Re: [PATCH] virtio_ring: add an error code check in virtqueue_resize

From: Su Hui
Date: Mon Oct 23 2023 - 05:51:00 EST


On 2023/10/23 13:46, Xuan Zhuo wrote:
Well, what are the cases where it can happen practically?
Device error. Such as vp_active_vq()

Thanks.
Hmm interesting. OK. But do callers know to recover?
No.

So I think WARN + broken is suitable.

Thanks.
Sorry for the late, is the following code okay?

@@ -2739,7 +2739,7 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
void (*recycle)(struct virtqueue *vq, void *buf))
{
struct vring_virtqueue *vq = to_vvq(_vq);
- int err;
+ int err, err_reset;

if (num > vq->vq.num_max)
return -E2BIG;
@@ -2759,7 +2759,15 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
else
err = virtqueue_resize_split(_vq, num);

- return virtqueue_enable_after_reset(_vq);
+ err_reset = virtqueue_enable_after_reset(_vq);
+
+ if (err) {
No err.

err is not important.
You can remove that.
Emm, I'm a little confused that which code should I remove ?


like this:
if (vq->packed_ring)
virtqueue_resize_packed(_vq, num);
else
virtqueue_resize_split(_vq, num);

And we should set broken and warn inside virtqueue_enable_after_reset()?

In my opinion, we should return the error code of virtqueue_resize_packed() / virtqueue_resize_split().
But if this err is not important, this patch makes no sense.
Maybe I misunderstand somewhere...
If you think it's worth sending a patch, you can send it :).(I'm not familiar with this code).

Thanks,
Su Hui