On Fri, Sep 04, 2020 at 02:18:37PM +0000, Mircea CIRJALIU - MELIU wrote: > > This seems really sketchy, get_user_pages is sensitive to the VMA, what > > happens when VMA flags are different/etc? > > A debugger shouldn't complain if a portion of the debuggee is read-only, > just overwrite the data. At this point the kernel API here is so incredibly limited you may as well use a memfd for passing the shared address space instead of trying to do and maintain this complexity. Your use case is only qemu, so what is the problem to replace the allocator backing VM memory in userspace? Other people have been talking about doing a memfd already for different reasons - and memfd can already be shared as this scheme desires. Jason
