New goldfish_pipe virtual device.

This adds a new virtual hardware device named "goldfish_pipe"
used to implement a very fast communication channel between the
guest system and the emulator.

IMPORTANT: This depends on a special kernel driver, see:

    https://review.source.android.com/#change,22496

Usage from the guest is simply the following:

   fd = open("/dev/qemu_pipe", O_RDWR);
   const char* pipename = "pipe:<name>";
   ret = write(fd, pipename, strlen(pipename)+1);
   if (ret < 0) {
        /* could not connect to service named <name> */
   }
   /* now you can read()/write()/close() as a normal
    * file descriptor to exchange data with the service.
    */

In addition, this implements the following pipe services in the
emulator:

   tcp:<port>
   tcp:<hostname>:<port>
   unix:<path>
   opengles

The 'tcp:' and 'unix:' services simply redirect to a TCP or Unix
socket on the host with minimal

The 'opengles' service simply connects to tcp:locahost:22468 for now.
We may change this to be more configurable in the future, but that's
the port number used by the current experimental OpenGL ES hardware
emulation host libraries / programs.

Benchmarking with a simple ping-pong program shows that the
guest <-> emulator can achieve a roundtrip bandwidth of 192 MB/s
(on a 2.7 Ghz Xeon PC).

Using the tcp: service to talk to a ping-pong server listening
on localhost reaches 102 MB/s on the same machine, using a Unix
socket reaches 140 MB/s.

By contrast, using standard sockets in the guest reaches only
3.8 MB/s on the same machine (and requires special privileges
from the application anyway).

1 files changed, 0 insertions, 15 deletions

diff --git a/hw/goldfish_trace.c b/hw/goldfish_trace.c
index ee51a8b..02f9b8d 100644
--- a/hw/goldfish_trace.c
+++ b/hw/goldfish_trace.c
@@ -15,7 +15,6 @@
  */
 #include "qemu_file.h"
 #include "goldfish_trace.h"
-#include "goldfish_pipe.h"
 #include "sysemu.h"
 #include "trace.h"
 #ifdef CONFIG_MEMCHECK
@@ -177,7 +176,6 @@ static void trace_dev_write(void *opaque, target_phys_addr_t offset, uint32_t va
             memcheck_exit(value);
         }
 #endif  // CONFIG_MEMCHECK
-        goldfish_pipe_thread_death((int)tid);
         break;
     case TRACE_DEV_REG_NAME:            // record thread name
         vstrcpy(value, exec_path, CLIENT_PAGE_SIZE);
@@ -350,13 +348,6 @@ static void trace_dev_write(void *opaque, target_phys_addr_t offset, uint32_t va
         break;
 #endif // CONFIG_MEMCHECK
 
-    case TRACE_DEV_PIPE_COMMAND:
-    case TRACE_DEV_PIPE_ADDRESS:
-    case TRACE_DEV_PIPE_SIZE:
-    case TRACE_DEV_PIPE_CHANNEL:
-        goldfish_pipe_write(tid, ((offset >> 2) - TRACE_DEV_PIPE_BASE), value);
-        break;
-
     default:
         if (offset < 4096) {
             cpu_abort(cpu_single_env, "trace_dev_write: Bad offset %x\n", offset);
@@ -379,12 +370,6 @@ static uint32_t trace_dev_read(void *opaque, target_phys_addr_t offset)
     case TRACE_DEV_REG_ENABLE:          // tracing enable
         return tracing;
 
-    case TRACE_DEV_PIPE_COMMAND:
-    case TRACE_DEV_PIPE_ADDRESS:
-    case TRACE_DEV_PIPE_SIZE:
-    case TRACE_DEV_PIPE_CHANNEL:
-        return goldfish_pipe_read(tid, (offset >> 2) - TRACE_DEV_PIPE_BASE);
-
     default:
         if (offset < 4096) {
             cpu_abort(cpu_single_env, "trace_dev_read: Bad offset %x\n", offset);