That is shockingly young, like the GP I had assumed MSI would've been designed in when the PLIC was designed (i.e. ≤ 2019). The PLIC doc says something about "

That is shockingly young, like the GP I had assumed MSI would've been designed in when the PLIC was designed (i.e. ≤ 2019). The PLIC doc says something about "Interrupt Gateways", did those not make it?