Re: [RFC 2/3] io_uring/bpf: allow to register and run BPF programs

[Pavel Begunkov <asml.silence@gmail.com>]

On 11/13/24 08:21, Ming Lei wrote:
> On Mon, Nov 11, 2024 at 01:50:45AM +0000, Pavel Begunkov wrote:
>> Let the user to register a BPF_PROG_TYPE_IOURING BPF program to a ring.
>> The progrma will be run in the waiting loop every time something
>> happens, i.e. the task was woken up by a task_work / signal / etc.
>>
>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>> ---
...
>>   	do {
>>   		unsigned long check_cq;
>> @@ -2879,6 +2886,13 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
>>   		if (ret < 0)
>>   			break;
>>   
>> +		if (io_bpf_enabled(ctx)) {
>> +			ret = io_run_bpf(ctx);
>> +			if (ret == IOU_BPF_RET_STOP)
>> +				break;
>> +			continue;
>> +		}
> 
> I believe 'struct_ops' is much simpler to run the prog and return the result.
> Then you needn't any bpf core change and the bpf register code.

Right, that's one of the things I need to look into, I have it in my
todo list, but I'm not sure at all I'd want to get rid of the register
opcode. It's a good idea to have stronger registration locking, i.e.
under ->ring_lock, but again I need to check it out.

-- 
Pavel Begunkov