Re: [PATCH v1 1/3] softmmu/physmem: fallback to opening guest RAM file as readonly in a MAP_PRIVATE mapping

[David Hildenbrand]

On 11.08.23 18:22, Peter Xu wrote:
> On Fri, Aug 11, 2023 at 06:17:05PM +0200, David Hildenbrand wrote:
> > We wouldn't touch "-mem-path".
>
> But still the same issue when someone uses -object memory-backend-file for
> hugetlb, mapping privately, expecting ram discard to work?
>
> Basically I see that example as, "hugetlb" in general made the private
> mapping over RW file usable, so forbidden that anywhere may take a risk.

These users can be directed to using hugetlb

a) using MAP_SHARED
b) using memory-backend-memfd, if MAP_PRIVATE is desired

Am I missing any important use case? Are we being a bit to careful about 
virtio-balloon and postcopy simply not being available for these corner 
cases?

--
Cheers,

David / dhildenb