Re: [PATCH v2 2/3] KVM: x86: introduce definitions to support static calls for kvm_x86_ops

Paolo Bonzini
2021-01-15T13:52:04Z

On 15/01/21 10:26, Peter Zijlstra wrote:
>> +#define KVM_X86_OP(func) \
>> + DEFINE_STATIC_CALL_NULL(kvm_x86_##func, \
>> + *(((struct kvm_x86_ops *)0)->func));
>> +#define KVM_X86_OP_NULL KVM_X86_OP
>> +#include <asm/kvm-x86-ops.h>
>> +EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits);
>> +EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg);
>> +EXPORT_STATIC_CALL_GPL(kvm_x86_tlb_flush_current);
> Would something like:
>
> https://lkml.kernel.org/r/20201110103909.GD2594@hirez.programming.kicks-ass.net
>
> Be useful? That way modules can call the static_call() but not change
> it.
>

Maybe not in these cases, but in general there may be cases where we
later want to change the static_call (for example replacing jump labels
with static_calls).

Paolo