On Wed, Jan 31, 2024, Anish Moorthy wrote:
> On Tue, Jan 30, 2024 at 4:26 PM James Houghton <jthoughton@xxxxxxxxxx> wrote:
> >
> > Feel free to add:
> >
> > Reviewed-by: James Houghton <jthoughton@xxxxxxxxxx>
>
> > If we include KVM_MEM_GUEST_MEMFD here, we should point the reader to
> > KVM_SET_USER_MEMORY_REGION2 and explain that using
> > KVM_SET_USER_MEMORY_REGION with this flag will always fail.
>
> Done and done (I've split the guest memfd doc update off into its own
> commit too).
>
> > > @@ -3070,6 +3074,15 @@ kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn,
> > > writable = NULL;
> > > }
> > >
> > > + if (!atomic && can_exit_on_missing
> > > + && kvm_is_slot_exit_on_missing(slot)) {
Operators go on the preceding line:
if (!atomic && can_exit_on_missing &&
kvm_is_slot_exit_on_missing(slot))
> > > + atomic = true;
> > > + if (async) {
> > > + *async = false;
> > > + async = NULL;
> > > + }
> > > + }
> > > +
> >
> > Perhaps we should have a comment for this? Maybe something like: "If
> > we want to exit-on-missing, we want to bail out if fast GUP fails, and
> > we do not want to go into slow GUP. Setting atomic=true does exactly
> > this."
>
> I was going to push back on the use of "we" but I see that it's all
> over kvm_main.c :).
Ignore the ancient art, push back. The KVM code base is 15 years old at this
point. A _lot_ of has changed in 15 years. The fact that KVM has existing code
that's in violation of current standards doesn't justify ignoring the standards
when adding new code.
