Re: [PATCH v10 02/26] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART

Tony Krowiak
2018-09-24T16:48:35Z

On 09/24/2018 06:49 AM, Christian Borntraeger wrote:
> On 09/12/2018 09:42 PM, Tony Krowiak wrote:
>> From: David Hildenbrand <david@redhat.com>
>>
>> When we change the crycb (or execution controls), we also have to make sure
>> that the vSIE shadow datastructures properly consider the changed
>> values before rerunning the vSIE. We can achieve that by simply using a
>> VCPU request now.
>>
>> This has to be a synchronous request (== handled before entering the
>> (v)SIE again).
>>
>> The request will make sure that the vSIE handler is left, and that the
>> request will be processed (NOP), therefore forcing a reload of all
>> vSIE data (including rebuilding the crycb) when re-entering the vSIE
>> interception handler the next time.
>>
>> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>
>
> same here? First David then Tomy?

Will do.

>
> otherwise
> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
>
>
>> ---
>> arch/s390/include/asm/kvm_host.h | 1 +
>> arch/s390/kvm/kvm-s390.c | 7 ++++++-
>> 2 files changed, 7 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index 29c940b..75d3962 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -44,6 +44,7 @@
>> #define KVM_REQ_ICPT_OPEREXC KVM_ARCH_REQ(2)
>> #define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
>> #define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4)
>> +#define KVM_REQ_VSIE_RESTART KVM_ARCH_REQ(5)
>>
>> #define SIGP_CTRL_C 0x80
>> #define SIGP_CTRL_SCN_MASK 0x3f
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 0b5aff0..876fbb2 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -844,8 +844,11 @@ void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm)
>>
>> kvm_s390_vcpu_block_all(kvm);
>>
>> - kvm_for_each_vcpu(i, vcpu, kvm)
>> + kvm_for_each_vcpu(i, vcpu, kvm) {
>> kvm_s390_vcpu_crypto_setup(vcpu);
>> + /* recreate the shadow crycb by leaving the VSIE handler */
>> + kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
>> + }
>>
>> kvm_s390_vcpu_unblock_all(kvm);
>> }
>> @@ -3203,6 +3206,8 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>>
>> /* nothing to do, just clear the request */
>> kvm_clear_request(KVM_REQ_UNHALT, vcpu);
>> + /* we left the vsie handler, nothing to do, just clear the request */
>> + kvm_clear_request(KVM_REQ_VSIE_RESTART, vcpu);
>>
>> return 0;
>> }
>>