x86 hvm: Expose TSC_DEADLINE CPU feature to guests via CPUID.

Signed-off-by: Wei Gang <gang.wei@intel.com>

tools/libxc/xc_cpufeature.h

@@ -100,6 +100,7 @@
 #define X86_FEATURE_SSE4_2	(4*32+20) /* Streaming SIMD Extensions 4.2 */
 #define X86_FEATURE_X2APIC      (4*32+21) /* x2APIC */
 #define X86_FEATURE_POPCNT	(4*32+23) /* POPCNT instruction */
+#define X86_FEATURE_TSC_DEADLINE (4*32+24) /* "tdt" TSC Deadline Timer */
 #define X86_FEATURE_AES		(4*32+25) /* AES acceleration instructions */
 #define X86_FEATURE_XSAVE	(4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
 #define X86_FEATURE_AVX		(4*32+28) /* Advanced Vector Extensions */

tools/libxc/xc_cpuid_x86.c

@@ -209,6 +209,7 @@ static void xc_cpuid_hvm_policy(
                       bitmaskof(X86_FEATURE_XSAVE)) : 0));
 
         regs[2] |= (bitmaskof(X86_FEATURE_HYPERVISOR) |
+                    bitmaskof(X86_FEATURE_TSC_DEADLINE) |
                     bitmaskof(X86_FEATURE_X2APIC));
 
         regs[3] &= (bitmaskof(X86_FEATURE_FPU) |