target/i386: Export MSR_ARCH_CAPABILITIES bits to guests

On Intel CPUs there are certain bits in MSR_ARCH_CAPABILITIES that
indicates if the CPU is not affected by a vulnerability. Without these
bits guests may try to deploy the mitigation even if the CPU is not
affected.

Export the bits to guests that indicate immunity to hardware
vulnerabilities.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Message-ID: <63d85cc76d4cdc51e6c732478b81d8f13be11e5a.1687551881.git.pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -1060,10 +1060,10 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             "rdctl-no", "ibrs-all", "rsba", "skip-l1dfl-vmentry",
             "ssb-no", "mds-no", "pschange-mc-no", "tsx-ctrl",
             "taa-no", NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
             NULL, "fb-clear", NULL, NULL,
             NULL, NULL, NULL, NULL,
-            NULL, NULL, NULL, NULL,
+            "pbrsb-no", NULL, NULL, NULL,
             NULL, NULL, NULL, NULL,
         },
         .msr = {