[experimental] add CI for transport runtime

.github/workflows/check-transport.yaml

@@ -0,0 +1,189 @@
+name: Check Transport Backends
+
+on:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - ready_for_review
+    paths:
+      - 'runtime/lib/transport/**'
+      - 'runtime/tests/Test_Transport*.cpp'
+      - 'runtime/tests/stubs/stub_transport_backend*'
+      - 'runtime/tests/CMakeLists.txt'
+      - 'runtime/CMakeLists.txt'
+      - 'runtime/lib/CMakeLists.txt'
+      - 'runtime/Makefile'
+      - 'Makefile'
+      - '.github/workflows/check-transport.yaml'
+  push:
+    branches: [ main ]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  determine_runner:
+    if: github.event.pull_request.draft == false
+    name: Determine runner type to use
+    uses: ./.github/workflows/determine-workflow-runner.yml
+    with:
+      default_runner: ubuntu-24.04
+
+  constants:
+    name: "Set build matrix"
+    uses: ./.github/workflows/constants.yaml
+    needs: [determine_runner]
+    with:
+      multiple_compilers: false
+      runs_on: ${{ needs.determine_runner.outputs.runner_group }}
+
+  transport-tests:
+    name: Transport Backend Tests (Soft-RoCE)
+    needs: [constants, determine_runner]
+    runs-on: ${{ needs.determine_runner.outputs.runner_group }}
+
+    steps:
+      - name: Checkout Catalyst repo
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ needs.constants.outputs.primary_python_version }}
+
+      - name: Install build and RDMA userland dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            cmake ninja-build clang make \
+            libibverbs-dev libibverbs1 ibverbs-providers ibverbs-utils \
+            rdma-core iproute2
+          python3 -m pip install "nanobind<2.13" pybind11
+
+      - name: Ensure rdma_rxe.ko is available for the running kernel
+        run: |
+          # Try linux-modules-extra first; if the .ko isn't there, build
+          # rdma_rxe out-of-tree from the matching upstream stable branch.
+          set -euo pipefail
+
+          KVER=$(uname -r)
+          echo "Running kernel: $KVER"
+
+          have_rxe() {
+            find /lib/modules/"$KVER" -name 'rdma_rxe*' -print -quit | grep -q .
+          }
+
+          # --- Path 1: standard Ubuntu extras package ----------------------
+          sudo apt-get install -y "linux-modules-extra-$KVER" 2>/dev/null || true
+          sudo depmod -a
+          if have_rxe; then
+            echo "rdma_rxe.ko provided by linux-modules-extra-$KVER"
+            find /lib/modules/"$KVER" -name 'rdma_rxe*' -print
+            exit 0
+          fi
+
+          echo "linux-modules-extra unavailable or missing rdma_rxe;" \
+               "falling back to out-of-tree build."
+
+          # --- Path 2: build rdma_rxe out-of-tree --------------------------
+          sudo apt-get install -y \
+            build-essential bc bison flex libssl-dev libelf-dev git \
+            "linux-headers-$KVER"
+
+          # Upstream stable branch matching the running kernel's major.minor.
+          KVER_MAJMIN=$(echo "$KVER" | cut -d- -f1 | cut -d. -f1-2)
+          SRC=/tmp/linux-src
+          echo "Cloning linux-${KVER_MAJMIN}.y stable branch..."
+          git clone --depth 1 \
+            --branch "linux-${KVER_MAJMIN}.y" \
+            https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git \
+            "$SRC"
+
+          # Force obj-m; Azure kernel has CONFIG_RDMA_RXE unset.
+          sed -i 's|obj-\$(CONFIG_RDMA_RXE)|obj-m|' \
+            "$SRC/drivers/infiniband/sw/rxe/Makefile"
+
+          make -C "/lib/modules/$KVER/build" \
+            M="$SRC/drivers/infiniband/sw/rxe" modules
+
+          KO="$SRC/drivers/infiniband/sw/rxe/rdma_rxe.ko"
+          if [ ! -f "$KO" ]; then
+            echo "::error::rdma_rxe.ko not produced by build"
+            ls -la "$SRC/drivers/infiniband/sw/rxe/"
+            exit 1
+          fi
+
+          sudo install -D -m 644 "$KO" \
+            "/lib/modules/$KVER/kernel/drivers/infiniband/sw/rxe/rdma_rxe.ko"
+          sudo depmod -a
+
+          if ! have_rxe; then
+            echo "::error::rdma_rxe.ko not resolvable after install"
+            exit 1
+          fi
+          echo "Built and installed rdma_rxe.ko from linux-${KVER_MAJMIN}.y"
+          modinfo rdma_rxe | head -20
+
+      - name: Configure Soft-RoCE (rxe0 on loopback)
+        run: |
+          # Attach rdma_rxe to `lo` so the tests find an ibverbs device named rxe0.
+          sudo modprobe rdma_rxe
+          sudo rdma link add rxe0 type rxe netdev lo
+          rdma link show
+          ibv_devices
+          ibv_devinfo -d rxe0
+          # Fail fast if rxe0 didn't come up - otherwise Catch2 tests would
+          # silently SKIP and the loopback would be the only thing exercising it.
+          ibv_devices | awk '{print $1}' | grep -q '^rxe0$'
+
+      - name: Get Cached LLVM Source
+        id: cache-llvm-source
+        uses: actions/cache/restore@v4
+        with:
+          path: mlir/llvm-project
+          key: llvm-${{ needs.constants.outputs.llvm_version }}-default-source
+          enableCrossOsArchive: true
+
+      - name: Clone LLVM Submodule
+        if: steps.cache-llvm-source.outputs.cache-hit != 'true'
+        uses: actions/checkout@v4
+        with:
+          repository: llvm/llvm-project
+          ref: ${{ needs.constants.outputs.llvm_version }}
+          path: mlir/llvm-project
+
+      - name: Build Catalyst-Runtime with ENABLE_TRANSPORT=ON
+        run: |
+          COMPILER_LAUNCHER="" \
+          C_COMPILER=$(which clang) \
+          CXX_COMPILER=$(which clang++) \
+          LLVM_DIR="$(pwd)/mlir/llvm-project" \
+          ENABLE_ASAN=OFF \
+          ENABLE_TRANSPORT=ON \
+          make runtime
+
+      - name: Run transport test suite (Catch2 + loopback)
+        run: |
+          COMPILER_LAUNCHER="" \
+          C_COMPILER=$(which clang) \
+          CXX_COMPILER=$(which clang++) \
+          LLVM_DIR="$(pwd)/mlir/llvm-project" \
+          make test-runtime-transport
+
+      - name: Upload loopback logs on failure
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: transport-loopback-logs
+          path: |
+            /tmp/cvl_coproc.log
+            /tmp/cvl_ctrl.log
+          if-no-files-found: ignore
+          retention-days: 7

Makefile

@@ -17,6 +17,7 @@ ENZYME_BUILD_DIR ?= $(MK_DIR)/mlir/Enzyme/build
 COVERAGE_REPORT ?= term-missing
 ENABLE_OPENQASM ?= ON
 ENABLE_OQD ?= OFF
+ENABLE_TRANSPORT ?= OFF
 TEST_BACKEND ?= "lightning.qubit"
 TEST_BRAKET ?= NONE
 ENABLE_ASAN ?= OFF
@@ -150,12 +151,12 @@ dialect-docs:
 	$(MAKE) -C mlir dialect-docs
 
 runtime:
-	$(MAKE) -C runtime runtime ENABLE_OQD=$(ENABLE_OQD)
+	$(MAKE) -C runtime runtime ENABLE_OQD=$(ENABLE_OQD) ENABLE_TRANSPORT=$(ENABLE_TRANSPORT)
 
 oqc:
 	$(MAKE) -C frontend/catalyst/third_party/oqc/src oqc
 
-.PHONY: test test-runtime test-frontend lit pytest test-demos test-oqc test-toml-spec
+.PHONY: test test-runtime test-runtime-transport test-frontend lit pytest test-demos test-oqc test-toml-spec
 test: test-runtime test-frontend test-demos
 
 test-toml-spec:
@@ -164,6 +165,9 @@ test-toml-spec:
 test-runtime:
 	$(MAKE) -C runtime test
 
+test-runtime-transport:
+	$(MAKE) -C runtime test-transport
+
 test-mlir:
 	$(MAKE) -C mlir test
 

doc/releases/changelog-dev.md

@@ -14,6 +14,15 @@
 
 * A new runtime transport layer for remote/local executors is introduced.
   [(#3043)](https://github.com/PennyLaneAI/catalyst/pull/3043)
+  [(#3045)](https://github.com/PennyLaneAI/catalyst/pull/3045)
+
+* A new `Transport` MLIR dialect is added, providing typed ops for driving a transport session's
+  lifecycle at the IR level.
+  [(#3047)](https://github.com/PennyLaneAI/catalyst/pull/3047)
+
+* A `convert-transport-to-llvm` pass is added, lowering the `Transport` dialect ops to the
+  transport runtime CAPI.
+  [(#3048)](https://github.com/PennyLaneAI/catalyst/pull/3048)
 
 * A new remote/local executor infrastructure has been added to Catalyst, enabling qnode kernels to
   be dispatched to a separate executor process. `executor` dialect models the session lifecycle
@@ -306,6 +315,9 @@
 * The `/benchmark` GitHub comment trigger can now accept additional arguments and has been renamed to `!benchmark`.
   [(#2947)](https://github.com/PennyLaneAI/catalyst/pull/2947)
 
+* Added CI checks for the runtime `cpu_verbs` transport backend via Soft-RoCE.
+  [(#3074)](https://github.com/PennyLaneAI/catalyst/pull/3074)
+
 * The frontend now generates MLIR in reference semantics when capture is enabled.
   [(#2663)](https://github.com/PennyLaneAI/catalyst/pull/2663)
   [(#2664)](https://github.com/PennyLaneAI/catalyst/pull/2664)

mlir/include/CMakeLists.txt

@@ -12,4 +12,5 @@ add_subdirectory(Quantum)
 add_subdirectory(QRef)
 add_subdirectory(Executor)
 add_subdirectory(RTIO)
+add_subdirectory(Transport)
 add_subdirectory(Test)

mlir/include/RegisterAllPasses.h

@@ -29,6 +29,7 @@
 #include "hlo-extensions/Transforms/Passes.h"
 
 #include "Executor/Transforms/Passes.h"
+#include "Transport/Transforms/Passes.h"
 
 namespace catalyst {
 
@@ -47,6 +48,7 @@ inline void registerAllPasses()
     quantum::registerQuantumPasses();
     executor::registerExecutorPasses();
     rtio::registerRTIOPasses();
+    transport::registerTransportPasses();
     test::registerTestPasses();
 }
 

mlir/include/Transport/CMakeLists.txt

@@ -0,0 +1,2 @@
+add_subdirectory(IR)
+add_subdirectory(Transforms)

mlir/include/Transport/IR/CMakeLists.txt

@@ -0,0 +1,8 @@
+add_mlir_dialect(TransportOps transport)
+add_mlir_doc(TransportDialect TransportDialect Transport/ -gen-dialect-doc)
+add_mlir_doc(TransportOps TransportOps Transport/ -gen-op-doc)
+
+set(LLVM_TARGET_DEFINITIONS TransportOps.td)
+mlir_tablegen(TransportEnums.h.inc -gen-enum-decls)
+mlir_tablegen(TransportEnums.cpp.inc -gen-enum-defs)
+add_public_tablegen_target(MLIRTransportEnumsIncGen)

mlir/include/Transport/IR/TransportDialect.h

@@ -0,0 +1,25 @@
+// Copyright 2026 Xanadu Quantum Technologies Inc.
+
+// 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.
+
+#pragma once
+
+#include "mlir/Bytecode/BytecodeOpInterface.h"
+#include "mlir/IR/Dialect.h"
+#include "mlir/IR/OpDefinition.h"
+
+#include "Transport/IR/TransportEnums.h.inc"
+#include "Transport/IR/TransportOpsDialect.h.inc"
+
+#define GET_TYPEDEF_CLASSES
+#include "Transport/IR/TransportOpsTypes.h.inc"