On Wed, Nov 4, 2020 at 1:32 PM Roja Eswaran <reswa...@binghamton.edu> wrote: > > Sorry for the previous email. Here is the email with Plaintext. > > > -- > Thanks, > Roja Eswaran > PhD Student, Operating Systems and Networks Laboratory > State University of New York, Binghamton > > > ---------- Forwarded message --------- > From: Roja Eswaran <reswa...@binghamton.edu> > Date: Wed, Nov 4, 2020 at 6:31 PM > Subject: Re: [External Email] Re: [vfio-users] Direct Assignment of > Non-PCI devices to VM > To: Micah Morton <mort...@chromium.org> > Cc: Auger Eric <eric.au...@redhat.com>, <vfio-users@redhat.com> > > > Mr. Morton, > Thank you so much for your insights. I have one quick question. Are > there any drivers other than VFIO that could be used with QEMU for the > direct assignment? Please let me know if you're aware of any such > drivers. Thanks again!
AFAIK no -- the UIO driver is the next closest thing but QEMU doesn't have any support for using it to assign HW devices to guest VMs. > -- > Thanks, > Roja Eswaran > PhD Student, Operating Systems and Networks Laboratory > State University of New York, Binghamton > > > On Wed, Nov 4, 2020 at 3:25 PM Micah Morton <mort...@chromium.org> wrote: > > > > On Wed, Nov 4, 2020 at 5:30 AM Roja Eswaran <reswa...@binghamton.edu> wrote: > > > > > > I am using Jetson Xavier NX which integrates a Realtek RTL8211FDI Gigabit > > > Ethernet controller. The on-module Ethernet controller supports > > > 10/100/1000 Gigabit Ethernet IEEE 802.3u Media Access Controller (MAC). > > > I am trying to assign Non-PCI NIC mentioned above directly to the > > > Vanilla VM. As it's not a PCI device, I have no idea how I can achieve > > > this. > > > > > > 1) Is it possible to do a direct assignment on Non-PCI devise to VM using > > > VFIO drivers? > > > > I don't see any mention of an IOMMU in any of these 3 DT files: > > > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/nvidia/tegra194-p2972-0000.dts > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/nvidia/tegra194-p2888.dtsi > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/nvidia/tegra194.dtsi > > > > Does the Jetson Xavier NX board have an iommu? If not, this is the > > most fundamental reason you wouldn't be able to use VFIO for > > assignment on that board -- especially if the ethernet controller is > > DMA-capable, since you won't be able to ensure the ethernet device's > > DMAs operate on the memory assigned to the guest. > > > > You could check for this by doing "dmesg | grep -i -e iommu -e smmu" > > on the device and seeing if it prints anything, or looking at > > /sys/kernel/iommu_groups to see if that dir exists. > > > > Beyond the IOMMU, vfio-platform/QEMU in their current state wouldn't > > be able to handle the embedded PHY device here: > > https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/nvidia/tegra194-p2888.dtsi#L43 > > , which would be another hurdle. > > > > > 2) If not, are there any other drivers that would help me achieve the > > > direct assignment? > > > The direct assignment is important because we are trying to reduce the > > > CPU utilization even though virtio drivers give us a very small network > > > latency overhead. Any comments or insights are really appreciated. Thank > > > you so much for your time! > > > > > > > > > -- > > > Thanks, > > > Roja Eswaran > > > Ph.D. Student, Operating Systems and Networks Laboratory > > > State University of New York, Binghamton > > > _______________________________________________ > > > vfio-users mailing list > > > vfio-users@redhat.com > > > https://www.redhat.com/mailman/listinfo/vfio-users _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
