bhyve: add VNC password support

Support setting a password for the VNC framebuffer using the passwd
attribute on the <graphics/> element, if the driver has the
BHYVE_CAP_VNC_PASSWORD capability.

Note that virsh domxml-from-native does not output the password in the
generated XML, as VIR_DOMAIN_DEF_FORMAT_SECURE is not set when
formatting the domain definition.

Signed-off-by: Fabian Freyer <fabian.freyer@physik.tu-berlin.de>
Signed-off-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

tests/bhyveargv2xmldata/bhyveargv2xml-vnc-password.args

@@ -0,0 +1,10 @@
+/usr/sbin/bhyve \
+-c 1 \
+-m 214 \
+-u \
+-H \
+-P \
+-s 0:0,hostbridge \
+-l bootrom,/path/to/test.fd \
+-s 4:0,fbuf,tcp=127.0.0.1:5904,password=s3cr3t \
+-s 1,lpc bhyve

tests/bhyveargv2xmldata/bhyveargv2xml-vnc-password.xml

@@ -0,0 +1,22 @@
+<domain type='bhyve'>
+  <name>bhyve</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type>hvm</type>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>destroy</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <graphics type='vnc' port='5904' autoport='no' listen='127.0.0.1' passwd='s3cr3t'>
+      <listen type='address' address='127.0.0.1'/>
+    </graphics>
+    <video>
+      <model type='default' heads='1'/>
+    </video>
+  </devices>
+</domain>