Re: [RFC PATCH 19/21] KVM: gmem: Split huge boundary leafs for punch hole of private memory

[Yan Zhao]

On Thu, Apr 24, 2025 at 12:19:32PM +0200, Francesco Lavra wrote:
> On 2025-04-24 at 3:08, Yan Zhao wrote:
> > diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
> > index 4bb140e7f30d..008061734ac5 100644
> > --- a/virt/kvm/guest_memfd.c
> > +++ b/virt/kvm/guest_memfd.c
> > @@ -292,13 +292,14 @@ static struct folio *kvm_gmem_get_folio(struct
> > inode *inode, pgoff_t index, int
> >  	return folio;
> >  }
> >  
> > -static void kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t
> > start,
> > -				      pgoff_t end)
> > +static int kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t
> > start,
> > +				     pgoff_t end, bool need_split)
> >  {
> >  	bool flush = false, found_memslot = false;
> >  	struct kvm_memory_slot *slot;
> >  	struct kvm *kvm = gmem->kvm;
> >  	unsigned long index;
> > +	int ret = 0;
> >  
> >  	xa_for_each_range(&gmem->bindings, index, slot, start, end -
> > 1) {
> >  		pgoff_t pgoff = slot->gmem.pgoff;
> > @@ -319,14 +320,23 @@ static void kvm_gmem_invalidate_begin(struct
> > kvm_gmem *gmem, pgoff_t start,
> >  			kvm_mmu_invalidate_begin(kvm);
> >  		}
> >  
> > +		if (need_split) {
> > +			ret = kvm_split_boundary_leafs(kvm,
> > &gfn_range);
> > +			if (ret < 0)
> > +				goto out;
> > +
> > +			flush |= ret;
> > +		}
> >  		flush |= kvm_mmu_unmap_gfn_range(kvm, &gfn_range);
> >  	}
> >  
> > +out:
> >  	if (flush)
> >  		kvm_flush_remote_tlbs(kvm);
> >  
> >  	if (found_memslot)
> >  		KVM_MMU_UNLOCK(kvm);
> > +	return 0;
> 
> Should return ret, not 0
Yes, thank you for the correction!