how to disable VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT in gfxstream?

[Kkaiwz]

I try to use virtio-gpu rutabaga with Mali-G310 and meet the unsupported issue: G310 only support VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT for vkbuffer, vkImage doesn't support this bit. So i cannot run virtio-gpu rutabaga successfully.
So i want to know if this external memory bit is necessary? If there any way to disable it?

/*code1: these code result in info->supported be set to false due to extInfo->pNext == VK_EXTERNAL_MEMORY_HANDLE_TYPE_OPAQUE_FD_BIT */
VkResult res = sVkEmulation->getImageFormatProperties2Func(physdev, &formatInfo2, &outProps2);

if (res != VK_SUCCESS) {
    if (res == VK_ERROR_FORMAT_NOT_SUPPORTED) {
        if (isTargetFormat) {printf("Ryan: info->supported = false | 3\n");}
        info->supported = false;

/code2: these code result in setupVkColorBufferLocked failed/
static bool isFormatVulkanCompatible(GLenum internalFormat) {
VkFormat vkFormat = glFormat2VkFormat(internalFormat);

for (const auto& supportInfo : sVkEmulation->imageSupportInfo) {
    if (supportInfo.format == vkFormat && supportInfo.supported) {
        return true;
    }
}

return false;

}

[jmacnak]

Hello!

Can you confirm what OS you are building Gfxstream for? You mentioned Mali, is this for an Android host?

gfxstream/host/vulkan/external_memory.cpp

Lines 48 to 71 in 7ff1e4b

	#if defined(_WIN32)
	std::array<Mode, 2> supportedModes = {
	Mode::OpaqueWin32,
	Mode::HostAllocation,
	};
	#elif defined(__ANDROID__)
	std::array<Mode, 1> supportedModes = {
	Mode::AndroidAHB,
	};
	#elif defined(__QNX__)
	// TODO(aruby@blackberry.com): Use (DMABUF|OPAQUE_FD) on QNX, when screen_buffer not supported?
	std::array<Mode, 1> supportedModes = {
	Mode::QnxScreenBuffer,
	};
	#elif defined(__APPLE__)
	std::array<Mode, 2> supportedModes = {
	Mode::Metal,
	Mode::OpaqueFd,
	};
	#else
	std::array<Mode, 1> supportedModes = {
	Mode::OpaqueFd,
	};
	#endif

should control which type of external memory is used.

The opaque fd bit is not necessarily needed but at least one type of external memory is needed with how Gfxstream works currently. Gfxstream on the host has 1 "global emulation VkInstance" and then also additional VkInstances corresponding to each VkInstance in the guest. External memory is used for sharing resources between the "global emulation VkInstance" and the "guest VkInstances".