Fixes #196

Switch to bus id instead of adapter index.

LibreHardwareMonitorLib/Hardware/Gpu/NvidiaGpu.cs

@@ -35,6 +35,8 @@ namespace LibreHardwareMonitor.Hardware.Gpu
             _handle = handle;
             _displayHandle = displayHandle;
 
+            bool hasPciBusId = NvApi.NvAPI_GPU_GetBusId(handle, out uint busId) == NvApi.NvStatus.OK;
+
             NvApi.NvGPUThermalSettings thermalSettings = GetThermalSettings();
             _temperatures = new Sensor[thermalSettings.Count];
             for (int i = 0; i < _temperatures.Length; i++)
@@ -105,7 +107,11 @@ namespace LibreHardwareMonitor.Hardware.Gpu
 
             if (NvidiaML.IsAvailable)
             {
-                _nvmlDevice = NvidiaML.NvmlDeviceGetHandleByIndex(adapterIndex);
+                if (hasPciBusId)
+                    _nvmlDevice = NvidiaML.NvmlDeviceGetHandleByPciBusId($" 0000:{busId:X2}:00.0") ?? NvidiaML.NvmlDeviceGetHandleByIndex(_adapterIndex);
+                else
+                    _nvmlDevice = NvidiaML.NvmlDeviceGetHandleByIndex(_adapterIndex);
+
                 if (_nvmlDevice.HasValue)
                 {
                     _powerUsage = new Sensor("GPU Package", 0, SensorType.Power, this, settings);

LibreHardwareMonitorLib/Hardware/Gpu/NvidiaGroup.cs

@@ -31,7 +31,6 @@ namespace LibreHardwareMonitor.Hardware.Gpu
             }
 
             NvApi.NvPhysicalGpuHandle[] handles = new NvApi.NvPhysicalGpuHandle[NvApi.MAX_PHYSICAL_GPUS];
-            int count;
             if (NvApi.NvAPI_EnumPhysicalGPUs == null)
             {
                 _report.AppendLine("Error: NvAPI_EnumPhysicalGPUs not available");
@@ -39,27 +38,26 @@ namespace LibreHardwareMonitor.Hardware.Gpu
                 return;
             }
 
+            NvApi.NvStatus status = NvApi.NvAPI_EnumPhysicalGPUs(handles, out int count);
+            if (status != NvApi.NvStatus.OK)
             {
-                NvApi.NvStatus status = NvApi.NvAPI_EnumPhysicalGPUs(handles, out count);
-                if (status != NvApi.NvStatus.OK)
-                {
-                    _report.AppendLine("Status: " + status);
-                    _report.AppendLine();
-                    return;
-                }
+                _report.AppendLine("Status: " + status);
+                _report.AppendLine();
+                return;
             }
 
             IDictionary<NvApi.NvPhysicalGpuHandle, NvApi.NvDisplayHandle> displayHandles = new Dictionary<NvApi.NvPhysicalGpuHandle, NvApi.NvDisplayHandle>();
             if (NvApi.NvAPI_EnumNvidiaDisplayHandle != null && NvApi.NvAPI_GetPhysicalGPUsFromDisplay != null)
             {
-                NvApi.NvStatus status = NvApi.NvStatus.OK;
+                status = NvApi.NvStatus.OK;
                 int i = 0;
                 while (status == NvApi.NvStatus.OK)
                 {
                     NvApi.NvDisplayHandle displayHandle = new NvApi.NvDisplayHandle();
                     status = NvApi.NvAPI_EnumNvidiaDisplayHandle(i, ref displayHandle);
                     i++;
-
+                    NvApi.NvDisplayHandle a;
+                    
                     if (status == NvApi.NvStatus.OK)
                     {
                         NvApi.NvPhysicalGpuHandle[] handlesFromDisplay = new NvApi.NvPhysicalGpuHandle[NvApi.MAX_PHYSICAL_GPUS];

LibreHardwareMonitorLib/Interop/NvApi.cs

@@ -41,6 +41,7 @@ namespace LibreHardwareMonitor.Interop
         public static readonly NvAPI_GPU_GetPCIIdentifiersDelegate NvAPI_GPU_GetPCIIdentifiers;
         public static readonly NvAPI_GPU_GetPStatesDelegate NvAPI_GPU_GetPStates;
         public static readonly NvAPI_GPU_GetTachReadingDelegate NvAPI_GPU_GetTachReading;
+        public static readonly NvAPI_GPU_GetBusIdDelegate NvAPI_GPU_GetBusId;
 
         public static readonly NvAPI_GPU_GetThermalSettingsDelegate NvAPI_GPU_GetThermalSettings;
         public static readonly NvAPI_GPU_GetUsagesDelegate NvAPI_GPU_GetUsages;
@@ -91,6 +92,9 @@ namespace LibreHardwareMonitor.Interop
         [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
         public delegate NvStatus NvAPI_GPU_SetCoolerLevelsDelegate(NvPhysicalGpuHandle gpuHandle, int coolerIndex, ref NvGPUCoolerLevels NvGPUCoolerLevels);
 
+        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+        public delegate NvStatus NvAPI_GPU_GetBusIdDelegate(NvPhysicalGpuHandle gpuHandle, out uint busId);
+        
         static NvApi()
         {
             NvAPI_InitializeDelegate nvApiInitialize;
@@ -129,6 +133,7 @@ namespace LibreHardwareMonitor.Interop
                 GetDelegate(0xF951A4D1, out NvAPI_GetDisplayDriverVersion);
                 GetDelegate(0x01053FA5, out _nvAPI_GetInterfaceVersionString);
                 GetDelegate(0x2DDFB66E, out NvAPI_GPU_GetPCIIdentifiers);
+                GetDelegate(0x1BE0B8E5, out NvAPI_GPU_GetBusId);
 
                 IsAvailable = true;
             }

LibreHardwareMonitorLib/Interop/NvidiaML.cs

@@ -16,6 +16,7 @@ namespace LibreHardwareMonitor.Interop
 
         private static WindowsNvmlGetHandleDelegate _windowsNvmlDeviceGetHandleByIndex;
         private static WindowsNvmlGetPowerUsageDelegate _windowsNvmlDeviceGetPowerUsage;
+        private static WindowsNvmlGetHandleByPciBusIdDelegate _windowsNvmlDeviceGetHandleByPciBusId;
         private static WindowsNvmlDelegate _windowsNvmlInit;
         private static WindowsNvmlDelegate _windowsNvmlShutdown;
 
@@ -118,6 +119,11 @@ namespace LibreHardwareMonitor.Interop
             else
                 return false;
 
+            IntPtr nvmlGetHandlePciBus = Kernel32.GetProcAddress(WindowsDll, "nvmlDeviceGetHandleByPciBusId_v2");
+            if (nvmlGetHandlePciBus != IntPtr.Zero)
+                _windowsNvmlDeviceGetHandleByPciBusId = (WindowsNvmlGetHandleByPciBusIdDelegate)Marshal.GetDelegateForFunctionPointer(nvmlGetHandlePciBus, typeof(WindowsNvmlGetHandleByPciBusIdDelegate));
+            else
+                return false;
 
             return true;
         }
@@ -165,6 +171,26 @@ namespace LibreHardwareMonitor.Interop
             return null;
         }
 
+
+        internal static NvmlDevice? NvmlDeviceGetHandleByPciBusId(string pciBusId)
+        {
+            if (IsAvailable)
+            {
+                NvmlDevice nvmlDevice;
+                if (Software.OperatingSystem.IsLinux)
+                {
+                    if (nvmlDeviceGetHandleByPciBusId(pciBusId, out nvmlDevice) == NvmlReturn.Success)
+                        return nvmlDevice;
+                }
+                else if (_windowsNvmlDeviceGetHandleByPciBusId(pciBusId, out nvmlDevice) == NvmlReturn.Success)
+                {
+                    return nvmlDevice;
+                }
+            }
+
+            return null;
+        }
+
         internal static int? NvmlDeviceGetPowerUsage(NvmlDevice nvmlDevice)
         {
             if (IsAvailable)
@@ -197,6 +223,9 @@ namespace LibreHardwareMonitor.Interop
         [DllImport(LinuxDllName, EntryPoint = "nvmlDeviceGetHandleByIndex_v2", ExactSpelling = true)]
         private static extern NvmlReturn nvmlDeviceGetHandleByIndex(int index, out NvmlDevice device);
 
+        [DllImport(LinuxDllName, EntryPoint = "nvmlDeviceGetHandleByPciBusId_v2", ExactSpelling = true)]
+        private static extern NvmlReturn nvmlDeviceGetHandleByPciBusId([MarshalAs(UnmanagedType.LPStr)] string pciBusId, out NvmlDevice device);
+
         [DllImport(LinuxDllName, EntryPoint = "nvmlDeviceGetHandleByIndex", ExactSpelling = true)]
         private static extern NvmlReturn nvmlDeviceGetHandleByIndexLegacy(int index, out NvmlDevice device);
 
@@ -207,8 +236,10 @@ namespace LibreHardwareMonitor.Interop
 
         private delegate NvmlReturn WindowsNvmlGetHandleDelegate(int index, out NvmlDevice device);
 
-        private delegate NvmlReturn WindowsNvmlGetPowerUsageDelegate(NvmlDevice device, out int power);
+        private delegate NvmlReturn WindowsNvmlGetHandleByPciBusIdDelegate([MarshalAs(UnmanagedType.LPStr)] string pciBusId, out NvmlDevice device);
 
+        private delegate NvmlReturn WindowsNvmlGetPowerUsageDelegate(NvmlDevice device, out int power);
+        
         [StructLayout(LayoutKind.Sequential)]
         internal struct NvmlDevice
         {