28/10/2021 13:32, Ferruh Yigit: > On 10/28/2021 12:11 PM, Xia, Chenbo wrote: > >> -----Original Message----- > >> From: Burakov, Anatoly <anatoly.bura...@intel.com> > >> Sent: Thursday, October 28, 2021 6:30 PM > >> To: Xia, Chenbo <chenbo....@intel.com>; dev@dpdk.org > >> Subject: Re: [dpdk-dev] [PATCH v1 1/2] vfio: make API return values > >> consistent > >> > >> Hi Chenbo, > >> > >>> And do we need backport? As 'return -1' does not align with the API > >>> doxygen. > >>> > >>> Thanks, > >>> Chenbo > >>> > >> Maybe it's the FreeBSD implementation that needs to be adjusted then, > >> because none of those functions are valid on FreeBSD, and the > >> documentation for VFIO functions explicitly mentions that on FreeBSD, > >> they should return an error. I went with adjusting Linux implementation > >> to minimize the amount of changes we have to make (and only change code > >> path that no one uses in the first place), but maybe that was a wrong > >> decision. > >> > >> I'm not sure if changing the API return value to match what was > >> documented counts as an API change, so maybe backport to stable is not > >> advised here. > > > > It's not a API change. My point is whether VFIO is present, users just use > > the API to check if vfio support is there. In a kernel version that does not > > support VFIO, he uses 'if(rte_vfio_is_enabled(XXX))' to check as the doxygen > > says its return value should be 1 as true or 0 as false. He will get true > > (-1) > > but VFIO is not there. That's why I think it's a bug and should be > > backported. > > > > But I think we can first discuss if we should drop the dummy implementation > > as DPDK requires Linux kernel version >= 4.4 now so VFIO is always present. > > I think it depends on by saying 'DPDK requires kernel version >= 4.4'. It's > > a real _requirement_ or only a recommendation? > > > > Ferruh, David & Thomas, What do you think? > > > > My understanding is, it is a requirement. DPDK does not guarantee support for > kernels < 4.4.
Do we have a kernel version check at runtime? I think we should add a warning if running too old kernel.
