[PATCH 00/10] winex11: Add Vulkan ICD.

[Roderick Colenbrander]

On Wed, Nov 1, 2017 at 3:44 AM, Alexandre Julliard <julliard at winehq.org> wrote:
> Józef Kucia <joseph.kucia at gmail.com> writes:
>
>> On Wed, Nov 1, 2017 at 11:26 AM, Alexandre Julliard <julliard at winehq.org> wrote:
>>> Roderick Colenbrander <thunderbird2k at gmail.com> writes:
>>>
>>>> The amount of code sharing between ICDs, I expect to be mostly in
>>>> generated code and maybe a few helper functions. For now
>>>> I think it is best to duplicate code and longer-term if
>>>> a little bit of sharing makes sense put this in a staticly
>>>> linked helper library. I want to avoid implementing our own
>>>> 'winevulkan' glue ICD library in between loader and display
>>>> driver as I fear this will cause many issues, because the object
>>>> design didn't lend for this (assumes 1 ICD = 1 driver). Besides
>>>> some applications load the ICD directly.
>>>>
>>>> This first wave of patches gets some initial ICD infrastructure
>>>> in place. Enough to create a minimal Vulkan Instance and get
>>>> some function loading going. It will take another 6-7 patches
>>>> or so before 'vulkaninfo' the Vulkan equivalent of glxinfo
>>>> will work to some degree.
>>>>
>>>> For now the easiest way to load the ICD is to add a registry key:
>>>> [HKEY_LOCAL_MACHINE\SOFTWARE\Khronos\Vulkan\Drivers\]
>>>> "C:\Windows\System32\winex11.json"=dword:00000000
>>>>
>>>> winex11.json:
>>>> {
>>>>     "file_format_version": "1.0.0",
>>>>     "ICD": {
>>>>         "library_path": "c:\\windows\\system32\\winex11.drv",
>>>>         "api_version": "1.0.51"
>>>>     }
>>>> }
>>>
>>> How would this be able to support multiple drivers with the same
>>> install? It seems to me that an intermediate library that calls the
>>> currently active driver would be better. What sort of issues do you
>>> think it would cause?
>>
>> In the current approach our Vulkan ICD uses the Linux Vulkan loader
>> internally. The Linux Vulkan loader should discover all drivers. In
>> other words, our Vulkan ICD may expose multiple Vulkan physical
>> devices.
>
> I mean multiple Wine drivers. For instance, once we have a Wayland
> driver, a proper Wine package would include both Wayland and X11
> drivers, and they would be selected at run-time based on the DISPLAY
> variable. So it seems to me the Vulkan ICD should retrieve the current
> driver from the HWND, similar to what opengl32.dll is doing.
>

There is not guaranteed to be an HWND, you can use Vulkan for
offscreen rendering with no interaction with X11 / Win32 concepts.
Any driver like enumeration is triggered through some of the 'global
vulkan calls' e.g. vkEnumerateInstanceProperties /
vkEnumeratePhysicalDevices. It is more about adapter enumeration
across drivers.
To make things more fun in some use cases you can use multiple GPUs
across different drivers to work together, to some extend managed by
the loader.