feat(gateway/transport_layer): qemu transport layer

quality/coverage/coverage_justifications.yaml

@@ -93,3 +93,47 @@ justifications:
        Coverage tool incorrectly marks this line as not covered. Lines immediately before and after are covered.
        Covered by the test BidirectionalTransportSocketFixture.DispatchThreadDeliversQueuedMessageToHandler
        inside score/mw/com/gateway/transport_layer/sample/bidirectional_transport_test.cpp
+
+  - id: ivshmem-bind-shm-to-bar-shm-ctl-special-success
+    category: defensive_programming
+    platforms: [qnx]
+    reason: >
+      QNX x86_64 only: shm_ctl_special() needs a real ivshmem device and WB-backed shared memory,
+      so the mock-fd test path always hits EBADF. Fallback to standard shm_ctl() on failure.
+    locations:
+      - file: score/mw/com/gateway/transport_layer/qemu/ivshmem/ivshmem_typed_memory_provider.cpp
+        line_start: 321
+        line_end: 329
+
+  - id: ivshmem-write-directory-entry-idempotent
+    category: defensive_programming
+    platforms: [qnx]
+    reason: >
+      Idempotent guard in WriteDirectoryEntry() requires multi-VM concurrent write race; 
+      single-process tests cache allocations on first write, preventing re-entry.
+    locations:
+      - file: score/mw/com/gateway/transport_layer/qemu/ivshmem/ivshmem_typed_memory_provider.cpp
+        line_start: 222
+        line_end: 230
+
+  - id: ivshmem-bar-discovery-hardware-path
+    category: defensive_programming
+    platforms: [qnx]
+    reason: >
+      QNX PCI API calls require real ivshmem device. Tests with no hardware hit pci_device_find→PCI_BDF_NONE 
+      and cannot mock PCI subsystem APIs.
+    locations:
+      - file: score/mw/com/gateway/transport_layer/qemu/ivshmem/ivshmem_bar_discovery.cpp
+        line_start: 45
+        line_end: 133
+
+  - id: qemu-worldwritable-ctor-gcc-artifact
+    category: defensive_programming
+    platforms: [qnx]
+    reason: >
+      GCC/GCOV x86_64 QNX emits separate counter for WorldWritable{} on continuation lines;
+      QCC omits sequence-point counter on trivial temporaries.
+    locations:
+      - file: score/mw/com/gateway/transport_layer/qemu/qemu_hypervisor_transport.cpp
+        line_start: 356
+        line_end: 357

quality/integration_testing/environments/dual_qemu/dual_qemu_process.py

@@ -78,7 +78,7 @@ def __init__(
         intervm=None,
         vm_index=0,
         max_boot_attempts=3,
-        boot_timeout=100,
+        boot_timeout=180,
     ):
         super().__init__(path_to_qemu_image, available_ram, available_cores, port_forwarding=port_forwarding)
         # Replace the base's default Qemu with our ivshmem-capable subclass.
@@ -119,6 +119,9 @@ def start(self):
                     self.stop()
                 except Exception:  # pylint: disable=broad-except
                     logger.exception("Failed to stop the wedged QEMU before retrying")
+                if attempt < self._max_boot_attempts:
+                    logger.info("Waiting 5 s before next boot attempt to let resources settle")
+                    time.sleep(5)
         raise RuntimeError(
             f"VM never booted into a usable state after {self._max_boot_attempts} attempts: {last_error}"
         )

quality/integration_testing/integration_testing.bzl

@@ -219,8 +219,11 @@ def dual_qemu_integration_test(
     # Two VMs require even more resources than a single one.
     if "size" not in kwargs:
         kwargs["size"] = "enormous"
+
+    # Dual-QEMU boots two guests and can fall back to slower TCG in CI, so give
+    # it more wall-clock budget than a single-VM integration test.
     if "timeout" not in kwargs:
-        kwargs["timeout"] = "moderate"
+        kwargs["timeout"] = "long"
 
     # Driving two real QNX guests under KVM has rare, environment-induced boot
     # nondeterminism (e.g. a guest occasionally wedging during device bring-up).

score/mw/com/gateway/README.md

@@ -78,10 +78,12 @@ files in its domain:
 2. The transport-layer config file referenced by the `config-path` field of the `transport-layer` section in
    `mw_com_gateway_config.json`. Its content is transport-specific and is parsed during
    `GatewayApplication::Setup()` by the selected transport (via `TransportFactory::Create()`). For the bundled
-   `sample_hypervisor` transport this is the hypervisor-socket config (remote IP, local/remote ports, request
-   timeout) — see its
+   `sample_hypervisor` and `qemu_hypervisor` transports this is the hypervisor-socket config (remote IP,
+   local/remote ports, request timeout) — see its
    [schema](transport_layer/sample/configuration/mw_com_gateway_sample_transport_config_schema.json) and
-   [example](transport_layer/sample/configuration/example/mw_com_gateway_sample_transport_config.json).
+   [example](transport_layer/sample/configuration/example/mw_com_gateway_sample_transport_config.json). For the
+   QEMU transport, the same file also carries the optional `ivshmem.preferred-bar-num` setting (default BAR2)
+   used when mapping the shared-memory BAR.
 3. `mw_com_config.json` — standard `mw::com` deployment config (provided as for all `mw::com` applications).
    Required by the `mw::com` runtime to resolve the `InstanceSpecifier`s referenced in
    `mw_com_gateway_config.json` into concrete deployment info (binding, number of slots, ASIL level, allowed

score/mw/com/gateway/gateway_application/BUILD

@@ -30,9 +30,7 @@ cc_library(
         "@score_baselibs//score/language/futurecpp",
         "@score_baselibs//score/mw/log",
     ],
-    visibility = [
-        "//score/mw/com/gateway:__subpackages__",
-    ],
+    visibility = ["//score/mw/com/gateway:__subpackages__"],
     deps = [
         ":gateway_core",
         "//score/mw/com/gateway/gateway_application/configuration:gateway_configuration",

score/mw/com/gateway/gateway_application/configuration/BUILD

@@ -37,6 +37,7 @@ cc_library(
     srcs = ["gateway_configuration.cpp"],
     hdrs = ["gateway_configuration.h"],
     features = COMPILER_WARNING_FEATURES,
+    visibility = ["//score/mw/com/gateway:__subpackages__"],
     deps = [
         "@score_baselibs//score/language/futurecpp",
     ],
@@ -50,6 +51,7 @@ cc_library(
     implementation_deps = [
         "@score_baselibs//score/mw/log",
     ],
+    visibility = ["//score/mw/com/gateway:__subpackages__"],
     deps = [
         ":gateway_configuration",
         "@score_baselibs//score/json",

score/mw/com/gateway/transport_layer/BUILD

@@ -56,7 +56,12 @@ cc_library(
     ],
     deps = [
         ":transport",
+        "//score/memory/shared",
         "//score/mw/com/gateway/gateway_application:gateway_core",
+        "//score/mw/com/gateway/transport_layer/qemu:qemu_hypervisor_transport",
+        "//score/mw/com/gateway/transport_layer/qemu/configuration:qemu_transport_config_parser",
+        "//score/mw/com/gateway/transport_layer/qemu/ivshmem:ivshmem_bar_discovery",
+        "//score/mw/com/gateway/transport_layer/qemu/ivshmem:ivshmem_typed_memory_provider",
         "//score/mw/com/gateway/transport_layer/sample:bidirectional_transport",
         "//score/mw/com/gateway/transport_layer/sample:sample_hypervisor_transport",
         "//score/mw/com/gateway/transport_layer/sample/configuration:hypervisor_socket_configuration",

score/mw/com/gateway/transport_layer/qemu/BUILD

@@ -0,0 +1,53 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+load("@rules_cc//cc:defs.bzl", "cc_library")
+load("@score_baselibs//score/language/safecpp:toolchain_features.bzl", "COMPILER_WARNING_FEATURES")
+load("//quality/unit_testing:unit_testing.bzl", "cc_unit_test")
+
+cc_library(
+    name = "qemu_hypervisor_transport",
+    srcs = ["qemu_hypervisor_transport.cpp"],
+    hdrs = ["qemu_hypervisor_transport.h"],
+    features = COMPILER_WARNING_FEATURES + [
+        "aborts_upon_exception",
+    ],
+    visibility = ["//score/mw/com/gateway:__subpackages__"],
+    deps = [
+        "//score/memory/shared",
+        "//score/mw/com/gateway/gateway_application:gateway_core",
+        "//score/mw/com/gateway/transport_layer:transport",
+        "//score/mw/com/gateway/transport_layer/qemu/ivshmem:ivshmem_typed_memory_provider",
+        "//score/mw/com/gateway/transport_layer/sample:i_bidirectional_transport",
+        "//score/mw/com/gateway/transport_layer/sample:sample_hypervisor_transport",
+        "//score/mw/com/gateway/transport_layer/sample/messages:gateway_messages",
+        "@score_baselibs//score/mw/log",
+    ],
+)
+
+cc_unit_test(
+    name = "qemu_hypervisor_transport_test",
+    srcs = ["qemu_hypervisor_transport_test.cpp"],
+    features = COMPILER_WARNING_FEATURES,
+    deps = [
+        ":qemu_hypervisor_transport",
+        "//score/mw/com/gateway/gateway_application:gateway_core_mock",
+        "//score/mw/com/gateway/transport_layer:transport_error",
+        "//score/mw/com/gateway/transport_layer/qemu/ivshmem:ivshmem_typed_memory_provider_mock",
+        "//score/mw/com/gateway/transport_layer/sample:bidirectional_transport_mock",
+        "@score_baselibs//score/mw/log",
+        "@score_baselibs//score/mw/log:recorder_mock",
+    ] + select({
+        "@platforms//os:qnx": ["@score_baselibs//score/os/mocklib/qnx:mman_mock"],
+        "//conditions:default": [],
+    }),
+)

score/mw/com/gateway/transport_layer/qemu/README.md

@@ -0,0 +1,57 @@
+<!--
+*******************************************************************************
+Copyright (c) 2026 Contributors to the Eclipse Foundation
+
+See the NOTICE file(s) distributed with this work for additional
+information regarding copyright ownership.
+
+This program and the accompanying materials are made available under the
+terms of the Apache License Version 2.0 which is available at
+https://www.apache.org/licenses/LICENSE-2.0
+
+SPDX-License-Identifier: Apache-2.0
+*******************************************************************************
+-->
+
+# QEMU Transport Layer
+
+Inter-VM communication and shared memory exchange for LoLa gateway using **ivshmem** (Inter-VM Shared Memory BAR) for zero-copy data transfer between QEMU virtual machines. Extends the [sample transport layer](../sample/README.md) with ivshmem-based memory sharing.
+
+## What It Provides
+
+- **Message Communication** — Service provisioning and lifecycle events via TCP over QEMU's intervm network (reuses sample transport layer)
+- **Shared Memory** — Zero-copy data exchange through ivshmem BAR mapping
+- **Cross-VM Coordination** — Shared directory for consistent memory region access
+
+## Main Components
+
+- **QemuHypervisorTransport** — Orchestrates message and memory layers
+- **IvshmemTypedMemoryProvider** — Manages named shared memory backed by ivshmem BAR
+
+## Configuration
+
+See [`configuration/example/mw_com_gateway_qemu_transport_config.json`](./configuration/example/mw_com_gateway_qemu_transport_config.json)
+
+The config contains the usual `hypervisor-socket` block plus an optional `ivshmem` block.
+`ivshmem.preferred-bar-num` selects which PCI BAR to map for the shared-memory region and
+defaults to BAR2 for QEMU `ivshmem-plain`.
+
+## How It Works
+
+**Offering a service (Source VM):**
+- Allocate CTRL and DATA shared memory regions via ivshmem BAR ([`IvshmemTypedMemoryProvider::AllocateNamedTypedMemory`](./ivshmem/ivshmem_typed_memory_provider.h))
+- Register allocation offsets in the shared directory (visible to both VMs)
+- Send service availability notification to remote gateway over TCP
+- Remote VMs can now discover and map to the same physical memory regions
+
+**Consuming a service (Destination VM):**
+- Receive service notification and look up memory offsets in the shared directory
+- Bind local shared memory objects to those discovered offsets in ivshmem BAR ([`IvshmemTypedMemoryProvider::AllocateNamedTypedMemoryAtOffset`](./ivshmem/ivshmem_typed_memory_provider.h))
+- Both VMs now access the exact same physical memory
+
+See [`QemuHypervisorTransport`](./qemu_hypervisor_transport.h) for the orchestration logic.
+
+## Supported Platforms
+
+- **QNX 7.1+** — Full ivshmem support
+- **Linux** — Message layer only

score/mw/com/gateway/transport_layer/qemu/configuration/BUILD

@@ -0,0 +1,51 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+
+load("@rules_cc//cc:defs.bzl", "cc_library")
+load("@score_baselibs//score/language/safecpp:toolchain_features.bzl", "COMPILER_WARNING_FEATURES")
+load("//quality/unit_testing:unit_testing.bzl", "cc_unit_test")
+
+package(
+    default_visibility = ["//score/mw/com/gateway/transport_layer/qemu:__subpackages__"],
+)
+
+exports_files(["example/mw_com_gateway_qemu_transport_config.json"])
+
+cc_library(
+    name = "qemu_transport_config_parser",
+    srcs = ["qemu_transport_config_parser.cpp"],
+    hdrs = [
+        "qemu_transport_config_parser.h",
+        "qemu_transport_configuration.h",
+    ],
+    features = COMPILER_WARNING_FEATURES,
+    implementation_deps = [
+        "@score_baselibs//score/mw/log",
+    ],
+    visibility = ["//score/mw/com/gateway/transport_layer:__subpackages__"],
+    deps = [
+        "//score/mw/com/gateway/transport_layer/qemu/ivshmem:ivshmem_bar_discovery",
+        "@score_baselibs//score/json",
+        "@score_baselibs//score/language/futurecpp",
+    ],
+)
+
+cc_unit_test(
+    name = "qemu_transport_config_parser_test",
+    srcs = ["qemu_transport_config_parser_test.cpp"],
+    deps = [
+        ":qemu_transport_config_parser",
+        "@googletest//:gtest",
+        "@score_baselibs//score/json",
+    ],
+)

score/mw/com/gateway/transport_layer/qemu/configuration/example/mw_com_gateway_qemu_transport_config.json

@@ -0,0 +1,11 @@
+{
+  "hypervisor-socket": {
+    "remote-ip": "10.0.2.2",
+    "local-port": 45001,
+    "remote-port": 45002,
+    "request-timeout-ms": 5000
+  },
+  "ivshmem": {
+    "preferred-bar-num": 2
+  }
+}

score/mw/com/gateway/transport_layer/qemu/configuration/qemu_transport_config_parser.cpp

@@ -0,0 +1,84 @@
+/********************************************************************************
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ********************************************************************************/
+#include "score/mw/com/gateway/transport_layer/qemu/configuration/qemu_transport_config_parser.h"
+
+#include "score/json/json_parser.h"
+#include "score/mw/log/logging.h"
+
+#include <score/assert.hpp>
+
+#include <string_view>
+
+namespace score::mw::com::gateway::qemu
+{
+namespace
+{
+
+using std::string_view_literals::operator""sv;
+
+constexpr auto kIvshmemConfigurationKey = "ivshmem"sv;
+constexpr auto kPreferredBarNumKey = "preferred-bar-num"sv;
+
+}  // namespace
+
+auto ParseQemuTransportConfig(const std::string_view path) noexcept -> QemuTransportConfiguration
+{
+    const score::json::JsonParser json_parser_obj;
+    // NOLINTNEXTLINE(score-banned-function): AoU of score::json::JsonParser — caller must guarantee path integrity.
+    auto json_result = json_parser_obj.FromFile(path);
+    if (!json_result.has_value())
+    {
+        ::score::mw::log::LogFatal("lola")
+            << "Parsing qemu transport config file" << path << "failed with error:" << json_result.error().Message()
+            << ": " << json_result.error().UserMessage() << " . Terminating.";
+        std::terminate();
+    }
+    return ParseQemuTransportConfig(std::move(json_result).value());
+}
+
+auto ParseQemuTransportConfig(score::json::Any json) noexcept -> QemuTransportConfiguration
+{
+    auto top_level_object = json.As<score::json::Object>();
+    if (!top_level_object.has_value())
+    {
+        ::score::mw::log::LogFatal("lola")
+            << "Parsing qemu transport configuration failed: Expected top-level JSON object. Terminating.";
+        std::terminate();
+    }
+
+    const auto& obj = top_level_object.value().get();
+
+    std::uint32_t preferred_bar_num = ivshmem::kDefaultIvshmemBarNum;
+    const auto ivshmem_entry = obj.find(kIvshmemConfigurationKey);
+    if (ivshmem_entry != obj.cend())
+    {
+        const auto ivshmem_obj_result = ivshmem_entry->second.As<score::json::Object>();
+        if (ivshmem_obj_result.has_value())
+        {
+            const auto& ivshmem_obj = ivshmem_obj_result.value().get();
+            const auto preferred_bar_num_entry = ivshmem_obj.find(kPreferredBarNumKey);
+            if (preferred_bar_num_entry != ivshmem_obj.cend())
+            {
+                const auto preferred_bar_num_result = preferred_bar_num_entry->second.As<std::uint32_t>();
+                if (preferred_bar_num_result.has_value())
+                {
+                    preferred_bar_num = preferred_bar_num_result.value();
+                }
+            }
+        }
+    }
+
+    return QemuTransportConfiguration{preferred_bar_num};
+}
+
+}  // namespace score::mw::com::gateway::qemu