[Qemu-devel] Error with Virtio DMA Remapping

[Nikos Dragazis]

Hi all,

I am trying to use QEMU vIOMMU for virtio DMA remapping. When I run the
VM, I get the following messages in stderr:

qemu-system-x86_64: vtd_iommu_translate: detected translation failure 
(dev=01:00:00, iova=0x0)
qemu-system-x86_64: New fault is not recorded due to compression of faults
qemu-system-x86_64: virtio: zero sized buffers are not allowed         

My QEMU configuration is:


./qemu-system-x86_64 -M accel=kvm -cpu host -smp 2 -m 4G \
      -enable-kvm -machine q35,accel=kvm,kernel-irqchip=split \
      -device intel-iommu,x-aw-bits=48,device-iotlb=on,pt=false \
      -device ioh3420,id=pcie.1,chassis=1 \
      -device virtio-scsi-pci,bus=pcie.1,id=scsi0,iommu_platform=on,ats=on,
disable-legacy=on,disable-modern=off \
      [...]

I use QEMU 3.0.50 and host kernel 4.4.0.

I followed the instructions here:
https://wiki.qemu.org/Features/VT-d#With_Virtio_Devices
to enable DMAR for the virtio-scsi device.

I see there is a related thread about this error here:
http://qemu.11.n7.nabble.com/PATCH-0-2-virtio-scsi-Fix-QEMU-hang-with-vIOMMU-and-ATS-td598736.html#a599086

Is this still an open issue or it has been solved?
Please let me know.

Thanks,
Nikos