arch: Don't set up serial device when vhost-user console is set

crosvm sets up an emulated serial device for ttyS0 as a default device
unless virtio-console is specified.
The setup should be skipped when a vhost-user console is specified as well.

BUG=b:196186396
BUG=b:227407433
TEST=no serial output when one vhost-user console is specified.

Change-Id: Ib17e218fd01a13c109fc1246fd3a6d99031d3181
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3557729
Reviewed-by: Morg <morg@chromium.org>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Keiichi Watanabe <keiichiw@chromium.org>

arch/src/serial.rs

@@ -26,11 +26,12 @@ use crate::DeviceRegistrationError;
 /// configured explicitly.
 pub fn set_default_serial_parameters(
     serial_parameters: &mut BTreeMap<(SerialHardware, u8), SerialParameters>,
+    is_vhost_user_console_enabled: bool,
 ) {
     // If no console device exists and the first serial port has not been specified,
     // set the first serial port as a stdout+stdin console.
     let default_console = (SerialHardware::Serial, 1);
-    if !serial_parameters.iter().any(|(_, p)| p.console) {
+    if !serial_parameters.iter().any(|(_, p)| p.console) && !is_vhost_user_console_enabled {
         serial_parameters
             .entry(default_console)
             .or_insert(SerialParameters {
@@ -148,6 +149,7 @@ pub type GetSerialCmdlineResult<T> = std::result::Result<T, GetSerialCmdlineErro
 /// Add serial options to the provided `cmdline` based on `serial_parameters`.
 /// `serial_io_type` should be "io" if the platform uses x86-style I/O ports for serial devices
 /// or "mmio" if the serial ports are memory mapped.
+// TODO(b/227407433): Support cases where vhost-user console is specified.
 pub fn get_serial_cmdline(
     cmdline: &mut kernel_cmdline::Cmdline,
     serial_parameters: &BTreeMap<(SerialHardware, u8), SerialParameters>,
@@ -207,7 +209,7 @@ mod tests {
         let mut cmdline = Cmdline::new(4096);
         let mut serial_parameters = BTreeMap::new();
 
-        set_default_serial_parameters(&mut serial_parameters);
+        set_default_serial_parameters(&mut serial_parameters, false);
         get_serial_cmdline(&mut cmdline, &serial_parameters, "io")
             .expect("get_serial_cmdline failed");
 
@@ -236,7 +238,7 @@ mod tests {
             },
         );
 
-        set_default_serial_parameters(&mut serial_parameters);
+        set_default_serial_parameters(&mut serial_parameters, false);
         get_serial_cmdline(&mut cmdline, &serial_parameters, "io")
             .expect("get_serial_cmdline failed");
 
@@ -281,7 +283,7 @@ mod tests {
             },
         );
 
-        set_default_serial_parameters(&mut serial_parameters);
+        set_default_serial_parameters(&mut serial_parameters, false);
         get_serial_cmdline(&mut cmdline, &serial_parameters, "io")
             .expect("get_serial_cmdline failed");
 
@@ -311,7 +313,7 @@ mod tests {
             },
         );
 
-        set_default_serial_parameters(&mut serial_parameters);
+        set_default_serial_parameters(&mut serial_parameters, false);
         get_serial_cmdline(&mut cmdline, &serial_parameters, "io")
             .expect_err("get_serial_cmdline succeeded");
     }

src/main.rs

@@ -2462,7 +2462,12 @@ fn validate_arguments(cfg: &mut Config) -> std::result::Result<(), argument::Err
             "'balloon-control' requires enabled balloon".to_owned(),
         ));
     }
-    set_default_serial_parameters(&mut cfg.serial_parameters);
+
+    set_default_serial_parameters(
+        &mut cfg.serial_parameters,
+        !cfg.vhost_user_console.is_empty(),
+    );
+
     Ok(())
 }
 

x86_64/src/test_integration.rs

@@ -154,7 +154,7 @@ where
 
     let mut serial_params = BTreeMap::new();
 
-    arch::set_default_serial_parameters(&mut serial_params);
+    arch::set_default_serial_parameters(&mut serial_params, false);
 
     X8664arch::setup_serial_devices(
         ProtectionType::Unprotected,