marifamd · Aug 17, 2026 · Aug 5, 2026 · Aug 10, 2026 · Aug 12, 2026 · Aug 12, 2026
@@ -115,6 +115,10 @@ Full documentation for amd_smi_lib is available at [https://rocm.docs.amd.com/pr
 
 ### Added
 
+- **Added an experimental, opt-in WSL (WDDM/dxg) GPU backend**.
+  - Built only with `-DENABLE_WSL_BACKEND=ON` (off by default); native builds and packages are unchanged.
+  - Reads real GPU telemetry through `librocdxg` (`rocdxg_smi_*` APIs); queries with no WDDM equivalent return `AMDSMI_STATUS_NOT_SUPPORTED`. See [Using AMD SMI under WSL](https://rocm.docs.amd.com/projects/amdsmi/en/latest/how-to/amdsmi-wsl-mode.html).
+
 - **Added NIC processor discovery and information API surface**.  
   - New C APIs: `amdsmi_get_nic_processor_handles()`, `amdsmi_get_nic_device_bdf()`, `amdsmi_get_nic_fw_info()`, `amdsmi_get_nic_port_statistics()`, and `amdsmi_get_nic_vendor_statistics()`.
   - `amdsmi_get_nic_processor_handles()` enumerates NIC processors by socket; the BDF, firmware, and port/vendor statistics getters are reserved and currently return `AMDSMI_STATUS_NOT_YET_IMPLEMENTED`.

@@ -124,6 +124,10 @@ include(GNUInstallDirs)
 option(BUILD_TESTS "Build test suite" OFF)
 option(ENABLE_ASAN_PACKAGING "" OFF)
 
+# WSL/WDDM GPU backend. Default OFF so native builds and CI are unchanged. When
+# ON, the WSL intercept hooks and mock backend are compiled
+option(ENABLE_WSL_BACKEND "Build the experimental WSL (WDDM/dxg) GPU backend" OFF)
+
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64")
     option(ENABLE_ESMI_LIB "Build ESMI Library" ON)
 else()
@@ -204,13 +208,13 @@ generic_package()
 
 # Dependencies
 find_package(Threads REQUIRED)
+find_package(PkgConfig REQUIRED)
 
 pkg_check_modules(DRM REQUIRED IMPORTED_TARGET libdrm)
 pkg_check_modules(DRM_AMDGPU REQUIRED IMPORTED_TARGET libdrm_amdgpu)
 
 # Netlink libraries for network interface functionality (required)
 # TheRock RUNTIME_DEPS automatically configure PKG_CONFIG_PATH for bundled sysdeps
-find_package(PkgConfig REQUIRED)
 
 # Try to use CMake config files first (bundled sysdeps provide these)
 find_package(libnl CONFIG QUIET)

@@ -71,8 +71,33 @@
 AMD_VENDOR_ID = 4098
 
 
+def check_wsl_dxg():
+    """Returns true if running under WSL2 (not Hyper-V) with /dev/dxg present.
+
+    /dev/dxg is created by dxgkrnl for any WDDM GPU, so we additionally require
+    the WSL2 kernel signature in /proc/version to avoid false-positives on
+    Hyper-V Linux guests or native hosts where dxgkrnl may be loaded.
+    Vendor confirmation (AMD 0x1002) is deferred to amdsmi_init(), which calls
+    into librocdxg and rejects non-AMD adapters.
+    """
+    if not Path("/dev/dxg").exists():
+        return False
+    try:
+        osrelease = Path("/proc/sys/kernel/osrelease").read_text(encoding="ascii").lower()
+        return "microsoft" in osrelease and "wsl" in osrelease
+    except OSError:
+        return False
+
+
 def check_amdgpu_driver():
     """Returns true if amdgpu is found in the list of initialized modules"""
+    # WSL2: no native amdgpu module; use /dev/dxg via dxgkrnl instead.
+    # check_wsl_dxg() requires the WSL2 kernel string, so this is safe for
+    # Hyper-V guests (which lack "wsl" in osrelease) and bare-metal hosts.
+    # Vendor confirmation (AMD 0x1002) is done inside librocdxg during amdsmi_init().
+    if check_wsl_dxg():
+        return True
+
     amd_gpu_status_file = Path("/sys/module/amdgpu/initstate")
     if amd_gpu_status_file.exists():
         try:

@@ -0,0 +1,116 @@
+---
+myst:
+  html_meta:
+    "description lang=en": "How to build and run AMD SMI under Windows Subsystem for Linux (WSL) using the experimental WSL/WDDM backend."
+    "keywords": "amd-smi, wsl, wsl2, dxg, dxgkrnl, wddm, d3dkmt, windows subsystem for linux, backend, feature flag"
+---
+
+# Using AMD SMI under WSL (experimental)
+
+AMD SMI targets native Linux, where it reads GPU data from the `amdgpu` kernel
+driver through DRM ioctls and sysfs. Under Windows Subsystem for Linux 2 (WSL2)
+those interfaces do not exist: there is no `/sys/class/drm` GPU tree and no
+`/dev/kfd`. The GPU is reached instead through the Windows WDDM display driver
+using the D3DKMT interface exposed by the `/dev/dxg` device node.
+
+To support this without maintaining a separate build of the tool, AMD SMI has an
+optional **WSL backend**. The public API, the CLI, and the Python bindings are
+unchanged. When the backend is active, the affected queries are answered from
+the WDDM path instead of DRM/sysfs; everything else behaves as before.
+
+```{note}
+The WSL backend is experimental and gated behind a build flag that is **off by
+default**. A default AMD SMI build and its packages are byte-for-byte the native
+tool. When enabled, the backend reads real GPU telemetry through `librocdxg`
+(`rocdxg_smi_*` APIs); queries with no WDDM equivalent return
+`AMDSMI_STATUS_NOT_SUPPORTED`.
+```
+
+## How it works
+
+AMD SMI keeps a single code path per API. The WSL-versus-native decision is made
+**once per process**, during `amdsmi_init()`, not scattered through every
+function:
+
+```text
+amdsmi_get_gpu_* (one dispatcher, backend-agnostic)
+        │
+        ├─ native  → DRM ioctls / sysfs        (default)
+        └─ WSL     → WSLGPUBackend → D3DKMT → /dev/dxg → dxgkrnl → Windows KMD
+```
+
+Queries that WDDM cannot serve (for example CPU/HSMP metrics, NIC, xGMI fabric,
+ECC, partitions) return `AMDSMI_STATUS_NOT_SUPPORTED` on WSL. This is the same
+status the native path returns for unsupported hardware, so existing error
+handling continues to work.
+
+## Prerequisites
+
+- Windows 11 (or Windows 10 with WSL2) with a WSL-capable AMD GPU driver.
+- A WSL2 Ubuntu distribution.
+- The `dxgkrnl` module present in the guest (verify with
+  `ls /sys/module/dxgkrnl`).
+- `librocdxg.so.1` installed and resolvable via `dlopen` (the WSL backend
+  loads it at `amdsmi_init()`; without it, calls return
+  `AMDSMI_STATUS_DRIVER_NOT_LOADED`). It ships with the ROCm-on-WSL driver
+  package, not a standard Linux ROCm devel package — verify with
+  `ldconfig -p | grep librocdxg`.
+- `libdxcore.so`, provided by the WSL installation
+  (`/usr/lib/wsl/lib/libdxcore.so`) — a transitive dependency of
+  `librocdxg`, not something you need to install directly.
+
+## Building with the WSL backend
+
+The backend is compiled in only when you enable the CMake option. It is off by
+default:
+
+```bash
+cmake -S . -B build -DENABLE_WSL_BACKEND=ON
+cmake --build build --target amd_smi -j"$(nproc)"
+```
+
+A build without `-DENABLE_WSL_BACKEND=ON` produces the standard native library;
+the WSL source is not compiled and the intercept hooks expand to nothing.
+
+Building with the flag on also requires `hsakmt/rocdxg_smi.h` at compile time,
+from a `rocr-runtime/libhsakmt` tree built with its `WIN_SDK`/dxg path —
+distinct from the runtime `librocdxg.so.1` dependency above. CMake fails with
+a `FATAL_ERROR` if that header is not found alongside the checkout.
+
+## Impact on existing scripts
+
+The WSL backend is designed to be a drop-in. For users with existing automation:
+
+- **No API, CLI, or output-schema changes.** Function signatures, CLI
+  subcommands, flags, and JSON field names are identical. Scripts that parse
+  `amd-smi --json` keep working.
+- **Some fields report `N/A` / `NOT_SUPPORTED` under WSL.** Where WDDM has no
+  equivalent (CPU, NIC, xGMI, ECC, partitions), the field is unavailable rather
+  than wrong. Scripts should already tolerate `N/A` for unsupported hardware;
+  the same handling covers WSL.
+- **Native installs are unaffected.** If you never build with
+  `-DENABLE_WSL_BACKEND=ON`, nothing changes.
+
+## Verifying
+
+```bash
+# Confirm you are on WSL
+ls /dev/dxg && echo "wsl present"
+
+ls /sys/module/dxgkrnl && echo "dxgkrnl present"
+
+# Confirm amd-smi is answering through the WSL backend
+amd-smi static --asic
+```
+
+If the backend is active you will see WDDM-sourced values for the supported
+fields and `N/A` for the rest.
+
+## Limitations
+
+- Experimental: the supported-query set is a subset of the native API and will
+  grow as `librocdxg` exposes more telemetry.
+- CPU/ESMI, NIC, switch, fabric, ECC, and partition features are not available
+  under WSL; those queries return `AMDSMI_STATUS_NOT_SUPPORTED`.
+- PCIe info, VRAM type, subvendor/subsystem IDs, and full VBIOS fields depend on
+  the installed `librocdxg` version and may show `N/A` on older drivers.
@@ -20,6 +20,8 @@ This AMD SMI project supports Linux bare metal and Linux virtual machine guest
 environments. For documentation regarding virtualization on SR-IOV Linux hosts,
 refer to the [AMD SMI for Virtualization
 documentation](https://instinct.docs.amd.com/projects/amd-smi-virt/en/latest/).
+Experimental WSL2 support is documented in [Using AMD SMI under
+WSL](./how-to/amdsmi-wsl-mode.md).
 ```
 
 ```{note}
@@ -42,6 +44,7 @@ AMD SMI is the successor to [ROCm SMI](https://github.com/ROCm/rocm-systems/tree
 * [CLI tool usage](./how-to/amdsmi-cli-tool.md)
 * [AI NIC integration](./how-to/amdsmi-nic-integration.md)
 * [Use AMD SMI in a Docker container](./how-to/setup-docker-container.md)
+* [Using AMD SMI under WSL (experimental)](./how-to/amdsmi-wsl-mode.md)
 :::
 
 :::{grid-item-card} Reference

@@ -32,6 +32,8 @@ subtrees:
     title: AI NIC integration
   - file: how-to/setup-docker-container.md
     title: Use AMD SMI in a Docker container
+  - file: how-to/amdsmi-wsl-mode.md
+    title: Using AMD SMI under WSL (experimental)
 
 - caption: Reference
   entries:

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) Advanced Micro Devices, Inc. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef AMD_SMI_INCLUDE_IMPL_AMD_SMI_GPU_BACKEND_H_
+#define AMD_SMI_INCLUDE_IMPL_AMD_SMI_GPU_BACKEND_H_
+
+#include <vector>
+
+#include "amd_smi/amdsmi.h"
+
+namespace amd::smi {
+
+// Per-GPU backend abstraction. amd_smi.cc dispatches to this instead of
+// branching on platform identity. Non-pure virtuals return NOT_SUPPORTED so
+// each backend only overrides what it actually implements.
+class IGPUBackend {
+ public:
+  virtual ~IGPUBackend() = default;
+
+  virtual amdsmi_status_t GetAsicInfo(amdsmi_asic_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetBoardInfo(amdsmi_board_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetKfdInfo(amdsmi_kfd_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetVramInfo(amdsmi_vram_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetMemoryTotal(amdsmi_memory_type_t, uint64_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetMemoryUsage(amdsmi_memory_type_t, uint64_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetTempMetric(amdsmi_temperature_type_t, amdsmi_temperature_metric_t,
+                                        int64_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetVoltMetric(amdsmi_voltage_type_t, amdsmi_voltage_metric_t, int64_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetPowerInfo(amdsmi_power_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetGpuActivity(amdsmi_engine_usage_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetBusyPercent(uint32_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetClockInfo(amdsmi_clk_type_t, amdsmi_clk_info_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetPcieInfo(amdsmi_pcie_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetDriverInfo(amdsmi_driver_info_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetVbiosInfo(amdsmi_vbios_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetUuid(unsigned int*, char*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetGpuCacheInfo(amdsmi_gpu_cache_info_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetFwInfo(amdsmi_fw_info_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetGpuMetricsInfo(amdsmi_gpu_metrics_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetPowerCapInfo(amdsmi_power_cap_info_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetFanRpms(uint32_t, int64_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetFanSpeed(uint32_t, int64_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t GetFanSpeedMax(uint32_t, uint64_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetVcnBusyPercent(uint32_t*) { return AMDSMI_STATUS_NOT_SUPPORTED; }
+  virtual amdsmi_status_t AllocFabricTelemetry(uint32_t, amdsmi_fabric_telemetry_t**) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetFabricTelemetryData(amdsmi_fabric_telemetry_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t FreeFabricTelemetry(amdsmi_fabric_telemetry_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+  virtual amdsmi_status_t GetGpuFabricInfo(amdsmi_fabric_info_t*) {
+    return AMDSMI_STATUS_NOT_SUPPORTED;
+  }
+
+  IGPUBackend(const IGPUBackend&) = delete;
+  IGPUBackend& operator=(const IGPUBackend&) = delete;
+
+ protected:
+  IGPUBackend() = default;
+};
+
+}  // namespace amd::smi
+
+#endif  // AMD_SMI_INCLUDE_IMPL_AMD_SMI_GPU_BACKEND_H_
@@ -33,6 +33,7 @@
 
 #include "amd_smi/amdsmi.h"
 #include "amd_smi/impl/amd_smi_drm.h"
+#include "amd_smi/impl/amd_smi_gpu_backend.h"
 #include "amd_smi/impl/amd_smi_processor.h"
 
 // Forward declaration of UALoE handle type to keep ualoe_lib/ualoe_lib.h out
@@ -137,6 +138,10 @@ class AMDSmiGPUDevice : public AMDSmiProcessor {
   AMDSmiGPUDevice(uint32_t gpu_id, AMDSmiDrm& drm);
   ~AMDSmiGPUDevice();
 
+  // Non-null only on non-Linux backends (e.g. WSL). amd_smi.cc checks this
+  // before falling through to the Linux rsmi/libdrm path.
+  IGPUBackend* backend() const { return backend_; }
+  void set_backend(IGPUBackend* b) { backend_ = b; }
   amdsmi_status_t get_drm_data();
   pthread_mutex_t* get_mutex();
   uint32_t get_gpu_id() const;
@@ -175,6 +180,7 @@ class AMDSmiGPUDevice : public AMDSmiProcessor {
   bool device_has_ualink() const;
 
  private:
+  IGPUBackend* backend_ = nullptr;
   uint32_t gpu_id_;
   std::string path_;
   amdsmi_bdf_t bdf_;