On 26.10.2021 20:19, Sean Christopherson wrote:
On Mon, Sep 20, 2021, Maciej S. Szmigiero wrote:
From: "Maciej S. Szmigiero" <maciej.szmigiero@xxxxxxxxxx>
The current memslots implementation only allows quick binary search by gfn,
quick lookup by hva is not possible - the implementation has to do a linear
scan of the whole memslots array, even though the operation being performed
might apply just to a single memslot.
This significantly hurts performance of per-hva operations with higher
memslot counts.
Since hva ranges can overlap between memslots an interval tree is needed
for tracking them.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@xxxxxxxxxx>
---
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 50597608d085..7ed780996910 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -472,6 +472,12 @@ static void kvm_null_fn(void)
}
#define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
+/* Iterate over each memslot intersecting [start, last] (inclusive) range */
+#define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \
+ for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \
+ node; \
+ node = interval_tree_iter_next(node, start, last)) \
Similar to kvm_for_each_memslot_in_gfn_range(), this should use an opaque iterator
to hide the implementation details from the caller, e.g. to avoid having to define
a "struct interval_tree_node" and do container_of.
Will convert to an iterator-based for_each implementation in the next version
of this patchset.
Thanks,
Maciej
