Messages in this thread | | | Subject | Re: [RFC 02/19] KVM: s390: refactor crypto initialization | From | Tony Krowiak <> | Date | Tue, 14 Nov 2017 10:53:12 -0500 |
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On 11/14/2017 06:50 AM, Cornelia Huck wrote: > On Thu, 2 Nov 2017 13:41:18 +0100 > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >> On 10/13/2017 07:38 PM, Tony Krowiak wrote: >>> This patch introduces the following changes to crypto initialization. >>> >>> * For key management operations support, the crypto control block >>> (CRYCB) referenced by the KVM guest's SIE state description is >>> formatted only if the Message-Security-Assist (MSA) extension 3 >>> facility is installed (STFLE.76 is set). Virtualization of AP >>> facilities, however; requires that a CRYCB of the appropriate >>> format be made available to SIE regardless of the value of STFLE.76. >>> >>> * The Execution Controls A (ECA) field bit 28 in the SIE block needs >>> to be set to enable interpretive execution mode of adjunct processor (AP) >>> instructions. >> We should fence setting ECA to cases where we have virtualization capability >> for crypto. In addition we need to bind this somehow to the CPU model, so >> I guess we need to add some CRYPTO feature e.g. add KVM_S390_VM_CPU_FEAT_AP to the >> list of know features >> (see arch/s390/include/uapi/asm/kvm.h) >> ---snip--- >> #define KVM_S390_VM_CPU_FEAT_ESOP 0 >> #define KVM_S390_VM_CPU_FEAT_SIEF2 1 >> #define KVM_S390_VM_CPU_FEAT_64BSCAO 2 >> #define KVM_S390_VM_CPU_FEAT_SIIF 3 >> #define KVM_S390_VM_CPU_FEAT_GPERE 4 >> #define KVM_S390_VM_CPU_FEAT_GSLS 5 >> #define KVM_S390_VM_CPU_FEAT_IB 6 >> #define KVM_S390_VM_CPU_FEAT_CEI 7 >> #define KVM_S390_VM_CPU_FEAT_IBS 8 >> #define KVM_S390_VM_CPU_FEAT_SKEY 9 >> #define KVM_S390_VM_CPU_FEAT_CMMA 10 >> #define KVM_S390_VM_CPU_FEAT_PFMFI 11 >> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12 >> #define KVM_S390_VM_CPU_FEAT_KSS 13 >> ---snip--- > So, we need this so userspace can add the appropriate flags, right? > >> >> I will try to find out a way to properly detect that. > Did you manage to find out The AP bus (drivers/s390/crypto/ap_bus.c) calls ap_instructions_available() function in drivers/s390/crypto/ap_asm.c to determine whether AP instructions are installed. This function executes the PQAP(TAPQ) function and incorporates exception table to catch the operation exception if the AP instructions are not installed. I propose externalizing that function so it can be called from KVM. > >> >> >>> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com> >>> --- >>> arch/s390/include/asm/kvm_host.h | 1 + >>> arch/s390/kvm/kvm-s390.c | 17 +++++++++++++---- >>> 2 files changed, 14 insertions(+), 4 deletions(-) >>> >>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>> index 50a6b25..5683f18 100644 >>> --- a/arch/s390/include/asm/kvm_host.h >>> +++ b/arch/s390/include/asm/kvm_host.h >>> @@ -188,6 +188,7 @@ struct kvm_s390_sie_block { >>> #define ECA_MVPGI 0x01000000 >>> #define ECA_VX 0x00020000 >>> #define ECA_PROTEXCI 0x00002000 >>> +#define ECA_AP 0x00000008 >>> #define ECA_SII 0x00000001 >>> __u32 eca; /* 0x004c */ >>> #define ICPT_INST 0x04 >>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >>> index 40d0a1a..e57fc9b 100644 >>> --- a/arch/s390/kvm/kvm-s390.c >>> +++ b/arch/s390/kvm/kvm-s390.c >>> @@ -1819,7 +1819,9 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm) >>> { >>> kvm->arch.crypto.crycbd = (__u32)(unsigned long) kvm->arch.crypto.crycb; >>> >>> - if (kvm_s390_apxa_installed()) >>> + if (!test_kvm_facility(kvm, 76)) >>> + kvm->arch.crypto.crycbd &= ~(CRYCB_FORMAT2); /* format 0 */ >>> + else if (kvm_s390_apxa_installed()) >>> kvm->arch.crypto.crycbd |= CRYCB_FORMAT2; >>> else >>> kvm->arch.crypto.crycbd |= CRYCB_FORMAT1; >>> @@ -1836,12 +1838,12 @@ static u64 kvm_s390_get_initial_cpuid(void) >>> >>> static void kvm_s390_crypto_init(struct kvm *kvm) >>> { >>> - if (!test_kvm_facility(kvm, 76)) >>> - return; >>> - >>> kvm->arch.crypto.crycb = &kvm->arch.sie_page2->crycb; >>> kvm_s390_set_crycb_format(kvm); >>> >>> + if (!test_kvm_facility(kvm, 76)) >>> + return; >>> + >>> /* Enable AES/DEA protected key functions by default */ >>> kvm->arch.crypto.aes_kw = 1; >>> kvm->arch.crypto.dea_kw = 1; >>> @@ -2366,8 +2368,15 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) >>> vcpu->arch.enabled_gmap = vcpu->arch.gmap; >>> } >>> >>> +static void kvm_s390_vcpu_set_crypto_exec_mode(struct kvm_vcpu *vcpu) >>> +{ >>> + vcpu->arch.sie_block->eca |= ECA_AP; >>> +} >>> + >>> static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu) >>> { >>> + kvm_s390_vcpu_set_crypto_exec_mode(vcpu); >>> + >>> if (!test_kvm_facility(vcpu->kvm, 76)) >>> return; >>>
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