xtask: fix status check at end of VM test

This was accidentally dropped when porting build.py to Rust. On AArch64, check that qemu exits 0, and on x86_64, expect an exit code of 3.

Author: nicholasbishop

xtask/src/qemu.rs

@@ -1,7 +1,7 @@
 use crate::arch::UefiArch;
 use crate::opt::QemuOpt;
 use crate::util::command_to_string;
-use anyhow::{bail, Result};
+use anyhow::{bail, Context, Result};
 use fs_err::{File, OpenOptions};
 use nix::sys::stat::Mode;
 use nix::unistd::mkfifo;
@@ -366,12 +366,38 @@ pub fn run_qemu(arch: UefiArch, opt: &QemuOpt) -> Result<()> {
  // Start a thread to process stdout from the child.
  let stdout_thread = thread::spawn(|| echo_filtered_stdout(child_io));
 
- // Capture the result to return it, but first wait for the child to
+ // Capture the result to check it, but first wait for the child to
  // exit.
- let ret = process_qemu_io(monitor_io, serial_io, tmp_dir);
- child.wait()?;
+ let res = process_qemu_io(monitor_io, serial_io, tmp_dir);
+ let status = child.wait()?;
 
  stdout_thread.join().expect("stdout thread panicked");
 
- ret
+ // Propagate earlier error if necessary.
+ res?;
+
+ // Get qemu's exit code if possible, or return an error if
+ // terminated by a signal.
+ let qemu_exit_code = status
+ .code()
+ .context(format!("qemu was terminated by a signal: {:?}", status))?;
+
+ let successful_exit_code = match arch {
+ UefiArch::AArch64 | UefiArch::IA32 => 0,
+
+ // The x86_64 version of uefi-test-runner uses exit code 3 to
+ // indicate success. See the `shutdown` function in
+ // uefi-test-runner for more details.
+ UefiArch::X86_64 => 3,
+ };
+
+ if qemu_exit_code != successful_exit_code {
+ bail!(
+ "qemu exited with code {}, expected {}",
+ qemu_exit_code,
+ successful_exit_code
+ );
+ }
+
+ Ok(())
 }