On 6/29/2026 12:04 AM, Stephen Hemminger wrote: > On Sat, 27 Jun 2026 08:09:09 +0800 > fengchengwen <[email protected]> wrote: > >>> >>> +static int >>> +ae4dma_dev_configure(struct rte_dma_dev *dev __rte_unused, >>> + const struct rte_dma_conf *dev_conf, >>> + uint32_t conf_sz) >>> +{ >>> + if (sizeof(struct rte_dma_conf) != conf_sz) >>> + return -EINVAL; >> >> This may break ABI compatible > > Ignore that suggestion. This is a reasonable way to handle new configuration > functions. You need/want a minimal set of values. If rte_dma_conf grows in > size > then the code can add compatability; by requiring a minimum set of values > and then setting the rest to zero. > > Something like > > static int > ae4dma_dev_configure(struct rte_dma_dev *dev __rte_unused, > const struct rte_dma_conf *dev_conf, > size_t conf_sz) > { > if (conf_sz < sizeof(struct orig_rte_dma_conf)) > return -EINVAL;
+1 for this > > struct rte_dma_conf conf; > memcpy(&conf, dev_conf, RTE_MIN(conf_sz, sizeof(conf))); > dev_conf = &conf; > > Looking at rte_dma_conf the structure has holes and dmadev lib > doesn't validate undefined flags, so it already has future ABI problems. Yes, it indeed
