Re: [PATCH v8 19/22] KVM: s390: Clear Crypto Control Block when using vSIE

Pierre Morel
2018-08-09T08:50:35Z

On 09/08/2018 10:10, David Hildenbrand wrote:
> On 08.08.2018 16:44, Tony Krowiak wrote:
>> From: Pierre Morel <pmorel@linux.ibm.com>
>>
>> When we clear the Crypto Control Block (CRYCB) used by a guest
>> level 2, the vSIE shadow CRYCB for guest level 3 must be updated
>> before the guest uses it.
>>
>> We achieve this by using the KVM_REQ_VSIE_RESTART synchronous
>> request for each vCPU belonging to the guest to force the reload
>> of the shadow CRYCB before rerunning the guest level 3.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>> arch/s390/kvm/kvm-s390.c | 7 +++++++
>> 1 files changed, 7 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 0d03249..9203f0b 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -1921,6 +1921,9 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm)
>>
>> void kvm_arch_crypto_clear_masks(struct kvm *kvm)
>> {
>> + int i;
>> + struct kvm_vcpu *vcpu;
>> +
>> mutex_lock(&kvm->lock);
>> kvm_s390_vcpu_block_all(kvm);
>>
>> @@ -1929,6 +1932,10 @@ void kvm_arch_crypto_clear_masks(struct kvm *kvm)
>> memset(&kvm->arch.crypto.crycb->apcb1, 0,
>> sizeof(kvm->arch.crypto.crycb->apcb1));
>>
>> + /* recreate the shadow crycb for each vcpu */
>> + kvm_for_each_vcpu(i, vcpu, kvm)
>> + kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
> We have kvm_s390_sync_request_broadcast(), which should boil down to a
> one-liner
right, thanks

>> +
>> kvm_s390_vcpu_unblock_all(kvm);
>> mutex_unlock(&kvm->lock);
>> }
>>
>

--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany