From patchwork Thu Sep 16 18:25:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Schoenebeck X-Patchwork-Id: 513498 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83ADBC433EF for ; Thu, 16 Sep 2021 19:30:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B262610E9 for ; Thu, 16 Sep 2021 19:30:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232907AbhIPTcJ (ORCPT ); Thu, 16 Sep 2021 15:32:09 -0400 Received: from lizzy.crudebyte.com ([91.194.90.13]:43941 "EHLO lizzy.crudebyte.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232803AbhIPTcD (ORCPT ); Thu, 16 Sep 2021 15:32:03 -0400 X-Greylist: delayed 1649 seconds by postgrey-1.27 at vger.kernel.org; Thu, 16 Sep 2021 15:32:03 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=lizzy; h=Cc:To:Subject:Date:From:References:In-Reply-To: Message-Id:Content-Type:Content-Transfer-Encoding:MIME-Version:Content-ID: Content-Description; bh=TXDvTjl8s9XWBla6TKW7Otq0soo3twuHwJi7HEGU8Sk=; b=SFDPZ QU375PVlK9KG1T8AmoNIEkV7YyIOBZpuRgXjkCTi37UBGFcSb6GEbvz5TO57a1kLCtG6d2lSK+qEE vcj7f1pDItzEo0+bTw2WGHuk0YQ390tkr0uAsQoUBiJwXteautFU4HrzpKw016Ove00GhRZEru3r3 sTwsQPM9hDr9xpGaIqIXl1VMbEf+Nu64/I0PE4LrKV96XeIeH4ACvUovoKhWTka8U9q36NYsUn4vZ VWtYW7UFdwPYqyFV+7lIhZnbBVuDl62G7YsIxaTLzP09NVeNchOE5WU/8quXRzjt/xj+VPg8YnBtO FFLruiAy60QpT7RNqEO+UXWghWzVQ==; Message-Id: <810050b76b9b04f045e3d21b0082358ea3f21391.1631816768.git.linux_oss@crudebyte.com> In-Reply-To: References: From: Christian Schoenebeck Date: Thu, 16 Sep 2021 20:25:16 +0200 Subject: [PATCH 6/7] 9p/trans_virtio: support larger msize values To: v9fs-developer@lists.sourceforge.net Cc: netdev@vger.kernel.org, Dominique Martinet , Eric Van Hensbergen , Latchesar Ionkov , Greg Kurz , Vivek Goyal Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The virtio transport supports by default a 9p 'msize' of up to approximately 500 kB. This patches adds support for larger 'msize' values by resizing the amount of scatter/gather lists if required. Signed-off-by: Christian Schoenebeck --- net/9p/trans_virtio.c | 52 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 1a45e0df2336..1f9a0283d7b8 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -195,6 +195,30 @@ static struct virtqueue_sg *vq_sg_alloc(unsigned int nsgl) return vq_sg; } +/** + * Resize passed virtqueue scatter/gather lists to the passed amount of + * list blocks. + * @_vq_sg: scatter/gather lists to be resized + * @nsgl: new amount of scatter/gather list blocks + */ +static int vq_sg_resize(struct virtqueue_sg **_vq_sg, unsigned int nsgl) +{ + struct virtqueue_sg *vq_sg; + + BUG_ON(!_vq_sg || !nsgl); + vq_sg = *_vq_sg; + if (vq_sg->nsgl == nsgl) + return 0; + + /* lazy resize implementation for now */ + vq_sg = vq_sg_alloc(nsgl); + if (!vq_sg) + return -ENOMEM; + + *_vq_sg = vq_sg; + return 0; +} + /** * p9_virtio_close - reclaim resources of a channel * @client: client instance @@ -766,6 +790,10 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args) struct virtio_chan *chan; int ret = -ENOENT; int found = 0; +#if !defined(CONFIG_ARCH_NO_SG_CHAIN) + size_t npages; + size_t nsgl; +#endif if (devname == NULL) return -EINVAL; @@ -788,6 +816,30 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args) return ret; } + /* + * if user supplied an 'msize' option that's larger than what this + * transport supports by default, then try to allocate more sg lists + */ + if (client->msize > client->trans_maxsize) { +#if !defined(CONFIG_ARCH_NO_SG_CHAIN) + npages = DIV_ROUND_UP(client->msize, PAGE_SIZE); + if (npages > chan->p9_max_pages) + npages = chan->p9_max_pages; + nsgl = DIV_ROUND_UP(npages, SG_USER_PAGES_PER_LIST); + if (nsgl > chan->vq_sg->nsgl) { + /* + * if resize fails, no big deal, then just + * continue with default msize instead + */ + if (!vq_sg_resize(&chan->vq_sg, nsgl)) { + client->trans_maxsize = + PAGE_SIZE * + ((nsgl * SG_USER_PAGES_PER_LIST) - 3); + } + } +#endif /* !defined(CONFIG_ARCH_NO_SG_CHAIN) */ + } + client->trans = (void *)chan; client->status = Connected; chan->client = client;