Re: [Qemu-devel] [PATCH RFC v4 19/20] intel_iommu: unmap existing pages before replay

[Jason Wang]

On 2017年01月20日 21:08, Peter Xu wrote:
> Previous replay works for domain switch only if the original domain does
> not have mapped pages. For example, if we switch domain from A to B, it
> will only work if A has no existing mapping. If there is, then there's
> problem - current replay didn't make sure the old mappings are cleared
> before replaying the new one.

I'm not quite sure this is needed. I thought the only thing we need to 
do is stop DMA of device during the moving? Or is there an example that 
will cause trouble?

Thanks