On Thu, May 12, 2016 at 01:54:13PM +0800, Jianbo Liu wrote: > On 12 May 2016 at 13:06, Santosh Shukla > <santosh.shukla at caviumnetworks.com> wrote: > > On Thu, May 12, 2016 at 11:42:26AM +0800, Jianbo Liu wrote: > >> On 12 May 2016 at 11:17, Santosh Shukla > >> <santosh.shukla at caviumnetworks.com> wrote: > >> > On Thu, May 12, 2016 at 10:01:05AM +0800, Jianbo Liu wrote: > >> >> On 12 May 2016 at 02:25, Stephen Hemminger <stephen at > >> >> networkplumber.org> wrote: > >> >> > On Wed, 11 May 2016 22:32:16 +0530 > >> >> > Jerin Jacob <jerin.jacob at caviumnetworks.com> wrote: > >> >> > > >> >> >> On Wed, May 11, 2016 at 08:22:59AM -0700, Stephen Hemminger wrote: > >> >> >> > On Wed, 11 May 2016 19:17:58 +0530 > >> >> >> > Hemant Agrawal <hemant.agrawal at nxp.com> wrote: > >> >> >> > > >> >> >> > > IGB_UIO not supported for arm64 arch in kernel so disable. > >> >> >> > > > >> >> >> > > Signed-off-by: Hemant Agrawal <hemant.agrawal at nxp.com> > >> >> >> > > Reviewed-by: Santosh Shukla <santosh.shukla at > >> >> >> > > caviumnetworks.com> > >> >> >> > > >> >> >> > Really, I have use IGB_UIO on ARM64 > >> >> >> > >> >> >> May I know what is the technical use case for igb_uio on arm64 > >> >> >> which cannot be addressed through vfio or vfioionommu. > >> >> > > >> >> > I was running on older kernel which did not support vfioionommu mode. > >> >> > >> >> As I said, most of DPDK developers are not kernel developers. They may > >> >> have their own kernel tree, and couldn't like to upgrade to latest > >> >> kernel. > >> >> They can choose to use or not use igb_uio when binding the driver. But > >> >> blindly disabling it in the base config seems unreasonable. > >> > > >> > if user keeping his own kernel so they could also keep IGB_UIO=y in > >> > their local > >> Most likely they don't have local dpdk tree. They write their own > >> applications, complie and link to dpdk lib, then done. > >> > >> > dpdk tree. Why are you imposing user-x custome depedancy on upstream > >> > dpdk base > >> Customer requiremnts is important. I want they can choose the way they > >> like. > >> > > > > so you choose to keep igb_uio option, provided arch doesn't support? > > new user did reported issues with igb_uio for arm64, refer this thread [1], > > as > > well hemanth too faced issues. we want to avoid that. > > > > If customer maintaing out-of-tree kernel then he can also switch to > > vfio-way. > > isn;t it? > > > >> > config. Is it not enough for explanation that - Base config ie.. armv8 > >> > doesn;t > >> > support pci mmap, so igb_uio is n/a. New user wont able to build/run > >> > dpdk/arm64 > >> > in igb_uio-way, He'll prefer to use upstream stuff. I think, you are not > >> > making > >> You are wrong, he can build dpdk. If he like to use upstream without > >> patching, he can use vfio. > > > > I disagree, we want to avoid [1] for new user. > > > >> But you can't ignore the need from old user which is more comfortable > >> with older kernel. > >> > > arm/arm64 dpdk support recently added and I am guessing, most likely > > customer > > using near latest kernel, switching to vfio won't be so difficult. > > > > Or can you take up responsibility of upstreaming pci mmap patch, then we > > don't > > need this patch. > > > > [1] http://dpdk.org/ml/archives/dev/2016-January/031313.html > > Can you read carefully about the guide at > http://dpdk.org/doc/guides/linux_gsg/build_dpdk.html? It says to use > uio_pci_generic, igb_uio or vfio-pci.
*** applicable and works for x86 only, not for arm64: because pci mmap support not present for arm64, in that case we should update the doc. > Could it be possible that the user in that thread has already read and > tried them all and found that he can't enable vifo with his kernel, > and igb_uio is the easy way for him and asked for help from community? > If so, we have no choice but keeping igb_uio enabled. By then vfionoiommu support was wip progress in dpdk/linux. but now it merged and it works. So no need to retain igb_uio in base config for which to work - user need to use mmap patch at linux side. Or can you maintain out-of-tree pci mmap patch/ kerne source and make it explicit somewhere in dpdk build doc that - if user want igb_uio way then use kernel/mmap patch from x location. > He use lsmod to show us the modules, most likely he know vifo-pci. > > Below are the details on modules, hugepages and device binding. > root at arm64:~# lsmod > Module Size Used by > rte_kni 292795 0 > igb_uio 4338 0 > ixgbe 184456 0
