Add openvmm as vmm backend option for wslc vms

CMakeLists.txt

@@ -41,6 +41,7 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin/${TARGET_PLATFORM})
 # BUNDLE_ONLY mode: skip all source builds; only configure the msixbundle target and nuspec files.
 # Used by the package pipeline stage to create the bundle from pre-built per-platform msix files.
 option(BUNDLE_ONLY "Only configure the msixbundle target, skip all source builds" OFF)
+option(INCLUDE_OPENVMM "Include OpenVMM build integrations" OFF)
 if (BUNDLE_ONLY)
     if (NOT PACKAGE_VERSION)
         message(FATAL_ERROR "PACKAGE_VERSION is required for BUNDLE_ONLY mode")
@@ -63,7 +64,8 @@ include(FetchContent)
 
 set(FETCHCONTENT_BASE_DIR ${CMAKE_BINARY_DIR}/_deps/${TARGET_PLATFORM})
 
-# N.B. Changes to any of the FetchContent dependencies below (GSL, nlohmannjson) must be reflected in cgmanifest.json
+# N.B. Changes to any of the FetchContent dependencies below (GSL, nlohmannjson, yaml-cpp, boost, protobuf)
+# must be reflected in cgmanifest.json
 
 FetchContent_Declare(GSL
                      URL https://github.com/microsoft/GSL/archive/refs/tags/v4.0.0.tar.gz
@@ -104,6 +106,48 @@ FetchContent_Declare(
 
 FetchContent_MakeAvailable(boost_headers)
 
+set(protobuf_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+set(protobuf_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
+set(protobuf_INSTALL OFF CACHE BOOL "" FORCE)
+
+if (INCLUDE_OPENVMM)
+    FetchContent_Declare(protobuf
+                         URL https://github.com/protocolbuffers/protobuf/releases/download/v34.1/protobuf-34.1.tar.gz
+                         URL_HASH SHA256=e4e6ff10760cf747a2decd1867741f561b216bd60cc4038c87564713a6da1848)
+
+    FetchContent_MakeAvailable(protobuf)
+    include(${protobuf_SOURCE_DIR}/cmake/protobuf-generate.cmake)
+endif()
+
+# Adds protobuf-generated C++ sources from VMService.proto to the given TARGET.
+# The target must already exist. This function handles code generation, include
+# directories, library linking, and MSVC warning suppression for generated code.
+function(wsl_add_openvmm_proto TARGET)
+    set(_proto_file ${WSL_DEVICE_HOST_SOURCE_DIR}/proto/VMService.proto)
+    set(_proto_out_dir ${CMAKE_CURRENT_BINARY_DIR}/generated)
+
+    if (NOT EXISTS ${_proto_file})
+        message(FATAL_ERROR "Expected DeviceHost proto file was not found: ${_proto_file}")
+    endif()
+
+    protobuf_generate(
+        TARGET ${TARGET}
+        PROTOS ${_proto_file}
+        IMPORT_DIRS ${WSL_DEVICE_HOST_SOURCE_DIR}/proto ${protobuf_SOURCE_DIR}/src
+        PROTOC_OUT_DIR ${_proto_out_dir}
+    )
+
+    target_include_directories(${TARGET} PRIVATE ${_proto_out_dir})
+    target_link_libraries(${TARGET} protobuf::libprotobuf)
+
+    if (MSVC)
+        set_source_files_properties(
+            ${_proto_out_dir}/VMService.pb.cc
+            TARGET_DIRECTORY ${TARGET}
+            PROPERTIES COMPILE_OPTIONS "/wd4267;/wd4244;/wd4018")
+    endif()
+endfunction()
+
 
 # Import modules
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")

cgmanifest.json

@@ -84,6 +84,17 @@
                     "hash": "sha256:42f6e95cad6ec532fd372391373363b62a14af6d771056dbfc86160e6dfff7aa"
                 }
             }
+        },
+        {
+            "component": {
+                "type": "other",
+                "other": {
+                    "name": "protobuf",
+                    "version": "34.1",
+                    "downloadUrl": "https://github.com/protocolbuffers/protobuf/releases/download/v34.1/protobuf-34.1.tar.gz",
+                    "hash": "sha256:e4e6ff10760cf747a2decd1867741f561b216bd60cc4038c87564713a6da1848"
+                }
+            }
         }
     ]
 }

msipackage/CMakeLists.txt

@@ -27,6 +27,13 @@ foreach(binary ${WINDOWS_BINARIES})
     list(APPEND BINARIES_DEPENDENCIES "${PACKAGE_INPUT_DIR}/${binary}")
 endforeach()
 
+if (INCLUDE_OPENVMM)
+    set(WSL_DEVICE_HOST_BINARIES wsldevicehost.dll;openvmm.exe)
+    foreach(binary ${WSL_DEVICE_HOST_BINARIES})
+        list(APPEND BINARIES_DEPENDENCIES "${WSL_DEVICE_HOST_SOURCE_DIR}/bin/${TARGET_PLATFORM}/${binary}")
+    endforeach()
+endif()
+
 set(LINUX_BINARIES init;initrd.img)
 foreach(binary ${LINUX_BINARIES})
     list(APPEND BINARIES_DEPENDENCIES "${BIN}/${binary}")

msipackage/package.wix.in

@@ -241,6 +241,7 @@
                 <ServiceControl Id="StopService" Stop="both" Remove="uninstall" Name="WSLService" Wait="yes" />
 
                 <File Id="wsldevicehost.dll" Source="${WSL_DEVICE_HOST_SOURCE_DIR}/bin/${TARGET_PLATFORM}/wsldevicehost.dll" />
+                <File Id="openvmm.exe" Source="${WSL_DEVICE_HOST_SOURCE_DIR}/bin/${TARGET_PLATFORM}/openvmm.exe" />
 
                 <!-- WSLC COM app - activated through WSLService -->
                 <RegistryKey Root="HKCR" Key="AppID\{E9B79997-57E3-4201-AECC-6A464E530DD2}">

packages.config

@@ -19,7 +19,7 @@
   <package id="Microsoft.WSL.bsdtar" version="0.0.2-2" />
   <package id="Microsoft.WSL.Dependencies.amd64fre" version="10.0.27820.1000-250318-1700.rs-base2-hyp" targetFramework="native" />
   <package id="Microsoft.WSL.Dependencies.arm64fre" version="10.0.27820.1000-250318-1700.rs-base2-hyp" targetFramework="native" />
-  <package id="Microsoft.WSL.DeviceHost" version="1.2.23-0" />
+  <package id="Microsoft.WSL.DeviceHost" version="1.2.25-0" />
   <package id="Microsoft.WSL.Kernel" version="6.18.26.1-1" targetFramework="native" />
   <package id="Microsoft.WSL.LinuxSdk" version="1.20.0" targetFramework="native" />
   <package id="Microsoft.WSL.TestData" version="0.4.0" />

src/linux/init/WSLCInit.cpp

@@ -670,6 +670,94 @@ void HandleMessageImpl(
     Transaction.SendResultMessage(result < 0 ? errno : 0);
 }
 
+void HandleMessageImpl(
+    wsl::shared::SocketChannel& Channel,
+    wsl::shared::Transaction& Transaction,
+    const WSLC_CONFIGURE_NETWORKING& Message,
+    const gsl::span<gsl::byte>& Buffer)
+{
+    int result = -EINVAL;
+    auto sendResult = wil::scope_exit([&]() { Transaction.SendResultMessage<int32_t>(result); });
+
+    const auto* iface = wsl::shared::string::FromSpan(Buffer, Message.InterfaceOffset);
+    const auto* address = wsl::shared::string::FromSpan(Buffer, Message.AddressOffset);
+    const auto* gateway = wsl::shared::string::FromSpan(Buffer, Message.GatewayOffset);
+    const auto* dnsServer = wsl::shared::string::FromSpan(Buffer, Message.DnsServerOffset);
+
+    THROW_ERRNO_IF(EINVAL, iface == nullptr || address == nullptr || gateway == nullptr || dnsServer == nullptr);
+
+    // Bring up the interface and configure the static address, route, and DNS.
+    auto configCmd = std::format(
+        "ip link set {} up && ip addr add {} dev {} && ip route add default via {}",
+        iface, address, iface, gateway);
+
+    // Use a pipe to detect child completion. The child inherits the write end;
+    // when it exits (via execl or _exit), the write end is closed and read()
+    // returns 0. This avoids racing with the WSLC_WATCH_PROCESSES handler's
+    // waitpid(-1) which may reap the child before we can.
+    int pipeFds[2]{};
+    THROW_LAST_ERROR_IF(pipe2(pipeFds, O_CLOEXEC) < 0);
+    wil::unique_fd pipeRead{pipeFds[0]};
+    wil::unique_fd pipeWrite{pipeFds[1]};
+
+    int childPid = UtilCreateChildProcess("ConfigureNetworking", [&configCmd, &pipeWrite]() {
+        // Clear CLOEXEC on the write end so it stays open across execl.
+        // When the shell exits, the fd is closed and the parent's read returns.
+        fcntl(pipeWrite.get(), F_SETFD, 0);
+        execl("/bin/sh", "/bin/sh", "-c", configCmd.c_str(), nullptr);
+        LOG_ERROR("execl(/bin/sh) failed, {}", errno);
+    });
+
+    // Close the write end in the parent — only the child holds it now.
+    pipeWrite.reset();
+
+    if (childPid < 0)
+    {
+        result = -errno;
+        return;
+    }
+
+    // Wait for the child to exit by reading from the pipe. When the child
+    // (and the shell it exec'd) exits, all write ends are closed and read
+    // returns 0.
+    char dummy{};
+    TEMP_FAILURE_RETRY(read(pipeRead.get(), &dummy, sizeof(dummy)));
+
+    // Try to reap the child. If WSLC_WATCH_PROCESSES already reaped it, we
+    // get ECHILD which is fine — the pipe close confirms the child exited.
+    int status = -1;
+    if (TEMP_FAILURE_RETRY(waitpid(childPid, &status, 0)) < 0)
+    {
+        if (errno == ECHILD)
+        {
+            // Child was already reaped by the WatchProcesses handler.
+            // The pipe confirmed it exited, so treat as success.
+            status = 0;
+        }
+        else
+        {
+            result = -errno;
+            return;
+        }
+    }
+
+    result = UtilProcessChildExitCode(status, "ConfigureNetworking");
+    if (result != 0)
+    {
+        return;
+    }
+
+    // Write DNS configuration.
+    auto resolv = std::format("nameserver {}\n", dnsServer);
+    if (WriteToFile("/etc/resolv.conf", resolv.c_str()) < 0)
+    {
+        result = -errno;
+        return;
+    }
+
+    result = 0;
+}
+
 void HandleMessageImpl(wsl::shared::SocketChannel& Channel, wsl::shared::Transaction& Transaction, const WSLC_UNMOUNT&, const gsl::span<gsl::byte>& Buffer)
 {
     auto* path = wsl::shared::string::FromMessageBuffer<WSLC_UNMOUNT>(Buffer);
@@ -831,7 +919,7 @@ void ProcessMessage(wsl::shared::SocketChannel& Channel, wsl::shared::Transactio
 {
     try
     {
-        HandleMessage<WSLC_GET_DISK, WSLC_MOUNT, WSLC_EXEC, WSLC_FORK, WSLC_CONNECT, WSLC_SIGNAL, WSLC_TTY_RELAY, WSLC_PORT_RELAY, WSLC_UNMOUNT, WSLC_DETACH, WSLC_ACCEPT, WSLC_WATCH_PROCESSES, WSLC_UNIX_CONNECT>(
+        HandleMessage<WSLC_GET_DISK, WSLC_MOUNT, WSLC_EXEC, WSLC_FORK, WSLC_CONNECT, WSLC_SIGNAL, WSLC_TTY_RELAY, WSLC_PORT_RELAY, WSLC_UNMOUNT, WSLC_DETACH, WSLC_ACCEPT, WSLC_WATCH_PROCESSES, WSLC_UNIX_CONNECT, WSLC_CONFIGURE_NETWORKING>(
             Channel, Transaction, Type, Buffer);
     }
     catch (...)