From 151cbf5d444ab746d05dc0757ec972df8880d0ec Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 13 Dec 2017 15:43:39 -0200 Subject: [PATCH 1/3] target-i386: cpu: add new CPUID bits for indirect branch predictor restrictions RH-Author: Eduardo Habkost Message-id: <20171213174341.20684-2-ehabkost@redhat.com> Patchwork-id: n/a O-Subject: [CONFIDENTIAL][RHEL-7.5 qemu-kvm PATCH v2 1/3] target-i386: cpu: add new CPUID bits for indirect branch predictor restrictions Bugzilla: CVE-2017-5715 RH-Acked-by: Paolo Bonzini RH-Acked-by: Miroslav Rezanina --- target-i386/cpu.c | 19 ++++++++++++++++++- target-i386/cpu.h | 1 + 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 539d659..335689b 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -172,6 +172,17 @@ static const char *cpuid_7_0_edx_feature_name[] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, + NULL, NULL, "spec-ctrl", "stibp", + NULL, "arch-facilities", NULL, NULL, +}; + +static const char *cpuid_80000008_ebx_feature_name[] = { + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + "ibpb", NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, }; @@ -314,6 +325,12 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .cpuid_reg = R_EDX, .tcg_features = TCG_7_0_EDX_FEATURES, }, + [FEAT_8000_0008_EBX] = { + .feat_names = cpuid_80000008_ebx_feature_name, + .cpuid_eax = 0x80000008, + .cpuid_needs_ecx = false, .cpuid_ecx = 0, + .cpuid_reg = R_EBX, + }, [FEAT_XSAVE] = { .feat_names = cpuid_xsave_feature_name, .cpuid_eax = 0xd, @@ -2470,7 +2487,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *eax = 0x00000020; /* 32 bits physical */ } } - *ebx = 0; + *ebx = env->features[FEAT_8000_0008_EBX]; *ecx = 0; *edx = 0; if (cs->nr_cores * cs->nr_threads > 1) { diff --git a/target-i386/cpu.h b/target-i386/cpu.h index 78b8072..1e5c980 100644 --- a/target-i386/cpu.h +++ b/target-i386/cpu.h @@ -406,6 +406,7 @@ typedef enum FeatureWord { FEAT_7_0_EDX, /* CPUID[EAX=7,ECX=0].EDX */ FEAT_8000_0001_EDX, /* CPUID[8000_0001].EDX */ FEAT_8000_0001_ECX, /* CPUID[8000_0001].ECX */ + FEAT_8000_0008_EBX, /* CPUID[8000_0008].EBX */ FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */ FEAT_KVM, /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */ FEAT_SVM, /* CPUID[8000_000A].EDX */ -- 1.8.3.1