Vulkan on Tesla P4 - is VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD is actually supported on Tesla P4?

Gaming and Visualization Technologies APIs Vulkan
1

I am trying to use the Vulkan API for compute on my Tesla P4. It works great in general, however I want to use a specific feature that was announced to be supported in recent driver updates:

  • Added support for the EGL_ANDROID_native_fence_sync EGL extension
    and the VK_EXTERNAL_SEMAPHORE_HANDLE_TYPE_SYNC_FD_BIT and
    VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT Vulkan external handle
    types when the nvidia-drm kernel module is loaded with the modeset=1
    parameter.

Specifically, I want to use VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD

I am reasonably convinced that my code is correct because I have no problem retrieving VK_EXTERNAL_FENCE_HANDLE_TYPE_OPAQUE_FD. I am of course happy to share my full code if needed but here is the critical section:

VkExportFenceCreateInfo exportFenceInfo =
{
.sType = VK_STRUCTURE_TYPE_EXPORT_FENCE_CREATE_INFO,
.handleTypes = VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT
};

VkFenceCreateInfo fenceCreateInfo =
{
.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO,
.pNext = &exportFenceInfo,
};

VkFence fence;
vkCreateFence(device, &fenceCreateInfo, NULL, &fence);

VkFenceGetFdInfoKHR getFdInfo = {
.sType = VK_STRUCTURE_TYPE_FENCE_GET_FD_INFO_KHR,
.fence = fence,
.handleType = VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT
};

Int fd;
vkGetFenceFdKHR( device, &getFdInfo, &fd ):

When I call vkGetFenceFdKHR it returns -8

VK_KHR_external_fence and VK_KHR_external_fence_fd extensions are loaded on the device and if I substitute VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD with VK_EXTERNAL_FENCE_HANDLE_TYPE_OPAQUE_FD the code works fine, vkGetFenceFdKHR return VK_SUCCESS and fd contain a valid file descriptor.

The release notes say “when the nvidia-drm kernel module is loaded with the modeset=1 parameter.”

I believe I have done this; if I run

sudo cat /sys/module/nvidia_drm/parameters/modeset

I get “Y”, so I believe modeset is set correctly.

Any insight your team may be able to provide is as always most welcomed! .. and this is of course not urgent in any way! 😊

I guess my fundamental question is whether VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD is actually supported on my Tesla P4?