On 06.02.20 10:18, Thomas Huth wrote:
> On 06/02/2020 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);
>> 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 {
>
> Right!
>
> But maybe you should also fence the other subcodes in case of PV:
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index d9e6bf3d54f0..f99e7d7af6ea 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -4274,6 +4274,10 @@ static long kvm_s390_guest_mem_op(struct kvm_vcpu
> *vcpu,
>
> switch (mop->op) {
> case KVM_S390_MEMOP_LOGICAL_READ:
> + if (kvm_s390_pv_is_protected(vcpu->kvm))
> + r = -EINVAL;
> + break;
> + }
Yes, I will add those.
