From 59dd4a8bb69d251aed90b97191e65a9126bc1bf5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Pierret=20=28fepitre=29?=
 <frederic.pierret@qubes-os.org>
Date: Fri, 3 May 2024 15:14:41 +0200
Subject: [PATCH] Support for providing audiovm on start for HVM

Inspired from https://forum.qubes-os.org/t/audio-qube/20685#special-cases-of-non-linux-hvm-16
---
 qubes/ext/audio.py        |  3 +-
 qubes/tests/vm/qubesvm.py | 78 ++++++++++++++++++++++++++++++++++++++-
 templates/libvirt/xen.xml |  9 ++++-
 3 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/qubes/ext/audio.py b/qubes/ext/audio.py
index c5c35a5d7..2cbbaa00b 100644
--- a/qubes/ext/audio.py
+++ b/qubes/ext/audio.py
@@ -93,6 +93,8 @@ def on_property_reset(self, subject, event, name, oldvalue=None):
 
     @staticmethod
     async def set_stubdom_audiovm_domid(qube, audiovm):
+        if not audiovm:
+            return
         try:
             await qube.run_service_for_stdio(
                 f"qubes.SetAudioVM+{audiovm.xid}",
@@ -120,7 +122,6 @@ def on_property_set(self, subject, event, name, newvalue, oldvalue=None):
             subject.log.warning("Cannot change dynamically audiovm: qrexec"
                                 " is not available (stubdom-qrexec feature)")
         if has_audio_model and has_stubdom_qrexec:
-            subject.log.warning(f"setting {newvalue.xid}")
             asyncio.ensure_future(
                 self.set_stubdom_audiovm_domid(subject, newvalue)
             )
diff --git a/qubes/tests/vm/qubesvm.py b/qubes/tests/vm/qubesvm.py
index 232745181..da4f502ba 100644
--- a/qubes/tests/vm/qubesvm.py
+++ b/qubes/tests/vm/qubesvm.py
@@ -1633,7 +1633,7 @@ def test_610_libvirt_xml_network(self):
                 <script path="vif-route-qubes" />
             </interface>
             <!-- server_ip is the address of stubdomain. It hosts it's own DNS server. -->
-            <emulator type="stubdom-linux" cmdline="-qubes-net:client_ip=10.137.0.1,dns_0=10.139.1.1,dns_1=10.139.1.2,gw=10.137.0.2,netmask=255.255.255.255" />
+            <emulator type="stubdom-linux" cmdline="-qubes-audio:audiovm_xid=0 -qubes-net:client_ip=10.137.0.1,dns_0=10.139.1.1,dns_1=10.139.1.2,gw=10.137.0.2,netmask=255.255.255.255" />
             <input type="tablet" bus="usb"/>
             <video>
                 <model type="vga"/>
@@ -1647,10 +1647,16 @@ def test_610_libvirt_xml_network(self):
         '''
         my_uuid = '7db78950-c467-4863-94d1-af59806384ea'
         netvm = self.get_vm(qid=2, name='netvm', provides_network=True)
+
+        dom0 = self.get_vm(name='dom0', qid=0)
+        dom0._qubesprop_xid = 0
+
         vm = self.get_vm(uuid=my_uuid)
         vm.netvm = netvm
         vm.virt_mode = 'hvm'
         vm.features['qrexec'] = True
+        vm.audiovm = dom0
+
         with self.subTest('ipv4_only'):
             libvirt_xml = vm.create_config_file()
             self.assertXMLEqual(lxml.etree.XML(libvirt_xml),
@@ -1663,6 +1669,76 @@ def test_610_libvirt_xml_network(self):
                     extra_ip='<ip address="{}::a89:1" family=\'ipv6\'/>'.format(
                         qubes.config.qubes_ipv6_prefix.replace(':0000', '')))))
 
+    def test_611_libvirt_xml_audiovm(self):
+        expected = '''<domain type="xen">
+        <name>test-inst-test</name>
+        <uuid>7db78950-c467-4863-94d1-af59806384ea</uuid>
+        <memory unit="MiB">500</memory>
+        <currentMemory unit="MiB">400</currentMemory>
+        <vcpu placement="static">2</vcpu>
+        <cpu mode='host-passthrough'>
+            <!-- disable nested HVM -->
+            <feature name='vmx' policy='disable'/>
+            <feature name='svm' policy='disable'/>
+            <!-- let the guest know the TSC is safe to use (no migration) -->
+            <feature name='invtsc' policy='require'/>
+        </cpu>
+        <os>
+            <type arch="x86_64" machine="xenfv">hvm</type>
+                <!--
+                     For the libxl backend libvirt switches between OVMF (UEFI)
+                     and SeaBIOS based on the loader type. This has nothing to
+                     do with the hvmloader binary.
+                -->
+            <loader type="rom">hvmloader</loader>
+            <boot dev="cdrom" />
+            <boot dev="hd" />
+        </os>
+        <features>
+            <pae/>
+            <acpi/>
+            <apic/>
+            <viridian/>
+        </features>
+        <clock offset="variable" adjustment="0" basis="utc" />
+        <on_poweroff>destroy</on_poweroff>
+        <on_reboot>destroy</on_reboot>
+        <on_crash>destroy</on_crash>
+        <devices>
+            <interface type="ethernet">
+                <mac address="00:16:3e:5e:6c:00" />
+                <ip address="10.137.0.1" />
+                <backenddomain name="test-inst-netvm" />
+                <script path="vif-route-qubes" />
+            </interface>
+            <!-- server_ip is the address of stubdomain. It hosts it's own DNS server. -->
+            <emulator type="stubdom-linux" cmdline="-qubes-audio:audiovm_xid={audiovm_xid} -qubes-net:client_ip=10.137.0.1,dns_0=10.139.1.1,dns_1=10.139.1.2,gw=10.137.0.2,netmask=255.255.255.255" />
+            <input type="tablet" bus="usb"/>
+            <video>
+                <model type="vga"/>
+            </video>
+            <graphics type="qubes"/>
+            <console type="pty">
+                <target type="xen" port="0"/>
+            </console>
+        </devices>
+        </domain>
+        '''
+        my_uuid = '7db78950-c467-4863-94d1-af59806384ea'
+        netvm = self.get_vm(qid=2, name='netvm', provides_network=True)
+        audiovm = self.get_vm(qid=3, name='sys-audio', provides_network=False)
+        audiovm._qubesprop_xid = audiovm.qid
+
+        vm = self.get_vm(uuid=my_uuid)
+        vm.netvm = netvm
+        vm.audiovm = audiovm
+        vm.virt_mode = 'hvm'
+        vm.features['qrexec'] = True
+
+        libvirt_xml = vm.create_config_file()
+        self.assertXMLEqual(lxml.etree.XML(libvirt_xml),
+            lxml.etree.XML(expected.format(audiovm_xid=audiovm.xid)))
+
     def test_615_libvirt_xml_block_devices(self):
         expected = '''<domain type="xen">
         <name>test-inst-test</name>
diff --git a/templates/libvirt/xen.xml b/templates/libvirt/xen.xml
index 74655315c..51222b339 100644
--- a/templates/libvirt/xen.xml
+++ b/templates/libvirt/xen.xml
@@ -1,3 +1,8 @@
+{% if vm.audiovm is defined and vm.audiovm %}
+ {% set audiovm_xid = vm.audiovm.xid %}
+{% else %}
+ {% set audiovm_xid = -1 %}
+{% endif %}
 <domain type="xen">
     {% block basic %}
         <name>{{ vm.name }}</name>
@@ -179,13 +184,13 @@
                     {% endif %}
                     {% if vm.netvm %}
                       {% if vm.features.check_with_template('linux-stubdom', True) %}
-                        cmdline="-qubes-net:client_ip={{ vm.ip -}}
+                        cmdline="-qubes-audio:audiovm_xid={{ audiovm_xid }} -qubes-net:client_ip={{ vm.ip -}}
                             ,dns_0={{ vm.dns[0] -}}
                             ,dns_1={{ vm.dns[1] -}}
                             ,gw={{ vm.netvm.gateway -}}
                             ,netmask={{ vm.netmask }}"
                       {% else %}
-                        cmdline="-net lwip,client_ip={{ vm.ip -}}
+                        cmdline="-qubes-audio:audiovm_xid={{ audiovm_xid }} -net lwip,client_ip={{ vm.ip -}}
                             ,server_ip={{ vm.dns[1] -}}
                             ,dns={{ vm.dns[0] -}}
                             ,gw={{ vm.netvm.gateway -}}