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 38E3FC433EF for ; Thu, 21 Jul 2022 09:14:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232820AbiGUJOM (ORCPT ); Thu, 21 Jul 2022 05:14:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232818AbiGUJOG (ORCPT ); Thu, 21 Jul 2022 05:14:06 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1D9343B961 for ; Thu, 21 Jul 2022 02:14:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658394844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=evkly4mzwl0OWnSDguyVCSXP+iuc3cHesZCTCuELO9c=; b=fwPCim4dSMnIA4MV0NWq3vqg7bkSSUaXaktAbdfgNMZsDFHE86z9BK4QkaNFn4WP0kdB7t e2IlzSgtAR3JgL57r7KaI+WDBl+EZmyzPMNy+OGaU8frd/S8fUHupC0sTAA9WAuZwCJzgS crCk3aYUWdFc/3yO7vgou5VwEJCochU= Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-517-uJK7y4PgPT-rFD6ydiaRmA-1; Thu, 21 Jul 2022 05:14:03 -0400 X-MC-Unique: uJK7y4PgPT-rFD6ydiaRmA-1 Received: by mail-pj1-f71.google.com with SMTP id o21-20020a17090a9f9500b001f0574225faso2549062pjp.6 for ; Thu, 21 Jul 2022 02:14:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=evkly4mzwl0OWnSDguyVCSXP+iuc3cHesZCTCuELO9c=; b=LEx34rUEpTL3MdoSwQpc7Mh7Hz/VobICm+r0ke0NcnW/95QxqqsuGYi6G6SIjYqde/ fpxilgpFQFOn3yNGWnixyE0QwB7S8s+xFnPdqQ4kDsdkRgncuIi4oRsC9WQpkkOfGtWx 9dR6KaoFLZ0iqtyv2AR49sFxHNIpImKaNFweFhUzrGm5lKy5ceXdyJLarw7ZVASkjp2W WXvT5zBBqZk79+SEOB2QJgJmmZ0IKqny3gv3/3kHxeXKVcyaPK+SL2Z4Aaywc8DIXHsW 0BihSoj5H/mGI/vnDRtfFeazjYtcUUcczO1IWYwtA99lbjDBuYlrMXJfrB/jCSw82n+7 R41Q== X-Gm-Message-State: AJIora8/JJ2dcSX7MH+FAWxeOfDoDWrD3DsLGJOZXNSPQmVxWx6Ek3Kl 1d4JI2VANY/r/GLmlA6qyEQk/lV7l4TdXbOjoiWFbuzROHO3wIVN3RDyGA3Z/k1Hv2iQIbNjCYd Yqz70542uSSZUn9kRC1lB9K1T8/vnY6Sgqg== X-Received: by 2002:a17:90b:681:b0:1f2:147a:5e55 with SMTP id m1-20020a17090b068100b001f2147a5e55mr10137474pjz.159.1658394841817; Thu, 21 Jul 2022 02:14:01 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vZd1H6ktLLHxg0oQu5yg8T5pv3EpQ1CpRpfXswCqn2eqimIJKu3rbioASMftx5YraJgvSUnw== X-Received: by 2002:a17:90b:681:b0:1f2:147a:5e55 with SMTP id m1-20020a17090b068100b001f2147a5e55mr10137436pjz.159.1658394841532; Thu, 21 Jul 2022 02:14:01 -0700 (PDT) Received: from [10.72.12.47] ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id z28-20020aa7949c000000b0052516db7123sm1181543pfk.35.2022.07.21.02.13.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Jul 2022 02:14:00 -0700 (PDT) Message-ID: <0b3c985d-d479-a554-4fe2-bfe94fc74070@redhat.com> Date: Thu, 21 Jul 2022 17:13:49 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v12 08/40] virtio_ring: split: extract the logic of alloc queue Content-Language: en-US To: Xuan Zhuo , virtualization@lists.linux-foundation.org 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 References: <20220720030436.79520-1-xuanzhuo@linux.alibaba.com> <20220720030436.79520-9-xuanzhuo@linux.alibaba.com> From: Jason Wang In-Reply-To: <20220720030436.79520-9-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org 在 2022/7/20 11:04, Xuan Zhuo 写道: > Separate the logic of split to create vring queue. > > This feature is required for subsequent virtuqueue reset vring. > > Signed-off-by: Xuan Zhuo > --- > drivers/virtio/virtio_ring.c | 68 ++++++++++++++++++++++-------------- > 1 file changed, 42 insertions(+), 26 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index c94c5461e702..c7971438bb2c 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -950,28 +950,19 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split, > kfree(vring_split->desc_extra); > } > > -static struct virtqueue *vring_create_virtqueue_split( > - unsigned int index, > - unsigned int num, > - unsigned int vring_align, > - struct virtio_device *vdev, > - bool weak_barriers, > - bool may_reduce_num, > - bool context, > - bool (*notify)(struct virtqueue *), > - void (*callback)(struct virtqueue *), > - const char *name) > +static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split, > + struct virtio_device *vdev, > + u32 num, > + unsigned int vring_align, > + bool may_reduce_num) > { > - struct virtqueue *vq; > void *queue = NULL; > dma_addr_t dma_addr; > - size_t queue_size_in_bytes; > - struct vring vring; > > /* We assume num is a power of 2. */ > if (num & (num - 1)) { > dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); > - return NULL; > + return -EINVAL; > } > > /* TODO: allocate each queue chunk individually */ > @@ -982,11 +973,11 @@ static struct virtqueue *vring_create_virtqueue_split( > if (queue) > break; > if (!may_reduce_num) > - return NULL; > + return -ENOMEM; > } > > if (!num) > - return NULL; > + return -ENOMEM; > > if (!queue) { > /* Try to get a single page. You are my only hope! */ > @@ -994,21 +985,46 @@ static struct virtqueue *vring_create_virtqueue_split( > &dma_addr, GFP_KERNEL|__GFP_ZERO); > } > if (!queue) > - return NULL; > + return -ENOMEM; > + > + vring_init(&vring_split->vring, num, queue, vring_align); > > - queue_size_in_bytes = vring_size(num, vring_align); > - vring_init(&vring, num, queue, vring_align); > + vring_split->queue_dma_addr = dma_addr; > + vring_split->queue_size_in_bytes = vring_size(num, vring_align); > + > + return 0; > +} > + > +static struct virtqueue *vring_create_virtqueue_split( > + unsigned int index, > + unsigned int num, > + unsigned int vring_align, > + struct virtio_device *vdev, > + bool weak_barriers, > + bool may_reduce_num, > + bool context, > + bool (*notify)(struct virtqueue *), > + void (*callback)(struct virtqueue *), > + const char *name) > +{ > + struct vring_virtqueue_split vring_split = {}; > + struct virtqueue *vq; > + int err; > + > + err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align, > + may_reduce_num); > + if (err) > + return NULL; > > - vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, > - notify, callback, name); > + vq = __vring_new_virtqueue(index, vring_split.vring, vdev, weak_barriers, > + context, notify, callback, name); > if (!vq) { > - vring_free_queue(vdev, queue_size_in_bytes, queue, > - dma_addr); > + vring_free_split(&vring_split, vdev); > return NULL; > } > > - to_vvq(vq)->split.queue_dma_addr = dma_addr; > - to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; > + to_vvq(vq)->split.queue_dma_addr = vring_split.queue_dma_addr; > + to_vvq(vq)->split.queue_size_in_bytes = vring_split.queue_size_in_bytes; This still seems a little bit redundant since the current logic is a little bit complicated since the vq->split is not initialized in a single place. I wonder if it's better to: vring_alloc_queue_split() vring_alloc_desc_extra() (reorder to make patch 9 come first) then we can simply assign vring_split to vq->split in __vring_new_virtqueue() since it has:     vq->split.queue_dma_addr = 0;     vq->split.queue_size_in_bytes = 0;     vq->split.vring = vring;     vq->split.avail_flags_shadow = 0;     vq->split.avail_idx_shadow = 0; This seems to simplify the logic and task of e.g virtqueue_vring_attach_split() to a simple: vq->split= vring_split; And if this makes sense, we can do something similar to packed ring. Thanks > to_vvq(vq)->we_own_ring = true; > > return vq;