On 2016-06-29 08:32, Peter Xu wrote: > Hi, all, > > I am thinking about whether it's possible to write up a unit test > program for emulated IOMMUs (of course, Intel IOMMU would be the first > one). This can provide us the chance to do quick functional regression > tests for IOMMU just like other devices, as well as customized test > sequences which is hard to do in real guests (e.g., specific cache > invalidations, error injections), etc.. > > I see that current qtest framework cannot support well on testing > IOMMUs. For DMA remapping, things would be quite smooth. The problem > is that, we still do not have a complete test framework on the > interrupts. E.g., currently qtest is still an acceleration type, in > which we have no vCPUs, as well as interrupt chips like APICs (please > correct me if I am wrong). It's even further if we want to test > something like kernel irqchips with QEMU. Not sure whether it's > possible to do test based on a much realistic VM (e.g., with KVM > enabled, but just keep the CPUs stall?). > > I'd say that IOMMU is still experimental, and there are only limited > number of patches for it (so maybe we do not need a unit test at all). > Just want to post this idea out, to see: > > - Whether we need a IOMMU unit test after all? > > - Whether there is other potential consumer who has similar needs to > IOMMU, so that we can see whether try to move qtest a step further > if there are common requirements. >
Adding David and Valentine as we were discussing this need in the context of the AMD IOMMU as well: You cannot test errors with workload (like Linux) that do not trigger them in normal conditions. Jan
signature.asc
Description: OpenPGP digital signature
