On 01.12.2021 17:36, Sean Christopherson wrote:
On Wed, Dec 01, 2021, Maciej S. Szmigiero wrote:
On 01.12.2021 04:41, Sean Christopherson wrote:
On Tue, Nov 30, 2021, Maciej S. Szmigiero wrote:
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 41efe53cf150..6fce6eb797a7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -848,6 +848,105 @@ struct kvm_memory_slot *id_to_memslot(struct kvm_memslots *slots, int id)
return NULL;
}
+/* Iterator used for walking memslots that overlap a gfn range. */
+struct kvm_memslot_iter {
+ struct kvm_memslots *slots;
+ gfn_t end;
+ struct rb_node *node;
+};
...
+static inline struct kvm_memory_slot *kvm_memslot_iter_slot(struct kvm_memslot_iter *iter)
+{
+ return container_of(iter->node, struct kvm_memory_slot, gfn_node[iter->slots->node_idx]);
Having to use a helper in callers of kvm_for_each_memslot_in_gfn_range() is a bit
ugly, any reason not to grab @slot as well? Then the callers just do iter.slot,
which IMO is much more readable.
"slot" can be easily calculated from "node" together with either "slots" or
"node_idx" (the code above just adjusts a pointer) so storing it in the
iterator makes little sense if the later are already stored there.
I don't want the callers to have to calculate the slot. It's mostly syntatic
sugar, but I really do think it improves readability. And since the first thing
every caller will do is retrieve the slot, I see no benefit in forcing the caller
to do the work.
E.g. in the simple kvm_check_memslot_overlap() usage, iter.slot->id is intuitive
and easy to parse, whereas kvm_memslot_iter_slot(&iter)->id is slightly more
difficult to parse and raises questions about why a function call is necessary
and what the function might be doing.
Personally, I don't think it's that much less readable, but I will change
the code to store "slots" instead (as you wish) since it's the last remaining
change - other than Paolo's call whether we should keep or drop the
kvm_arch_flush_shadow_memslot()-related patch 25.
Thanks,
Maciej
