[Bug / Interop Contradiction] Vulkan-HIP External Timeline Semaphore Export Succeeds but HIP Runtime Rejects Import on Windows RDNA3 (gfx1102)

[timiburya]

Problem Description

Environment

Vulkan: apiVersion=1.4.349 driverVersion(raw)=8389003 vendorID=0x1002 deviceID=0x7480
HIP: runtime version=70260201 (7.2.60201) driver version=70260201
Device: AMD Radeon RX 7600S gcnArch=gfx1102 PCI bus=3 dev=0
OS: Windows 11
Driver: AMD Software: Adrenalin Edition 26.7.1
Summary & Core Contradiction

On Windows RDNA3 hardware, HIP's own API surface contradicts itself for the exact same handle type (OPAQUE_WIN32 timeline) on the exact same GPU:

HIP declares support, then denies it at two separate layers. hip_runtime_api.h declares hipExternalSemaphoreHandleTypeTimelineSemaphoreWin32 as a valid import target for hipImportExternalSemaphore — i.e. HIP's own public API claims to support importing a Windows timeline semaphore handle. But hipGetDeviceProperties self-reports timelineSemaphoreInteropSupported = 0 for this device, and calling hipImportExternalSemaphore with that exact declared handle type fails with hipErrorInvalidValue. The enum exists; the capability flag and the runtime both say it doesn't.

Vulkan's side of the handoff works correctly, ruling out a Vulkan-side or driver-export defect as the cause: vkGetPhysicalDeviceExternalSemaphoreProperties reports exportable=1, importable=1 for VK_EXTERNAL_SEMAPHORE_HANDLE_TYPE_OPAQUE_WIN32_BIT with VK_SEMAPHORE_TYPE_TIMELINE, and creating + exporting the Windows handle via vkGetSemaphoreWin32HandleKHR succeeds completely. The handle HIP receives is valid and well-formed.

The result is a dead end for any application trying to coordinate HIP and Vulkan work via a wait-capable (non-binary) semaphore on this hardware: the export side works, HIP's API declares an import path for exactly that handle type, and the import is rejected anyway — by both the documented capability flag and the runtime call itself, consistently.

Questions

Why does Vulkan advertise exportable=1, importable=1 for timeline handles on Windows RDNA3 when the matching HIP runtime self-reports timelineSemaphoreInteropSupported = 0?
Is matching support for hipExternalSemaphoreHandleTypeTimelineSemaphoreWin32 planned to align the HIP runtime on Windows RDNA3 with Vulkan's export capabilities?

Operating System

Windows 11 10.0.26200

CPU

AMD Ryzen 7 7435HS

GPU

AMD Radeon RX 7600S (gfx1102)

ROCm Version

ROCm 7.2.6

ROCm Component

No response

Steps to Reproduce

#include <hip/hip_runtime.h>
#include

int main() {
hipDeviceProp_t prop{};
hipGetDeviceProperties(&prop, 0);
printf("Device: %s\n", prop.name);
printf("timelineSemaphoreInteropSupported = %d\n", prop.timelineSemaphoreInteropSupported);
return 0;
}

// --- Vulkan side: create + export a real timeline semaphore ---
VkExportSemaphoreCreateInfo exportCI{VK_STRUCTURE_TYPE_EXPORT_SEMAPHORE_CREATE_INFO};
exportCI.handleTypes = VK_EXTERNAL_SEMAPHORE_HANDLE_TYPE_OPAQUE_WIN32_BIT;

VkSemaphoreTypeCreateInfo typeCI{VK_STRUCTURE_TYPE_SEMAPHORE_TYPE_CREATE_INFO};
typeCI.semaphoreType = VK_SEMAPHORE_TYPE_TIMELINE;
typeCI.initialValue = 0;
typeCI.pNext = &exportCI;

VkSemaphoreCreateInfo semCI{VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO};
semCI.pNext = &typeCI;
VkSemaphore vkSem;
vkCreateSemaphore(device, &semCI, nullptr, &vkSem); // SUCCEEDS

VkSemaphoreGetWin32HandleInfoKHR getHandle{VK_STRUCTURE_TYPE_SEMAPHORE_GET_WIN32_HANDLE_INFO_KHR};
getHandle.semaphore = vkSem;
getHandle.handleType = VK_EXTERNAL_SEMAPHORE_HANDLE_TYPE_OPAQUE_WIN32_BIT;
HANDLE h = nullptr;
vkGetSemaphoreWin32HandleKHR_(device, &getHandle, &h); // SUCCEEDS

// --- HIP side: import the handle Vulkan just exported ---
hipExternalSemaphoreHandleDesc semDesc{};
semDesc.type = hipExternalSemaphoreHandleTypeTimelineSemaphoreWin32;
semDesc.handle.win32.handle = h;
semDesc.flags = 0;

hipExternalSemaphore_t hipSem;
hipError_t err = hipImportExternalSemaphore(&hipSem, &semDesc);

// Expected: hipSuccess (HIP declares TimelineSemaphoreWin32 as a valid import type)
// Actual: err == hipErrorInvalidValue