CTX_RING_BUFFER_START
ce->lrc_reg_state[CTX_RING_BUFFER_START+1] =
regs[CTX_RING_BUFFER_START + 1] = i915_ggtt_offset(request->ring->vma);
CTX_REG(regs, CTX_RING_BUFFER_START, RING_START(base), 0);