This document describes the high-level plan to integrate the MLIR codegen (using Linalg/Affine/GPU dialect/...) with XLA on the short term. We are starting this transition by hooking MLIR starting at the LHLO dialect level: this dialect models "HLO operating on buffers", instead of immutable tensor values. We convert the entire XLA module to an LHLO module after XLA completes the buffer assignment. The main entry point at the moment for this HLO dialect -> LHLO dialect conversion by involving XLA is https://github.com/tensorflow/tensorflow/blob/master/tensorflow/compiler/mlir/xla/transforms/xla_hlo_to_lhlo_with_xla.cc ; note that it is incomplete and actively under development, mainly by Tim (CC).