From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754794AbeDTM07 (ORCPT ); Fri, 20 Apr 2018 08:26:59 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42886 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754591AbeDTM05 (ORCPT ); Fri, 20 Apr 2018 08:26:57 -0400 Subject: Re: [PATCH] KVM: s390: reset crypto attributes for all vcpus To: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: borntraeger@de.ibm.com, cohuck@redhat.com, pmorel@linux.vnet.ibm.com, pasic@linux.vnet.ibm.com, pbonzini@redhat.com, rkrcmar@redhat.com References: <1524172432-26211-1-git-send-email-akrowiak@linux.vnet.ibm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Fri, 20 Apr 2018 14:26:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <1524172432-26211-1-git-send-email-akrowiak@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19.04.2018 23:13, Tony Krowiak wrote: > Introduces a new function to reset the crypto attributes for all > vcpus whether they are running or not. Each vcpu in KVM will > be removed from SIE prior to resetting the crypto attributes in its > SIE state description. After all vcpus have had their crypto attributes > reset the vcpus will be restored to SIE. > > This function is incorporated into the kvm_s390_vm_set_crypto(kvm) > function to fix a reported issue whereby the crypto key wrapping > attributes could potentially get out of synch for running vcpus. > > Reported-by: Halil Pasic A reported-by for a code refactoring is strange. > Signed-off-by: Tony Krowiak > --- > arch/s390/kvm/kvm-s390.c | 18 ++++++++++++++---- > arch/s390/kvm/kvm-s390.h | 13 +++++++++++++ > 2 files changed, 27 insertions(+), 4 deletions(-) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index fa355a6..4fa3037 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -789,6 +789,19 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att > return ret; > } > > +void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm) > + { > + int i; > + struct kvm_vcpu *vcpu; > + > + kvm_s390_vcpu_block_all(kvm); > + > + kvm_for_each_vcpu(i, vcpu, kvm) > + kvm_s390_vcpu_crypto_setup(vcpu); > + > + kvm_s390_vcpu_unblock_all(kvm); This code has to be protected by kvm->lock. Can that be guaranteed by the caller? > +} > + > static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu); > > static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) > @@ -832,10 +845,7 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) > return -ENXIO; > } > > - kvm_for_each_vcpu(i, vcpu, kvm) { > - kvm_s390_vcpu_crypto_setup(vcpu); > - exit_sie(vcpu); > - } > + kvm_s390_vcpu_crypto_reset_all(kvm); > mutex_unlock(&kvm->lock); > return 0; > } > diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h > index 1b5621f..981e3ba 100644 > --- a/arch/s390/kvm/kvm-s390.h > +++ b/arch/s390/kvm/kvm-s390.h > @@ -410,4 +410,17 @@ static inline int kvm_s390_use_sca_entries(void) > } > void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu, > struct mcck_volatile_info *mcck_info); > + > +/** > + * kvm_s390_vcpu_crypto_reset_all > + * > + * Reset the crypto attributes for each vcpu. This can be done while the vcpus > + * are running as each vcpu will be removed from SIE before resetting the crypt > + * attributes and restored to SIE afterward. > + * > + * Note: The kvm->lock must be held while calling this function > + * > + * @kvm: the KVM guest > + */ > +void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm); > #endif > -- Thanks, David / dhildenb