Re: [RFC PATCH v12 11/33] KVM: Introduce per-page memory attributes

From: Binbin Wu
Date: Wed Sep 27 2023 - 01:23:25 EST




On 9/21/2023 5:03 AM, Sean Christopherson wrote:
On Mon, Sep 18, 2023, Binbin Wu wrote:

On 9/14/2023 9:55 AM, Sean Christopherson wrote:
From: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
[...]
+#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
+/*
+ * Returns true if _all_ gfns in the range [@start, @end) have attributes
+ * matching @attrs.
+ */
+bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
+ unsigned long attrs)
+{
+ XA_STATE(xas, &kvm->mem_attr_array, start);
+ unsigned long index;
+ bool has_attrs;
+ void *entry;
+
+ rcu_read_lock();
+
+ if (!attrs) {
+ has_attrs = !xas_find(&xas, end);
IIUIC, xas_find() is inclusive for "end", so here should be "end - 1" ?
Yes, that does appear to be the case. Inclusive vs. exclusive on gfn ranges has
is the bane of my existence.

Seems this one is not included in the "KVM: guest_memfd fixes" patch series?
https://lore.kernel.org/kvm/20230921203331.3746712-1-seanjc@xxxxxxxxxx/