target/i386: Export BHI_NO bit to guests

Branch History Injection (BHI) is a CPU side-channel vulnerability, where
an attacker may manipulate branch history before transitioning from user
to supervisor mode or from VMX non-root/guest to root mode. CPUs that set
BHI_NO bit in MSR IA32_ARCH_CAPABILITIES to indicate no additional
mitigation is required to prevent BHI.

Make BHI_NO bit available to guests.

Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250121020650.1899618-3-tao1.su@linux.intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Tao Su 2025-01-21 10:06:48 +08:00 committed by Paolo Bonzini
parent c597ff5339
commit b611931d4f

View File

@ -1364,7 +1364,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
"taa-no", NULL, NULL, NULL,
NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no",
NULL, "fb-clear", NULL, NULL,
NULL, NULL, NULL, NULL,
"bhi-no", NULL, NULL, NULL,
"pbrsb-no", NULL, "gds-no", "rfds-no",
"rfds-clear", NULL, NULL, NULL,
},