On Fri, Oct 13, 2023 at 05:44:27PM +0800, Zhu, Lingshan wrote:
> > As Michael said, software based nesting is used..
> > See if actual hw based devices can implement it or not. Many components of cpu cannot do N level nesting either, but may be virtio can.
> > I donât know how yet.
> two facts:
> 1. virito works for nested for years
> 2. your admin vq lm solution does not work for nested
First virtio works but nested migration doesn't: the way virtio works doesn't
allow L1 hypervisor to migrate L2 if it passes virtio through to L2,
except by using full emulation approaches such as shadow vq -
surely, these are still possible.
Second doesn't work is an overstatement. It remains to be seen what else can
be done though. You hinted at a depdenency on PASID. Have owner be a
PASID and Parav's approach seems to work with little to no change.
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MST