target/i386: Export RFDS bit to guests

Register File Data Sampling (RFDS) is a CPU side-channel vulnerability
that may expose stale register value. CPUs that set RFDS_NO bit in MSR
IA32_ARCH_CAPABILITIES indicate that they are not vulnerable to RFDS.
Similarly, RFDS_CLEAR indicates that CPU is affected by RFDS, and has
the microcode to help mitigate RFDS.

Make RFDS_CLEAR and RFDS_NO bits available to guests.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <9a38877857392b5c2deae7e7db1b170d15510314.1710341348.git.pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index c295491d8ae5018b17edec1b7a4e84fc48caed3f..eda15b0d4c70775c8065c5a77498d46ba262ebbf 100644 (file)
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1158,8 +1158,8 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
             NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
             NULL, "fb-clear", NULL, NULL,
             NULL, NULL, NULL, NULL,
-            "pbrsb-no", NULL, "gds-no", NULL,
-            NULL, NULL, NULL, NULL,
+            "pbrsb-no", NULL, "gds-no", "rfds-no",
+            "rfds-clear", NULL, NULL, NULL,
         },
         .msr = {
             .index = MSR_IA32_ARCH_CAPABILITIES,