From: Yury Norov <yury.norov@gmail.com>
Date: Sun, 20 Jul 2025 01:58:45 +0000 (-0400)
Subject: kvm: x86: simplify kvm_vector_to_index()
X-Git-Tag: v6.18-rc1~55^2~6^2~49
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cc63f918a215a24a72992295566cab5f8f89b08e;p=thirdparty%2Fkernel%2Flinux.git

kvm: x86: simplify kvm_vector_to_index()

Use find_nth_bit() and make the function almost a one-liner.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 8172c2042dd6..5bfa6ec324af 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1064,16 +1064,9 @@ EXPORT_SYMBOL_GPL(kvm_apic_match_dest);
 int kvm_vector_to_index(u32 vector, u32 dest_vcpus,
 		       const unsigned long *bitmap, u32 bitmap_size)
 {
-	u32 mod;
-	int i, idx = -1;
-
-	mod = vector % dest_vcpus;
-
-	for (i = 0; i <= mod; i++) {
-		idx = find_next_bit(bitmap, bitmap_size, idx + 1);
-		BUG_ON(idx == bitmap_size);
-	}
+	int idx = find_nth_bit(bitmap, bitmap_size, vector % dest_vcpus);
 
+	BUG_ON(idx >= bitmap_size);
 	return idx;
 }