diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-07 16:35:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-07 16:35:44 -0700 |
| commit | 138bcddb86d8a4f842e4ed6f0585abc9b1a764ff (patch) | |
| tree | ca19614fcb87e39ad2214c95e331d17b2c23d26b /arch/x86/kvm/svm | |
| parent | 14f9643dc90adea074a0ffb7a17d337eafc6a5cc (diff) | |
| parent | 5a15d8348881e9371afdf9f5357a135489496955 (diff) | |
Merge tag 'x86_bugs_srso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/srso fixes from Borislav Petkov:
"Add a mitigation for the speculative RAS (Return Address Stack)
overflow vulnerability on AMD processors.
In short, this is yet another issue where userspace poisons a
microarchitectural structure which can then be used to leak privileged
information through a side channel"
* tag 'x86_bugs_srso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/srso: Tie SBPB bit setting to microcode patch detection
x86/srso: Add a forgotten NOENDBR annotation
x86/srso: Fix return thunks in generated code
x86/srso: Add IBPB on VMEXIT
x86/srso: Add IBPB
x86/srso: Add SRSO_NO support
x86/srso: Add IBPB_BRTYPE support
x86/srso: Add a Speculative RAS Overflow mitigation
x86/bugs: Increase the x86 bugs vector size to two u32s
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/vmenter.S | 3 |
2 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 956726d867aa..03e852dedcc1 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1498,7 +1498,9 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (sd->current_vmcb != svm->vmcb) { sd->current_vmcb = svm->vmcb; - indirect_branch_prediction_barrier(); + + if (!cpu_feature_enabled(X86_FEATURE_IBPB_ON_VMEXIT)) + indirect_branch_prediction_barrier(); } if (kvm_vcpu_apicv_active(vcpu)) avic_vcpu_load(vcpu, cpu); diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 8e8295e774f0..265452fc9ebe 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -224,6 +224,9 @@ SYM_FUNC_START(__svm_vcpu_run) */ UNTRAIN_RET + /* SRSO */ + ALTERNATIVE "", "call entry_ibpb", X86_FEATURE_IBPB_ON_VMEXIT + /* * Clear all general purpose registers except RSP and RAX to prevent * speculative use of the guest's values, even those that are reloaded |