diff options
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index e9af87b12814..c4ae73541fc5 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2058,6 +2058,10 @@ static int sev_check_source_vcpus(struct kvm *dst, struct kvm *src) struct kvm_vcpu *src_vcpu; unsigned long i; + if (src->created_vcpus != atomic_read(&src->online_vcpus) || + dst->created_vcpus != atomic_read(&dst->online_vcpus)) + return -EBUSY; + if (!sev_es_guest(src)) return 0; @@ -3957,16 +3961,12 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm) /* * The target vCPU is valid, so the vCPU will be kicked unless the - * request is for CREATE_ON_INIT. For any errors at this stage, the - * kick will place the vCPU in an non-runnable state. + * request is for CREATE_ON_INIT. */ kick = true; mutex_lock(&target_svm->sev_es.snp_vmsa_mutex); - target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; - target_svm->sev_es.snp_ap_waiting_for_reset = true; - /* Interrupt injection mode shouldn't change for AP creation */ if (request < SVM_VMGEXIT_AP_DESTROY) { u64 sev_features; @@ -4012,20 +4012,23 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm) target_svm->sev_es.snp_vmsa_gpa = svm->vmcb->control.exit_info_2; break; case SVM_VMGEXIT_AP_DESTROY: + target_svm->sev_es.snp_vmsa_gpa = INVALID_PAGE; break; default: vcpu_unimpl(vcpu, "vmgexit: invalid AP creation request [%#x] from guest\n", request); ret = -EINVAL; - break; + goto out; } -out: + target_svm->sev_es.snp_ap_waiting_for_reset = true; + if (kick) { kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu); kvm_vcpu_kick(target_vcpu); } +out: mutex_unlock(&target_svm->sev_es.snp_vmsa_mutex); return ret; @@ -4579,6 +4582,8 @@ void sev_es_vcpu_reset(struct vcpu_svm *svm) void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_area *hostsa) { + struct kvm *kvm = svm->vcpu.kvm; + /* * All host state for SEV-ES guests is categorized into three swap types * based on how it is handled by hardware during a world switch: @@ -4602,10 +4607,15 @@ void sev_es_prepare_switch_to_guest(struct vcpu_svm *svm, struct sev_es_save_are /* * If DebugSwap is enabled, debug registers are loaded but NOT saved by - * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU both - * saves and loads debug registers (Type-A). + * the CPU (Type-B). If DebugSwap is disabled/unsupported, the CPU does + * not save or load debug registers. Sadly, on CPUs without + * ALLOWED_SEV_FEATURES, KVM can't prevent SNP guests from enabling + * DebugSwap on secondary vCPUs without KVM's knowledge via "AP Create". + * Save all registers if DebugSwap is supported to prevent host state + * from being clobbered by a misbehaving guest. */ - if (sev_vcpu_has_debug_swap(svm)) { + if (sev_vcpu_has_debug_swap(svm) || + (sev_snp_guest(kvm) && cpu_feature_enabled(X86_FEATURE_DEBUG_SWAP))) { hostsa->dr0 = native_get_debugreg(0); hostsa->dr1 = native_get_debugreg(1); hostsa->dr2 = native_get_debugreg(2); |