Re: [PATCH v10 03/26] KVM: s390: refactor crypto initialization

David Hildenbrand
2018-09-24T08:35:41Z

On 22/09/2018 01:18, Tony Krowiak wrote:
> On 09/12/2018 03:42 PM, Tony Krowiak wrote:
>> From: Tony Krowiak <akrowiak@linux.ibm.com>
>>
>> This patch refactors the code that initializes and sets up the
>> crypto configuration for a guest. The following changes are
>> implemented via this patch:
>>
>> 1. Prior to the introduction of AP device virtualization, it
>> was not necessary to provide guest access to the CRYCB
>> unless the MSA extension 3 (MSAX3) facility was installed
>> on the host system. With the introduction of AP device
>> virtualization, the CRYCB must be made accessible to the
>> guest if the AP instructions are installed on the host
>> and are to be provided to the guest.
>>
>> 2. Introduces a flag indicating AP instructions executed on
>> the guest shall be interpreted by the firmware. It is
>> initialized to indicate AP instructions are to be
>> to be interpreted and is used to set the SIE bit for
>> each vcpu during vcpu setup.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> Acked-by: Janosch Frank <frankja@linux.ibm.com>
>> Tested-by: Michael Mueller <mimu@linux.ibm.com>
>> Tested-by: Farhan Ali <alifm@linux.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>> arch/s390/include/asm/kvm_host.h | 2 +
>> arch/s390/include/uapi/asm/kvm.h | 1 +
>> arch/s390/kvm/kvm-s390.c | 71 ++++++++++++++++++--------------------
>> 3 files changed, 37 insertions(+), 37 deletions(-)
>>
>
> (...)
>
>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
>> index 9a50f02..8c23afc 100644
>> --- a/arch/s390/include/uapi/asm/kvm.h
>> +++ b/arch/s390/include/uapi/asm/kvm.h
>> @@ -130,6 +130,7 @@ struct kvm_s390_vm_cpu_machine {
>> #define KVM_S390_VM_CPU_FEAT_PFMFI 11
>> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12
>> #define KVM_S390_VM_CPU_FEAT_KSS 13
>> +#define KVM_S390_VM_CPU_FEAT_AP 14
>> struct kvm_s390_vm_cpu_feat {
>> __u64 feat[16];
>> };
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 876fbb2..d717041 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -40,6 +40,7 @@
>> #include <asm/sclp.h>
>> #include <asm/cpacf.h>
>> #include <asm/timex.h>
>> +#include <asm/ap.h>
>> #include "kvm-s390.h"
>> #include "gaccess.h"
>>
>
> (...)
>
>> @@ -2586,17 +2575,25 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
>>
>> static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
>> {
>> - if (!test_kvm_facility(vcpu->kvm, 76))
>> + /*
>> + * If neither the AP instructions nor the MSAX3 facility are configured
>> + * for the guest, there is nothing to set up.
>> + */
>> + if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP) &&
>> + !test_kvm_facility(vcpu->kvm, 76))
>> return;
>>
>> + vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
>> vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA);
>>
>> + if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP))
>> + vcpu->arch.sie_block->eca |= ECA_APIE;
>> +
>> + /* Set up protected key support */
>> if (vcpu->kvm->arch.crypto.aes_kw)
>> vcpu->arch.sie_block->ecb3 |= ECB3_AES;
>> if (vcpu->kvm->arch.crypto.dea_kw)
>> vcpu->arch.sie_block->ecb3 |= ECB3_DEA;
>> -
>> - vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
>> }
>>
>> void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu)
>>
>
> The fixup! patch below modifies this patch (03/26) to illustrate how
>
> David's recommendation will be implemented for v11 of the series. It
>
> is one of three fixup! patches (the other two are in responses to
> 11/26
> and 25/26) included to generate discussion in v10 rather than
>
> waiting until v11 for comments.
>
> -----------------------------------8<-----------------------------------
>
> From: Tony Krowiak <akrowiak@linux.ibm.com>
> Date: Thu, 20 Sep 2018 12:26:08 -0400
> Subject: [FIXUP v10] fixup!: KVM: s390: refactor crypto initialization
>
> ---
> arch/s390/include/asm/kvm_host.h | 1 +
> arch/s390/include/uapi/asm/kvm.h | 1 -
> arch/s390/kvm/kvm-s390.c | 9 ++++-----
> 3 files changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h
> b/arch/s390/include/asm/kvm_host.h
> index 423cce7..79fa0a3 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -718,6 +718,7 @@ struct kvm_s390_crypto {
> __u32 crycbd;
> __u8 aes_kw;
> __u8 dea_kw;
> + __u8 apie;
> };
>
> #define APCB0_MASK_SIZE 1
> diff --git a/arch/s390/include/uapi/asm/kvm.h
> b/arch/s390/include/uapi/asm/kvm.h
> index 8c23afc..9a50f02 100644
> --- a/arch/s390/include/uapi/asm/kvm.h
> +++ b/arch/s390/include/uapi/asm/kvm.h
> @@ -130,7 +130,6 @@ struct kvm_s390_vm_cpu_machine {
> #define KVM_S390_VM_CPU_FEAT_PFMFI 11
> #define KVM_S390_VM_CPU_FEAT_SIGPIF 12
> #define KVM_S390_VM_CPU_FEAT_KSS 13
> -#define KVM_S390_VM_CPU_FEAT_AP 14
> struct kvm_s390_vm_cpu_feat {
> __u64 feat[16];
> };
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index d717041..ae4769b 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -2576,17 +2576,16 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
> static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
> {
> /*
> - * If neither the AP instructions nor the MSAX3 facility are configured
> - * for the guest, there is nothing to set up.
> + * If the AP instructions are not available and the MSAX3 facility
> + * is not configured for the guest, there is nothing to set up.
> */
> - if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP) &&
> - !test_kvm_facility(vcpu->kvm, 76))
> + if (!ap_instructions_available() && !test_kvm_facility(vcpu->kvm, 76))
> return;
>
> vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd;
> vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA);
>
> - if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_AP))
> + if (vcpu->kvm->arch.crypto.apie)
> vcpu->arch.sie_block->eca |= ECA_APIE;
>
> /* Set up protected key support */
>

Looks sane, too.

--

Thanks,

David / dhildenb