vm_tools/concierge/arc_vm.cc

// Copyright 2019 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "vm_tools/concierge/arc_vm.h"

#include <fcntl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

// Needs to be included after sys/socket.h
#include <linux/vm_sockets.h>

#include <utility>

#include <arc/network/guest_events.h>
#include <base/files/file.h>
#include <base/files/file_path.h>
#include <base/files/file_util.h>
#include <base/files/scoped_file.h>
#include <base/logging.h>
#include <base/memory/ptr_util.h>
#include <base/strings/string_number_conversions.h>
#include <base/strings/stringprintf.h>
#include <base/strings/string_util.h>
#include <base/strings/string_split.h>
#include <base/sys_info.h>
#include <base/time/time.h>

#include "vm_tools/common/constants.h"
#include "vm_tools/concierge/tap_device_builder.h"
#include "vm_tools/concierge/vm_util.h"

using std::string;

namespace vm_tools {
namespace concierge {
namespace {

// Name of the control socket used for controlling crosvm.
constexpr char kCrosvmSocket[] = "arcvm.sock";

// Path to the wayland socket.
constexpr char kWaylandSocket[] = "/run/chrome/wayland-0";

// How long to wait before timing out on child process exits.
constexpr base::TimeDelta kChildExitTimeout = base::TimeDelta::FromSeconds(10);

// Offset in a subnet of the gateway/host.
constexpr size_t kHostAddressOffset = 0;

// Offset in a subnet of the client/guest.
constexpr size_t kGuestAddressOffset = 1;

// The CPU cgroup where all the ARCVM's crosvm processes should belong to.
constexpr char kArcvmCpuCgroup[] = "/sys/fs/cgroup/cpu/vms/arc";

// Port for arc-powerctl running on the guest side.
constexpr unsigned int kVSockPort = 4242;

// Path to the custom parameter file.
constexpr char kCustomParameterFilePath[] = "/etc/arcvm_dev.conf";

// Custom parameter key to override the kernel path
constexpr char kKeyToOverrideKernelPath[] = "KERNEL_PATH";

base::ScopedFD ConnectVSock(int cid) {
  DLOG(INFO) << "Creating VSOCK...";
  struct sockaddr_vm sa = {};
  sa.svm_family = AF_VSOCK;
  sa.svm_cid = cid;
  sa.svm_port = kVSockPort;

  base::ScopedFD fd(
      socket(AF_VSOCK, SOCK_STREAM | SOCK_CLOEXEC, 0 /* protocol */));
  if (!fd.is_valid()) {
    PLOG(ERROR) << "Failed to create VSOCK";
    return {};
  }

  DLOG(INFO) << "Connecting VSOCK";
  if (HANDLE_EINTR(connect(fd.get(),
                           reinterpret_cast<const struct sockaddr*>(&sa),
                           sizeof(sa))) == -1) {
    fd.reset();
    PLOG(ERROR) << "Failed to connect.";
    return {};
  }

  DLOG(INFO) << "VSOCK connected.";
  return fd;
}

bool ShutdownArcVm(int cid) {
  base::ScopedFD vsock(ConnectVSock(cid));
  if (!vsock.is_valid())
    return false;

  const std::string command("poweroff");
  if (HANDLE_EINTR(write(vsock.get(), command.c_str(), command.size()) !=
                   command.size())) {
    PLOG(WARNING) << "Failed to write to ARCVM VSOCK";
    return false;
  }

  DLOG(INFO) << "Started shutting down ARCVM";
  return true;
}

}  // namespace

ArcVm::ArcVm(arc_networkd::MacAddress mac_addr,
             std::unique_ptr<arc_networkd::Subnet> subnet,
             uint32_t vsock_cid,
             std::unique_ptr<SeneschalServerProxy> seneschal_server_proxy,
             base::FilePath runtime_dir,
             ArcVmFeatures features)
    : mac_addr_(std::move(mac_addr)),
      subnet_(std::move(subnet)),
      vsock_cid_(vsock_cid),
      seneschal_server_proxy_(std::move(seneschal_server_proxy)),
      features_(features) {
  CHECK(subnet_);
  CHECK(base::DirectoryExists(runtime_dir));

  // Take ownership of the runtime directory.
  CHECK(runtime_dir_.Set(runtime_dir));
}

ArcVm::~ArcVm() {
  Shutdown();
}

std::unique_ptr<ArcVm> ArcVm::Create(
    base::FilePath kernel,
    base::FilePath rootfs,
    base::FilePath fstab,
    uint32_t cpus,
    std::vector<ArcVm::Disk> disks,
    arc_networkd::MacAddress mac_addr,
    std::unique_ptr<arc_networkd::Subnet> subnet,
    uint32_t vsock_cid,
    std::unique_ptr<SeneschalServerProxy> seneschal_server_proxy,
    base::FilePath runtime_dir,
    ArcVmFeatures features,
    std::vector<string> params) {
  auto vm = base::WrapUnique(new ArcVm(
      std::move(mac_addr), std::move(subnet), vsock_cid,
      std::move(seneschal_server_proxy), std::move(runtime_dir), features));

  if (!vm->Start(std::move(kernel), std::move(rootfs), std::move(fstab), cpus,
                 std::move(disks), std::move(params))) {
    vm.reset();
  }

  return vm;
}

std::string ArcVm::GetVmSocketPath() const {
  return runtime_dir_.GetPath().Append(kCrosvmSocket).value();
}

bool ArcVm::Start(base::FilePath kernel,
                  base::FilePath rootfs,
                  base::FilePath fstab,
                  uint32_t cpus,
                  std::vector<ArcVm::Disk> disks,
                  std::vector<string> params) {
  // Set up the tap device.
  base::ScopedFD tap_fd =
      BuildTapDevice(mac_addr_, GatewayAddress(), Netmask(), true /*vnet_hdr*/);
  if (!tap_fd.is_valid()) {
    LOG(ERROR) << "Unable to build and configure TAP device";
    return false;
  }

  // Build up the process arguments.
  // clang-format off
  base::StringPairs args = {
    { kCrosvmBin,         "run" },
    { "--cpus",           std::to_string(cpus) },
    { "--mem",            GetVmMemoryMiB() },
    { "--disk",           rootfs.value() },
    { "--tap-fd",         std::to_string(tap_fd.get()) },
    { "--cid",            std::to_string(vsock_cid_) },
    { "--socket",         GetVmSocketPath() },
    { "--wayland-sock",   kWaylandSocket },
    { "--wayland-dmabuf", "" },
    { "--serial",         "type=syslog,num=1" },
    { "--syslog-tag",     base::StringPrintf("ARCVM(%u)", vsock_cid_) },
    { "--cras-audio",     "" },
    { "--cras-capture",   "" },
    { "--android-fstab",  fstab.value() },
    { "--params",         base::JoinString(params, " ") },
  };
  // clang-format on

  if (features_.gpu)
    args.emplace_back("--gpu", "");

  // Add any extra disks.
  for (const auto& disk : disks) {
    if (disk.writable) {
      args.emplace_back("--rwdisk", disk.path.value());
    } else {
      args.emplace_back("--disk", disk.path.value());
    }
  }

  // Add any custom parameters from file.
  base::FilePath file_path(kCustomParameterFilePath);
  std::string data;
  if (base::ReadFileToString(file_path, &data))
    LoadCustomParameters(data, &args);

  // Finally list the path to the kernel.
  const std::string kernel_path =
      RemoveParametersWithKey(kKeyToOverrideKernelPath, kernel.value(), &args);
  args.emplace_back(kernel_path, "");

  // Put everything into the brillo::ProcessImpl.
  for (std::pair<std::string, std::string>& arg : args) {
    process_.AddArg(std::move(arg.first));
    if (!arg.second.empty())
      process_.AddArg(std::move(arg.second));
  }

  // Change the process group before exec so that crosvm sending SIGKILL to the
  // whole process group doesn't kill us as well. The function also changes the
  // cpu cgroup for ARCVM's crosvm processes.
  process_.SetPreExecCallback(base::Bind(
      &SetUpCrosvmProcess, base::FilePath(kArcvmCpuCgroup).Append("tasks")));

  if (!process_.Start()) {
    LOG(ERROR) << "Failed to start VM process";
    return false;
  }

  // Notify arc-networkd that ARCVM is up.
  if (!arc_networkd::NotifyArcVmStart(vsock_cid_)) {
    LOG(WARNING) << "Unable to notify networking services";
  }

  return true;
}

bool ArcVm::Shutdown() {
  // Notify arc-networkd that ARCVM is down.
  if (!arc_networkd::NotifyArcVmStop()) {
    LOG(WARNING) << "Unable to notify networking services";
  }

  // Do a sanity check here to make sure the process is still around.  It may
  // have crashed and we don't want to be waiting around for an RPC response
  // that's never going to come.  kill with a signal value of 0 is explicitly
  // documented as a way to check for the existence of a process.
  if (!CheckProcessExists(process_.pid())) {
    LOG(INFO) << "ARCVM process is already gone. Do nothing";
    process_.Release();
    return true;
  }

  // Ask arc-powerctl running on the guest to power off the VM.
  // TODO(yusukes): We should call ShutdownArcVm() only after the guest side
  // service is fully started. b/143711798
  LOG(INFO) << "Shutting down ARCVM";
  if (ShutdownArcVm(vsock_cid_) &&
      WaitForChild(process_.pid(), kChildExitTimeout)) {
    LOG(INFO) << "ARCVM is shut down";
    process_.Release();
    return true;
  }

  LOG(WARNING) << "Failed to shut down ARCVM gracefully. Trying to turn it "
               << "down via the crosvm socket.";
  RunCrosvmCommand("stop", GetVmSocketPath());

  // We can't actually trust the exit codes that crosvm gives us so just see if
  // it exited.
  if (WaitForChild(process_.pid(), kChildExitTimeout)) {
    process_.Release();
    return true;
  }

  LOG(WARNING) << "Failed to stop VM " << vsock_cid_ << " via crosvm socket";

  // Kill the process with SIGTERM.
  if (process_.Kill(SIGTERM, kChildExitTimeout.InSeconds())) {
    process_.Release();
    return true;
  }

  LOG(WARNING) << "Failed to kill VM " << vsock_cid_ << " with SIGTERM";

  // Kill it with fire.
  if (process_.Kill(SIGKILL, kChildExitTimeout.InSeconds())) {
    process_.Release();
    return true;
  }

  LOG(ERROR) << "Failed to kill VM " << vsock_cid_ << " with SIGKILL";
  return false;
}

bool ArcVm::AttachUsbDevice(uint8_t bus,
                            uint8_t addr,
                            uint16_t vid,
                            uint16_t pid,
                            int fd,
                            UsbControlResponse* response) {
  return vm_tools::concierge::AttachUsbDevice(GetVmSocketPath(), bus, addr, vid,
                                              pid, fd, response);
}

bool ArcVm::DetachUsbDevice(uint8_t port, UsbControlResponse* response) {
  return vm_tools::concierge::DetachUsbDevice(GetVmSocketPath(), port,
                                              response);
}

bool ArcVm::ListUsbDevice(std::vector<UsbDevice>* devices) {
  return vm_tools::concierge::ListUsbDevice(GetVmSocketPath(), devices);
}

void ArcVm::HandleSuspendImminent() {
  RunCrosvmCommand("suspend", GetVmSocketPath());
}

void ArcVm::HandleSuspendDone() {
  RunCrosvmCommand("resume", GetVmSocketPath());
}

// static
bool ArcVm::SetVmCpuRestriction(CpuRestrictionState cpu_restriction_state) {
  int cpu_shares = 1024;
  switch (cpu_restriction_state) {
    case CPU_RESTRICTION_FOREGROUND:
      break;
    case CPU_RESTRICTION_BACKGROUND:
      cpu_shares = 64;
      break;
    default:
      NOTREACHED();
  }
  return UpdateCpuShares(base::FilePath(kArcvmCpuCgroup), cpu_shares);
}

uint32_t ArcVm::GatewayAddress() const {
  return subnet_->AddressAtOffset(kHostAddressOffset);
}

uint32_t ArcVm::IPv4Address() const {
  return subnet_->AddressAtOffset(kGuestAddressOffset);
}

uint32_t ArcVm::Netmask() const {
  return subnet_->Netmask();
}

VmInterface::Info ArcVm::GetInfo() {
  VmInterface::Info info = {
      .ipv4_address = IPv4Address(),
      .pid = pid(),
      .cid = cid(),
      .seneschal_server_handle = seneschal_server_handle(),
      .status = VmInterface::Status::RUNNING,
  };

  return info;
}

bool ArcVm::GetVmEnterpriseReportingInfo(
    GetVmEnterpriseReportingInfoResponse* response) {
  response->set_success(false);
  response->set_failure_reason("Not implemented");
  return false;
}

}  // namespace concierge
}  // namespace vm_tools