Re: [PATCH v1 10/17] xen/riscv: introduce vintc_state_{save,restore}()

On 8/13/26 11:42 AM, Baptiste Le Duc wrote:
>>   #endif /* ASM__RISCV__INTERRUPT_CONTOLLER_H */
>> diff --git a/xen/arch/riscv/intc.c b/xen/arch/riscv/intc.c
>> index 372c8d3a20..879d513374 100644
>> --- a/xen/arch/riscv/intc.c
>> +++ b/xen/arch/riscv/intc.c
>> @@ -163,3 +163,17 @@ bool vintc_reserve_virq(const struct domain *d, unsigned int virq)
>>   
>>       return !test_and_set_bit(virq, d->arch.vintc->used_irqs);
>>   }
>> +
>> +void vintc_state_save(struct vcpu *vcpu)
>> +{
>> +    const struct vintc_ops *ops = vcpu->domain->arch.vintc->ops;
> Is there a situation where ops could be NULL? If yes, add a check.

It is unlikely that there is nothing to do during a context switch for 
vINTC, so vINTC should provide an implementation for saving and 
restoring its context. This also ensures that a NULL pointer dereference 
will lead to a trap, allowing us to catch cases where a 
context-switch/restore handler is missing.

Even if it turns out that vINTC does not need to perform any actions 
during a context switch, it is perfectly fine to provide an empty 
implementation. However, as mentioned above, this is unlikely. 
Therefore, having a NULL pointer dereference here is intentional: it 
helps catch cases where someone adds a new interrupt controller driver 
but forgets to implement the corresponding context switch functionality.

~ Oleksii