Re: [PATCH v13 19/85] KVM: Introduce kvm_follow_pfn() to eventually replace "gfn_to_pfn" APIs

Yan Zhao
2024-10-22T01:29:30Z

On Mon, Oct 21, 2024 at 11:08:49AM -0700, Sean Christopherson wrote:
> On Mon, Oct 21, 2024, Yan Zhao wrote:
> > On Thu, Oct 10, 2024 at 11:23:21AM -0700, Sean Christopherson wrote:
> > > --- a/virt/kvm/pfncache.c
> > > +++ b/virt/kvm/pfncache.c
> > > @@ -159,6 +159,12 @@ static kvm_pfn_t hva_to_pfn_retry(struct gfn_to_pfn_cache *gpc)
> > > kvm_pfn_t new_pfn = KVM_PFN_ERR_FAULT;
> > > void *new_khva = NULL;
> > > unsigned long mmu_seq;
> > > + struct kvm_follow_pfn kfp = {
> > > + .slot = gpc->memslot,
> > > + .gfn = gpa_to_gfn(gpc->gpa),
> > > + .flags = FOLL_WRITE,
> > > + .hva = gpc->uhva,
> > > + };
> > Is .map_writable uninitialized?
>
> Nope, per C99, "subobjects without explicit initializers are initialized to zero",
> i.e. map_writable is initialized to "false".
Ah, thanks, good to know that!