CPTX_PF_VFX_MBOXX
cpt_write_csr64(cpt->reg_base, CPTX_PF_VFX_MBOXX(0, vf, 1),
cpt_write_csr64(cpt->reg_base, CPTX_PF_VFX_MBOXX(0, vf, 0), mbx->msg);
mbx.msg = cpt_read_csr64(cpt->reg_base, CPTX_PF_VFX_MBOXX(0, vf, 0));
mbx.data = cpt_read_csr64(cpt->reg_base, CPTX_PF_VFX_MBOXX(0, vf, 1));