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authorGravatar Borislav Petkov <bp@suse.de> 2018-05-02 18:15:14 +0200
committerGravatar Thomas Gleixner <tglx@linutronix.de> 2018-05-17 17:09:16 +0200
commite7c587da125291db39ddf1f49b18e5970adbac17 (patch)
tree6c8ca082d4e34cfff4b8f06a3e926be837832c12 /arch/x86/kvm
parentKVM: SVM: Move spec control call after restore of GS (diff)
downloadlinux-e7c587da1252.tar.gz
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x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
Intel and AMD have different CPUID bits hence for those use synthetic bits which get set on the respective vendor's in init_speculation_control(). So that debacles like what the commit message of c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload") talks about don't happen anymore. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-by: Jörg Otte <jrg.otte@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/cpuid.c10
-rw-r--r--arch/x86/kvm/svm.c6
-rw-r--r--arch/x86/kvm/vmx.c9
3 files changed, 10 insertions, 15 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 865c9a769864..e5ba48599428 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -379,7 +379,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
/* cpuid 0x80000008.ebx */
const u32 kvm_cpuid_8000_0008_ebx_x86_features =
- F(IBPB) | F(IBRS);
+ F(AMD_IBPB) | F(AMD_IBRS);
/* cpuid 0xC0000001.edx */
const u32 kvm_cpuid_C000_0001_edx_x86_features =
@@ -648,10 +648,10 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
entry->eax = g_phys_as | (virt_as << 8);
entry->edx = 0;
/* IBRS and IBPB aren't necessarily present in hardware cpuid */
- if (boot_cpu_has(X86_FEATURE_IBPB))
- entry->ebx |= F(IBPB);
- if (boot_cpu_has(X86_FEATURE_IBRS))
- entry->ebx |= F(IBRS);
+ if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
+ entry->ebx |= F(AMD_IBPB);
+ if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
+ entry->ebx |= F(AMD_IBRS);
entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
break;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fa891c8af842..1a7a811118a8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4108,7 +4108,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
break;
case MSR_IA32_SPEC_CTRL:
if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
return 1;
msr_info->data = svm->spec_ctrl;
@@ -4203,7 +4203,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
break;
case MSR_IA32_SPEC_CTRL:
if (!msr->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS))
return 1;
/* The STIBP bit doesn't fault even if it's not advertised */
@@ -4230,7 +4230,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
break;
case MSR_IA32_PRED_CMD:
if (!msr->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBPB))
+ !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB))
return 1;
if (data & ~PRED_CMD_IBPB)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 9b8d80bf3889..210e1b63d4b5 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3523,9 +3523,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return kvm_get_msr_common(vcpu, msr_info);
case MSR_IA32_SPEC_CTRL:
if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
- !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
- !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
+ !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
return 1;
msr_info->data = to_vmx(vcpu)->spec_ctrl;
@@ -3643,9 +3641,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
break;
case MSR_IA32_SPEC_CTRL:
if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) &&
- !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) &&
- !guest_cpuid_has(vcpu, X86_FEATURE_SSBD))
+ !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
return 1;
/* The STIBP bit doesn't fault even if it's not advertised */
@@ -3675,7 +3671,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
break;
case MSR_IA32_PRED_CMD:
if (!msr_info->host_initiated &&
- !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) &&
!guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL))
return 1;