[libvirt] [PATCH v3 3/7] cpu_x86: Introduce virCPUx86FeatureFilter*MSR

[Jiri Denemark]

This functions may be used as a virCPUDefFeatureFilter callbacks for
virCPUDefCheckFeatures, virCPUDefFilerFeatures, and similar functions to
select (virCPUx86FeatureFilterSelectMSR) or drop
(virCPUx86FeatureFilterDropMSR) features reported via MSR.

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---

Notes:
    Version 2:
    - new patch

    Version 3:
    - former virCPUx86FeatureIsMSR function was split in two filters
      and a common helper

 src/cpu/cpu_x86.c        | 57 ++++++++++++++++++++++++++++++++++++++++
 src/cpu/cpu_x86.h        |  6 +++++
 src/libvirt_private.syms |  3 ++-
 3 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index 6eef5cef00..4624ebaff5 100644
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -3362,6 +3362,63 @@ virCPUx86DataAddFeature(virCPUDataPtr cpuData,
 }
 
 
+static bool
+virCPUx86FeatureIsMSR(const char *name)
+{
+    virCPUx86FeaturePtr feature;
+    virCPUx86DataIterator iter;
+    virCPUx86DataItemPtr item;
+    virCPUx86MapPtr map;
+
+    if (!(map = virCPUx86GetMap()))
+        return false;
+
+    if (!(feature = x86FeatureFind(map, name)) &&
+        !(feature = x86FeatureFindInternal(name)))
+        return false;
+
+    virCPUx86DataIteratorInit(&iter, &feature->data);
+    while ((item = virCPUx86DataNext(&iter))) {
+        if (item->type == VIR_CPU_X86_DATA_MSR)
+            return true;
+    }
+
+    return false;
+}
+
+
+/**
+ * virCPUx86FeatureFilterSelectMSR:
+ *
+ * This is a callback for functions filtering features in virCPUDef. The result
+ * will contain only MSR features.
+ *
+ * Returns true if @name is an MSR feature, false otherwise.
+ */
+bool
+virCPUx86FeatureFilterSelectMSR(const char *name,
+                                void *opaque ATTRIBUTE_UNUSED)
+{
+    return virCPUx86FeatureIsMSR(name);
+}
+
+
+/**
+ * virCPUx86FeatureFilterDropMSR:
+ *
+ * This is a callback for functions filtering features in virCPUDef. The result
+ * will not contain any MSR feature.
+ *
+ * Returns true if @name is not an MSR feature, false otherwise.
+ */
+bool
+virCPUx86FeatureFilterDropMSR(const char *name,
+                              void *opaque ATTRIBUTE_UNUSED)
+{
+    return !virCPUx86FeatureIsMSR(name);
+}
+
+
 struct cpuArchDriver cpuDriverX86 = {
     .name = "x86",
     .arch = archs,
diff --git a/src/cpu/cpu_x86.h b/src/cpu/cpu_x86.h
index 28ae46647a..3ea38d1701 100644
--- a/src/cpu/cpu_x86.h
+++ b/src/cpu/cpu_x86.h
@@ -40,3 +40,9 @@ uint32_t virCPUx86DataGetSignature(virCPUDataPtr cpuData,
 
 int virCPUx86DataSetVendor(virCPUDataPtr cpuData,
                            const char *vendor);
+
+bool virCPUx86FeatureFilterSelectMSR(const char *name,
+                                     void *opaque);
+
+bool virCPUx86FeatureFilterDropMSR(const char *name,
+                                   void *opaque);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 90a6d10666..c06fa67d6a 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1268,7 +1268,8 @@ virCPUx86DataAdd;
 virCPUx86DataGetSignature;
 virCPUx86DataSetSignature;
 virCPUx86DataSetVendor;
-
+virCPUx86FeatureFilterDropMSR;
+virCPUx86FeatureFilterSelectMSR;
 
 # datatypes.h
 virConnectClass;
-- 
2.22.0