On 10/27/21 01:37, Christian Borntraeger wrote:
> Am 27.10.21 um 04:54 schrieb Collin Walling:
>> The diag 318 data contains values that denote information regarding the
>> guest's environment. Currently, it is unecessarily difficult to observe
>> this value (either manually-inserted debug statements, gdb stepping, mem
>> dumping etc). It's useful to observe this information to obtain an
>> at-a-glance view of the guest's environment, so lets add a simple VCPU
>> event that prints the CPNC to the s390dbf logs.
>>
>> Signed-off-by: Collin Walling <walling@xxxxxxxxxxxxx>
>
> Acked-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>
> And it even finds a bug in QEMU. We clear the CPNC on local CPU resets.
> Can you have a look? I think we just have to move the cpnc in the env
> field from the normal/initial reset range to the full reset range.
I'll take a look at this right away.
>> ---
>> arch/s390/kvm/kvm-s390.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 6a6dd5e1daf6..da3ff24eabd0 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -4254,6 +4254,7 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu)
>> if (kvm_run->kvm_dirty_regs & KVM_SYNC_DIAG318) {
>> vcpu->arch.diag318_info.val = kvm_run->s.regs.diag318;
>> vcpu->arch.sie_block->cpnc = vcpu->arch.diag318_info.cpnc;
>> + VCPU_EVENT(vcpu, 2, "setting cpnc to %d",
>> vcpu->arch.diag318_info.cpnc);
>> }
>> /*
>> * If userspace sets the riccb (e.g. after migration) to a valid
>> state,
>>
--
Regards,
Collin
Stay safe and stay healthy
