Add tftp protocol support for cdrom disk

qemu/KVM also supports a tftp URL while specifying the cdrom ISO image.

The xml should be as following:

    <disk type='network' device='cdrom'>
      <source protocol='tftp' name='/url/path'>
        <host name='host.name' port='69'/>
      </source>
    </disk>

Signed-off-by: Aline Manera <alinefm@br.ibm.com>

docs/formatdomain.html.in

@@ -1533,6 +1533,14 @@
       <target dev='hdc' bus='ide' tray='open'/>
       <readonly/>
     </disk>
+    <disk type='network' device='cdrom'>
+      <driver name='qemu' type='raw'/>
+      <source protocol="tftp" name="url_path">
+        <host name="hostname" port="69"/>
+      </source>
+      <target dev='hdc' bus='ide' tray='open'/>
+      <readonly/>
+    </disk>
     <disk type='block' device='lun'>
       <driver name='qemu' type='raw'/>
       <source dev='/dev/sda'/>

docs/schemas/domaincommon.rng

@@ -1234,6 +1234,7 @@
         <value>https</value>
         <value>ftp</value>
         <value>ftps</value>
+        <value>tftp</value>
       </choice>
     </attribute>
     <optional>

src/conf/domain_conf.c

@@ -267,7 +267,8 @@ VIR_ENUM_IMPL(virDomainDiskProtocol, VIR_DOMAIN_DISK_PROTOCOL_LAST,
               "http",
               "https",
               "ftp",
-              "ftps")
+              "ftps",
+              "tftp")
 
 VIR_ENUM_IMPL(virDomainDiskProtocolTransport, VIR_DOMAIN_DISK_PROTO_TRANS_LAST,
               "tcp",

src/conf/domain_conf.h

@@ -546,6 +546,7 @@ enum virDomainDiskProtocol {
     VIR_DOMAIN_DISK_PROTOCOL_HTTPS,
     VIR_DOMAIN_DISK_PROTOCOL_FTP,
     VIR_DOMAIN_DISK_PROTOCOL_FTPS,
+    VIR_DOMAIN_DISK_PROTOCOL_TFTP,
 
     VIR_DOMAIN_DISK_PROTOCOL_LAST
 };

src/qemu/qemu_command.c

@@ -3923,6 +3923,12 @@ qemuBuildDriveStr(virConnectPtr conn ATTRIBUTE_UNUSED,
                                   disk->hosts->port ? disk->hosts->port : "990");
                 virBufferEscape(&opt, ',', ",", "%s,", disk->src);
                 break;
+            case VIR_DOMAIN_DISK_PROTOCOL_TFTP:
+                virBufferAsprintf(&opt, "file=tftp://%s:%s",
+                                  disk->hosts->name,
+                                  disk->hosts->port ? disk->hosts->port : "69");
+                virBufferEscape(&opt, ',', ",", "%s,", disk->src);
+                break;
             }
         } else if (disk->type == VIR_DOMAIN_DISK_TYPE_VOLUME) {
             if (qemuBuildVolumeString(conn, disk, &opt) < 0)

tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-network-tftp.args

@@ -0,0 +1,7 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/kvm -S \
+-M pc-1.2 -m 1024 -smp 1 -nographic -nodefaults \
+-monitor unix:/tmp/test-monitor,server,nowait -boot d -usb \
+-drive file=tftp://host.name:69/url/path/file.iso,if=none,media=cdrom,id=drive-ide0-1-0 \
+-device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

tests/qemuxml2argvdata/qemuxml2argv-disk-cdrom-network-tftp.xml

@@ -0,0 +1,37 @@
+<domain type='kvm'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc-1.2'>hvm</type>
+    <boot dev='cdrom'/>
+  </os>
+  <features>
+    <acpi/>
+    <apic/>
+    <pae/>
+  </features>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>restart</on_crash>
+  <devices>
+    <emulator>/usr/bin/kvm</emulator>
+    <disk type='network' device='cdrom'>
+      <driver name='qemu' type='raw'/>
+      <source protocol='tftp' name='/url/path/file.iso'>
+        <host name='host.name' port='69'/>
+      </source>
+      <target dev='hdc' bus='ide'/>
+      <readonly/>
+      <alias name='ide0-1-0'/>
+      <address type='drive' controller='0' bus='1' target='0' unit='0'/>
+    </disk>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -451,6 +451,8 @@ mymain(void)
             QEMU_CAPS_DRIVE);
     DO_TEST("disk-cdrom-network-ftps", QEMU_CAPS_KVM, QEMU_CAPS_DEVICE,
             QEMU_CAPS_DRIVE);
+    DO_TEST("disk-cdrom-network-tftp", QEMU_CAPS_KVM, QEMU_CAPS_DEVICE,
+            QEMU_CAPS_DRIVE);
     DO_TEST("disk-cdrom-empty", QEMU_CAPS_DRIVE);
     DO_TEST("disk-cdrom-tray",
             QEMU_CAPS_DRIVE, QEMU_CAPS_DEVICE, QEMU_CAPS_VIRTIO_TX_ALG);