Thanks for your reply. What do you mean "device assignment" ? You mean pass-through? > Yes, the same thing. Pass through of PCI device to VM via qemu (pci-assign, vfio-pci, ivshmem etc)
As I knows, the answer is *NO*, because the iommu is not support in guest. > NO was essentially what I was looking for, aware of it now :) On Wed, Dec 10, 2014 at 12:42 PM, Qiu, Michael <michael.qiu at intel.com> wrote: > On 12/6/2014 3:01 AM, Aashima Arora wrote: > > Hi, > > I was trying to access the pci config space(BAR) of the virtual function > > device visible in the virtual machine, similar to what DPDK does on host > > via both UIO and VFIO. Did the following steps. > > > > 1. Bound PF Drivers to ixgbe and spawned virtual function drivers , bound > > them to vfio-pci and set their mac addresses via ip link. Ran Qemu and > > assigned the VF Device using vfio-pci device assignment and initialized > the > > virtual machine. > > insmod igb max_vfs=2 > > > > ./x86_64-softmmu/qemu-system-x86_64 -cpu host -boot c -hda > > /home/vm-images/vm2.imgsnapshot -m 2048M -smp 2 --enable-kvm -name 'vm2' > > -vnc :2 -pidfile /tmp/vm2.pid -driile=fat:rw:/tmp/share,snapshot=off > > -device vfio-pci,host=01:10.1,id=net1 > > > > > > 2. The VF Device was visible with another pci address. > > > > 00:04.0 Ethernet controller: Intel Corporation 82599ES 10-Gigabit > SFI/SFP+ > > Network > > Connection (rev 01) > > > > Further ran DPDK testpmd on top of VM but bound the virtual function > driver > > to igb_uio instead of vfio-pci. It ran successfully. The ixgbevf pmd > > driver is able to access the BAR registers in pci_uio_map_resource via > > mmaping somewhere close to hugepages. I was not able to bind the virtual > > function driver in VM to vfio-pci and hence DPDK would not be able to run > > with VFIO enabled as it complains of no IOMMU support. I also believe > that > > there is little logic in binding the vf device to vfio-pci again since > qemu > > has already taken care of it and hardware support is involved. > > > > So my questions are > > a. vfio is meant to be a replacement for both uio and device assignment > > for qemu. This doesnt seem simultaneous. Comment? > > What do you mean "device assignment" ? You mean pass-through? > > b. Is there any way to access VF device using VFIO in guest userspace? > > Have you run DPDK in guest machine with VFIO support enabled and all > > dependent modules inserted and did it work? > > As I knows, the answer is *NO*, because the iommu is not support in guest. > > c. Is igb_uio or uio_pci_generic in future the only way to access the > > device in guest userspace? > > It depends, who knows what will happen in future :) > > Thanks, > Michael > > *Regards* > > > > -- *Regards,* *Aashima Arora* *arora.aa91 at gmail.com <arora.aa91 at gmail.com>*
