linux: drop VM before exiting to allow cleanup

Clean up the `linux` object (which contains the devices) before the
control sockets passed to `run_control` are closed.  This allows crosvm
to shut down cleanly without any error messages about short reads from
the control sockets.

BUG=chromium:992494
TEST=exit crosvm without errors

Change-Id: I1040c2f9ecbd03f820c7082da3327962ecc445f1
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1802155
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/linux.rs b/src/linux.rs
index 7ce7c82..58e0971 100644
--- a/src/linux.rs
+++ b/src/linux.rs
@@ -10,6 +10,7 @@ use std::ffi::CStr;
 use std::fmt::{self, Display};
 use std::fs::{File, OpenOptions};
 use std::io::{self, stdin, Read};
+use std::mem;
 use std::net::Ipv4Addr;
 #[cfg(feature = "gpu")]
 use std::num::NonZeroU8;
@@ -1517,7 +1518,8 @@ fn run_control(
     let vcpu_thread_barrier = Arc::new(Barrier::new(linux.vcpus.len() + 1));
     let run_mode_arc = Arc::new(VcpuRunMode::default());
     setup_vcpu_signal_handler()?;
-    for (cpu_id, vcpu) in linux.vcpus.into_iter().enumerate() {
+    let vcpus = linux.vcpus.split_off(0);
+    for (cpu_id, vcpu) in vcpus.into_iter().enumerate() {
         let handle = run_vcpu(
             vcpu,
             cpu_id as u32,
@@ -1804,6 +1806,10 @@ fn run_control(
         }
     }
 
+    // Explicitly drop the VM structure here to allow the devices to clean up before the
+    // control sockets are closed when this function exits.
+    mem::drop(linux);
+
     stdin_lock
         .set_canon_mode()
         .expect("failed to restore canonical mode for terminal");