> -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monja...@6wind.com] > Sent: Tuesday, February 14, 2017 6:07 PM > To: Zhang, Helin <helin.zh...@intel.com>; Wu, Jingjing <jingjing...@intel.com> > Cc: Mcnamara, John <john.mcnam...@intel.com>; dev@dpdk.org > Subject: i40e queues per VF > > Hi, > > When reading the documentation, it is not easy to understand the capability of > i40evf for the number of queues. > > First, please could you explain why we need a build-time config option? > In the doc, there is neither justification nor tuning guidelines: > > http://dpdk.org/doc/guides/nics/i40e.html#config-file-options > " > CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_PF (default 64) Number of > queues reserved for PF. > CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF (default 4) Number of > queues reserved for each SR-IOV VF. > "
This number is used as initialization time to allocate queue number for PF/VF for HW's queue pool. Will add more description in i40e.rst. > > I feel these are hard limits and should be some constants in the code, not > some > build configuration options. > > The other doc to look at is: > http://dpdk.org/doc/guides/nics/intel_vf.html#intel-fortville-10-40-gigabit- > ethernet-controller-vf-infrastructure > " > Each VF can have a maximum of 16 queue pairs. > " > > Do we agree that a queue pair is 1 Rx queue / 1 Tx queue? > Note: the concept of queue pairs in Intel VF should be explained somewhere. > Yes. > Below, a different limitation is given: > " > The available queue number(at most 4) per VF depends on the total number of > pool, which is determined by the max number of VF at PF initialization stage > and > the number of queue specified in config " > I think there may be some inconsistent description in doc intel_vf.rst due to Multiple kinds of NICs. We should correct them. Thanks for pointing that. > So what is the real maximum of queue pairs? 4 or 16? > The datasheet talks about 16 queues. Is it 8 pairs? That's is 16 queue pairs. 16 RX queues and 16 Tx queues. > > Is there something to configure the number of queues when creating VF with the > kernel driver? In kernel driver, it seems at most only 4 queues are supported. That's Why we add build-time config option to make more queues are possible. Thanks Jingjing