Call qemu directly when host packages support it

Bug: 79170615
Test: Run on gce
Change-Id: Ic082ff9fc1c34687fbe895ffe6d155f362c61250
diff --git a/host/libs/vm_manager/qemu_manager.cpp b/host/libs/vm_manager/qemu_manager.cpp
new file mode 100644
index 0000000..a12bc61
--- /dev/null
+++ b/host/libs/vm_manager/qemu_manager.cpp
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "host/libs/vm_manager/qemu_manager.h"
+
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <cstdlib>
+#include <sstream>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include <gflags/gflags.h>
+#include <glog/logging.h>
+
+#include "common/libs/utils/subprocess.h"
+#include "host/libs/config/cuttlefish_config.h"
+
+extern char** environ;
+
+DEFINE_string(qemu_binary,
+              "/usr/bin/qemu-system-x86_64",
+              "The qemu binary to use");
+
+namespace vm_manager {
+
+namespace {
+
+std::string GetMonitorPath() {
+  return vsoc::CuttlefishConfig::Get()->PerInstancePath("qemu_monitor.sock");
+}
+
+int BuildAndRunQemuCmd() {
+  auto config = vsoc::CuttlefishConfig::Get();
+  std::vector<std::string> qemu_envp;
+  // Copy this process' environment
+  char** env = environ;
+  while (*env) {
+    qemu_envp.push_back(*env);
+    ++env;
+  }
+  // Set the config values in the environment
+  qemu_envp.push_back("qemu_binary=" + FLAGS_qemu_binary);
+  qemu_envp.push_back("instance_name=" + config->instance_name());
+  qemu_envp.push_back("memory_mb=" + std::to_string(config->memory_mb()));
+  qemu_envp.push_back("cpus=" + std::to_string(config->cpus()));
+  qemu_envp.push_back("uuid=" + config->uuid());
+  qemu_envp.push_back("monitor_path=" +
+                      config->PerInstancePath("qemu_monitor.sock"));
+  qemu_envp.push_back("kernel_image_path=" + config->kernel_image_path());
+  qemu_envp.push_back("ramdisk_image_path=" + config->ramdisk_image_path());
+  qemu_envp.push_back("kernel_args=" + config->kernel_args());
+  qemu_envp.push_back("dtb_path=" + config->dtb_path());
+  qemu_envp.push_back("system_image_path=" + config->system_image_path());
+  qemu_envp.push_back("data_image_path=" + config->data_image_path());
+  qemu_envp.push_back("cache_image_path=" + config->cache_image_path());
+  qemu_envp.push_back("vendor_image_path=" + config->vendor_image_path());
+  qemu_envp.push_back("mobile_tap_name=" + config->mobile_tap_name());
+  qemu_envp.push_back("kernel_log_socket_name=" +
+                      config->kernel_log_socket_name());
+  qemu_envp.push_back("console_path=" + config->console_path());
+  qemu_envp.push_back("logcat_path=" + config->logcat_path());
+  qemu_envp.push_back("ivshmem_qemu_socket_path=" +
+                      config->ivshmem_qemu_socket_path());
+  qemu_envp.push_back("ivshmem_vector_count=" +
+                      std::to_string(config->ivshmem_vector_count()));
+  for (const auto& arg : qemu_envp) {
+    LOG(INFO) << arg;
+  }
+  return cvd::execute({vsoc::DefaultHostArtifactsPath("bin/cf_qemu.sh")},
+                      qemu_envp);
+}
+
+}  // namespace
+
+bool QemuManager::Start() const {
+  // Create a thread that will make the launcher abort if the qemu process
+  // crashes, this avoids having the launcher waiting forever for
+  // VIRTUAL_DEVICE_BOOT_COMPLETED in this cases.
+  std::thread waiting_thread([]() {
+    int status = BuildAndRunQemuCmd();
+    if (status != 0) {
+      LOG(FATAL) << "Qemu process exited prematurely";
+    } else {
+      LOG(ERROR) << "Qemu process exited normally, it shouldn't happen";
+    }
+  });
+  waiting_thread.detach();
+  return true;
+}
+bool QemuManager::Stop() const {
+  int errno_;
+  int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+  if (fd == -1) {
+    errno_ = errno;
+    LOG(ERROR) << "Error creating socket: " << strerror(errno_);
+    return false;
+  }
+
+  struct sockaddr_un addr;
+  memset(&addr, 0, sizeof(addr));
+  addr.sun_family = AF_UNIX;
+  std::string monitor_path = GetMonitorPath();
+  strncpy(addr.sun_path, monitor_path.c_str(), sizeof(addr.sun_path) - 1);
+
+  if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
+    errno_ = errno;
+    LOG(ERROR) << "Error connecting to qemu monitor: " << strerror(errno_);
+    return false;
+  }
+
+  char msg[] = "{\"execute\":\"qmp_capabilities\"}{\"execute\":\"quit\"}";
+  ssize_t len = sizeof(msg) - 1;
+  while (len > 0) {
+    int tmp = TEMP_FAILURE_RETRY(write(fd, msg, len));
+    if (tmp < 0) {
+      LOG(ERROR) << "Error writing to socket";
+    }
+    len -= tmp;
+  }
+  // Log the reply
+  char buff[1000];
+  while ((len = TEMP_FAILURE_RETRY(read(fd, buff, sizeof(buff) - 1))) > 0) {
+    buff[len] = '\0';
+    LOG(INFO) << "From qemu monitor: " << buff;
+  }
+
+  return true;
+}
+
+}  // namespace vm_manager