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 8ACAAC19F21 for ; Wed, 27 Jul 2022 07:44:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230401AbiG0HoW (ORCPT ); Wed, 27 Jul 2022 03:44:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231279AbiG0HoJ (ORCPT ); Wed, 27 Jul 2022 03:44:09 -0400 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B0E73FA0F; Wed, 27 Jul 2022 00:44:06 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=36;SR=0;TI=SMTPD_---0VKZx5Pm_1658907838; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VKZx5Pm_1658907838) by smtp.aliyun-inc.com; Wed, 27 Jul 2022 15:43:59 +0800 Message-ID: <1658907413.1860468-2-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH v13 16/42] virtio_ring: split: introduce virtqueue_resize_split() Date: Wed, 27 Jul 2022 15:36:53 +0800 From: Xuan Zhuo To: Jason Wang Cc: Richard Weinberger , Anton Ivanov , Johannes Berg , "Michael S. Tsirkin" , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Vincent Whitchurch , linux-um@lists.infradead.org, netdev@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org, kangjie.xu@linux.alibaba.com, virtualization@lists.linux-foundation.org References: <20220726072225.19884-1-xuanzhuo@linux.alibaba.com> <20220726072225.19884-17-xuanzhuo@linux.alibaba.com> <15aa26f2-f8af-5dbd-f2b2-9270ad873412@redhat.com> In-Reply-To: <15aa26f2-f8af-5dbd-f2b2-9270ad873412@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org On Wed, 27 Jul 2022 11:12:19 +0800, Jason Wang wrote: > > =E5=9C=A8 2022/7/26 15:21, Xuan Zhuo =E5=86=99=E9=81=93: > > virtio ring split supports resize. > > > > Only after the new vring is successfully allocated based on the new num, > > we will release the old vring. In any case, an error is returned, > > indicating that the vring still points to the old vring. > > > > In the case of an error, re-initialize(virtqueue_reinit_split()) the > > virtqueue to ensure that the vring can be used. > > > > Signed-off-by: Xuan Zhuo > > Acked-by: Jason Wang > > --- > > drivers/virtio/virtio_ring.c | 34 ++++++++++++++++++++++++++++++++++ > > 1 file changed, 34 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index b6fda91c8059..58355e1ac7d7 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -220,6 +220,7 @@ static struct virtqueue *__vring_new_virtqueue(unsi= gned int index, > > void (*callback)(struct virtqueue *), > > const char *name); > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int n= um); > > +static void vring_free(struct virtqueue *_vq); > > > > /* > > * Helpers. > > @@ -1117,6 +1118,39 @@ static struct virtqueue *vring_create_virtqueue_= split( > > return vq; > > } > > > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > > +{ > > + struct vring_virtqueue_split vring_split =3D {}; > > + struct vring_virtqueue *vq =3D to_vvq(_vq); > > + struct virtio_device *vdev =3D _vq->vdev; > > + int err; > > + > > + err =3D vring_alloc_queue_split(&vring_split, vdev, num, > > + vq->split.vring_align, > > + vq->split.may_reduce_num); > > + if (err) > > + goto err; > > > I think we don't need to do anything here? Am I missing something? > > > > + > > + err =3D vring_alloc_state_extra_split(&vring_split); > > + if (err) { > > + vring_free_split(&vring_split, vdev); > > + goto err; > > > I suggest to move vring_free_split() into a dedicated error label. Will change. Thanks. > > Thanks > > > > + } > > + > > + vring_free(&vq->vq); > > + > > + virtqueue_vring_init_split(&vring_split, vq); > > + > > + virtqueue_init(vq, vring_split.vring.num); > > + virtqueue_vring_attach_split(vq, &vring_split); > > + > > + return 0; > > + > > +err: > > + virtqueue_reinit_split(vq); > > + return -ENOMEM; > > +} > > + > > > > /* > > * Packed ring specific functions - *_packed(). >