Re: [PATCH v8 10/46] KVM: guest_memfd: Wire up core private/shared attribute interfaces
From: Binbin Wu <hidden>
Date: 2026-06-23 06:15:18
Also in:
kvm, linux-coco, linux-doc, linux-kselftest, linux-mm, lkml
On 6/19/2026 8:31 AM, Ackerley Tng via B4 Relay wrote: [...]
quoted hunk ↗ jump to hunk
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index bca912db5be6e..e0e544ef47d69 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c@@ -926,6 +926,24 @@ 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_gmem_range_is_private(struct file *file, pgoff_t index, + size_t nr_pages, struct kvm *kvm, gfn_t gfn) +{ + struct maple_tree *mt = &GMEM_I(file_inode(file))->attributes; + pgoff_t end = index + nr_pages - 1; + 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_for_each(mt, entry, index, end) { + if (xa_to_value(entry) != KVM_MEMORY_ATTRIBUTE_PRIVATE) + return false; + }
Patch 1 noted that "Ensuring every index is represented in the maple tree at all times". So I think the queried range should not be a hole in the maple tree. However, there is a inconsistency: in patch 1 kvm_gmem_get_attributes() explicitly checks for holes, but this patch does not.
+ return true; +}