crosvm: use pipe instead of socket for vcpu communication

Pipes have better performance than sockets, so switch the vcpu
communication over to pipes.  The vm communication channels will
continue to use sockets since that communication isn't performance
critical (and those messages sometimes exchange file descriptors, and
that functionality requires sockets).

TEST=local compile and confirmed that my diagnostic plugin is still
happy. The time it takes to run my benchmark plugin has decreased by
20%.  This combined with my prior commit results in a net wall-clock
time reduction of 32%.
BUG=None

Change-Id: I44c198d62a3bbe3b539ff6ac79707d02488876e3
Signed-off-by: Matt Delco <delco@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1572873
Commit-Ready: Matt Delco <delco@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Zach Reizner <zachr@chromium.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/protos/src/plugin.proto b/protos/src/plugin.proto
index 5b6eec2..de76089 100644
--- a/protos/src/plugin.proto
+++ b/protos/src/plugin.proto
@@ -323,6 +323,9 @@ message VcpuRequest {
         repeated CpuidEntry entries = 1;
     }
 
+    message Shutdown {
+    }
+
     // The type of the message is determined by which of these oneof fields is present in the
     // protobuf.
     oneof message {
@@ -333,6 +336,7 @@ message VcpuRequest {
         GetMsrs get_msrs = 5;
         SetMsrs set_msrs = 6;
         SetCpuid set_cpuid = 7;
+        Shutdown shutdown = 8;
     }
 }