What is the fastest interface between an STM32 and an FPGA?

[snkparty1]

I am designing a system with an STM32 and an FPGA(Xilinx 7 series).

STM32 is in charge of the user interface and the FPGA is in charge of driving the LCD to show images.

Information needs to be exchanged between the STM32 and the FPGA. (STM32 send a command to the FPGA to choose which image to display or to stop displaying. STM32 also need to write all logs to the SD card through the FPGA. FPGA needs to report to the STM32 how many images are displayed and how many remain.)

After some research, I found SPI seems to be fast and easy to implement.(I am not sure which interface is commonly used for communication between STM32 and FPGA?). I wonder if there is another interface that is faster or easier to implement?

[Ozone]

The "fastest" option would be a Cortex core in the FPGA itself.
However ...

> STM32 send a command to the FPGA to choose which image to display or to stop displaying. STM32 also need to write all logs to the SD card through the FPGA. FPGA needs to report to the STM32 how many images are displayed and how many remain.

This does not sound as you need a high bandwidth here, a proper protocol between both seems more important.

> STM32 is in charge of the user interface and the FPGA is in charge of driving the LCD to show images.

Which suggests "fast" means without noticeable delay for the operator.
I suspect reading the actual images and rendering them to the display require more time than the transfer of GUI commands.

[Tesla DeLorean]

Which STM32?

FMC, QUADSPI, OCTOSPI, DCMI (inbound), PSSI

LCD, then perhaps LTDC and an RGB interface.