[Qemu-devel] issues of region cache and iommu reset

[Jason Wang]

Hi:

I meet an issue when doing reboot for a guest with two virtio-net-pci 
cards when iommu is enabled. What happens is:


1) vtd was reset first

2) during the reset of virtio-net-pci #1, deletion of msix subregion 
will cause a commit of all memory listeners

3) virito-net-pci #2's region cache will be update, but since vtd has 
already been reset, it can't get a valid mappings here


Any ideas on how to fix this? Need region cache be aware of IOMMU/IOTLB 
state in this case? Or can we simply reset IOMMU as the last one?

Thanks