From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v4 05/15] KVM: s390: enable/disable AP interpretive execution Date: Tue, 17 Apr 2018 11:09:54 -0400 Message-ID: References: <1523827345-11600-1-git-send-email-akrowiak@linux.vnet.ibm.com> <1523827345-11600-6-git-send-email-akrowiak@linux.vnet.ibm.com> <15b60572-40d6-0f03-11f9-c50cb7eb00e8@linux.vnet.ibm.com> <15bb0c9b-e605-232b-4dd2-826b6ee0d045@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <15bb0c9b-e605-232b-4dd2-826b6ee0d045@linux.vnet.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Pierre Morel , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, cohuck@redhat.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com List-ID: On 04/16/2018 07:13 AM, Pierre Morel wrote: > On 16/04/2018 12:51, Pierre Morel wrote: >> On 15/04/2018 23:22, Tony Krowiak wrote: >>> The VFIO AP device model exploits interpretive execution of AP >>> instructions (APIE) to provide guests passthrough access to AP >>> devices. This patch introduces a new interface to enable and >>> disable APIE. >>> >>> Signed-off-by: Tony Krowiak >>> --- >>> arch/s390/include/asm/kvm-ap.h | 16 ++++++++++++++++ >>> arch/s390/include/asm/kvm_host.h | 1 + >>> arch/s390/kvm/kvm-ap.c | 20 ++++++++++++++++++++ >>> arch/s390/kvm/kvm-s390.c | 9 +++++++++ >>> 4 files changed, 46 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/s390/include/asm/kvm-ap.h >>> b/arch/s390/include/asm/kvm-ap.h >>> index 736e93e..a6c092e 100644 >>> --- a/arch/s390/include/asm/kvm-ap.h >>> +++ b/arch/s390/include/asm/kvm-ap.h >>> @@ -35,4 +35,20 @@ >>> */ >>> void kvm_ap_build_crycbd(struct kvm *kvm); >>> >>> +/** >>> + * kvm_ap_interpret_instructions >>> + * >>> + * Indicate whether AP instructions shall be interpreted. If they >>> are not >>> + * interpreted, all AP instructions will be intercepted and routed >>> back to >>> + * userspace. >>> + * >>> + * @kvm: the virtual machine attributes >>> + * @enable: indicates whether AP instructions are to be interpreted >>> (true) or >>> + * or not (false). >>> + * >>> + * Returns 0 if completed successfully; otherwise, returns -EOPNOTSUPP >>> + * indicating that AP instructions are not installed on the guest. >>> + */ >>> +int kvm_ap_interpret_instructions(struct kvm *kvm, bool enable); >>> + >>> #endif /* _ASM_KVM_AP */ >>> diff --git a/arch/s390/include/asm/kvm_host.h >>> b/arch/s390/include/asm/kvm_host.h >>> index 3162783..5470685 100644 >>> --- a/arch/s390/include/asm/kvm_host.h >>> +++ b/arch/s390/include/asm/kvm_host.h >>> @@ -715,6 +715,7 @@ struct kvm_s390_crypto { >>> __u32 crycbd; >>> __u8 aes_kw; >>> __u8 dea_kw; >>> + __u8 apie; >>> }; >>> >>> #define APCB0_MASK_SIZE 1 >>> diff --git a/arch/s390/kvm/kvm-ap.c b/arch/s390/kvm/kvm-ap.c >>> index 991bae4..55d11b5 100644 >>> --- a/arch/s390/kvm/kvm-ap.c >>> +++ b/arch/s390/kvm/kvm-ap.c >>> @@ -58,3 +58,23 @@ void kvm_ap_build_crycbd(struct kvm *kvm) >>> } >>> } >>> EXPORT_SYMBOL(kvm_ap_build_crycbd); >>> + >>> +int kvm_ap_interpret_instructions(struct kvm *kvm, bool enable) >>> +{ >>> + int ret = 0; >>> + >>> + mutex_lock(&kvm->lock); >>> + >>> + if (!test_kvm_cpu_feat(kvm, KVM_S390_VM_CPU_FEAT_AP)) { >> >> Do we really need to test CPU_FEAT_AP? >> >> I understand that KVM_S390_VM_CPU_FEAT_AP means AP instructions are >> interpreted. >> shouldn't we add this information in the name? >> like KVM_S390_VM_CPU_FEAT_APIE > > If I misunderstood and FEAT_AP really mean AP instructions available > in the guest, > same question: > is this function called if AP instructions are not available in the > guest? > >> >>> + ret = -EOPNOTSUPP; >>> + goto done; >>> + } >>> + >>> + kvm->arch.crypto.apie = enable; >>> + kvm_s390_vcpu_crypto_reset_all(kvm); >>> + >>> +done: >>> + mutex_unlock(&kvm->lock); >>> + return ret; >>> +} >>> +EXPORT_SYMBOL(kvm_ap_interpret_instructions); >>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>> index 55cd897..1dc8566 100644 >>> --- a/arch/s390/kvm/kvm-s390.c >>> +++ b/arch/s390/kvm/kvm-s390.c >>> @@ -1901,6 +1901,9 @@ static void kvm_s390_crypto_init(struct kvm *kvm) >>> kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb; >>> kvm_ap_build_crycbd(kvm); >>> >>> + /* Default setting indicating SIE shall interpret AP >>> instructions */ >>> + kvm->arch.crypto.apie = 1; >>> + >>> if (!test_kvm_facility(kvm, 76)) >>> return; >>> >>> @@ -2434,6 +2437,12 @@ static void kvm_s390_vcpu_crypto_setup(struct >>> kvm_vcpu *vcpu) >>> { >>> vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd; >>> >>> + vcpu->arch.sie_block->eca &= ~ECA_APIE; >>> + if (vcpu->kvm->arch.crypto.apie && >>> + test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP)) >> >> Do we call xxx_crypto_setup() if KVM does not support AP interpretation? > > sorry, I should have written AP instructions here: > is this function called if AP instructions are not available in the guest? Yes, as I stated in a previous email, this function is called by kvm_arch_vcpu_setup(vcpu) regardless of whether AP instructions are available on the guest or not. > > >> >>> + vcpu->arch.sie_block->eca |= ECA_APIE; >>> + >>> + >>> if (!test_kvm_facility(vcpu->kvm, 76)) >>> return; >>> >> >