main: log responses to command line vm control requests

Now that the connection oriented seqpacket sockets are used for vm
control messages, a response can be received by the requested. This
change prints out that response.

TEST=crosvm suspend|resume|balloon|stop <socket>
BUG=chromium:848187

Change-Id: I18ac23c26127332e2be498113cc0c3310fd09a7d
Reviewed-on: https://chromium-review.googlesource.com/1482370
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/vm_control/src/lib.rs b/vm_control/src/lib.rs
index f0fc209..72531fb 100644
--- a/vm_control/src/lib.rs
+++ b/vm_control/src/lib.rs
@@ -293,3 +293,24 @@ pub enum VmResponse {
         desc: GpuMemoryDesc,
     },
 }
+
+impl Display for VmResponse {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use self::VmResponse::*;
+
+        match self {
+            Ok => write!(f, "ok"),
+            Err(e) => write!(f, "error: {}", e),
+            RegisterMemory { pfn, slot } => write!(
+                f,
+                "memory registered to page frame number {:#x} and memory slot {}",
+                pfn, slot
+            ),
+            AllocateAndRegisterGpuMemory { pfn, slot, .. } => write!(
+                f,
+                "gpu memory allocated and registered to page frame number {:#x} and memory slot {}",
+                pfn, slot
+            ),
+        }
+    }
+}