On Mon, Dec 9, 2019 at 12:05 PM Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > > On Mon, 9 Dec 2019 14:07:02 +0000 > Robin Murphy <robin.murphy@xxxxxxx> wrote: > > > On 09/12/2019 1:28 pm, Peter Geis wrote: > > > Good Morning, > > > > > > I'm back with more pcie fun on the rk3399. > > > I'm trying to get pcie passthrough working for a vm on the rk3399, and > > > have encountered some roadblocks. > > > > > > First, vfio-pci doesn't work on the rk3399, as the pcie controller > > > doesn't bind explicitly to a iommu. > > > [37528.138212] vfio-pci 0000:01:00.0: assign IRQ: got 226 > > > [37528.138254] vfio-pci: probe of 0000:01:00.0 failed with error -22 > > > > > > # find /sys/kernel/iommu_groups/ -type l > > > /sys/kernel/iommu_groups/1/devices/ff8f0000.vop > > > /sys/kernel/iommu_groups/2/devices/ff900000.vop > > > > > > # virsh start openwrt > > > error: Failed to start domain openwrt > > > error: internal error: Process exited prior to exec: libvirt: error : > > > internal error: Invalid device 0000:01:00.0 iommu_group file > > > /sys/bus/pci/devices/0000:01:00.0/iommu_group is not a symlink > > > > That much I can help with somewhat: the major impediment is that RK3399 > > doesn't have an IOMMU in front of PCIe. As far as I'm aware your only > > option is to resort to the "here be dragons" CONFIG_VFIO_NOIOMMU mode > > (which I don't know an awful lot about beyond that it's a thing). > > And it's a thing that's really only useful if your motivation is to run > something like DPDK in the host and you're not concerned about > isolation between userspace drivers and the host kernel, and you don't > mind tainting the kernel. It's not useful for things like assigning a > device to a VM as we can't readily do that without an IOMMU for > translation. Thanks, > > Alex Thanks Robin, That is an unfortunate limitation, especially considering the device is supposed to support sr-iov. I did try getting VFIO_NOIOMMU to work, but qemu does not like it, at least for pci devices. >
