Re: [Qemu-devel] [PATCH 1/2] s390x/migration: use zero flag parameter

[Christian Borntraeger]

On 11/20/2017 01:57 PM, Cornelia Huck wrote:
> On Mon, 20 Nov 2017 13:35:24 +0100
> Christian Borntraeger <address@hidden> wrote:
> 
>> valgrind pointed out that we call KVM_S390_GET_IRQ_STATE with an
>> undefined value for flags. Right now this is unused, but we
>> better play safe.
>>
>> Signed-off-by: Christian Borntraeger <address@hidden>
>> ---
>>  target/s390x/kvm.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index 343fcec..b0439a1 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -2069,7 +2069,10 @@ int kvm_s390_set_cpu_state(S390CPU *cpu, uint8_t 
>> cpu_state)
>>  
>>  void kvm_s390_vcpu_interrupt_pre_save(S390CPU *cpu)
>>  {
>> -    struct kvm_s390_irq_state irq_state;
>> +    struct kvm_s390_irq_state irq_state = {
>> +        .buf = (uint64_t) cpu->irqstate,
>> +        .len = VCPU_IRQ_BUF_SIZE,
>> +    };
>>      CPUState *cs = CPU(cpu);
>>      int32_t bytes;
>>  
>> @@ -2077,9 +2080,6 @@ void kvm_s390_vcpu_interrupt_pre_save(S390CPU *cpu)
>>          return;
>>      }
>>  
>> -    irq_state.buf = (uint64_t) cpu->irqstate;
>> -    irq_state.len = VCPU_IRQ_BUF_SIZE;
>> -
>>      bytes = kvm_vcpu_ioctl(cs, KVM_S390_GET_IRQ_STATE, &irq_state);
>>      if (bytes < 0) {
>>          cpu->irqstate_saved_size = 0;
> 
> I'm wondering why it does not also complain for KVM_S390_SET_IRQ_STATE?

I guess that my tests do not having peding interrupts during migration and we 
exit early in

int kvm_s390_vcpu_interrupt_post_load(S390CPU *cpu)
{
    CPUState *cs = CPU(cpu);
    struct kvm_s390_irq_state irq_state;
    int r;

-->    if (cpu->irqstate_saved_size == 0) {
-->        return 0;
    }




> It would make sense to use a struct initializer there as well.

Yes, I think you are right.
>