i386: Add CPUID bit for WBNOINVD

WBNOINVD: Write back and do not invalidate cache, enumerated by
CPUID.(EAX=80000008H, ECX=0):EBX[bit 9].
Signed-off-by: NRobert Hoo <robert.hu@linux.intel.com>
Message-Id: <1530781798-183214-5-git-send-email-robert.hu@linux.intel.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

target/i386/cpu.c

@@ -1028,7 +1028,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         .feat_names = {
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            NULL, "wbnoinvd", NULL, NULL,
             "ibpb", NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,

target/i386/cpu.h

@@ -694,6 +694,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
 #define CPUID_7_0_EDX_ARCH_CAPABILITIES (1U << 29)  /*Arch Capabilities*/
 #define CPUID_7_0_EDX_SPEC_CTRL_SSBD  (1U << 31) /* Speculative Store Bypass Disable */
 
+#define CPUID_8000_0008_EBX_WBNOINVD  (1U << 9)  /* Write back and
+                                                                             do not invalidate cache */
 #define CPUID_8000_0008_EBX_IBPB    (1U << 12) /* Indirect Branch Prediction Barrier */
 
 #define CPUID_XSAVE_XSAVEOPT   (1U << 0)