Re: [PATCH] KVM: x86/hyperv: do not overwrite hc->ingpa for slow SIGNAL_EVENT hypercall

[Paolo Bonzini]

On 9/22/26 01:23, James Houghton wrote:
> > James, how are you feeling about an early morning PUCK in the near future?
> No problems here; the 23rd is fine. The only day I can't do in the
> near-ish future is Oct 14. Thanks!

Great.  To sum up what I would like to understand, this is it:

1) the overlap between memory protection attributes and kvm-userfault. 
It seems to me that they are almost the same, but I may be wrong.

In particular, they are almost the same in that they are both 
stop-and-retry interfaces, unlike userfaultfd which hides the 
stop-and-retry behind a page fault and a stopped thread.

2) what strategy you have implemented, or you have in mind, to handle 
stop-and-retry for code that does many consecutive memory accesses.  The 
main one is nested vmentry/vmexit.  I have here some mostly untested 
code that splits them into prepare/commit/cancel phases, but I haven't 
dared posting it.

(Secondarily, we have a TDX-sized dependency between planes, memory 
attributes, VBS, and kvm-userfault.  That is probably something worth 
discussing too, sooner or later).

Paolo