vk: Disable conditional rendering on MacOS

rpcs3/Emu/RSX/VK/VKGSRender.cpp

@@ -749,10 +749,10 @@ VKGSRender::VKGSRender(utils::serial* ar) noexcept : GSRender(ar)
 	// Confirmed in BLES01916 (The Evil Within) which uses RGB565 for some virtual texturing data.
 	backend_config.supports_hw_renormalization = (vk::get_driver_vendor() == vk::driver_vendor::NVIDIA);
 
-#ifndef __APPLE__
 	// Conditional rendering support
-	backend_config.supports_hw_conditional_render = true;
-#endif
+	// Do not use on MVK due to a speedhack we rely on (streaming results without stopping the current renderpass)
+	// If we break the renderpasses, MVK loses around 75% of its performance in troublesome spots compared to just doing a CPU sync
+	backend_config.supports_hw_conditional_render = (vk::get_driver_vendor() != vk::driver_vendor::MVK);
 
 	// Passthrough DMA
 	backend_config.supports_passthrough_dma = m_device->get_external_memory_host_support();

rpcs3/Emu/RSX/VK/VKQueryPool.cpp

@@ -170,6 +170,8 @@ namespace vk
 
 	void query_pool_manager::get_query_result_indirect(vk::command_buffer& cmd, u32 index, VkBuffer dst, VkDeviceSize dst_offset)
 	{
+		// We're technically supposed to stop any active renderpasses before streaming the results out, but that doesn't matter on IMR hw
+		// On TBDR setups like the apple M series, the stop is required (results are all 0 if you don't flush the RP), but this introduces a very heavy performance loss.
 		vkCmdCopyQueryPoolResults(cmd, *query_slot_status[index].pool, index, 1, dst, dst_offset, 4, VK_QUERY_RESULT_WAIT_BIT);
 	}