Re: [PATCH v2 6/8] KVM: s390: vsie: Fix unshadowing while shadowing

[Claudio Imbrenda]

On Tue, 24 Mar 2026 15:52:02 +0100
Janosch Frank <frankja@xxxxxxxxxxxxx> wrote:

> On 3/20/26 17:15, Claudio Imbrenda wrote:
> > If shadowing causes the shadow gmap to get unshadowed, exit early to  
> 
> How can this happen?

one possibility is if g2 maps g3 memory pages over the top-level table
of the g2 -> g3 asce

there are probably other cases I can't think of

> 
> > prevent an attempt to dereference the parent pointer, which at this
> > point is NULL.
> > 
> > Opportunistically add some more checks to prevent NULL parents.