On 12 May 2016 at 18:31, Santosh Shukla <santosh.shukla at caviumnetworks.com> wrote: > On Thu, May 12, 2016 at 05:52:54PM +0800, Jianbo Liu wrote: >> On 12 May 2016 at 16:57, Santosh Shukla >> <santosh.shukla at caviumnetworks.com> wrote: >> > 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. >> >> We can't decide which kernel user will use. >> > > yes, we can't decide kernel for user but we should be explicit to user on - > what > works for dpdk/linux out-of-box vs what could work with use of out-of-tree > patch/RFC's.. example igb_uio. >
OK, please persuade Stephen Hemminger and the other guy to use upstream kernel first! >> > >> > 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. >> >> The patch is in the kernel maillist, and user google it. > > there are feature specific rfc's in plenty in lkml/qemu mailing list, and you > suggest- user to hunt for all those information. Is this how we;re officially > supporting igb_uio for arm64.. that let user to google? > Sorry I don't know you are offically support users here. And you also don't know what they really want. >> And isn't funny to ask someone to do something again and again (3 >> times) in this thread? >> > > I am asking becasue your in favour of keeping igb_uio for arm64 but not > agreeing to streamline (writing a note in dpdk doc for igb_uio for arm64 or > pointing to working tree).. so that user don;t need to grep or google for > known > findings. > > I find discussion going in circle and nothing will conclude, So given up. >> > >> >> 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