Re: [PATCH v9 07/41] KVM: guest_memfd: Wire up core private/shared attribute interfaces
Xiaoyao Li <[email protected]>
| Newsgroups | org.kernel.vger.linux-kselftest,dev.linux.lists.linux-coco,org.kernel.vger.kvm,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-trace-kernel,org.kvack.linux-mm |
|---|---|
| Message-ID | <[email protected]> |
On 7/29/2026 8:35 AM, Ackerley Tng via B4 Relay wrote:
> diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
> index 33c9830190e2e..89cf922232920 100644
> --- a/virt/kvm/guest_memfd.c
> +++ b/virt/kvm/guest_memfd.c
> @@ -893,6 +893,27 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
> EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_gmem_get_pfn);
>
> #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE
> +static bool kvm_range_is_private(struct file *file, pgoff_t index,
> + size_t nr_pages, struct kvm *kvm, gfn_t gfn)
> +{
> + struct inode *inode = file_inode(file);
> + pgoff_t last = index + nr_pages - 1;
> + struct maple_tree *mt;
> + void *entry;
> +
> + if (!gmem_in_place_conversion)
> + return kvm_range_has_vm_memory_attributes(kvm, gfn, gfn + nr_pages,
> + KVM_MEMORY_ATTRIBUTE_PRIVATE,
> + KVM_MEMORY_ATTRIBUTE_PRIVATE);
> +
> + mt = &GMEM_I(inode)->attributes;
> + mt_for_each(mt, entry, index, last) {
> + if (kvm_gmem_interpret_entry(inode, entry) !=
> + KVM_MEMORY_ATTRIBUTE_PRIVATE)
> + return false;
> + }
> + return true;
> +}
>
> static long __kvm_gmem_populate(struct kvm *kvm, struct kvm_memory_slot *slot,
> struct file *file, gfn_t gfn, struct page *src_page,
> @@ -913,9 +934,7 @@ static long __kvm_gmem_populate(struct kvm *kvm, struct kvm_memory_slot *slot,
>
> folio_unlock(folio);
>
> - if (!kvm_range_has_vm_memory_attributes(kvm, gfn, gfn + 1,
> - KVM_MEMORY_ATTRIBUTE_PRIVATE,
> - KVM_MEMORY_ATTRIBUTE_PRIVATE)) {
> + if (!kvm_range_is_private(file, index, 1, kvm, gfn)) {
It's checking if a single gfn is private.
We can just use kvm_mem_is_private()? And it seems can be a separate patch.
> ret = -EINVAL;
> goto out_put_folio;
> }