> +static struct folio *kvm_gmem_get_huge_folio(struct inode *inode, pgoff_t index, > + unsigned int order) > +{ > + pgoff_t npages = 1UL << order; > + pgoff_t huge_index = round_down(index, npages); > + struct address_space *mapping = inode->i_mapping; > + gfp_t gfp = mapping_gfp_mask(mapping) | __GFP_NOWARN; > + loff_t size = i_size_read(inode); > + struct folio *folio; > + > + /* Make sure hugepages would be fully-contained by inode */ > + if ((huge_index + npages) * PAGE_SIZE > size) > + return NULL; > + > + if (filemap_range_has_page(mapping, (loff_t)huge_index << PAGE_SHIFT, > + (loff_t)(huge_index + npages - 1) << PAGE_SHIFT)) > + return NULL; > + > + folio = filemap_alloc_folio(gfp, order); > + if (!folio) > + return NULL; Instead of returning NULL here, what about invoking __filemap_get_folio() directly as below? > + if (filemap_add_folio(mapping, folio, huge_index, gfp)) { > + folio_put(folio); > + return NULL; > + } > + > + return folio; > +} > + > /* > * Returns a locked folio on success. The caller is responsible for > * setting the up-to-date flag before the memory is mapped into the guest. > @@ -284,8 +314,15 @@ static int kvm_gmem_prepare_folio(struct kvm *kvm, struct file *file, > */ > static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index) > { > - /* TODO: Support huge pages. */ > - return filemap_grab_folio(inode->i_mapping, index); > + struct folio *folio = NULL; > + > + if (gmem_2m_enabled) > + folio = kvm_gmem_get_huge_folio(inode, index, PMD_ORDER); > + > + if (!folio) Also need to check IS_ERR(folio). > + folio = filemap_grab_folio(inode->i_mapping, index); > + > + return folio; > } Could we introduce a common helper to calculate max_order by checking for gfn/index alignment and ensuring memory attributes in range are uniform? Then we can pass in the max_order to kvm_gmem_get_folio() and only allocate huge folio when it's necessary. static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index, int max_order) { struct folio *folio = NULL; if (max_order >= PMD_ORDER) { fgf_t fgp_flags = FGP_LOCK | FGP_ACCESSED | FGP_CREAT; fgp_flags |= fgf_set_order(1U << (PAGE_SHIFT + PMD_ORDER)); folio = __filemap_get_folio(inode->i_mapping, index, fgp_flags, mapping_gfp_mask(inode->i_mapping)); } if (!folio || IS_ERR(folio)) folio = filemap_grab_folio(inode->i_mapping, index); return folio; }