cpu: Introduce virCPUGetHostIsSupported

Sometimes we want to call virCPUGetHost only when it is implemented for
a given architecture to avoid logging expected and possibly misleading
errors. The new virCPUGetHostIsSupported API may be used to guard such
calls to virCPUGetHost.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

src/cpu/cpu.c

@@ -357,6 +357,26 @@ virCPUDataFree(virCPUDataPtr data)
 }
 
 
+/**
+ * virCPUGetHostIsSupported:
+ *
+ * @arch: CPU architecture
+ *
+ * Check whether virCPUGetHost is supported for @arch.
+ *
+ * Returns true if virCPUGetHost is supported, false otherwise.
+ */
+bool
+virCPUGetHostIsSupported(virArch arch)
+{
+    struct cpuArchDriver *driver;
+
+    VIR_DEBUG("arch=%s", virArchToString(arch));
+
+    return (driver = cpuGetSubDriver(arch)) && driver->getHost;
+}
+
+
 /**
  * virCPUGetHost:
  *

src/cpu/cpu.h

@@ -183,6 +183,9 @@ virCPUDataNew(virArch arch);
 void
 virCPUDataFree(virCPUDataPtr data);
 
+bool
+virCPUGetHostIsSupported(virArch arch);
+
 virCPUDefPtr
 virCPUGetHost(virArch arch,
               virCPUType type,

src/libvirt_private.syms

@@ -1039,6 +1039,7 @@ virCPUDataNew;
 virCPUDataParse;
 virCPUExpandFeatures;
 virCPUGetHost;
+virCPUGetHostIsSupported;
 virCPUGetModels;
 virCPUProbeHost;
 virCPUTranslate;