[libvirt PATCH v3 2/3] cpu: Introduce virCPUCheckForbiddenFeatures

[Tim Wiederhake]

Signed-off-by: Tim Wiederhake <twiederh at redhat.com>
---
 src/cpu/cpu.c            | 37 +++++++++++++++++++++++++++++++++++++
 src/cpu/cpu.h            |  6 ++++++
 src/libvirt_private.syms |  1 +
 3 files changed, 44 insertions(+)

diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index dfedf5bbf0..3fd7035f7a 100644
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -690,6 +690,43 @@ virCPUCheckFeature(virArch arch,
 }
 
 
+/**
+ * virCPUCheckForbiddenFeatures:
+ *
+ * @guest: CPU definition
+ * @host: CPU definition
+ *
+ * Checks that @host enables no feature explicitly disabled by @guest.
+ *
+ * Returns 0 on success or -1 on error.
+ */
+int
+virCPUCheckForbiddenFeatures(virCPUDefPtr guest, const virCPUDef *host)
+{
+    size_t i;
+    for (i = 0; i < guest->nfeatures; ++i) {
+        virCPUFeatureDefPtr feature;
+
+        if (guest->features[i].policy != VIR_CPU_FEATURE_FORBID)
+            continue;
+
+        feature = virCPUDefFindFeature(host, guest->features[i].name);
+        if (!feature)
+            continue;
+
+        if (feature->policy == VIR_CPU_FEATURE_DISABLE)
+            continue;
+
+        virReportError(VIR_ERR_CPU_INCOMPATIBLE,
+                       _("Host CPU provides forbidden feature '%s'"),
+                       guest->features[i].name);
+        return -1;
+    }
+
+    return 0;
+}
+
+
 /**
  * virCPUDataCheckFeature:
  *
diff --git a/src/cpu/cpu.h b/src/cpu/cpu.h
index ff4fb7e103..0b00f0b98d 100644
--- a/src/cpu/cpu.h
+++ b/src/cpu/cpu.h
@@ -228,6 +228,12 @@ virCPUCheckFeature(virArch arch,
     ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 
 
+int
+virCPUCheckForbiddenFeatures(virCPUDefPtr guest,
+                             const virCPUDef *host)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
+
 int
 virCPUDataCheckFeature(const virCPUData *data,
                        const char *feature)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 526dcee11a..fa8859a6e3 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1420,6 +1420,7 @@ cpuEncode;
 virCPUArchIsSupported;
 virCPUBaseline;
 virCPUCheckFeature;
+virCPUCheckForbiddenFeatures;
 virCPUCompare;
 virCPUCompareXML;
 virCPUConvertLegacy;
-- 
2.26.2