Hi From: Stephen Hemminger > Sent: Tuesday, August 6, 2019 6:40 PM > To: Matan Azrad <ma...@mellanox.com> > Cc: dev@dpdk.org; Stephen Hemminger <sthem...@microsoft.com> > Subject: Re: [dpdk-dev] [PATCH v5 1/4] > examples/multi_process/client_server_mp: check port validity > > On Tue, 6 Aug 2019 08:19:01 +0000 > Matan Azrad <ma...@mellanox.com> wrote: > > > From: Stephen Hemminger > > > On Sun, 4 Aug 2019 08:31:54 +0000 > > > Matan Azrad <ma...@mellanox.com> wrote: > > > > > > > > > > /* convert parameter to a number and verify */ > > > > > > > pm = strtoul(portmask, &end, 16); > > > > > > > - if (end == NULL || *end != '\0' || pm == 0) > > > > > > > + if (end == NULL || *end != '\0' || pm > UINT16_MAX || pm > > > == 0) > > > > > > > > > > > > Why pm > UINT16_MAX ? should be something like > (1 << > > > > > RTE_MAX_ETHPORTS) - 1. > > > > > > And need to be sure pm type can hold RTE_MAX_ETHPORTS bits, > > > > > otherwise port 0 may unlikely be all the time visible in the loop > > > > > below. > > > > > > > > > > > > > > > > The DPDK assumes a lot of places that unsigned long will hold a > > > > > port > > > mask. > > > > > > > > So, all are bugs, no? > > > > > > I don't think 32 bit build is that well tested. But yes a mask needs > > > to hold 64 ports. > > > > What if someone changes RTE_MAX_ETHPORTS to be bigger than 64 in > config file? > > > > Assume the user changes RTE_MAX_ETHPORTS to 128, and there is a valid > port in range [64, 127]. > > Then, assume the failsafe sub device owns port ID 0. > > > > Because the mask bits are not enough to handle the above range, you will > get port 0 as valid port - bug. > > > > I think you need one more check to the RTE_MAX_ETHPORTS > 64 case. > > Not really needed. > > The DPDK has lots of hard coded assumptions of all ports fitting in 64 bits. > Examples include testpmd/parameters.c etc.
Yes, I understand, but the user should know not to change the default value of RTE_MAX_ETHPORTS, at least it should be documented. > The original concept of a small set of assigned values for portid is not > going to > scale. It really should have been more like ifindex; something that is not > used > by common API's much larger range; and assigned purely sequentially. > > The API's should all be using names, but the DPDK port naming is also a > mess... Port ID is OK, user can run port info, then to find the wanted port ID and configure it by port id list\bitmap.
