Add string feature 'VulkanExternalMemoryMode' to override the memoryMode

[aaron-ruby]

…ver using OpaqueFd memoryMode. And add OpaqueFd as a supported externalMemory mode on QNX.

[jmacnak]

So is the desired behavior just that screen buffer is selected over opaque fd in some cases?

I guess I'm just curious if would make more sense to just introduce some kind of "ExternalMemoryMode" feature that is a string where you can explicitly specify the mode you want (or potentially a "SupportedExternalMemoryModes" feature that is like a list of supported modes in the preferred order). Then we can add like a

GFXSTREAM_SET_FEATURE(&features, ExternalMemoryMode, 
#if defined(ANDROID)
   "ahb"
#elif defined(QNX)
  "screenbuffer"
#elif ...

#endif
   );

[aaron-ruby]

Yeah exactly, you got it.

Yeah I was trying to figure out how to do this in the most universal way. Right now, i guess calculateMode() prioritizes based on the order in this list, but you're right; we basically just want a way to change that order, otherwise default to what is already there.

What you've suggested is a great idea! I will prototype that ...

[aaron-ruby]

@jmacnak updated the review ... allows for some features to specify a string value, instead of just their enabled/disabled boolean. That's the "features" part of the change. Then the rest is actually using that string value (as a optional<string>) as input to the calculateMode() function.

This is a bit of an extension of the "Features" functionality ... so maybe I went to heavy-handed. Please let me know.

[aaron-ruby]

Some testing:

With VulkanExternalMemoryMode:badValue

[a16-aarch64-auto.conf:140] [virtio-gpu] [vulkan_dispatch.cpp(189)] Added library: libvulkan.so
[a16-aarch64-auto.conf:140] [virtio-gpu] [external_memory.cpp(92)] calculateMode(): Could not find an ExternalMemoryMode matching the provided VulkanExternalMemoryMode string: badValue 
[a16-aarch64-auto.conf:140] [virtio-gpu] [external_memory.cpp(199)] getDeviceExtensionsForMode: Invalid external memory mode Unknown!

With VulkanExternalMemoryMode:HostAllocation, but the Vulkan driver does not have the required features:

[a16-aarch64-auto.conf:140] [virtio-gpu] [external_memory.cpp(84)] calculateMode(): Vulkan driver does not support the memory mode provided by the VulkanExternalMemoryMode string: HostAllocation
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1289)] Selecting Vulkan device: V3D 7.1.7.0, Version: 1.3.311
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1293)] Using Vulkan externalMemoryMode: NotSupported for VkEmulation
...
(eventually ...)
[virtio-gpu] [external_memory.cpp(154)] getHandleType: Unhandled external memory mode 'NotSupported'
[virtio-gpu] [external_memory.cpp(154)] getHandleType: Unhandled external memory mode 'NotSupported'
...

With VulkanExternalMemoryMode:OpaqueFd, and it's supported by the Vulkan driver!

[a16-aarch64-auto.conf:140] [virtio-gpu] [vulkan_dispatch.cpp(189)] Added library: libvulkan.so
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1289)] Selecting Vulkan device: V3D 7.1.7.0, Version: 1.3.311
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1293)] Using Vulkan externalMemoryMode: OpaqueFd for VkEmulation
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(260)] Warning: using non-cached HOST_VISIBLE type for staging memory
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1586)] Initializing VkEmulation features:
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1587)]     glInteropSupported: false
[a16-aarch64-auto.conf:140] [virtio-gpu] [vk_common_operations.cpp(1589)]     useDeferredCommands: true
...

[aaron-ruby]

Latest patchset includes:

• Split FeatureInfo into BoolFeatureInfo and StringFeatureInfo
• Move featureString parsing/processing to the FeatureSet class
• Add string feature 'VulkanExternalMemoryMode' to override the memoryMode
• Enable OpaqueFd as a secondary-supported externalMemoryMode on QNX

If desired, please review invidual commits to see grouped/related changes.

[aaron-ruby]

@jmacnak ready for review.