Re: [PATCH 02/22] kvm: mmu: Introduce tdp_iter

[Paolo Bonzini]

On 25/09/20 23:22, Ben Gardon wrote:
> +	bool done;
> +
> +	done = try_step_down(iter);
> +	if (done)
> +		return;
> +
> +	done = try_step_side(iter);
> +	while (!done) {
> +		if (!try_step_up(iter)) {
> +			iter->valid = false;
> +			break;
> +		}
> +		done = try_step_side(iter);

Seems easier to read without the "done" boolean:

	if (try_step_down(iter))
		return;

	do {
		/* Maybe try_step_right? :) */
		if (try_step_side(iter))
			return;
	} while (try_step_up(iter));
	iter->valid = false;

Also it may be worth adding an "end_level" argument to the constructor,
and checking against it in try_step_down instead of using PG_LEVEL_4K.
By passing in PG_LEVEL_2M, you can avoid adding
tdp_iter_next_no_step_down in patch 17 and generally simplify the logic
there.

Paolo