Hello Alexander,
On Mon, Jun 13, 2016 at 6:02 PM, Alexander Duyck <alexander.duyck at gmail.com> wrote: > On Mon, Jun 13, 2016 at 4:56 AM, Mauricio V?squez > <mauricio.vasquezbernal at studenti.polito.it> wrote: > > Hello Alexander, > > > > On Tue, Jun 7, 2016 at 11:31 PM, Alexander Duyck < > alexander.duyck at gmail.com> > > wrote: > >> > >> On Tue, Jun 7, 2016 at 1:49 PM, Mauricio V?squez > >> <mauricio.vasquezbernal at studenti.polito.it> wrote: > >> > Dear All, > >> > > >> > I implemented a program that uses flow director to forward packets to > a > >> > specific virtual function, however I faced the problem that I did not > >> > know > >> > which queue belongs to a VF. I found in [1] that in the case of Intel > >> > 82599, queues 0-7 belongs to VF0, 8-15 to VF1 and so on, I tested it > but > >> > it > >> > did not work, using the trial and error method I found that queue 0 is > >> > in > >> > VF0, queue 4 in VF1 and so on. > >> > > >> > My question is: is there a standard way to know which queues belong > to a > >> > specific VF? > >> > > >> > Thanks in advance > >> > > >> > Mauricio V, > >> > > >> > [1] > >> > > >> > > http://www.intel.it/content/dam/www/public/us/en/documents/datasheets/82599-10-gbe-controller-datasheet.pdf > , > >> > Table 7-72 > >> > >> If you are using the kernel driver the way the queues are laid out > >> depends on the number of VFs allocated and what features are enabled > >> in the kernel. > > > > > > I forgot to mention that I am using the DPDK ixgbe PMD. > > > >> > >> Assuming you are not using DCB you should be able to > >> figure out how many queues are being allocated via VF by looking at > >> the output of "ethtool -l <iface>". The upper limit on RSS is t he > >> number of queues each pool is allocated. > >> > >> So for example if you only enable up to 31 VFs then the PF driver > >> allocates 4 queues per VF so you would have queues 0 - 3 allocated to > >> VF0, queues 4-7 allocated to VF1, etc all the way through to the PF > >> occupying (num_vfs * 4) to 127. If you enable 32 or more VFs then the > >> number of queues drops to 2 per VF and RSS on the PF will be limited > >> to the 2 queues following the block reserved for the VFs. > >> > > > > I found that the behavior of the DPDK PMD is almost the same you > described: > > 1 - 15 VFs -> 8 queues per VF > > 16 - 31 VFs -> 4 queues per VF > >>= 32 VFs -> 2 queues per VF > > > > But, according to the datasheet it should be > > 16 VFs -> 8 queues per VF > > 32 VFs -> 4 queues per VF > > 64 VFs -> 2 queues per VF > > > > Am I missing something? > > The datasheet should be referring to "VM pools". The PF consumes one > pool for any queues it is using. As such VFs + 1 is the total number > of pools in use if the PF is active. > > > One extra thing that I am not understanding, in the case I assign the > > maximum number of possible VFs, the PF remains without queues? > > The device can support at most 64 pools. So if you are allocating 64 > VFs then there are no resources left for the PF to allocate queues > from. > > I hope this helps to make it a bit clearer. > This made everything clear for me, thanks. > > - Alex > Mauricio V,
