From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C40FBCDB474 for ; Mon, 23 Oct 2023 02:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233114AbjJWC2O (ORCPT ); Sun, 22 Oct 2023 22:28:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbjJWC2N (ORCPT ); Sun, 22 Oct 2023 22:28:13 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2DA28E6; Sun, 22 Oct 2023 19:28:08 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046050;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0Vud6gWk_1698028084; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0Vud6gWk_1698028084) by smtp.aliyun-inc.com; Mon, 23 Oct 2023 10:28:05 +0800 Message-ID: <1698028017.8052797-1-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH] virtio_ring: add an error code check in virtqueue_resize Date: Mon, 23 Oct 2023 10:26:57 +0800 From: Xuan Zhuo To: "Michael S. Tsirkin" Cc: Su Hui , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org References: <20231020092320.209234-1-suhui@nfschina.com> <20231020053047-mutt-send-email-mst@kernel.org> <1697794601.5857713-2-xuanzhuo@linux.alibaba.com> <20231020054140-mutt-send-email-mst@kernel.org> <1697795422.0986886-1-xuanzhuo@linux.alibaba.com> <20231020055943-mutt-send-email-mst@kernel.org> In-Reply-To: <20231020055943-mutt-send-email-mst@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Oct 2023 06:08:06 -0400, "Michael S. Tsirkin" wrote: > On Fri, Oct 20, 2023 at 05:50:22PM +0800, Xuan Zhuo wrote: > > On Fri, 20 Oct 2023 05:42:14 -0400, "Michael S. Tsirkin" wrote: > > > On Fri, Oct 20, 2023 at 05:36:41PM +0800, Xuan Zhuo wrote: > > > > On Fri, 20 Oct 2023 05:34:32 -0400, "Michael S. Tsirkin" wrote: > > > > > On Fri, Oct 20, 2023 at 05:23:21PM +0800, Su Hui wrote: > > > > > > virtqueue_resize_packed() or virtqueue_resize_split() can return > > > > > > error code if failed, so add a check for this. > > > > > > > > > > > > Signed-off-by: Su Hui > > > > > > --- > > > > > > > > > > > > I'm not sure that return directly is right or not, > > > > > > maybe there are some process should do before return. > > > > > > > > > > yes - presizely what virtqueue_enable_after_reset does. > > > > > > > > > > Error handling in virtqueue_enable_after_reset is really weird BTW. > > > > > For some reason it overrides the error code returned. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > drivers/virtio/virtio_ring.c | 3 +++ > > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > > > index 51d8f3299c10..cf662c3a755b 100644 > > > > > > --- a/drivers/virtio/virtio_ring.c > > > > > > +++ b/drivers/virtio/virtio_ring.c > > > > > > @@ -2759,6 +2759,9 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num, > > > > > > else > > > > > > err = virtqueue_resize_split(_vq, num); > > > > > > > > > > > > + if (err) > > > > > > + return err; > > > > > > + > > > > > > return virtqueue_enable_after_reset(_vq); > > > > > > > > > > So I think it should be something like: > > > > > > > > > > int err_reset = virtqueue_enable_after_reset(_vq); > > > > > BUG_ON(err_reset); > > > > > > > > > > return err; > > > > > > > > > > > > > How about WARN and vq->broken? > > > > > > > > Thanks. > > > > > > 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. > > > > > > > > > > > > > > > > > > > > > > > > > > } > > > > > > EXPORT_SYMBOL_GPL(virtqueue_resize); > > > > > > -- > > > > > > 2.30.2 > > > > > > > > > > _______________________________________________ > Virtualization mailing list > Virtualization@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/virtualization