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. > > > > 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? > 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
