From 70feb9269b5741ae2d911d81a035bdc574aaf564 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Wed, 13 Dec 2017 15:48:12 -0200 Subject: [PATCH 2/3] target-i386: cpu: add new CPUID bits for indirect branch predictor restrictions RH-Author: Eduardo Habkost Message-id: <20171213174813.21283-3-ehabkost@redhat.com> Patchwork-id: n/a O-Subject: [CONFIDENTIAL][RHEL-7.4.z qemu-kvm-rhev PATCH v2 2/3] 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 RH-Acked-by: Wainer dos Santos Moschetta --- target/i386/cpu.c | 23 ++++++++++++++++++++--- target/i386/cpu.h | 1 + 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index dec6c78..30abc47 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -460,8 +460,8 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, + NULL, NULL, "spec-ctrl", "stibp", + NULL, "arch-facilities", NULL, NULL, }, .cpuid_eax = 7, .cpuid_needs_ecx = true, .cpuid_ecx = 0, @@ -484,6 +484,22 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .tcg_features = TCG_APM_FEATURES, .unmigratable_flags = CPUID_APM_INVTSC, }, + [FEAT_8000_0008_EBX] = { + .feat_names = { + 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, + }, + .cpuid_eax = 0x80000008, + .cpuid_reg = R_EBX, + .tcg_features = 0, + .unmigratable_flags = 0, + }, [FEAT_XSAVE] = { .feat_names = { "xsaveopt", "xsavec", "xgetbv1", "xsaves", @@ -2991,7 +3007,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, } else { *eax = cpu->phys_bits; } - *ebx = 0; + *ebx = env->features[FEAT_8000_0008_EBX]; *ecx = 0; *edx = 0; if (cs->nr_cores * cs->nr_threads > 1) { @@ -3447,6 +3463,7 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp) x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_EDX); x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_ECX); x86_cpu_adjust_feat_level(cpu, FEAT_8000_0007_EDX); + x86_cpu_adjust_feat_level(cpu, FEAT_8000_0008_EBX); x86_cpu_adjust_feat_level(cpu, FEAT_C000_0001_EDX); x86_cpu_adjust_feat_level(cpu, FEAT_SVM); x86_cpu_adjust_feat_level(cpu, FEAT_XSAVE); diff --git a/target/i386/cpu.h b/target/i386/cpu.h index cc322d6..5f69ad4 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -452,6 +452,7 @@ typedef enum FeatureWord { FEAT_8000_0001_EDX, /* CPUID[8000_0001].EDX */ FEAT_8000_0001_ECX, /* CPUID[8000_0001].ECX */ FEAT_8000_0007_EDX, /* CPUID[8000_0007].EDX */ + 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_HYPERV_EAX, /* CPUID[4000_0003].EAX */ -- 1.8.3.1