[microTVM][RVM] Skip USB device attach if device is already attached (#…

…8737)

* [microTVM][RVM] Skip USB device attach if device is already attached

Currently, when the VirtualBox provider is selected, if base-box-tool.py
'test' command is used and a VM is already running with the USB device
necessary to perform the tests already attached to it the command fails
because it tries to blindly attach again the USB device without checking
if device is already attached.

The failure can be reproduced by first running a VM for testing (the
tests need to fail and leave the VM running):

$ ./base-box-tool.py --provider virtualbox test --microtvm-board=stm32f746g_disco

then one tries to re-run the tests without building the whole VM again:

$ ./base-box-tool.py --provider virtualbox test --skip-build zephyr --microtvm-board=stm32f746g_disco

This commit fixes that error by checking and properly skipping the USB
device attach if it's already attached to the VirtualBox VM.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>

* areusch review: Use --machinereadable for the output

Use 'showvminfo --machinereadable' output to parse for more robustness
to updates in VBoxManage.

apps/microtvm/reference-vm/base-box-tool.py

@@ -97,10 +97,26 @@ def parse_virtualbox_devices():
     return devices
 
 
+VIRTUALBOX_USB_DEVICE_RE = (
+    "USBAttachVendorId[0-9]+=0x([0-9a-z]{4})\n" +
+    "USBAttachProductId[0-9]+=0x([0-9a-z]{4})"
+)
+
+
+def parse_virtualbox_attached_usb_devices(vm_uuid):
+    output = subprocess.check_output(["VBoxManage", "showvminfo", "--machinereadable", vm_uuid], encoding="utf-8")
+
+    r = re.compile(VIRTUALBOX_USB_DEVICE_RE)
+    attached_usb_devices = r.findall(output, re.MULTILINE)
+
+    # List of couples (VendorId, ProductId) for all attached USB devices
+    return attached_usb_devices
+
+
 VIRTUALBOX_VID_PID_RE = re.compile(r"0x([0-9A-Fa-f]{4}).*")
 
 
-def attach_virtualbox(uuid, vid_hex=None, pid_hex=None, serial=None):
+def attach_virtualbox(vm_uuid, vid_hex=None, pid_hex=None, serial=None):
     usb_devices = parse_virtualbox_devices()
     for dev in usb_devices:
         m = VIRTUALBOX_VID_PID_RE.match(dev["VendorId"])
@@ -122,6 +138,12 @@ def attach_virtualbox(uuid, vid_hex=None, pid_hex=None, serial=None):
             and pid_hex == dev_pid_hex
             and (serial is None or serial == dev["SerialNumber"])
         ):
+            attached_devices = parse_virtualbox_attached_usb_devices(vm_uuid)
+            for vid, pid in parse_virtualbox_attached_usb_devices(vm_uuid):
+                if vid_hex == vid and pid_hex == pid:
+                    print(f"USB dev {vid_hex}:{pid_hex} already attached. Skipping attach.")
+                    return
+
             rule_args = [
                 "VBoxManage",
                 "usbfilter",
@@ -132,7 +154,7 @@ def attach_virtualbox(uuid, vid_hex=None, pid_hex=None, serial=None):
                 "--name",
                 "test device",
                 "--target",
-                uuid,
+                vm_uuid,
                 "--vendorid",
                 vid_hex,
                 "--productid",
@@ -141,8 +163,7 @@ def attach_virtualbox(uuid, vid_hex=None, pid_hex=None, serial=None):
             if serial is not None:
                 rule_args.extend(["--serialnumber", serial])
             subprocess.check_call(rule_args)
-            # TODO(mehrdadh): skip usb attach if it's already attached
-            subprocess.check_call(["VBoxManage", "controlvm", uuid, "usbattach", dev["UUID"]])
+            subprocess.check_call(["VBoxManage", "controlvm", vm_uuid, "usbattach", dev["UUID"]])
             return
 
     raise Exception(