From 3335b5e0db21375053c5005be9f820f7ba945010 Mon Sep 17 00:00:00 2001
Message-Id: <3335b5e0db21375053c5005be9f820f7ba945010@dist-git>
From: Jiri Denemark <jdenemar@redhat.com>
Date: Fri, 21 Jun 2019 09:25:02 +0200
Subject: [PATCH] cpu_x86: Log decoded CPU model and signatures
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The log message may be useful when debugging why a specific CPU model
was selected for a given set of CPUID data.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
(cherry picked from commit 5ced12decea42f1d588f2cb28b10ca7a5772098e)

https://bugzilla.redhat.com/show_bug.cgi?id=1686895

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Message-Id: <cae19825427465e352de05433920c96dc44552ff.1561068591.git.jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/cpu/cpu_x86.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index 7bd8119c23..ba14a6097d 100644
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -1769,6 +1769,26 @@ x86ModelHasSignature(virCPUx86ModelPtr model,
 }
 
 
+static char *
+x86FormatSignatures(virCPUx86ModelPtr model)
+{
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    size_t i;
+
+    for (i = 0; i < model->nsignatures; i++) {
+        virBufferAsprintf(&buf, "%06lx,",
+                          (unsigned long)model->signatures[i]);
+    }
+
+    virBufferTrim(&buf, ",", -1);
+
+    if (virBufferCheckError(&buf) < 0)
+        return NULL;
+
+    return virBufferContentAndReset(&buf);
+}
+
+
 /*
  * Checks whether a candidate model is a better fit for the CPU data than the
  * current model.
@@ -1892,6 +1912,7 @@ x86Decode(virCPUDefPtr cpu,
     virCPUx86Data features = VIR_CPU_X86_DATA_INIT;
     virCPUx86VendorPtr vendor;
     virDomainCapsCPUModelPtr hvModel = NULL;
+    VIR_AUTOFREE(char *) sigs = NULL;
     uint32_t signature;
     ssize_t i;
     int rc;
@@ -1984,6 +2005,11 @@ x86Decode(virCPUDefPtr cpu,
     if (vendor && VIR_STRDUP(cpu->vendor, vendor->name) < 0)
         goto cleanup;
 
+    sigs = x86FormatSignatures(model);
+
+    VIR_DEBUG("Using CPU model %s (signatures %s) for CPU with signature %06lx",
+              model->name, NULLSTR(sigs), (unsigned long)signature);
+
     VIR_STEAL_PTR(cpu->model, cpuModel->model);
     VIR_STEAL_PTR(cpu->features, cpuModel->features);
     cpu->nfeatures = cpuModel->nfeatures;
-- 
2.22.0