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 8910DC433F5 for ; Tue, 12 Apr 2022 05:54:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348517AbiDLF41 (ORCPT ); Tue, 12 Apr 2022 01:56:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348484AbiDLF4Z (ORCPT ); Tue, 12 Apr 2022 01:56:25 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 80C11CCB for ; Mon, 11 Apr 2022 22:54:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649742845; 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=691Yo4tOxFREJuTeRonUH/gcyvI9lkMUJMdeyqkXSWQ=; b=VLRpx/y604ulpSnHd3oBgBryQ40YJV47hpgWmgMyhOka4OkTXOmdYl039yS9UbH5WW8vMr JQqbFsSZ5kawEQqCUqaptL4VTrq5vhk913MGoiaYk7WMI7ScN+j+9xyLpa89O6AuJ5tyGF Rd9a2H4W64zl+dIpveDfj4zkO3f8sbw= Received: from mail-pg1-f198.google.com (mail-pg1-f198.google.com [209.85.215.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-636-AG-utSCbO_y0qkJuyOhijQ-1; Tue, 12 Apr 2022 01:54:03 -0400 X-MC-Unique: AG-utSCbO_y0qkJuyOhijQ-1 Received: by mail-pg1-f198.google.com with SMTP id z132-20020a63338a000000b003844e317066so10017484pgz.19 for ; Mon, 11 Apr 2022 22:54:02 -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=691Yo4tOxFREJuTeRonUH/gcyvI9lkMUJMdeyqkXSWQ=; b=NWruIDEp3xXShuT67OX1Y5MNPE7s4nCCHtIc3g5f83fExZ3nKQNScSyqcETTGND8Kg 7wbARlwuKHpUi17vNIDpOSczt9StfbvG0l81u5936JgjoQ7pg0HeIiBLi+uY5xq18fUf yIH5r7WU7NwBDrQNzPFBo5luj3wtuvRgsCXr4lGTRYZgcQ9OY/c0sREXcsktuajjBn4k S0zm2CRyg0UkNHE+mHmzPz2N3zNLoX2t7j6Wf5urByNiQQJOx0tawHu3EOIF5V778C6q 694GLuCwGLemFLUnUpIRAEGClk/Z/asB7zwKBbeAGJ+wF3ptcvFNnS69yk9OEywJUjiG A2jw== X-Gm-Message-State: AOAM533S96gc25cKkJqb8MpTtob29GQ1b9ZHf0u9TSt9us/Ce56/W9jX No2d/pR8VLZ+lPM4k+8wacqWwKF8XLMVzYSa/Nsj2IwfP8y8u856zEw2Ca8OgzAsL9bzANZjnjn oGfjx7oblbTA2M+BevQ2oOQ== X-Received: by 2002:a17:902:f683:b0:158:8178:e7a0 with SMTP id l3-20020a170902f68300b001588178e7a0mr3510833plg.160.1649742841848; Mon, 11 Apr 2022 22:54:01 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwOjt8nlerN6jXVH9ANx2m0/Qvxoufl1r0WhRPAfaTl2kJvP+NMMrr2TTbfemTY216uBaWV4Q== X-Received: by 2002:a17:902:f683:b0:158:8178:e7a0 with SMTP id l3-20020a170902f68300b001588178e7a0mr3510808plg.160.1649742841583; Mon, 11 Apr 2022 22:54:01 -0700 (PDT) Received: from [10.72.14.5] ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id g12-20020a056a001a0c00b004e1307b249csm37755988pfv.69.2022.04.11.22.53.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Apr 2022 22:54:01 -0700 (PDT) Message-ID: Date: Tue, 12 Apr 2022 13:53:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v9 11/32] virtio_ring: split: introduce virtqueue_resize_split() Content-Language: en-US To: Xuan Zhuo , virtualization@lists.linux-foundation.org Cc: Jeff Dike , Richard Weinberger , Anton Ivanov , "Michael S. Tsirkin" , "David S. Miller" , Jakub Kicinski , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Alexander Gordeev , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Johannes Berg , 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 References: <20220406034346.74409-1-xuanzhuo@linux.alibaba.com> <20220406034346.74409-12-xuanzhuo@linux.alibaba.com> From: Jason Wang In-Reply-To: <20220406034346.74409-12-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org 在 2022/4/6 上午11:43, Xuan Zhuo 写道: > 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, the caller must > re-initialize(virtqueue_reinit_split()) the virtqueue to ensure that the > vring can be used. > > In addition, vring_align, may_reduce_num are necessary for reallocating > vring, so they are retained for creating vq. > > Signed-off-by: Xuan Zhuo > --- > drivers/virtio/virtio_ring.c | 47 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 3dc6ace2ba7a..33864134a744 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -139,6 +139,12 @@ struct vring_virtqueue { > /* DMA address and size information */ > dma_addr_t queue_dma_addr; > size_t queue_size_in_bytes; > + > + /* The parameters for creating vrings are reserved for > + * creating new vring. > + */ > + u32 vring_align; > + bool may_reduce_num; > } split; > > /* Available for packed ring */ > @@ -199,6 +205,7 @@ struct vring_virtqueue { > }; > > static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num); > +static void vring_free(struct virtqueue *_vq); > > /* > * Helpers. > @@ -1088,6 +1095,8 @@ static struct virtqueue *vring_create_virtqueue_split( > return NULL; > } > > + to_vvq(vq)->split.vring_align = vring_align; > + to_vvq(vq)->split.may_reduce_num = may_reduce_num; It looks to me the above should belong to patch 6. > to_vvq(vq)->split.queue_dma_addr = dma_addr; > to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; > to_vvq(vq)->we_own_ring = true; > @@ -1095,6 +1104,44 @@ static struct virtqueue *vring_create_virtqueue_split( > return vq; > } > > +static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + struct virtio_device *vdev = _vq->vdev; > + struct vring_desc_state_split *state; > + struct vring_desc_extra *extra; > + size_t queue_size_in_bytes; > + dma_addr_t dma_addr; > + struct vring vring; > + int err = -ENOMEM; > + void *queue; > + > + queue = vring_alloc_queue_split(vdev, &dma_addr, &num, > + vq->split.vring_align, > + vq->weak_barriers, > + vq->split.may_reduce_num); > + if (!queue) > + return -ENOMEM; > + > + queue_size_in_bytes = vring_size(num, vq->split.vring_align); > + > + err = vring_alloc_state_extra_split(num, &state, &extra); > + if (err) { > + vring_free_queue(vdev, queue_size_in_bytes, queue, dma_addr); > + return -ENOMEM; > + } > + > + vring_free(&vq->vq); > + > + vring_init(&vring, num, queue, vq->split.vring_align); > + vring_virtqueue_attach_split(vq, vring, state, extra); > + vq->split.queue_dma_addr = dma_addr; > + vq->split.queue_size_in_bytes = queue_size_in_bytes; I wonder if it's better to move the above assignments to vring_virtqueue_attach_split(). Other looks good. Thanks > + > + vring_virtqueue_init_split(vq, vdev, true); > + return 0; > +} > + > > /* > * Packed ring specific functions - *_packed().