From d0fead905623475fecb981356b5f5818c87b0928 Mon Sep 17 00:00:00 2001
From: Ethan Tillison <etillison@nvidia.com>
Date: Fri, 14 Apr 2023 13:14:02 -0700
Subject: [PATCH] nvapi: Implement NVAPI_GetLogicalGPUFromPhysicalGPU

---
 src/nvapi.cpp                | 18 ++++++++++++++++++
 src/nvapi_interface.cpp      |  1 +
 tests/nvapi_sysinfo_topo.cpp | 13 +++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/src/nvapi.cpp b/src/nvapi.cpp
index 2d101585..a8807923 100644
--- a/src/nvapi.cpp
+++ b/src/nvapi.cpp
@@ -127,6 +127,24 @@ extern "C" {
         return Ok(n);
     }
 
+    NvAPI_Status __cdecl NvAPI_GetLogicalGPUFromPhysicalGPU(NvPhysicalGpuHandle hPhysicalGPU, NvLogicalGpuHandle* pLogicalGPU) {
+        constexpr auto n = __func__;
+
+        if (nvapiAdapterRegistry == nullptr)
+            return ApiNotInitialized(n);
+
+        if (hPhysicalGPU == nullptr)
+            return InvalidArgument(n);
+
+        auto adapter = reinterpret_cast<NvapiAdapter*>(hPhysicalGPU);
+        if (!nvapiAdapterRegistry->IsAdapter(adapter))
+            return ExpectedPhysicalGpuHandle(n);
+
+        *pLogicalGPU = reinterpret_cast<NvLogicalGpuHandle>(adapter);
+
+        return Ok(n);
+    }
+
     NvAPI_Status __cdecl NvAPI_GetPhysicalGPUsFromLogicalGPU(NvLogicalGpuHandle hLogicalGPU, NvPhysicalGpuHandle hPhysicalGPU[NVAPI_MAX_PHYSICAL_GPUS], NvU32* pGpuCount) {
         constexpr auto n = __func__;
 
diff --git a/src/nvapi_interface.cpp b/src/nvapi_interface.cpp
index ef249d0a..6047c17b 100644
--- a/src/nvapi_interface.cpp
+++ b/src/nvapi_interface.cpp
@@ -121,6 +121,7 @@ extern "C" {
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_GetGPUIDfromPhysicalGPU)
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_GetDisplayDriverVersion)
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_GetPhysicalGPUsFromDisplay)
+        INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_GetLogicalGPUFromPhysicalGPU)
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_GetPhysicalGPUsFromLogicalGPU)
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_EnumNvidiaDisplayHandle)
         INSERT_AND_RETURN_WHEN_EQUALS(NvAPI_EnumNvidiaUnAttachedDisplayHandle)
diff --git a/tests/nvapi_sysinfo_topo.cpp b/tests/nvapi_sysinfo_topo.cpp
index 4d7a5f5e..ee343ecc 100644
--- a/tests/nvapi_sysinfo_topo.cpp
+++ b/tests/nvapi_sysinfo_topo.cpp
@@ -93,6 +93,19 @@ TEST_CASE("Topology methods succeed", "[.sysinfo-topo]") {
         REQUIRE(handle == nullptr);
     }
 
+    SECTION("GetLogicalGPUFromPhysicalGPU succeeds") {
+        NvPhysicalGpuHandle handles[NVAPI_MAX_PHYSICAL_GPUS]{};
+        NvU32 count;
+        REQUIRE(NvAPI_EnumPhysicalGPUs(handles, &count) == NVAPI_OK);
+
+        NvLogicalGpuHandle logicalhandle;
+        REQUIRE(NvAPI_GetLogicalGPUFromPhysicalGPU(handles[0], &logicalhandle) == NVAPI_OK);
+        REQUIRE(logicalhandle == reinterpret_cast<NvLogicalGpuHandle>(handles[0]));
+
+        REQUIRE(NvAPI_GetLogicalGPUFromPhysicalGPU(handles[1], &logicalhandle) == NVAPI_OK);
+        REQUIRE(logicalhandle == reinterpret_cast<NvLogicalGpuHandle>(handles[1]));
+    }
+
     SECTION("GetPhysicalGPUsFromLogicalGPU succeeds") {
         NvLogicalGpuHandle handles[NVAPI_MAX_LOGICAL_GPUS]{};
         NvU32 count;