Support VirtiofsMounts

carthage/resources/templates/vm-config.mako

@@ -24,6 +24,12 @@ def is_vnc():
     <carthage:layout xmlns:carthage='https://github.com/hadron/carthage' layout='${layout_name}' orphan_policy='${orphan_policy.name}'/>
     </metadata>
   <memory unit='KiB'>${memory_mb*1024}</memory>
+%if virtiofs_mounts:
+  <memoryBacking>
+    <source type='memfd'/>
+    <access mode='shared'/>
+  </memoryBacking>
+%endif
 
   <vcpu placement='static' >${cpus}</vcpu>
   <cpu mode='host-model'>
@@ -91,7 +97,17 @@ def is_vnc():
       <backend type='emulator' version='2.0'/>
     </tpm>
 %endif
-    %for i, link in links.items():
+%for mount in virtiofs_mounts:
+    <filesystem type='mount' accessmode='passthrough'>
+      <driver type='virtiofs'/>
+      <source dir='${mount.source}'/>
+      <target dir='${mount.destination}'/>
+      %if mount.readonly:
+      <readonly />
+      %endif
+    </filesystem>
+    %endfor
+%for i, link in links.items():
     <% if link.local_type: continue %>\
         <interface type='bridge'>
 %if link.mac is not None:

carthage/vm.py

@@ -38,10 +38,18 @@
 
 vm_image_key = InjectionKey('vm-image')
 
-# Our capitalization rules are kind of under-sspecified.  We're not
-# upcasing all letters of acronyms in camel-case compounds, but Vm
-# seems strange.  VM is canonical but Vm is an accepted alias.
+#dataclasses.dataclass
+class VirtiofsMount(Injectable):
 
+    destination: str
+    source:str
+    readonly:bool = False
+    priority:int = 100
+
+    def default_instance_injection_key(self):
+        return InjectionKey(VirtiofsMount, destination=self.destination, priority=self.priority)
+
+
 
 @inject_autokwargs(
     injector=Injector,
@@ -144,6 +152,7 @@ async def write_config(self):
                 links=self.network_links,
                 model_in=self.model,
                 disk_config=disk_config,
+                virtiofs_mounts=self.virtiofs_mounts,
                 if_name=lambda n: carthage.network.base.if_name(
                     "vn", self.config_layout.container_prefix, n.name, self.name),
                 uuid=self.uuid,
@@ -372,6 +381,15 @@ async def delete(self):
         except Exception: pass
         del self.stamp_path
 
+    @memoproperty
+    def virtiofs_mounts(self):
+        '''
+        Return a list of VirtiofsMounts that should be mounted by this VM in config order. By default self.injector.filter_instantiate is used.
+        '''
+        res =  [x[1] for x in self.injector.filter_instantiate(VirtiofsMount, ['destination'])]
+        res.sort(key=lambda k:k.priority)
+        return res
+
 VM = Vm
 
 
@@ -567,4 +585,4 @@ def __init__(self, **kwargs):
         cl = self.injector.get_instance(ConfigLayout)
         cl.container_prefix = ""
 
-        __all__ = ('VM', 'Vm', 'InstallQemuAgent')
+        __all__ = ('VM', 'Vm', 'InstallQemuAgent', 'VirtiofsMount')