);
@@ -3653,7 +3682,8 @@ qemuBuildCommandLine(virConnectPtr conn,
 
             virCommandAddArg(cmd, "-chardev");
             if (!(devstr = qemuBuildChrChardevStr(&channel->source,
-                                                  channel->info.alias)))
+                                                  channel->info.alias,
+                                                  qemuCmdFlags)))
                 goto error;
             virCommandAddArg(cmd, devstr);
             VIR_FREE(devstr);
@@ -3682,7 +3712,8 @@ qemuBuildCommandLine(virConnectPtr conn,
 
             virCommandAddArg(cmd, "-chardev");
             if (!(devstr = qemuBuildChrChardevStr(&console->source,
-                                                  console->info.alias)))
+                                                  console->info.alias,
+                                                  qemuCmdFlags)))
                 goto error;
             virCommandAddArg(cmd, devstr);
             VIR_FREE(devstr);

tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.args

@@ -0,0 +1,9 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=spice \
+/usr/bin/qemu -S -M pc -m 214 -smp 1 -nodefconfig -nodefaults \
+-monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -device \
+virtio-serial-pci,id=virtio-serial1,bus=pci.0,addr=0xa -hda \
+/dev/HostVG/QEMUGuest1 -chardev spicevmc,id=charchannel0,name=vdagent -device \
+virtserialport,bus=virtio-serial1.0,nr=3,chardev=charchannel0,id=channel0\
+,name=com.redhat.spice.0 -usb -spice port=5903,tls-port=5904,addr=127.0.0.1,\
+x509-dir=/etc/pki/libvirt-spice,tls-channel=main -device \
+virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvdata/qemuxml2argv-channel-spicevmc.xml

@@ -0,0 +1,34 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219136</memory>
+  <vcpu cpuset='1-4,8-20,525'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>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</emulator>
+    <disk type='block' device='disk'>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <controller type='virtio-serial' index='1'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
+    </controller>
+    <graphics type='spice' port='5903' tlsPort='5904' autoport='no' listen='127.0.0.1'>
+      <channel name='main' mode='secure'/>
+    </graphics>
+    <channel type='spicevmc'>
+      <target type='virtio' name='com.redhat.spice.0'/>
+      <address type='virtio-serial' controller='1' bus='0' port='3'/>
+    </channel>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -407,6 +407,9 @@ mymain(int argc, char **argv)
             QEMUD_CMD_FLAG_NODEFCONFIG, false);
     DO_TEST("console-virtio", QEMUD_CMD_FLAG_DEVICE |
             QEMUD_CMD_FLAG_NODEFCONFIG, false);
+    DO_TEST("channel-spicevmc", QEMUD_CMD_FLAG_DEVICE |
+            QEMUD_CMD_FLAG_NODEFCONFIG | QEMUD_CMD_FLAG_SPICE |
+            QEMUD_CMD_FLAG_CHARDEV_SPICEVMC, false);
 
     DO_TEST("smartcard-host",
             QEMUD_CMD_FLAG_CHARDEV | QEMUD_CMD_FLAG_DEVICE |