virtmgr: Support dumping guest DT for debugging
Give a way to make crosvm dump the guest DT it generated without needing
to recompile and/or reinstall any part of the stack, by detecting the
newly-introduced boolean system property
hypervisor.virtualizationmanager.dump_device_tree
which can be set on devices being debugged.
Note: this propery is redundant if you pass a path to dump the device
tree using --dump-device-tree
Bug: 335160369
Test: m virtmgr && TH
Test: adb shell setprop
hypervisor.virtualizationmanager.dump_device_tree true && /apex/.../vm
run-microdroid && check
/data/misc/virtualizationservice/CID/device_tree.dtb exists
Change-Id: I71ba56f14812ccb9bc5dab1ad3789656aa9a8460
diff --git a/android/virtmgr/src/aidl.rs b/android/virtmgr/src/aidl.rs
index 87d7a88..4555ebc 100644
--- a/android/virtmgr/src/aidl.rs
+++ b/android/virtmgr/src/aidl.rs
@@ -534,7 +534,13 @@
clone_or_prepare_logger_fd(console_out_fd, format!("Console({})", cid))?;
let console_in_fd = console_in_fd.map(clone_file).transpose()?;
let log_fd = clone_or_prepare_logger_fd(log_fd, format!("Log({})", cid))?;
- let dump_dt_fd = dump_dt_fd.map(clone_file).transpose()?;
+ let dump_dt_fd = if let Some(fd) = dump_dt_fd {
+ Some(clone_file(fd)?)
+ } else if debug_config.dump_device_tree {
+ Some(prepare_dump_dt_file(&temporary_directory)?)
+ } else {
+ None
+ };
// Counter to generate unique IDs for temporary image files.
let mut next_temporary_image_id = 0;
@@ -1669,6 +1675,16 @@
Ok(ramdump)
}
+/// Create the empty device tree dump file
+fn prepare_dump_dt_file(temporary_directory: &Path) -> binder::Result<File> {
+ let path = temporary_directory.join("device_tree.dtb");
+ let file = File::create(path)
+ .context("Failed to prepare device tree dump file")
+ .with_log()
+ .or_service_specific_exception(-1)?;
+ Ok(file)
+}
+
fn is_protected(config: &VirtualMachineConfig) -> bool {
match config {
VirtualMachineConfig::RawConfig(config) => config.protectedVm,