Mir

Merge lp:~kdub/mir/passthrough-ipc-plumbing into lp:mir

passthrough-ipc-plumbing
Merge into development-branch

Proposed by Kevin DuBois on 2016-09-14

Status:	Merged
Approved by:	Daniel van Vugt on 2016-09-28
Approved revision:	3718
Merged at revision:	3725
Proposed branch:	lp:~kdub/mir/passthrough-ipc-plumbing
Merge into:	lp:mir
Prerequisite:	lp:~kdub/mir/nested-native-buffer
Diff against target:	1083 lines (+479/-47) 33 files modified include/common/mir_toolkit/mir_native_buffer.h (+2/-1) src/client/mir_buffer_api.cpp (+14/-0) src/client/symbols.map (+1/-0) src/include/client/mir/client_buffer.h (+1/-0) src/include/client/mir_toolkit/mir_buffer.h (+8/-0) src/include/platform/mir/graphics/buffer_ipc_message.h (+1/-1) src/platforms/android/client/buffer.cpp (+14/-7) src/platforms/android/client/buffer.h (+2/-0) src/platforms/android/client/gralloc_registrar.cpp (+4/-4) src/platforms/android/include/native_buffer.h (+0/-5) src/platforms/android/server/ipc_operations.cpp (+3/-2) src/platforms/eglstream-kms/client/client_buffer.cpp (+5/-0) src/platforms/eglstream-kms/client/client_buffer.h (+1/-0) src/platforms/mesa/client/client_buffer.cpp (+5/-0) src/platforms/mesa/client/client_buffer.h (+1/-0) src/server/frontend/protobuf_buffer_packer.cpp (+5/-0) src/server/frontend/protobuf_buffer_packer.h (+1/-0) src/server/graphics/nested/CMakeLists.txt (+1/-0) src/server/graphics/nested/ipc_operations.cpp (+92/-0) src/server/graphics/nested/ipc_operations.h (+48/-0) src/server/graphics/nested/native_buffer.h (+4/-0) tests/acceptance-tests/throwback/test_presentation_chain.cpp (+22/-0) tests/include/mir/test/doubles/mock_buffer_ipc_message.h (+1/-0) tests/include/mir/test/doubles/mock_client_buffer.h (+1/-0) tests/include/mir/test/doubles/null_client_buffer.h (+2/-0) tests/include/mir/test/doubles/stub_client_buffer.h (+9/-5) tests/unit-tests/client/test_aging_buffer.cpp (+5/-0) tests/unit-tests/platforms/android/client/test_buffer.cpp (+8/-8) tests/unit-tests/platforms/android/client/test_gralloc_registrar.cpp (+8/-8) tests/unit-tests/platforms/android/server/test_platform.cpp (+6/-5) tests/unit-tests/platforms/nested/CMakeLists.txt (+1/-0) tests/unit-tests/platforms/nested/test_buffer.cpp (+4/-1) tests/unit-tests/platforms/nested/test_ipc_operations.cpp (+199/-0)
To merge this branch:	bzr merge lp:~kdub/mir/passthrough-ipc-plumbing
Related bugs:	Link a bug report

Reviewer	Review Type	Date Requested	Status
Mir CI Bot	continuous-integration		Approve on 2016-09-27
Brandon Schaefer (community)			Approve on 2016-09-26
Cemil Azizoglu (community)		2016-09-14	Approve on 2016-09-14
Review via email: mp+305698@code.launchpad.net

Commit Message

ipc: add the ability to pass MirBuffers in the nested server to the nested clients.

This needed some rework of android's fence-passing mechanism to be a bit more generic, so the nested platform can forward fences along properly.

Description of the Change

ipc: add the ability to pass MirBuffers in the nested server to the nested clients.

This needed some rework of android's fence-passing mechanism to be a bit more generic, so the nested platform can forward fences along properly.

Mir CI Bot (mir-ci-bot) wrote on 2016-09-14:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1715/rebuild

review: Needs Fixing (continuous-integration)

Cemil Azizoglu (cemil-azizoglu) wrote on 2016-09-14:

Mildly prefer to have the nested platform in place before adding to it.

review: Approve

Kevin DuBois (kdub) wrote on 2016-09-15:

Hmm, not sure what having the nested platform in place means. Its currently organized as a mg::Platform and the code lives in the libmirserver.so library.

Splitting out the code into its own .so is in-progress, but the nested passthrough work doesn't depend on the nested code being in its own platform library.

Mir CI Bot (mir-ci-bot) wrote on 2016-09-16:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1746/rebuild

review: Needs Fixing (continuous-integration)

Mir CI Bot (mir-ci-bot) wrote on 2016-09-22:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1786/rebuild

review: Needs Fixing (continuous-integration)

Mir CI Bot (mir-ci-bot) wrote on 2016-09-23:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1807/rebuild

review: Needs Fixing (continuous-integration)

Daniel van Vugt (vanvugt) wrote on 2016-09-26:

^^^
Bug 1523621 and also Android vivid+overlay says:

19:26:42 ../../../../../tests/unit-tests/platforms/nested/test_ipc_operations.cpp:85:64: error: missing initializer for member ��mir::graphics::PlatformOperationMessage::data�� [-Werror=missing-field-initializers]
19:26:42 .WillByDefault(Return(mg::PlatformOperationMessage{}));
19:26:42 ^
19:26:42 ../../../../../tests/unit-tests/platforms/nested/test_ipc_operations.cpp:85:64: error: missing initializer for member ��mir::graphics::PlatformOperationMessage::fds�� [-Werror=missing-field-initializers]
19:26:42 ../../../../../tests/unit-tests/platforms/nested/test_ipc_operations.cpp: In member function ��virtual void NestedIPCOperations_uses_guest_platform_for_platform_ops_Test::TestBody()��:
19:26:42 ../../../../../tests/unit-tests/platforms/nested/test_ipc_operations.cpp:194:67: error: missing initializer for member ��mir::graphics::PlatformOperationMessage::data�� [-Werror=missing-field-initializers]
19:26:42 operations.platform_operation(0, mg::PlatformOperationMessage{});
19:26:42 ^
19:26:42 ../../../../../tests/unit-tests/platforms/nested/test_ipc_operations.cpp:194:67: error: missing initializer for member ��mir::graphics::PlatformOperationMessage::fds�� [-Werror=missing-field-initializers]
19:26:42 cc1plus: all warnings being treated as errors

Mir CI Bot (mir-ci-bot) wrote on 2016-09-26:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1817/rebuild

review: Approve (continuous-integration)

Brandon Schaefer (brandontschaefer) wrote on 2016-09-26:

lgtm

review: Approve

Mir CI Bot (mir-ci-bot) wrote on 2016-09-27:

review: Needs Fixing (continuous-integration)

Mir CI Bot (mir-ci-bot) wrote on 2016-09-27:

review: Needs Fixing (continuous-integration)

Daniel van Vugt (vanvugt) wrote on 2016-09-27:

08:07:21 Text conflict in src/client/mir_buffer_api.cpp
08:07:21 Text conflict in src/client/symbols.map
08:07:21 Text conflict in src/platforms/eglstream-kms/client/client_buffer.cpp
08:07:21 Text conflict in src/platforms/eglstream-kms/client/client_buffer.h
08:07:21 Text conflict in src/platforms/mesa/client/client_buffer.cpp
08:07:21 Text conflict in src/server/graphics/nested/native_buffer.h
08:07:21 Text conflict in tests/include/mir/test/doubles/mock_client_buffer.h
08:07:21 Text conflict in tests/unit-tests/client/test_aging_buffer.cpp
08:07:21 Text conflict in tests/unit-tests/platforms/nested/test_buffer.cpp
08:07:21 9 conflicts encountered.

lp:~kdub/mir/passthrough-ipc-plumbing updated on 2016-09-27

3718. By Kevin DuBois on 2016-09-27: merge mir, fix 9 conflicts

Mir CI Bot (mir-ci-bot) wrote on 2016-09-27:

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/1830/rebuild

review: Approve (continuous-integration)

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Emanuele Antonio Faraone

Gerry Boland

Kevin DuBois

Mir development team

 === modified file 'include/common/mir_toolkit/mir_native_buffer.h'
 --- include/common/mir_toolkit/mir_native_buffer.h	2016-05-03 06:55:25 +0000
 +++ include/common/mir_toolkit/mir_native_buffer.h	2016-09-27 19:07:08 +0000
@@ -24,7 +24,8 @@
  typedef enum
+ {
--    mir_buffer_flag_can_scanout = 1
++    mir_buffer_flag_can_scanout = 1,
++    mir_buffer_flag_fenced = 1 << 1
  } MirBufferFlag;
  typedef struct MirBufferPackage
 === modified file 'src/client/mir_buffer_api.cpp'
 --- src/client/mir_buffer_api.cpp	2016-09-15 17:46:10 +0000
 +++ src/client/mir_buffer_api.cpp	2016-09-27 19:07:08 +0000
@@ -22,6 +22,7 @@
  #include "presentation_chain.h"
  #include "mir_connection.h"
  #include "buffer.h"
++#include "mir/client_buffer.h"
  #include "mir/require.h"
  #include "mir/uncaught.h"
  #include "mir/require.h"
@@ -220,6 +221,19 @@
      MIR_LOG_UNCAUGHT_EXCEPTION(ex);
+ }
++MirBufferPackage* mir_buffer_get_buffer_package(MirBuffer* b)
++try
++{
++    mir::require(b);
++    auto buffer = reinterpret_cast<mcl::Buffer*>(b);
++    return buffer->client_buffer()->package();
++}
++catch (std::exception const& ex)
++{
++    MIR_LOG_UNCAUGHT_EXCEPTION(ex);
++    return nullptr;
++}
++
  void mir_buffer_egl_image_parameters(
      MirBuffer* b, EGLenum* type, EGLClientBuffer* client_buffer, EGLint** attr)
  try
 === modified file 'src/client/symbols.map'
 --- src/client/symbols.map	2016-09-22 18:17:43 +0000
 +++ src/client/symbols.map	2016-09-27 19:07:08 +0000
@@ -384,6 +384,7 @@
      mir_buffer_get_buffer_usage;
      mir_buffer_is_valid;
      mir_buffer_get_error_message;
++    mir_buffer_get_buffer_package;
      mir_buffer_egl_image_parameters;
    local:
      *;
 === modified file 'src/include/client/mir/client_buffer.h'
 --- src/include/client/mir/client_buffer.h	2016-09-15 16:42:54 +0000
 +++ src/include/client/mir/client_buffer.h	2016-09-27 19:07:08 +0000
@@ -69,6 +69,7 @@
      virtual std::shared_ptr<graphics::NativeBuffer> native_buffer_handle() const = 0;
      virtual void update_from(MirBufferPackage const& update_package) = 0;
      virtual void fill_update_msg(MirBufferPackage& message) = 0;
++    virtual MirBufferPackage* package() const = 0;
      virtual MirNativeBuffer* as_mir_native_buffer() const = 0;
      virtual void set_fence(MirNativeFence, MirBufferAccess) = 0;
 === modified file 'src/include/client/mir_toolkit/mir_buffer.h'
 --- src/include/client/mir_toolkit/mir_buffer.h	2016-09-15 16:42:54 +0000
 +++ src/include/client/mir_toolkit/mir_buffer.h	2016-09-27 19:07:08 +0000
@@ -101,6 +101,14 @@
   **/
  MirNativeBuffer* mir_buffer_get_native_buffer(MirBuffer*, MirBufferAccess access);
++/**
++ * Access the MirBufferPackage
++ *
++ *   \param [in] buffer    The buffer
++ *   \return               The MirBufferPackage representing buffer
++ */
++MirBufferPackage* mir_buffer_get_buffer_package(MirBuffer* buffer);
++
  /** Access a CPU-mapped region associated with a given buffer for the given purpose.
   *  This will synchronize the buffer for the given purpose.
+  *
 === modified file 'src/include/platform/mir/graphics/buffer_ipc_message.h'
 --- src/include/platform/mir/graphics/buffer_ipc_message.h	2015-02-22 07:46:25 +0000
 +++ src/include/platform/mir/graphics/buffer_ipc_message.h	2016-09-27 19:07:08 +0000
@@ -41,7 +41,7 @@
      virtual std::vector<Fd> fds() = 0;
      virtual std::vector<int> data() = 0;
--
++    virtual unsigned int flags() = 0;
  protected:
      BufferIpcMessage() = default;
      BufferIpcMessage(BufferIpcMessage const&) = delete;
 === modified file 'src/platforms/android/client/buffer.cpp'
 --- src/platforms/android/client/buffer.cpp	2016-09-15 16:42:54 +0000
 +++ src/platforms/android/client/buffer.cpp	2016-09-27 19:07:08 +0000
@@ -16,6 +16,7 @@
   * Authored by: Kevin DuBois<kevin.dubois@canonical.com>
   */
++#include "mir/graphics/platform_ipc_operations.h"
  #include "android_native_buffer.h"
  #include "sync_fence.h"
  #include "mir_toolkit/mir_client_library.h"
@@ -27,6 +28,7 @@
  namespace mcl=mir::client;
  namespace mcla=mir::client::android;
  namespace geom=mir::geometry;
++namespace mg=mir::graphics;
  namespace mga=mir::graphics::android;
  mcla::Buffer::Buffer(
@@ -37,7 +39,8 @@
      native_buffer{registrar->register_buffer(package, pf)},
      buffer_pf(pf),
      buffer_stride{package.stride},
--    buffer_size{package.width, package.height}
++    buffer_size{package.width, package.height},
++    creation_package(package)
+ {
+ }
@@ -76,9 +79,8 @@
  void mcla::Buffer::update_from(MirBufferPackage const& update_package)
+ {
--    if ((update_package.data_items != 0) &&
--        (update_package.fd_items != 0) &&
--        (update_package.data[0] == static_cast<int>(mga::BufferFlag::fenced)))
++    if ((update_package.flags & mir_buffer_flag_fenced) &&
++        (update_package.fd_items != 0))
+     {
          auto fence_fd = update_package.fd[0];
          native_buffer->update_usage(fence_fd, mga::BufferAccess::read);
@@ -87,17 +89,17 @@
  void mcla::Buffer::fill_update_msg(MirBufferPackage& message)
+ {
--    message.data_items = 1;
++    message.data_items = 0;
      auto fence = native_buffer->copy_fence();
      if (fence > 0)
+     {
--        message.data[0] = static_cast<int>(mga::BufferFlag::fenced);
++        message.flags = mir_buffer_flag_fenced;
          message.fd[0] = fence;
          message.fd_items = 1;
+     }
      else
+     {
--        message.data[0] = static_cast<int>(mga::BufferFlag::unfenced);
++        message.flags = 0;
          message.fd_items = 0;
+     }
+ }
@@ -153,3 +155,8 @@
      BOOST_THROW_EXCEPTION(std::invalid_argument("invalid MirBufferAccess"));
+ }
++
++MirBufferPackage* mcla::Buffer::package() const
++{
++    return const_cast<MirBufferPackage*>(&creation_package);
++}
 === modified file 'src/platforms/android/client/buffer.h'
 --- src/platforms/android/client/buffer.h	2016-09-22 18:17:43 +0000
 +++ src/platforms/android/client/buffer.h	2016-09-27 19:07:08 +0000
@@ -50,6 +50,7 @@
      std::shared_ptr<graphics::NativeBuffer> native_buffer_handle() const override;
      void update_from(MirBufferPackage const& update_package) override;
      void fill_update_msg(MirBufferPackage& message) override;
++    MirBufferPackage* package() const override;
      MirNativeBuffer* as_mir_native_buffer() const override;
      void set_fence(MirNativeFence, MirBufferAccess) override;
      MirNativeFence get_fence() const override;
@@ -69,6 +70,7 @@
      MirPixelFormat const buffer_pf;
      geometry::Stride const buffer_stride;
      geometry::Size const buffer_size;
++    MirBufferPackage const creation_package;
  };
+ }
 === modified file 'src/platforms/android/client/gralloc_registrar.cpp'
 --- src/platforms/android/client/gralloc_registrar.cpp	2016-09-19 04:16:15 +0000
 +++ src/platforms/android/client/gralloc_registrar.cpp	2016-09-27 19:07:08 +0000
@@ -16,6 +16,7 @@
   * Authored by: Kevin DuBois <kevin.dubois@canonical.com>
   */
++#include "mir/graphics/platform_ipc_operations.h"
  #include "egl_sync_fence.h"
  #include "android_native_buffer.h"
  #include "sync_fence.h"
@@ -91,8 +92,7 @@
      MirBufferPackage const& package,
      MirPixelFormat pf) const
+ {
--    bool const fence_present{package.data[0] == static_cast<int>(mga::BufferFlag::fenced)};
--    int const mir_flag_offset{1};
++    auto fence_present = package.flags & mir_buffer_flag_fenced;
      int native_handle_header_size = sizeof(native_handle_t);
      int total_size = sizeof(int) *
@@ -118,9 +118,9 @@
              handle->data[i] = package.fd[i];
+     }
--    handle->numInts = package.data_items - mir_flag_offset;
++    handle->numInts = package.data_items;
      for (auto i = 0; i < handle->numInts; i++)
--        handle->data[handle->numFds+i] = package.data[i + mir_flag_offset];
++        handle->data[handle->numFds+i] = package.data[i];
      if (gralloc_module->registerBuffer(gralloc_module.get(), handle))
+     {
 === modified file 'src/platforms/android/include/native_buffer.h'
 --- src/platforms/android/include/native_buffer.h	2016-09-19 04:16:15 +0000
 +++ src/platforms/android/include/native_buffer.h	2016-09-27 19:07:08 +0000
@@ -31,11 +31,6 @@
  namespace android
+ {
--enum class BufferFlag
--{
--    unfenced = 0,
--    fenced
--};
  enum class BufferAccess
+ {
      read,
 === modified file 'src/platforms/android/server/ipc_operations.cpp'
 --- src/platforms/android/server/ipc_operations.cpp	2016-09-19 04:16:15 +0000
 +++ src/platforms/android/server/ipc_operations.cpp	2016-09-27 19:07:08 +0000
@@ -22,6 +22,7 @@
  #include "mir/graphics/buffer_ipc_message.h"
  #include "mir/graphics/platform_operation_message.h"
  #include "mir/libname.h"
++#include "mir_toolkit/mir_native_buffer.h"
  #include "android_native_buffer.h"
  #include "ipc_operations.h"
@@ -40,12 +41,12 @@
      mir::Fd fence_fd(native_buffer->copy_fence());
      if (fence_fd != mir::Fd::invalid)
+     {
--        msg.pack_data(static_cast<int>(mga::BufferFlag::fenced));
++        msg.pack_flags(mir_buffer_flag_fenced);
          msg.pack_fd(fence_fd);
+     }
      else
+     {
--        msg.pack_data(static_cast<int>(mga::BufferFlag::unfenced));
++        msg.pack_flags(0);
+     }
      if (msg_type == mg::BufferIpcMsgType::full_msg)
 === modified file 'src/platforms/eglstream-kms/client/client_buffer.cpp'
 --- src/platforms/eglstream-kms/client/client_buffer.cpp	2016-09-22 18:17:43 +0000
 +++ src/platforms/eglstream-kms/client/client_buffer.cpp	2016-09-27 19:07:08 +0000
@@ -166,6 +166,11 @@
      return true;
+ }
++MirBufferPackage* mcle::ClientBuffer::package() const
++{
++    return creation_package.get();
++}
++
  void mcle::ClientBuffer::egl_image_creation_parameters(EGLenum*, EGLClientBuffer*, EGLint**)
+ {
      BOOST_THROW_EXCEPTION(std::invalid_argument("not implemented yet"));
 === modified file 'src/platforms/eglstream-kms/client/client_buffer.h'
 --- src/platforms/eglstream-kms/client/client_buffer.h	2016-09-22 18:17:43 +0000
 +++ src/platforms/eglstream-kms/client/client_buffer.h	2016-09-27 19:07:08 +0000
@@ -55,6 +55,7 @@
      void set_fence(MirNativeFence, MirBufferAccess);
      MirNativeFence get_fence() const;
      bool wait_fence(MirBufferAccess, std::chrono::nanoseconds timeout);
++    MirBufferPackage* package() const;
      void egl_image_creation_parameters(EGLenum*, EGLClientBuffer*, EGLint**);
  private:
 === modified file 'src/platforms/mesa/client/client_buffer.cpp'
 --- src/platforms/mesa/client/client_buffer.cpp	2016-09-22 18:17:43 +0000
 +++ src/platforms/mesa/client/client_buffer.cpp	2016-09-27 19:07:08 +0000
@@ -170,6 +170,11 @@
      return true;
+ }
++MirBufferPackage* mclm::ClientBuffer::package() const
++{
++    return as_mir_native_buffer();
++}
++
  void mclm::ClientBuffer::egl_image_creation_parameters(EGLenum*, EGLClientBuffer*, EGLint**)
+ {
      BOOST_THROW_EXCEPTION(std::invalid_argument("not implemented yet"));
 === modified file 'src/platforms/mesa/client/client_buffer.h'
 --- src/platforms/mesa/client/client_buffer.h	2016-09-22 18:17:43 +0000
 +++ src/platforms/mesa/client/client_buffer.h	2016-09-27 19:07:08 +0000
@@ -53,6 +53,7 @@
      std::shared_ptr<graphics::NativeBuffer> native_buffer_handle() const;
      void update_from(MirBufferPackage const&);
      void fill_update_msg(MirBufferPackage&);
++    MirBufferPackage* package() const;
      MirNativeBuffer* as_mir_native_buffer() const;
      void set_fence(MirNativeFence, MirBufferAccess);
      MirNativeFence get_fence() const;
 === modified file 'src/server/frontend/protobuf_buffer_packer.cpp'
 --- src/server/frontend/protobuf_buffer_packer.cpp	2016-09-19 04:16:15 +0000
 +++ src/server/frontend/protobuf_buffer_packer.cpp	2016-09-27 19:07:08 +0000
@@ -141,3 +141,8 @@
+ {
      return {buffer_response->data().begin(), buffer_response->data().end()};
+ }
++
++unsigned int mfd::ProtobufBufferPacker::flags()
++{
++    return buffer_response->flags();
++}
 === modified file 'src/server/frontend/protobuf_buffer_packer.h'
 --- src/server/frontend/protobuf_buffer_packer.h	2015-06-17 05:20:42 +0000
 +++ src/server/frontend/protobuf_buffer_packer.h	2016-09-27 19:07:08 +0000
@@ -55,6 +55,7 @@
      std::vector<Fd> fds();
      std::vector<int> data();
++    unsigned int flags();
  private:
      std::vector<mir::Fd> fds_;
      protobuf::Buffer* buffer_response;
 === modified file 'src/server/graphics/nested/CMakeLists.txt'
 --- src/server/graphics/nested/CMakeLists.txt	2016-08-15 13:28:21 +0000
 +++ src/server/graphics/nested/CMakeLists.txt	2016-09-27 19:07:08 +0000
@@ -13,4 +13,5 @@
    cursor.cpp
    platform.cpp
    buffer.cpp
++  ipc_operations.cpp
+ )
 === added file 'src/server/graphics/nested/ipc_operations.cpp'
 --- src/server/graphics/nested/ipc_operations.cpp	1970-01-01 00:00:00 +0000
 +++ src/server/graphics/nested/ipc_operations.cpp	2016-09-27 19:07:08 +0000
@@ -0,0 +1,92 @@
++/*
++ * Copyright © 2016 Canonical Ltd.
++ *
++ * This program is free software: you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 3,
++ * as published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ *
++ * Authored by: Kevin DuBois <kevin.dubois@canonical.com>
++ */
++
++#include "native_buffer.h"
++#include "ipc_operations.h"
++#include "mir_toolkit/mir_native_buffer.h"
++#include "mir/graphics/platform_operation_message.h"
++#include "mir/graphics/buffer.h"
++#include "mir/graphics/buffer_ipc_message.h"
++
++namespace mg = mir::graphics;
++namespace mgn = mir::graphics::nested;
++namespace geom = mir::geometry;
++
++mgn::IpcOperations::IpcOperations(
++    std::shared_ptr<mg::PlatformIpcOperations> const& host_operations) :
++    ipc_operations(host_operations)
++{
++}
++
++void mgn::IpcOperations::pack_buffer(
++    mg::BufferIpcMessage& message, mg::Buffer const& buffer, mg::BufferIpcMsgType msg_type) const
++{
++    if (auto native = std::dynamic_pointer_cast<mgn::NativeBuffer>(buffer.native_buffer_handle()))
++    {
++        auto package = native->package();
++        auto fence = native->fence();
++        if (fence > mir::Fd::invalid)
++        {
++            message.pack_flags(mir_buffer_flag_fenced | package->flags);
++            message.pack_fd(fence);
++        }
++        else
++        {
++            message.pack_flags(~mir_buffer_flag_fenced & package->flags);
++        }
++
++        if (msg_type == mg::BufferIpcMsgType::full_msg)
++        {
++            for (auto i = 0; i < package->data_items; i++)
++                message.pack_data(package->data[i]);
++            for (auto i = 0; i < package->fd_items; i++)
++                message.pack_fd(mir::Fd(IntOwnedFd{package->fd[i]}));
++            message.pack_stride(geom::Stride{package->stride});
++            message.pack_size(geom::Size{package->width, package->height});
++        }
++    }
++    else
++    {
++        ipc_operations->pack_buffer(message, buffer, msg_type);
++    }
++}
++
++void mgn::IpcOperations::unpack_buffer(mg::BufferIpcMessage& message, mg::Buffer const& buffer) const
++{
++    if (auto native = std::dynamic_pointer_cast<mgn::NativeBuffer>(buffer.native_buffer_handle()))
++    {
++        auto fds = message.fds();
++        if ( (message.flags() & mir_buffer_flag_fenced) && !fds.empty())
++            native->set_fence(fds.front());
++    }
++    else
++    {
++        ipc_operations->unpack_buffer(message, buffer);
++    }
++}
++
++std::shared_ptr<mg::PlatformIPCPackage> mgn::IpcOperations::connection_ipc_package()
++{
++    return ipc_operations->connection_ipc_package();
++}
++
++mg::PlatformOperationMessage mgn::IpcOperations::platform_operation(
++    unsigned int const opcode, mg::PlatformOperationMessage const& message)
++{
++    return ipc_operations->platform_operation(opcode, message);
++}
 === added file 'src/server/graphics/nested/ipc_operations.h'
 --- src/server/graphics/nested/ipc_operations.h	1970-01-01 00:00:00 +0000
 +++ src/server/graphics/nested/ipc_operations.h	2016-09-27 19:07:08 +0000
@@ -0,0 +1,48 @@
++/*
++ * Copyright © 2016 Canonical Ltd.
++ *
++ * This program is free software: you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 3,
++ * as published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ *
++ * Authored by: Kevin DuBois <kevin.dubois@canonical.com>
++ */
++
++#ifndef MIR_GRAPHICS_NESTED_IPC_OPERATIONS_H_
++#define MIR_GRAPHICS_NESTED_IPC_OPERATIONS_H_
++
++#include "mir/graphics/platform_ipc_operations.h"
++#include <memory>
++
++namespace mir
++{
++namespace graphics
++{
++namespace nested
++{
++class IpcOperations : public PlatformIpcOperations
++{
++public:
++    IpcOperations(std::shared_ptr<graphics::PlatformIpcOperations> const& host_operations);
++
++    void pack_buffer(BufferIpcMessage& message, Buffer const& buffer, BufferIpcMsgType msg_type) const override;
++    void unpack_buffer(BufferIpcMessage& message, Buffer const& buffer) const override;
++    std::shared_ptr<PlatformIPCPackage> connection_ipc_package() override;
++    PlatformOperationMessage platform_operation(
++        unsigned int const opcode, PlatformOperationMessage const& message) override;
++
++private:
++    std::shared_ptr<graphics::PlatformIpcOperations> const ipc_operations;
++};
++}
++}
++}
++#endif /* MIR_GRAPHICS_NESTED_IPC_OPERATIONS_H_ */
 === modified file 'src/server/graphics/nested/native_buffer.h'
 --- src/server/graphics/nested/native_buffer.h	2016-09-15 16:20:24 +0000
 +++ src/server/graphics/nested/native_buffer.h	2016-09-27 19:07:08 +0000
@@ -21,6 +21,7 @@
  #include "mir/geometry/size.h"
  #include "mir/graphics/native_buffer.h"
++#include "mir/fd.h"
  #include "mir_toolkit/client_types_nbs.h"
  #include "mir_toolkit/client_types.h"
  #include "mir_toolkit/mir_native_buffer.h"
@@ -45,6 +46,9 @@
      virtual MirGraphicsRegion get_graphics_region() = 0;
      virtual geometry::Size size() const = 0;
      virtual MirPixelFormat format() const = 0;
++    virtual MirBufferPackage* package() const = 0;
++    virtual Fd fence() const = 0;
++    virtual void set_fence(Fd) = 0;
      virtual std::tuple<EGLenum, EGLClientBuffer, EGLint*> egl_image_creation_hints() const = 0;
  protected:
      NativeBuffer() = default;
 === modified file 'tests/acceptance-tests/throwback/test_presentation_chain.cpp'
 --- tests/acceptance-tests/throwback/test_presentation_chain.cpp	2016-09-27 15:07:45 +0000
 +++ tests/acceptance-tests/throwback/test_presentation_chain.cpp	2016-09-27 19:07:08 +0000
@@ -226,6 +226,28 @@
      EXPECT_THAT(mir_buffer_get_native_buffer(buffer, mir_none), Eq(nullptr));
+ }
++TEST_F(PresentationChain, can_access_platform_message_representing_buffer)
++{
++    SurfaceWithChainFromStart surface(connection, size, pf);
++
++    MirBufferSync context;
++    mir_connection_allocate_buffer(
++        connection,
++        size.width.as_int(), size.height.as_int(), pf, usage,
++        buffer_callback, &context);
++
++    EXPECT_TRUE(context.wait_for_buffer(10s));
++    auto buffer = context.buffer();
++    EXPECT_THAT(context.buffer(), Ne(nullptr));
++
++    auto message = mir_buffer_get_buffer_package(buffer);
++    ASSERT_THAT(message, Ne(nullptr));
++    EXPECT_THAT(message->data_items, Ge(1));
++    EXPECT_THAT(message->fd_items, Ge(1));
++    EXPECT_THAT(message->width, Eq(size.width.as_int()));
++    EXPECT_THAT(message->height, Eq(size.height.as_int()));
++}
++
  TEST_F(PresentationChain, has_native_fence)
+ {
      SurfaceWithChainFromStart surface(connection, size, pf);
 === modified file 'tests/include/mir/test/doubles/mock_buffer_ipc_message.h'
 --- tests/include/mir/test/doubles/mock_buffer_ipc_message.h	2016-08-24 02:09:08 +0000
 +++ tests/include/mir/test/doubles/mock_buffer_ipc_message.h	2016-09-27 19:07:08 +0000
@@ -40,6 +40,7 @@
      MOCK_METHOD1(pack_size, void(geometry::Size const&));
      MOCK_METHOD0(fds, std::vector<mir::Fd>());
      MOCK_METHOD0(data, std::vector<int>());
++    MOCK_METHOD0(flags, unsigned int());
  };
+ }
 === modified file 'tests/include/mir/test/doubles/mock_client_buffer.h'
 --- tests/include/mir/test/doubles/mock_client_buffer.h	2016-09-15 16:42:54 +0000
 +++ tests/include/mir/test/doubles/mock_client_buffer.h	2016-09-27 19:07:08 +0000
@@ -47,6 +47,7 @@
      MOCK_METHOD2(set_fence, void(MirNativeFence, MirBufferAccess));
      MOCK_CONST_METHOD0(get_fence, MirNativeFence());
      MOCK_METHOD2(wait_fence, bool(MirBufferAccess, std::chrono::nanoseconds));
++    MOCK_CONST_METHOD0(package, MirBufferPackage*());
      MOCK_METHOD3(egl_image_creation_parameters, void(EGLenum*, EGLClientBuffer*, EGLint**));
      int age_{0};
  };
 === modified file 'tests/include/mir/test/doubles/null_client_buffer.h'
 --- tests/include/mir/test/doubles/null_client_buffer.h	2016-09-15 16:42:54 +0000
 +++ tests/include/mir/test/doubles/null_client_buffer.h	2016-09-27 19:07:08 +0000
@@ -51,6 +51,8 @@
+     {
          return nullptr;
+     }
++    MirBufferPackage* package() const { return nullptr; }
++
      geometry::Size sz;
      MirNativeBuffer* as_mir_native_buffer() const { return nullptr; }
 === modified file 'tests/include/mir/test/doubles/stub_client_buffer.h'
 --- tests/include/mir/test/doubles/stub_client_buffer.h	2016-09-15 16:42:54 +0000
 +++ tests/include/mir/test/doubles/stub_client_buffer.h	2016-09-27 19:07:08 +0000
@@ -35,7 +35,7 @@
          std::shared_ptr<MirBufferPackage> const& package,
          geometry::Size size, MirPixelFormat pf,
          std::shared_ptr<graphics::NativeBuffer> const& buffer) :
--        package{package}, size_{size}, pf_{pf}, buffer{buffer}
++        package_{package}, size_{size}, pf_{pf}, buffer{buffer}
+     {
+     }
@@ -48,8 +48,8 @@
      ~StubClientBuffer()
+     {
--        for (int i = 0; i < package->fd_items; i++)
--            ::close(package->fd[i]);
++        for (int i = 0; i < package_->fd_items; i++)
++            ::close(package_->fd[i]);
+     }
      std::shared_ptr<client::MemoryRegion> secure_for_cpu_write() override
@@ -65,7 +65,7 @@
+     }
      geometry::Size size() const override { return size_; }
--    geometry::Stride stride() const override { return geometry::Stride{package->stride}; }
++    geometry::Stride stride() const override { return geometry::Stride{package_->stride}; }
      MirPixelFormat pixel_format() const override { return pf_; }
      uint32_t age() const override { return 0; }
      void increment_age() override {}
@@ -75,6 +75,10 @@
+     {
          return buffer;
+     }
++    MirBufferPackage* package() const
++    {
++        return package_.get();
++    }
      void update_from(MirBufferPackage const&) override {}
      void fill_update_msg(MirBufferPackage&)  override{}
@@ -84,7 +88,7 @@
      bool wait_fence(MirBufferAccess, std::chrono::nanoseconds) override { return true; }
      void egl_image_creation_parameters(EGLenum*, EGLClientBuffer*, EGLint**) {}
--    std::shared_ptr<MirBufferPackage> const package;
++    std::shared_ptr<MirBufferPackage> const package_;
      geometry::Size size_;
      MirPixelFormat pf_;
      std::shared_ptr<graphics::NativeBuffer> buffer;
 === modified file 'tests/unit-tests/client/test_aging_buffer.cpp'
 --- tests/unit-tests/client/test_aging_buffer.cpp	2016-09-15 16:42:54 +0000
 +++ tests/unit-tests/client/test_aging_buffer.cpp	2016-09-27 19:07:08 +0000
@@ -84,6 +84,11 @@
          exit(1);
+     }
++    MirBufferPackage* package() const override
++    {
++        exit(1);
++    }
++
      void egl_image_creation_parameters(EGLenum*, EGLClientBuffer*, EGLint**) override
+     {
          exit(1);
 === modified file 'tests/unit-tests/platforms/android/client/test_buffer.cpp'
 --- tests/unit-tests/platforms/android/client/test_buffer.cpp	2016-08-01 07:24:32 +0000
 +++ tests/unit-tests/platforms/android/client/test_buffer.cpp	2016-09-27 19:07:08 +0000
@@ -18,6 +18,7 @@
  #include "mir/test/doubles/mock_buffer_registrar.h"
  #include "mir/test/doubles/mock_android_native_buffer.h"
++#include "mir/graphics/platform_ipc_operations.h"
  #include "src/platforms/android/client/buffer.h"
  #include "mir_toolkit/mir_client_library.h"
@@ -95,20 +96,19 @@
          .Times(1);
      mcla::Buffer buffer(mock_registrar, package, pf);
--    package.data_items = 1;
++    package.data_items = 0;
      package.fd_items = 1;
--    package.data[0] = static_cast<int>(mga::BufferFlag::fenced);
++    package.flags = mir_buffer_flag_fenced;
      package.fd[0] = fake_fence;
      buffer.update_from(package);
--    package.data[0] = static_cast<int>(mga::BufferFlag::unfenced);
++    package.flags = 0;
      buffer.update_from(package);
+ }
  TEST_F(AndroidClientBuffer, fills_update_msg)
+ {
      using namespace testing;
--    using mir::graphics::android::BufferFlag;
      int stub_fence{44};
      int invalid_fence{-1};
@@ -122,15 +122,15 @@
      buffer.fill_update_msg(msg);
--    EXPECT_THAT(msg.data_items, Eq(1));
--    EXPECT_THAT(msg.data[0], Eq(static_cast<int>(BufferFlag::fenced)));
++    EXPECT_THAT(msg.data_items, Eq(0));
++    EXPECT_THAT(msg.flags, Eq(mir_buffer_flag_fenced));
      EXPECT_THAT(msg.fd_items, Eq(1));
      EXPECT_THAT(msg.fd[0], Eq(stub_fence));
      buffer.fill_update_msg(msg);
--    EXPECT_THAT(msg.data_items, Eq(1));
--    EXPECT_THAT(msg.data[0], Eq(static_cast<int>(BufferFlag::unfenced)));
++    EXPECT_THAT(msg.data_items, Eq(0));
++    EXPECT_THAT(msg.flags, Eq(0));
      EXPECT_THAT(msg.fd_items, Eq(0));
+ }
 === modified file 'tests/unit-tests/platforms/android/client/test_gralloc_registrar.cpp'
 --- tests/unit-tests/platforms/android/client/test_gralloc_registrar.cpp	2016-01-29 08:18:22 +0000
 +++ tests/unit-tests/platforms/android/client/test_gralloc_registrar.cpp	2016-09-27 19:07:08 +0000
@@ -17,6 +17,7 @@
   */
  #include "native_buffer.h"
++#include "mir/graphics/platform_ipc_operations.h"
  #include "src/platforms/android/client/gralloc_registrar.h"
  #include "mir/test/doubles/mock_android_native_buffer.h"
  #include <stdexcept>
@@ -93,8 +94,8 @@
          stub_package.data_items = 21;
          for (auto i = 0; i < stub_package.fd_items; i++)
              stub_package.fd[i] = (i*4);
--        stub_package.data[0] = static_cast<int>(mir::graphics::android::BufferFlag::unfenced);
--        for (auto i = 1; i < stub_package.data_items; i++)
++        stub_package.flags = 0;
++        for (auto i = 0; i < stub_package.data_items; i++)
              stub_package.data[i] = (i*3);
+     }
@@ -113,18 +114,17 @@
  TEST_F(GrallocRegistrar, client_buffer_converts_stub_package)
+ {
--    int const flag_offset{1};
      mcla::GrallocRegistrar registrar(mock_module);
      auto buffer = registrar.register_buffer(stub_package, pf);
      auto handle = buffer->handle();
      ASSERT_NE(nullptr, handle);
      ASSERT_EQ(stub_package.fd_items, handle->numFds);
--    ASSERT_EQ(stub_package.data_items - 1, handle->numInts);
++    ASSERT_EQ(stub_package.data_items, handle->numInts);
      for (auto i = 0; i < stub_package.fd_items; i++)
          EXPECT_EQ(stub_package.fd[i], handle->data[i]);
--    for (auto i = 0; i < stub_package.data_items - 1; i++)
--        EXPECT_EQ(stub_package.data[i + flag_offset], handle->data[i + stub_package.fd_items]);
++    for (auto i = 0; i < stub_package.data_items; i++)
++        EXPECT_EQ(stub_package.data[i], handle->data[i + stub_package.fd_items]);
+ }
  TEST_F(GrallocRegistrar, client_sets_correct_version)
@@ -160,8 +160,8 @@
      using namespace testing;
      MirBufferPackage stub_package;
      memset(&stub_package, 0, sizeof(MirBufferPackage));
--    stub_package.data_items = 1;
--    stub_package.data[0] = static_cast<int>(mir::graphics::android::BufferFlag::unfenced);
++    stub_package.data_items = 0;
++    stub_package.flags = 0;
      stub_package.fd_items = 2;
      EXPECT_EQ(0, pipe(static_cast<int*>(stub_package.fd)));
 === modified file 'tests/unit-tests/platforms/android/server/test_platform.cpp'
 --- tests/unit-tests/platforms/android/server/test_platform.cpp	2016-09-01 12:16:41 +0000
 +++ tests/unit-tests/platforms/android/server/test_platform.cpp	2016-09-27 19:07:08 +0000
@@ -33,6 +33,7 @@
  #include "mir/test/doubles/null_gl_context.h"
  #include "mir_test_framework/executable_path.h"
  #include "mir/shared_library.h"
++#include "mir_toolkit/mir_native_buffer.h"
  #include "native_window_report.h"
  #include <system/window.h>
  #include <gtest/gtest.h>
@@ -120,7 +121,7 @@
      mtd::MockBufferIpcMessage mock_ipc_msg;
      int offset = 0;
--    EXPECT_CALL(mock_ipc_msg, pack_data(static_cast<int>(mga::BufferFlag::fenced)));
++    EXPECT_CALL(mock_ipc_msg, pack_flags(mir_buffer_flag_fenced));
      EXPECT_CALL(mock_ipc_msg, pack_fd(mtd::RawFdMatcher(fake_fence)));
      for (auto i = 0u; i < num_fds; i++)
          EXPECT_CALL(mock_ipc_msg, pack_fd(mtd::RawFdMatcher(native_buffer_handle->data[offset++])));
@@ -155,7 +156,7 @@
      mtd::MockBufferIpcMessage mock_ipc_msg;
      int offset = 0;
--    EXPECT_CALL(mock_ipc_msg, pack_data(static_cast<int>(mga::BufferFlag::unfenced)));
++    EXPECT_CALL(mock_ipc_msg, pack_flags(0));
      EXPECT_CALL(mock_ipc_msg, pack_fd(mtd::RawFdMatcher(-1)))
          .Times(0);
@@ -203,7 +204,7 @@
          EXPECT_CALL(mock_ipc_msg, pack_fd(mtd::RawFdMatcher(native_buffer_handle->data[offset++])))
              .Times(1);
+     }
--    EXPECT_CALL(mock_ipc_msg, pack_data(static_cast<int>(mga::BufferFlag::unfenced)));
++    EXPECT_CALL(mock_ipc_msg, pack_flags(0));
      for (auto i = 0u; i < num_ints; i++)
+     {
          EXPECT_CALL(mock_ipc_msg, pack_data(native_buffer_handle->data[offset++]))
@@ -238,11 +239,11 @@
      mtd::MockBufferIpcMessage mock_ipc_msg;
      Sequence seq;
--    EXPECT_CALL(mock_ipc_msg, pack_data(static_cast<int>(mga::BufferFlag::fenced)))
++    EXPECT_CALL(mock_ipc_msg, pack_flags(mir_buffer_flag_fenced))
          .InSequence(seq);
      EXPECT_CALL(mock_ipc_msg, pack_fd(mtd::RawFdMatcher(fake_fence)))
          .InSequence(seq);
--    EXPECT_CALL(mock_ipc_msg, pack_data(static_cast<int>(mga::BufferFlag::unfenced)))
++    EXPECT_CALL(mock_ipc_msg, pack_flags(0))
          .InSequence(seq);
      EXPECT_CALL(*native_buffer, copy_fence())
 === modified file 'tests/unit-tests/platforms/nested/CMakeLists.txt'
 --- tests/unit-tests/platforms/nested/CMakeLists.txt	2016-08-29 11:15:35 +0000
 +++ tests/unit-tests/platforms/nested/CMakeLists.txt	2016-09-27 19:07:08 +0000
@@ -5,6 +5,7 @@
    ${CMAKE_CURRENT_SOURCE_DIR}/test_nested_cursor.cpp
    ${CMAKE_CURRENT_SOURCE_DIR}/test_buffer.cpp
    ${CMAKE_CURRENT_SOURCE_DIR}/test_nested_display_buffer.cpp
++  ${CMAKE_CURRENT_SOURCE_DIR}/test_ipc_operations.cpp
    $<TARGET_OBJECTS:mir-test-doubles-udev>
    ${MIR_PLATFORM_OBJECTS}
    ${MIR_SERVER_OBJECTS}
 === modified file 'tests/unit-tests/platforms/nested/test_buffer.cpp'
 --- tests/unit-tests/platforms/nested/test_buffer.cpp	2016-09-22 18:17:43 +0000
 +++ tests/unit-tests/platforms/nested/test_buffer.cpp	2016-09-27 19:07:08 +0000
@@ -44,6 +44,7 @@
  using namespace testing;
  namespace
+ {
++
  struct MockNativeBuffer : mgn::NativeBuffer
+ {
      MOCK_CONST_METHOD0(client_handle, MirBuffer*());
@@ -52,6 +53,9 @@
      MOCK_CONST_METHOD0(size, geom::Size());
      MOCK_CONST_METHOD0(format, MirPixelFormat());
      MOCK_METHOD2(sync, void(MirBufferAccess, std::chrono::nanoseconds));
++    MOCK_CONST_METHOD0(package, MirBufferPackage*());
++    MOCK_CONST_METHOD0(fence, mir::Fd());
++    MOCK_METHOD1(set_fence, void(mir::Fd));
      MOCK_CONST_METHOD0(egl_image_creation_hints, std::tuple<EGLenum, EGLClientBuffer, EGLint*>());
  };
@@ -203,7 +207,6 @@
      EXPECT_CALL(mock_egl, eglGetCurrentDisplay());
      EXPECT_CALL(mock_egl, eglGetCurrentContext());
--    EXPECT_CALL(mock_egl, eglCreateImageKHR(_,_,_,_,_));
      EXPECT_CALL(*client_buffer, sync(mir_read, _));
      EXPECT_CALL(mock_egl, glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, _));
 === added file 'tests/unit-tests/platforms/nested/test_ipc_operations.cpp'
 --- tests/unit-tests/platforms/nested/test_ipc_operations.cpp	1970-01-01 00:00:00 +0000
 +++ tests/unit-tests/platforms/nested/test_ipc_operations.cpp	2016-09-27 19:07:08 +0000
@@ -0,0 +1,199 @@
++/*
++ * Copyright © 2016 Canonical Ltd.
++ *
++ * This program is free software: you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 3 as
++ * published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ *
++ * Authored by: Kevin DuBois <kevin.dubois@canonical.com>
++ */
++
++#include "src/server/graphics/nested/ipc_operations.h"
++#include "src/server/graphics/nested/native_buffer.h"
++#include "mir/test/doubles/stub_buffer.h"
++#include "mir/test/doubles/mock_buffer_ipc_message.h"
++#include "mir/test/fake_shared.h"
++#include "mir/graphics/platform_ipc_operations.h"
++#include "mir/graphics/platform_operation_message.h"
++#include "mir/graphics/buffer_ipc_message.h"
++#include "mir/geometry/size.h"
++#include <gtest/gtest.h>
++#include <gmock/gmock.h>
++
++using namespace testing;
++
++namespace geom = mir::geometry;
++namespace mg = mir::graphics;
++namespace mgn = mir::graphics::nested;
++namespace mt = mir::test;
++namespace mtd = mir::test::doubles;
++
++namespace
++{
++struct ForeignBuffer : mg::NativeBuffer
++{
++};
++
++struct StubNestedBuffer : mgn::NativeBuffer
++{
++public:
++    void sync(MirBufferAccess, std::chrono::nanoseconds) override {}
++    MirBuffer* client_handle() const override { return nullptr; }
++    MirNativeBuffer* get_native_handle() override { return nullptr; }
++    MirGraphicsRegion get_graphics_region() override
++    {
++        return MirGraphicsRegion { 0, 0, 0, mir_pixel_format_invalid, nullptr };
++    }
++    geom::Size size() const override { return {}; }
++    MirPixelFormat format() const override { return mir_pixel_format_invalid; }
++    MirBufferPackage* package() const override { return nullptr; }
++    mir::Fd fence() const override { return mir::Fd(); }
++    void set_fence(mir::Fd) override {}
++    std::tuple<EGLenum, EGLClientBuffer, EGLint*> egl_image_creation_hints() const override
++    {
++        return {};
++    }
++};
++
++struct MockNestedBuffer : StubNestedBuffer
++{
++    MOCK_CONST_METHOD0(package, MirBufferPackage*());
++    MOCK_CONST_METHOD0(fence, mir::Fd());
++    MOCK_METHOD1(set_fence, void(mir::Fd));
++};
++
++struct MockIpcOperations : mg::PlatformIpcOperations
++{
++    MOCK_CONST_METHOD3(pack_buffer, void(mg::BufferIpcMessage&, mg::Buffer const&, mg::BufferIpcMsgType));
++    MOCK_CONST_METHOD2(unpack_buffer, void(mg::BufferIpcMessage&, mg::Buffer const&));
++    MOCK_METHOD0(connection_ipc_package, std::shared_ptr<mg::PlatformIPCPackage>());
++    MOCK_METHOD2(platform_operation,
++        mg::PlatformOperationMessage(unsigned int const, mg::PlatformOperationMessage const&));
++};
++
++struct NestedIPCOperations : testing::Test
++{
++    NestedIPCOperations()
++    {
++        ON_CALL(mock_ops, connection_ipc_package())
++            .WillByDefault(Return(nullptr));
++        ON_CALL(mock_ops, platform_operation(_,_))
++            .WillByDefault(Return(mg::PlatformOperationMessage{ {}, {} }));
++    }
++    mtd::StubBuffer foreign_buffer{std::make_shared<ForeignBuffer>()};
++    mtd::StubBuffer nested_buffer{std::make_shared<MockNestedBuffer>()};
++    MockIpcOperations mock_ops;
++};
++}
++
++TEST_F(NestedIPCOperations, uses_guest_platform_on_guest_buffers)
++{
++    mtd::MockBufferIpcMessage msg;
++    EXPECT_CALL(mock_ops, pack_buffer(Ref(msg), Ref(foreign_buffer), _));
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++    operations.pack_buffer(msg, foreign_buffer, mg::BufferIpcMsgType::full_msg);
++}
++
++TEST_F(NestedIPCOperations, packs_unfenced_buffer_itself_when_native)
++{
++    EXPECT_CALL(mock_ops, pack_buffer(_, _, _))
++        .Times(0);
++
++    auto nested = std::make_shared<MockNestedBuffer>();
++    mtd::StubBuffer nested_buffer{nested};
++    mtd::MockBufferIpcMessage msg;
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++
++    MirBufferPackage package;
++    package.data_items = 1;
++    package.data[0] = 11;
++    package.fd_items = 1;
++    package.fd[0] = 11222;
++    package.stride = 33;
++    package.width = 10;
++    package.height = 100;
++    package.flags = 0;
++
++    EXPECT_CALL(*nested, package())
++        .WillOnce(Return(&package));
++    EXPECT_CALL(*nested, fence())
++        .WillOnce(Return(mir::Fd(-1)));
++
++    EXPECT_CALL(msg, pack_data(package.data[0]));
++    EXPECT_CALL(msg, pack_fd(mir::Fd(mir::IntOwnedFd{package.fd[0]})));
++    EXPECT_CALL(msg, pack_flags(0));
++#ifndef __clang__
++    //(LP: #1609612)
++    EXPECT_CALL(msg, pack_stride(geom::Stride{package.stride}));
++#endif
++    operations.pack_buffer(msg, nested_buffer, mg::BufferIpcMsgType::full_msg);
++}
++
++TEST_F(NestedIPCOperations, packs_fenced_buffer_itself_when_native)
++{
++    EXPECT_CALL(mock_ops, pack_buffer(_, _, _))
++        .Times(0);
++
++    auto nested = std::make_shared<MockNestedBuffer>();
++    mtd::StubBuffer nested_buffer{nested};
++    mtd::MockBufferIpcMessage msg;
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++
++    MirBufferPackage package;
++    package.data_items = 0;
++    package.fd_items = 0;
++    package.flags = 0;
++
++    EXPECT_CALL(*nested, package())
++        .WillOnce(Return(&package));
++    EXPECT_CALL(*nested, fence())
++        .WillOnce(Return(mir::Fd(mir::IntOwnedFd{111})));
++    EXPECT_CALL(msg, pack_fd(mir::Fd(mir::IntOwnedFd{111})));
++    EXPECT_CALL(msg, pack_flags(mir_buffer_flag_fenced));
++    operations.pack_buffer(msg, nested_buffer, mg::BufferIpcMsgType::update_msg);
++}
++
++TEST_F(NestedIPCOperations, unpacks_fenced_buffer_itself_when_foreign)
++{
++    mtd::MockBufferIpcMessage msg;
++    EXPECT_CALL(mock_ops, unpack_buffer(Ref(msg), Ref(foreign_buffer)));
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++    operations.unpack_buffer(msg, foreign_buffer);
++}
++
++TEST_F(NestedIPCOperations, unpacks_fenced_buffer_itself_when_native)
++{
++    auto nested = std::make_shared<MockNestedBuffer>();
++    mtd::StubBuffer nested_buffer{nested};
++    mir::Fd fake(mir::IntOwnedFd{1111});
++    mtd::MockBufferIpcMessage msg;
++    EXPECT_CALL(msg, flags())
++        .WillOnce(Return(mir_buffer_flag_fenced));
++    EXPECT_CALL(msg, fds())
++        .WillOnce(Return( std::vector<mir::Fd>{fake} ));
++    EXPECT_CALL(*nested, set_fence(_));
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++    operations.unpack_buffer(msg, nested_buffer);
++}
++
++TEST_F(NestedIPCOperations, uses_guest_platform_for_connection_package)
++{
++    EXPECT_CALL(mock_ops, connection_ipc_package());
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++    operations.connection_ipc_package();
++}
++
++TEST_F(NestedIPCOperations, uses_guest_platform_for_platform_ops)
++{
++    EXPECT_CALL(mock_ops, platform_operation(_,_));
++    mgn::IpcOperations operations(mt::fake_shared(mock_ops));
++    operations.platform_operation(0, mg::PlatformOperationMessage{ {}, {} });
++}