i386: Change stepping of Haswell to non-blacklisted value

glibc blacklists TSX on Haswell CPUs with model==60 and
stepping < 4. To make the Haswell CPU model more useful, make
those guests actually use TSX by changing CPU stepping to 4.

References:
* glibc commit 2702856bf45c82cf8e69f2064f5aa15c0ceb6359
  https://sourceware.org/git/?p=glibc.git;a=commit;h=2702856bf45c82cf8e69f2064f5aa15c0ceb6359Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170309181212.18864-4-ehabkost@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

include/hw/i386/pc.h

@@ -389,6 +389,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
         .driver   = TYPE_X86_CPU,\
         .property = "vmware-cpuid-freq",\
         .value    = "off",\
+    },\
+    {\
+        .driver   = "Haswell-" TYPE_X86_CPU,\
+        .property = "stepping",\
+        .value    = "1",\
     },
 
 #define PC_COMPAT_2_7 \

target/i386/cpu.c

@@ -1196,7 +1196,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
         .vendor = CPUID_VENDOR_INTEL,
         .family = 6,
         .model = 60,
-        .stepping = 1,
+        .stepping = 4,
         .features[FEAT_1_EDX] =
             CPUID_VME | CPUID_SSE2 | CPUID_SSE | CPUID_FXSR | CPUID_MMX |
             CPUID_CLFLUSH | CPUID_PSE36 | CPUID_PAT | CPUID_CMOV | CPUID_MCA |