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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E81E8C3A5A1 for ; Thu, 22 Aug 2019 11:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8FC1233FD for ; Thu, 22 Aug 2019 11:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388310AbfHVLdq (ORCPT ); Thu, 22 Aug 2019 07:33:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46382 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388192AbfHVLdn (ORCPT ); Thu, 22 Aug 2019 07:33:43 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C765389F38E; Thu, 22 Aug 2019 11:33:42 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (unknown [10.36.118.90]) by smtp.corp.redhat.com (Postfix) with ESMTP id 97F1F1001B32; Thu, 22 Aug 2019 11:33:38 +0000 (UTC) Subject: Re: [PATCH v5] drm/virtio: use virtio_max_dma_size To: Gerd Hoffmann , dri-devel@lists.freedesktop.org Cc: David Airlie , Daniel Vetter , "open list:VIRTIO GPU DRIVER" , open list References: <20190821111210.27165-1-kraxel@redhat.com> From: Laszlo Ersek Message-ID: <2e6eba7b-5f46-e9e8-f6b2-3e80e95754e9@redhat.com> Date: Thu, 22 Aug 2019 13:33:37 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190821111210.27165-1-kraxel@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.68]); Thu, 22 Aug 2019 11:33:42 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/21/19 13:12, Gerd Hoffmann wrote: > We must make sure our scatterlist segments are not too big, otherwise > we might see swiotlb failures (happens with sev, also reproducable with > swiotlb=force). > > Suggested-by: Laszlo Ersek > Signed-off-by: Gerd Hoffmann > --- > drivers/gpu/drm/virtio/virtgpu_object.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c > index b2da31310d24..09b526518f5a 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_object.c > +++ b/drivers/gpu/drm/virtio/virtgpu_object.c > @@ -204,6 +204,7 @@ int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev, > .interruptible = false, > .no_wait_gpu = false > }; > + size_t max_segment; > > /* wtf swapping */ > if (bo->pages) > @@ -215,8 +216,13 @@ int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev, > if (!bo->pages) > goto out; > > - ret = sg_alloc_table_from_pages(bo->pages, pages, nr_pages, 0, > - nr_pages << PAGE_SHIFT, GFP_KERNEL); > + max_segment = virtio_max_dma_size(qdev->vdev); > + max_segment &= PAGE_MASK; > + if (max_segment > SCATTERLIST_MAX_SEGMENT) > + max_segment = SCATTERLIST_MAX_SEGMENT; > + ret = __sg_alloc_table_from_pages(bo->pages, pages, nr_pages, 0, > + nr_pages << PAGE_SHIFT, > + max_segment, GFP_KERNEL); > if (ret) > goto out; > return 0; > Reviewed-by: Laszlo Ersek Thanks! Laszlo