Requirements for DXVK support..

[oscarbg]

Hi,
this is just a report of "things" missing in MoltenVK to support DXVK now that Wine supports Vulkan on MacOS via MoltenVK (I use v1.0.12 included in Vulkan MacOS SDK 1.0.77)..
I tested DXVK 0.6.3 on Wine 3.13 with Vulkan support enabled on MacOS and simple programs like included d3d11-compute or d3d11-triangle failed due to unsupported extensions so I checked logs and seems it needs this extensions (as of 0.6.3):

From:
https://github.com/doitsujin/dxvk/blob/master/src/dxvk/dxvk_extensions.h
we see requirements for DxvkInstanceExtensions:
VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2
the other two are emulated by Wine already..

for DxvkDeviceExtensions it needs:
VK_KHR_DEDICATED_ALLOCATION_EXTENSION_NAME,
VK_KHR_DESCRIPTOR_UPDATE_TEMPLATE_EXTENSION_NAME,
VK_KHR_GET_MEMORY_REQUIREMENTS_2_EXTENSION_NAME,
VK_KHR_IMAGE_FORMAT_LIST_EXTENSION_NAME,
VK_KHR_MAINTENANCE1_EXTENSION_NAME
VK_KHR_MAINTENANCE2_EXTENSION_NAME
VK_KHR_SHADER_DRAW_PARAMETERS

I modified code of this exts from DxvkExtMode::Required to DxvkExtMode::Optional but then it complains it can't create a D3D device with support for any feature levels ranging from D3D_FEATURE_LEVEL_9_1 to D3D_FEATURE_LEVEL_11_1..

it's because needs features missing in MoltenVK (as of 1.0.12 in Vulkan SDK 1.0.77):
code checking feature level is here:
https://github.com/doitsujin/dxvk/blob/master/src/d3d11/d3d11_device.cpp
`

if (featureLevel >= D3D_FEATURE_LEVEL_9_1) {
enabled.depthClamp = VK_TRUE;
enabled.depthBiasClamp = VK_TRUE;
enabled.fillModeNonSolid = VK_TRUE;
enabled.pipelineStatisticsQuery = supported.pipelineStatisticsQuery;
enabled.sampleRateShading = VK_TRUE;
enabled.samplerAnisotropy = VK_TRUE;
enabled.shaderClipDistance = VK_TRUE;
enabled.shaderCullDistance = VK_TRUE;
enabled.robustBufferAccess = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_9_2) {
  enabled.occlusionQueryPrecise                 = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_9_3) {
  enabled.multiViewport                         = VK_TRUE;
  enabled.independentBlend                      = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_10_0) {
  enabled.fullDrawIndexUint32                   = VK_TRUE;
  enabled.fragmentStoresAndAtomics              = VK_TRUE;
  enabled.geometryShader                        = VK_TRUE;
  enabled.logicOp                               = supported.logicOp;
  enabled.shaderImageGatherExtended             = VK_TRUE;
  enabled.textureCompressionBC                  = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_10_1) {
  enabled.dualSrcBlend                          = VK_TRUE;
  enabled.imageCubeArray                        = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_11_0) {
  enabled.shaderFloat64                         = supported.shaderFloat64;
  enabled.shaderInt64                           = supported.shaderInt64;
  enabled.tessellationShader                    = VK_TRUE;
  // TODO enable unconditionally once RADV gains support
  enabled.shaderStorageImageMultisample         = supported.shaderStorageImageMultisample;
  enabled.shaderStorageImageReadWithoutFormat   = supported.shaderStorageImageReadWithoutFormat;
  enabled.shaderStorageImageWriteWithoutFormat  = VK_TRUE;
}

if (featureLevel >= D3D_FEATURE_LEVEL_11_1) {
  enabled.logicOp                               = VK_TRUE;
  enabled.vertexPipelineStoresAndAtomics        = VK_TRUE;
}

`

had to comment these lines (due to missing MoltenVK support):
for getting up to D3D_FEATURE_LEVEL_9_1:
enabled.sampleRateShading = VK_TRUE;
enabled.shaderCullDistance = VK_TRUE;
enabled.robustBufferAccess = VK_TRUE;
for D3D_FEATURE_LEVEL_9_3:
enabled.multiViewport = VK_TRUE;
for D3D_FEATURE_LEVEL_10_1:
enabled.fullDrawIndexUint32 = VK_TRUE;
enabled.geometryShader = VK_TRUE;
enabled.logicOp = supported.logicOp;
for D3D_FEATURE_LEVEL_11_0:
enabled.shaderFloat64 = supported.shaderFloat64;
enabled.shaderInt64 = supported.shaderInt64;
enabled.tessellationShader = VK_TRUE;
enabled.shaderStorageImageWriteWithoutFormat = VK_TRUE;

with all these "hacks" it doesn't complain but crashes executing simple d3d11 apps because it may be using missing features..

of course MoltenVK supporting DXVK might be a herculean effort but DXVK has shown it's able to run lots of DX11 modern games and this will be awesome on Mac..
this is just a report of things needed to do (as a means of guiding priorities of things to implement)..

hope is useful for someone..

[johnothwolo]

How did you get wine to recognise moltenVK? I get

checking for -lMoltenVK... not found

[oscarbg]

I think had some issues but copied everywhre /lib /usr/lib /usr/local/lib..

[KenThomases]

You configure with LDFLAGS="-L/path/to/the/MVK/libdir". At runtime, you need to set the DYLD_FALLBACK_LIBRARY_PATH environment variable to contain the same path. However, System Integrity Protection will strip any DYLD_* environment variables when a system executable is run and that included shell script interpreters. So, depending on how you're running Wine, you may need to take extra measures.

If you're running your own build using the top-level "wine" script, create a file names .winewrapper next to it that contains "export DYLD_FALLBACK_LIBRARY_PATH=/path/to/the/MVK/libdir:/usr/lib". That will be automatically sourced by the wine script at a point after SIP has done its stripping.

If you're running an installed Wine, then the "wine" command may be just the Wine loader program, not a shell script. In that case, SIP is not involved.

[iain-benson]

I've been experimenting with this on my fork (https://github.com/iain-benson/MoltenVK/tree/dx11), as I was hoping to play Witcher 3 on the Mac, without rebooting.

• Added (and implemented) vkGetPhysicalDeviceFeatures2KHR and vkGetPhysicalDeviceProperties2KHR
• Added stubs for the remaining methods for VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2, and the methods listed above
• Set the flags to true for the device features required for DX11

It gets further, and starts setting up the shader modules, but the conversion of the SPIR-V code fails as it tries to use an undefined method spvTexelBufferCoord.

I am fully aware the changes I made wouldn't actually result in a working system, but I was looking to see what work was required, and will continue attempting to implement what I can, to see if I can get anything working.

[oscarbg]

Hi @iain-benson,
nice work..
strange thing is spvTexelBufferCoord seems to be introduced recently in https://github.com/KhronosGroup/SPIRV-Cross/blob/master/spirv_msl.cpp by :
KhronosGroup/SPIRV-Cross@4c5142b
"Emit and use spvTexelBufferCoord() function to convert 1D texel buffer coordinates to 2D Metal texture coordinates."

uint2 spvTexelBufferCoord(uint tc)
{
    return uint2(tc % 4096, tc / 4096);
}

just for curiosity what MoltenVK version are you using? from 1.1.82?

[cdavis5e]

So far, of those extensions, I've implemented VK_KHR_maintenance1, VK_KHR_shader_draw_parameters, VK_KHR_get_physical_device_properties2, and VK_KHR_descriptor_update_template. The patches for the first three were merged (#230, #232, #235). The patch for the last one depends on another patch I have to implement VK_KHR_push_descriptor (#236), which vkd3d (a different library for D3D12) wants but doesn't need to work. The reason for that is that those two extensions interact--there's a call that's available only if both extensions are supported. You can see the patch for VK_KHR_descriptor_update_template at my fork.

I still need to investigate the core Vulkan features that DXVK needs but MoltenVK doesn't have yet.

[oscarbg]

Amazing work @cdavis5e !!
I thought we were months from seeing real progress on this..
Thanks..

[banzr]

Hey, I'd love to help but I'm not sure where to start. Can someone help fill me in on what references/documentation are out there? Thanks! I stumbled on this while trying to install Steam Proton on my macbook pro. I'm a Sr CS undergrad with no experience with DXVK or vulkan, but I am very familiar with C/C++.

[oscarbg]

Hi @banzr,
I don't know what's the best answer I can gave you, but I will try..
basically for this specific issue you need to gain some Metal and Vulkan knowledge/experience..
as this is what MoltenVK is about..
For Metal see:
https://developer.apple.com/documentation/metal
(deprecated) https://developer.apple.com/library/archive/documentation/Miscellaneous/Conceptual/MetalProgrammingGuide/Introduction/Introduction.html
useful will be:
https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf
also see : https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf
(some things are only avaiable in newer OS or GPUs)
then familiarize with MoltenVK codebase and also SPIR-V Cross as this is used for shader translation.. then seeing the extensions/optional Vulkan features DXVK needs (first post in this thread) and try to know how you map these to Metal and implement it..
in theory, you don't even need to know anything about DXVK.. as far as MoltenVK exposes all required DXVK Vulkan functionality you are done..
or you may forgot everything I said until now and go the opposite way.. of learning as needed to implement individual items.. let's take two examples:
1)Imagine you want to add double precision support to MoltenVK (really DXVK can use it but not useful in real games):
you read Metal-Shading-Language-Specification and see:
"Metal does not support the double.."
so it can't be done.. well not easily.. it can be emulated by doing something similar to guys in Mesa have done:
"The Student Working On "Soft" FP64 Support Is Good News For Older GPUs"..
on mesa cgit you should find shader code emulating doubles via floats..
2) Similar thing will be found for geometry shader, you will find Metal doesn't support it..
3) Imagine you want to add tesselation support to MoltenVK:
read in Apple how it's exposed:
https://developer.apple.com/library/archive/documentation/Miscellaneous/Conceptual/MetalProgrammingGuide/Tessellation/Tessellation.html
find a Vulkan simple sample:
https://github.com/SaschaWillems/Vulkan/tree/master/examples/tessellation
you will find MoltenVK uses SPIR-V Cross for shader translation you will need to add translation from tesselation stage to Metal..

hope it helps (a little)..