On 10.06.21 21:18, Derek Lesho wrote:
On 6/9/21 9:56 PM, Zebediah Figura (she/her) wrote:
On 6/5/21 10:53 AM, Georg Lehmann wrote:
On 05.06.21 01:23, Zebediah Figura (she/her) wrote:
On 6/1/21 10:17 AM, Derek Lesho wrote:
On 5/31/21 10:43 AM, Zebediah Figura (she/her) wrote:
On 5/26/21 9:21 AM, Derek Lesho wrote: > On 5/25/21 10:07 PM, Zebediah Figura (she/her) wrote: > >> >>>> >>>> * Shared resources in d3d9-11, when using the OpenGL backend >>> >>> As mentioned, the EXT_external_objects extension exists, ( >>> https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_external_objects.... >>> >>> >>> >>> >>> ), which accepts and produces file descriptors compatible with the >>> ones >>> Vulkan produces and accepts. The interactions here seem to be >>> well >>> defined. >> >> According to my reading, neither GL_EXT_external_objects nor >> GL_EXT_external_objects_fd provide for export of an object from an >> OpenGL context; they only allow importing objects created by >> Vulkan. > > Yeah, from what I can see, openGL has no standard way to share > memory > across processes without the use of this extension and Vulkan. I > suspect this would be difficult due to all the user mode driver code > protecting against invalid use of resources. I think the most > reasonable path forward is to create a Vulkan dummy object in > wined3d, > then import it into GL. Of course, this would make shared resources > unsupported for old GPUs and systems that don't support Vulkan, > but the > API is half a decade old at this point, and only GPUs from almost a > decade ago don't support it.
There is no free software NVidia Vulkan driver, which is a rather glaring hole. There also exist cards released as recently as 2014 that don't support Vulkan. And in general, although it's sometimes convenient for the implementer to require the latest hardware, it's a rather mean thing to do to users.
Keep in mind that we need Direct3D shared resources for bug 44985, which affects a very long list of applications.
Now, with that in mind, two options I immediately see are:
- Create all contexts as shared. It's not clear to me whether this
has negative consequences, however. It's also not clear to me whether this can be done across processes.
- Try to introduce an OpenGL extension that allows exporting file
descriptors.
The second option definitely sounds better, as with the first you're still limited to in-process sharing, if my understanding is correct. Additionally, the case where you're using wined3d's d3d9 for example, create a shared resource, then try importing it into DXVK for d3d10/11, would only work with the second solution from what I can see. I imagine that we could cover the vast majority of users by implementing the "vulkan helper" path that I suggested before, and quite easily transition into using an extension if/when needed.
> > Alternatively we could get try to use platform-specific buffer > sharing > APIs like EGLStreams or GBM, or just support in-process shared > resources > through the eglCreateContext API, which allows the creation of > "shared > contexts", in which the GPU resources are shared. > >>>> >>>> * Shared resources between d3d9-12 devices, when using wined3d or >>>> libvkd3d on Windows >>> Putting aside how rare and questionable of a use-case this must >>> be, I >>> don't think this concerns any of my patches. My future patches >>> would >>> provide a way for translation layers on wine to store metadata >>> alongside >>> the host handlers, it doesn't have any correspondence to >>> Windows. If >>> you really wanted to (why?), you could probably create your own >>> backing >>> storage in a shared memory object and accept the caveats that come >>> along >>> with that. >> >> I suspect those of us who have worked with Direct3D for multiple >> decades would take issue with "rare and questionable", but >> regardless, >> part of the point here is to ask: *is* it possible to use a >> native set >> of APIs, like perhaps the D3DKMT*() functions from gdi32, to share >> resources? I.e. should the implementation live in gdi32 instead of >> winevulkan/opengl32/wined3d? Just from a quick scan I see several >> which look like the ones we want, and they're even documented. > > Could you link these APIs so I can look further into them? I > conferred > with Josh and he didn't find anything.
Sure, here are some APIs that look promising, and are documented:
- D3DKMTCreateAllocation()
- D3DKMTOpenResource()
- D3DKMTOpenResourceFromNtHandle()
- D3DKMTQueryResourceInfo()
- D3DKMTQueryResourceInfoFromNtHandle()
So I discussed this with Josh and Georg, and the problems with these APIs for our usecases are
- In order to interface with any of these APIs, you need a KMT device
handle. This roughly corresponds to a Vulkan device object or OpenGL context, but according to Josh they don't have to map 1:1.
It's a bit unfortunate that this discussion still isn't happening in a public place,
I'm sorry, but I get very annoyed by comments like these when at the same time most of wine's development happens behind closed doors inside codeweavers. It's not like wine-devel is used for architecture discussion or anything like that, no it's just patches and sometimes reviews. And somehow you now criticize me (well, us, but I can only speak for myself) for not communicating only via wine-devel? I send patches via wine-devel and I review patches on wine-devel, just like everyone else.
So for what it's worth—and I'm not speaking for CodeWeavers here—I don't think "most of wine's development" happens anywhere at all. Large-scale architectural decisions aren't really discussed often. But if they are, they're usually discussed on wine-devel, Bugzilla, #winehackers, WineConf, or privately via e-mail.
The last is a bit unfortunate, but it's also not specific to CodeWeavers—I can think of two people with whom I'm currently engaged in architectural discussion, and only one of those is a CodeWeavers employee.
And I get the impression that CodeWeavers, or at least its employees, try to encourage discussing things openly where possible (not constrained by NDA, etc.) And when it comes to patches, we *are* encouraged and even expected to explain ourselves from the point of view of an outsider; see [2] for example.
By contrast, when I tried to get the VKx community to discuss things openly, it was made quickly clear to me that they were not interested in using official Wine channels or coöperating with upstream Wine developers, but rather wanted Wine developers to use their channels (and their development practices, and their forks, etc...)
So I'm being more than a little passive-aggressive, and I'm sorry for that. But I also really do want to point out that the people most involved in Direct3D/GPU work in Wine have not been involved in this discussion at all, and before some point in this reply chain they/we had no idea it was even happening. And as a result when a submitter acts like some fact is obvious, to the point of not explaining it at all, just because they discussed it privately with someone else, it's more than a little frustrating.
The only thing I have to say here is that my experiences working for codeweavers give me a different impression. We regularly get updated on what everyone is working on, and have been shared much more information about the ongoing PE/unix architectural rework than the outside community.
The bottom line is: it's really not clear that this patch set is taking the right approach. Not "it's taking the wrong approach", but it's really not clear that it's taking the right one. And most of that unclarity comes from a lack of public discussion, or even private discussion with the Wine contributors involved in Direct3D/GPU APIs.
I'd like to reiterate here that this current patchset is not opinionated on the approach we end up taking for D3D resources. It simply implements 1:1 an exclusively Vulkan/GL feature with the almost identical corresponding Unix API. The discussions we are having about what to do in those cases are important, but they don't affect whether or not this current patch series should be merged. If you disagree with that statement, please refer to the code that would have to be substantially changed in any thus-far proposed approach to the greater problem, so that we can address it separately from the broader discussion of how we want to handle resources and interop with D3D.
[2] https://www.winehq.org/pipermail/wine-devel/2019-June/147452.html
Anyway, back to the actual discussion.
but anyway, we already use KMT device handles; see e.g. wined3d_output_init().
- There's no way to update the private runtime data once the resource
is created. In the current and simpler flow, the host graphics API will create the object, and the translation layer will then attach the needed private data. For this to work on windows, the translation layers would have to agree on some way to get Vulkan to set the desired private data, and that's assuming that no Windows drivers already use this for their own purposes.
Part of my point here is that, ideally, we shouldn't need to. Presumably if a Win32 application creates a Vulkan resource and tries to import it into Direct3D, the Microsoft Direct3D runtime will call such functions to get information from it. It seems at least plausible that we could do the same.
You can *not* import a Vulkan resource into Direct3D. The vulkan specification [1] says:
VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_BIT specifies an NT handle that has only limited valid usage outside of Vulkan and other compatible APIs. It must be compatible with the functions DuplicateHandle, CloseHandle, CompareObjectHandles, GetHandleInformation, and SetHandleInformation.
VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_WIN32_KMT_BIT specifies a global share handle that has only limited valid usage outside of Vulkan and other compatible APIs. It is not compatible with any native APIs.
Note the "outside of Vulkan and other compatible APIs" part, which to my knowledge means Vulkan and the OpenGL import extension.
These handles also can *not* include the info needed for e.g. D3D11 because they are memory objects, not image/buffer objects. If you bind e.g. a 2D image to the memory, you don't know the width, the height or the format on import because it's *just* memory.
[1] https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/vkspec.htm...
That may be true for the OPAQUE bit, but that's not the only bit. E.g. as far as I can tell from my reading of the Vulkan specification, VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT isn't forbidden from being specified in VkExportMemoryAllocateInfo, and the language even seems to "explicitly imply", as it were, that it's allowed. See the Vulkan 1.2 specification § 11.2.4 in particular.
Granted, the documentation for VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT itself (no section number, I guess?) says "VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT specifies an NT handle returned by IDXGIResource1::CreateSharedHandle referring to a Direct3D 10 or 11 texture resource," which is a bit unclear. I haven't actually tested whether it works in practice, either, although of course even if it doesn't now it might in the future.
Good catch, I think we overlooked this possibility before. I wrote some tests to see whether any drivers support this on windows, and it seems they don't. (When querying the properties of sharing an image through VK_EXTERNAL_MEMORY_HANDLE_TYPE_D3D11_TEXTURE_BIT, both the NVIDIA and AMD windows drivers report only VK_EXTERNAL_MEMORY_FEATURE_DEDICATED_ONLY_BIT|VK_EXTERNAL_MEMORY_FEATURE_IMPORTABLE_BIT).
It seems that we could however expose this functionality in wine, and then write the relevant translation layer code that would work on windows if this were ever to be supported by a windows driver. Nevertheless, I'm still leaning against using this approach, as
- It requires us to reverse engineer the undocumented runtime data
format, which has a good chance of changing from windows version to windows version. I doubt that any windows applications have any reason to use these APIs when they can just go through D3D11 to get the information they want in a well-defined manner, meaning Microsoft probably doesn't have to worry about changing this.
- This approach would require us to wrap the VkImage structure in
winevulkan, since it is inferred that the runtime data we need is derived from VkImage used in the dedicated+shared allocation. (The spec doesn't specify this, but it's the only possible way this data is shared with the call creating the shared resource). According the Georg, doing this would slow down some critical hotpath functions, namely the descriptor update functions.
But I also think if we actually want to go down that path we could find other ways to store data per VkImage. VK_EXT_private_data is the most simplistic one at the cost of requiring that it's available if we want to expose VK_KHR_external_memory_win32.