On 2/6/20 10:20 AM, Christian Borntraeger wrote:
> 
> 
> On 06.02.20 10:07, Christian Borntraeger wrote:
>> On 05.02.20 18:00, Thomas Huth wrote:
>>
>>>>>
>>>>> Uh, why the mix of a new ioctl with the existing mem_op stuff? Could you
>>>>> please either properly integrate this into the MEM_OP ioctl (and e.g.
>>>>> use gaddr as offset for the new SIDA_READ and SIDA_WRITE subcodes), or
>>>>> completely separate it for a new ioctl, i.e. introduce a new struct for
>>>>> the new ioctl instead of recycling the struct kvm_s390_mem_op here?
>>>>> (and in case you ask me, I'd slightly prefer to integrate everything
>>>>> into MEM_OP instead of introducing a new ioctl here).
>>>>
>>>> *cough* David and Christian didn't like the memop solution and it took
>>>> me a long time to get this to work properly in QEMU...
>>>
>>> I also don't like to re-use MEMOP_LOGICAL_READ and MEMOP_LOGICAL_WRITE
>>> for the SIDA like you've had it in RFC v1 ... but what's wrong with
>>> using KVM_S390_MEMOP_SIDA_READ and KVM_S390_MEMOP_SIDA_WRITE with the
>>> MEM_OP ioctl directly?
>>>
>>>  Thomas
>>>
>>
>> In essence something like the following?
>>
>> @@ -4583,6 +4618,9 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu *vcpu,
>>                 }
>>                 r = write_guest(vcpu, mop->gaddr, mop->ar, tmpbuf, mop->size);
>>                 break;
>> +       case KVM_S390_MEMOP_SIDA_READ:
>> +       case KVM_S390_MEMOP_SIDA_WRITE:
>> +               kvm_s390_guest_sida_op(vcpu, mop);
> 
> a break; here
> 
>>         default:
>>                 r = -EINVAL;
>>         }
>>
>>
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index ea2b4d66e0c3..6e029753c955 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -1519,7 +1519,6 @@ struct kvm_pv_cmd {
>>  /* Available with KVM_CAP_S390_PROTECTED */
>>  #define KVM_S390_PV_COMMAND            _IOW(KVMIO, 0xc5, struct kvm_pv_cmd)
>>  #define KVM_S390_PV_COMMAND_VCPU       _IOW(KVMIO, 0xc6, struct kvm_pv_cmd)
>> -#define KVM_S390_SIDA_OP               _IOW(KVMIO, 0xc7, struct kvm_s390_mem_op)
>>  
>>  /* Secure Encrypted Virtualization command */
>>  enum sev_cmd_id {
>>
> 
> 
> Janosch, I just checked your qemu tree
> the change would be just the following when we go down that path. (and it makes perfect sense)

Well, it's one less new ioctl and I was worried about the amount of new
ioctls anyway...

> 
> 
> 
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 42d6ef5fad..29bcdf839f 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -862,7 +862,7 @@ int kvm_s390_mem_op_pv(S390CPU *cpu, uint64_t offset, void *hostbuf,
>          return -ENOSYS;
>      }
>  
> -    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_S390_SIDA_OP, &mem_op);
> +    ret = kvm_vcpu_ioctl(CPU(cpu), KVM_S390_MEM_OP, &mem_op);
>      if (ret < 0) {
>          warn_report("KVM_S390_MEM_OP failed: %s", strerror(-ret));
>      }
>