From e075af4319c7c30531421e6667845abd30cd28e9 Mon Sep 17 00:00:00 2001
Message-Id: <e075af4319c7c30531421e6667845abd30cd28e9@dist-git>
From: Jiri Denemark <jdenemar@redhat.com>
Date: Tue, 26 Apr 2022 11:58:07 +0200
Subject: [PATCH] cpu_x86: Consolidate signature match in x86DecodeUseCandidate

Checking the signature in two different places makes no sense since the
code in between can only mark the candidate as the best option so far,
which is what the second signature match does as well.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 35ce086667e68e8f546cf36473591dd7c19c72eb)

https://bugzilla.redhat.com/show_bug.cgi?id=2084030

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/cpu/cpu_x86.c | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index 5cb9caef8a..f007487824 100644
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -2020,15 +2020,22 @@ x86DecodeUseCandidate(virCPUx86Model *current,
     }
 
     /* Ideally we want to select a model with family/model equal to
-     * family/model of the real CPU. Once we found such model, we only
+     * family/model of the real CPU and once we found such model, we only
      * consider candidates with matching family/model.
      */
-    if (signature &&
-        virCPUx86SignaturesMatch(current->signatures, signature) &&
-        !virCPUx86SignaturesMatch(candidate->signatures, signature)) {
-        VIR_DEBUG("%s differs in signature from matching %s",
-                  cpuCandidate->model, cpuCurrent->model);
-        return 0;
+    if (signature) {
+        if (virCPUx86SignaturesMatch(current->signatures, signature) &&
+            !virCPUx86SignaturesMatch(candidate->signatures, signature)) {
+            VIR_DEBUG("%s differs in signature from matching %s",
+                      cpuCandidate->model, cpuCurrent->model);
+            return 0;
+        }
+
+        if (!virCPUx86SignaturesMatch(current->signatures, signature) &&
+            virCPUx86SignaturesMatch(candidate->signatures, signature)) {
+            VIR_DEBUG("%s provides matching signature", cpuCandidate->model);
+            return 1;
+        }
     }
 
     if (cpuCurrent->nfeatures > cpuCandidate->nfeatures) {
@@ -2037,16 +2044,6 @@ x86DecodeUseCandidate(virCPUx86Model *current,
         return 1;
     }
 
-    /* Prefer a candidate with matching signature even though it would
-     * result in longer list of features.
-     */
-    if (signature &&
-        virCPUx86SignaturesMatch(candidate->signatures, signature) &&
-        !virCPUx86SignaturesMatch(current->signatures, signature)) {
-        VIR_DEBUG("%s provides matching signature", cpuCandidate->model);
-        return 1;
-    }
-
     VIR_DEBUG("%s does not result in shorter feature list than %s",
               cpuCandidate->model, cpuCurrent->model);
     return 0;
-- 
2.35.1