Hi Nicolin, On 4/19/22 5:26 AM, Nicolin Chen wrote: > On Sun, Apr 17, 2022 at 12:30:40PM +0200, Eric Auger wrote: > >>>> - More tests >>> I did a quick test on my ARM64 platform, using "iommu=smmuv3" >>> string. The behaviors are different between using default and >>> using legacy "iommufd=off". >>> >>> The legacy pathway exits the VM with: >>> vfio 0002:01:00.0: >>> failed to setup container for group 1: >>> memory listener initialization failed: >>> Region smmuv3-iommu-memory-region-16-0: >>> device 00.02.0 requires iommu MAP notifier which is not currently supported >>> >>> while the iommufd pathway started the VM but reported errors >>> from host kernel about address translation failures, probably >>> because of accessing unmapped addresses. >>> >>> I found iommufd pathway also calls error_propagate_prepend() >>> to add to errp for not supporting IOMMU_NOTIFIER_MAP, but it >>> doesn't get a chance to print errp out. Perhaps there should >>> be a final error check somewhere to exit? >> thank you for giving it a try. >> >> vsmmuv3 + vfio is not supported as we miss the HW nested stage support >> and SMMU does not support cache mode. If you want to test viommu on ARM >> you shall test virtio-iommu+vfio. This should work but this is not yet >> tested. > I tried "-device virtio-iommu" and "-device virtio-iommu-pci" > separately with vfio-pci, but neither seems to work. The host > SMMU driver reports Translation Faults. > > Do you know what commands I should use to run QEMU for that > combination? you shall use : -device virtio-iommu-pci -device vfio-pci,host=<BDF> Please make sure the "-device virtio-iommu-pci" is set *before* the "-device vfio-pci," Otherwise the IOMMU MR notifiers are not set properly and this may be the cause of your physical SMMU translations faults. Eric > >> I pushed a fix for the error notification issue: >> qemu-for-5.17-rc6-vm-rfcv2-rc0 on my git https://github.com/eauger/qemu.git > Yes. This fixes the problem. Thanks! >
