concierge: Support passing multiple fds to StartVm

Concierge can accept arbitrarily many fds for the kernel, initramfs,
firmware etc, but the chrome client code currently only supports
passing a single fd. Installing bruschetta requires (at least for the
time being) passing in two fds, so expand the client code accordingly.

Bug: b:233289313
Change-Id: I43f582632de038e88917cfed6ae7af4ad3d20ed3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3831616
Reviewed-by: David Munro <davidmunro@google.com>
Commit-Queue: Fergus Dall <sidereal@google.com>
Cr-Commit-Position: refs/heads/main@{#1034989}

chromeos/ash/components/dbus/concierge/concierge_client.cc

@@ -141,6 +141,14 @@ class ConciergeClientImpl : public ConciergeClient {
                      std::move(callback));
   }
 
+  void StartVmWithFds(std::vector<base::ScopedFD> fds,
+                      const vm_tools::concierge::StartVmRequest& request,
+                      DBusMethodCallback<vm_tools::concierge::StartVmResponse>
+                          callback) override {
+    CallMethodWithFds(concierge::kStartVmMethod, request, std::move(fds),
+                      std::move(callback));
+  }
+
   void StopVm(const concierge::StopVmRequest& request,
               DBusMethodCallback<concierge::StopVmResponse> callback) override {
     CallMethod(concierge::kStopVmMethod, request, std::move(callback));
@@ -290,10 +298,10 @@ class ConciergeClientImpl : public ConciergeClient {
 
  private:
   template <typename RequestProto, typename ResponseProto>
-  void CallMethodWithFd(const std::string& method_name,
-                        const RequestProto& request,
-                        base::ScopedFD fd,
-                        DBusMethodCallback<ResponseProto> callback) {
+  void CallMethodWithFds(const std::string& method_name,
+                         const RequestProto& request,
+                         std::vector<base::ScopedFD> fds,
+                         DBusMethodCallback<ResponseProto> callback) {
     dbus::MethodCall method_call(concierge::kVmConciergeInterface, method_name);
     dbus::MessageWriter writer(&method_call);
 
@@ -304,15 +312,28 @@ class ConciergeClientImpl : public ConciergeClient {
       return;
     }
 
-    if (fd.is_valid())
-      writer.AppendFileDescriptor(fd.get());
+    for (auto& fd : fds) {
+      if (fd.is_valid())
+        writer.AppendFileDescriptor(fd.get());
+    }
 
     concierge_proxy_->CallMethod(
         &method_call, kConciergeDBusTimeoutMs,
         base::BindOnce(&ConciergeClientImpl::OnDBusProtoResponse<ResponseProto>,
                        weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   }
 
+  template <typename RequestProto, typename ResponseProto>
+  void CallMethodWithFd(const std::string& method_name,
+                        const RequestProto& request,
+                        base::ScopedFD fd,
+                        DBusMethodCallback<ResponseProto> callback) {
+    std::vector<base::ScopedFD> fds;
+    fds.push_back(std::move(fd));
+    CallMethodWithFds(method_name, request, std::move(fds),
+                      std::move(callback));
+  }
+
   template <typename RequestProto, typename ResponseProto>
   void CallMethod(const std::string& method_name,
                   const RequestProto& request,

chromeos/ash/components/dbus/concierge/concierge_client.h

@@ -149,13 +149,22 @@ class COMPONENT_EXPORT(CONCIERGE) ConciergeClient : public DBusClient {
       DBusMethodCallback<vm_tools::concierge::StartVmResponse> callback) = 0;
 
   // Starts a Termina VM if there is not already one running.
-  // |fd| references an extra image for concierge to use.
+  // |fds| references an extra image for concierge to use.
   // |callback| is called after the method call finishes.
   virtual void StartVmWithFd(
       base::ScopedFD fd,
       const vm_tools::concierge::StartVmRequest& request,
       DBusMethodCallback<vm_tools::concierge::StartVmResponse> callback) = 0;
 
+  // Starts a Termina VM if there is not already one running.
+  // |fds| contains any number of file descriptors to be passed to concierge in
+  // |the order they appear in the vector.
+  // |callback| is called after the method call finishes.
+  virtual void StartVmWithFds(
+      std::vector<base::ScopedFD> fds,
+      const vm_tools::concierge::StartVmRequest& request,
+      DBusMethodCallback<vm_tools::concierge::StartVmResponse> callback) = 0;
+
   // Stops the named Termina VM if it is running.
   // |callback| is called after the method call finishes.
   virtual void StopVm(

chromeos/ash/components/dbus/concierge/fake_concierge_client.cc

@@ -213,6 +213,13 @@ void FakeConciergeClient::StartVmWithFd(
   StartVm(std::move(request), std::move(callback));
 }
 
+void FakeConciergeClient::StartVmWithFds(
+    std::vector<base::ScopedFD> fds,
+    const vm_tools::concierge::StartVmRequest& request,
+    DBusMethodCallback<vm_tools::concierge::StartVmResponse> callback) {
+  StartVm(std::move(request), std::move(callback));
+}
+
 void FakeConciergeClient::NotifyTremplinStarted(
     const vm_tools::cicerone::TremplinStartedSignal& signal) {
   DCHECK(fake_cicerone_client_)

chromeos/ash/components/dbus/concierge/fake_concierge_client.h

@@ -78,6 +78,10 @@ class COMPONENT_EXPORT(CONCIERGE) FakeConciergeClient : public ConciergeClient {
                      const vm_tools::concierge::StartVmRequest& request,
                      DBusMethodCallback<vm_tools::concierge::StartVmResponse>
                          callback) override;
+  void StartVmWithFds(std::vector<base::ScopedFD> fd,
+                      const vm_tools::concierge::StartVmRequest& request,
+                      DBusMethodCallback<vm_tools::concierge::StartVmResponse>
+                          callback) override;
   void StopVm(const vm_tools::concierge::StopVmRequest& request,
               DBusMethodCallback<vm_tools::concierge::StopVmResponse> callback)
       override;