On Fri, Dec 18, 2015 at 6:25 PM, Santosh Shukla <sshukla at mvista.com> wrote: > On Fri, Dec 18, 2015 at 1:51 PM, Yuanhan Liu > <yuanhan.liu at linux.intel.com> wrote: >> On Fri, Dec 18, 2015 at 01:24:41PM +0530, Santosh Shukla wrote: >>> >> I guess we have done enough evaluation / investigation that suggest - >>> >> so to map iopci region to userspace in arch agnostic-way - >>> >> >>> >> # either we need to modify kernel >>> >> - Make sure all the non-x86 arch to support mapping for >>> >> iopci region (i.e. pci_mmap_page_range). I don;t think its a correct >>> >> approach though. >>> >> or >>> >> - include /dev/ioport char-mem device file who could do >>> >> more than byte operation, Note that this implementation does not exist >>> >> in kernel. I could send an RFC to lkml. >>> > >>> > Maybe you could propose the two to lkml, to get some feedbacks from >>> > those kernel/ARM gurus? Please cc me if you do so. >>> > >>> >>> The latter one I already shared old lkml thread, Pl. revisit my v1 0/6 >>> patch [1] and in that refer [2]. >> >> Oops, sorry, a bit busy, that I didn't look at it carefully. My bad, >> anyway. >> >>> Josh has already proposed to lkml but for some reason thread didn't >>> went far. I can restart that discussion giving dpdk use-case as an >>> example/ requirement. >> >> I had a quick go through of the discussion. Both hpa and Arnd seem >> to be fine with the ioctl interface on /dev/port. Have you tried >> that? And if you want to restart it, ioctl might be a better option >> than /dev/ioport, judging from the discussion. >> > > I tried legacy patch and re-writing with ioctl-way; doing changes in > dpdk port as well in kernel, had to test on quite other hw not only > arm64 though! so it will take time for me, I am travelling tomorrow so > bit delayed, We'll post patch to lkml and share dpdk-virtio feedback > perhaps by Monday. >
I posted a query about /dev/ioports approach in lkml thread [1], and Arnd suggested to use vfio framework but it looks like vfio too does not map ioresource_io region. Same communicated to Arnd and waiting for his reply. In mean time I like to ask general question; - Has anyone tried vfio/non-iommu approach for virtio pmd driver? If not then Is there any plan? Someone planning to take up. [1] https://lkml.org/lkml/2015/12/23/145
