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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,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 017C4C4742C for ; Mon, 16 Nov 2020 05:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F79522280 for ; Mon, 16 Nov 2020 05:26:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e8bai97i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbgKPFZw (ORCPT ); Mon, 16 Nov 2020 00:25:52 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:21590 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgKPFZw (ORCPT ); Mon, 16 Nov 2020 00:25:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605504350; 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=idWyoh7qRbmkwmAn0b59fT2mdkgJ00GkL/2MJYUzIjo=; b=e8bai97ithVujj29iog96SA1D5Xv7SHRVLlBUkIURTqvMVuXjcdL9XygPNxwE/z49XGXUo jgD/ml4QcS16UbCf0G9Wu3zSOVNuPQ1wECJjT5l7OaBq+HPKDkWuc67t9XRjs0EYfwMc6g 8o8fQWk77tMWYK4uEdHLUg7pDcUEiLU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-251-4WXemXDFM6qUD7zKhShcKw-1; Mon, 16 Nov 2020 00:25:44 -0500 X-MC-Unique: 4WXemXDFM6qUD7zKhShcKw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3CF5710074C5; Mon, 16 Nov 2020 05:25:43 +0000 (UTC) Received: from [10.72.13.92] (ovpn-13-92.pek2.redhat.com [10.72.13.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id A83466B8E5; Mon, 16 Nov 2020 05:25:33 +0000 (UTC) Subject: Re: [PATCH RFC 12/12] vdpa_sim_blk: implement ramdisk behaviour To: Stefano Garzarella , virtualization@lists.linux-foundation.org Cc: Stefan Hajnoczi , Laurent Vivier , linux-kernel@vger.kernel.org, Eli Cohen , "Michael S. Tsirkin" , Max Gurtovoy References: <20201113134712.69744-1-sgarzare@redhat.com> <20201113134712.69744-13-sgarzare@redhat.com> From: Jason Wang Message-ID: <56d8c992-44ca-f365-fb92-f5da94896680@redhat.com> Date: Mon, 16 Nov 2020 13:25:31 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201113134712.69744-13-sgarzare@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/11/13 下午9:47, Stefano Garzarella wrote: > The previous implementation wrote only the status of each request. > This patch implements a more accurate block device simulator, > providing a ramdisk-like behavior. > > Also handle VIRTIO_BLK_T_GET_ID request, always answering the > "vdpa_blk_sim" string. Let's use a separate patch for this. > > Signed-off-by: Stefano Garzarella > --- > drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 151 +++++++++++++++++++++++---- > 1 file changed, 133 insertions(+), 18 deletions(-) > > diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c > index 8e41b3ab98d5..68e74383322f 100644 > --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c > +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c > @@ -7,6 +7,7 @@ > */ > > #include > +#include > #include > > #include "vdpa_sim.h" > @@ -24,10 +25,137 @@ > > static struct vdpasim *vdpasim_blk_dev; > > +static int vdpasim_blk_handle_req(struct vdpasim *vdpasim, > + struct vdpasim_virtqueue *vq) > +{ > + size_t wrote = 0, to_read = 0, to_write = 0; > + struct virtio_blk_outhdr hdr; > + uint8_t status; > + uint32_t type; > + ssize_t bytes; > + loff_t offset; > + int i, ret; > + > + vringh_kiov_cleanup(&vq->riov); > + vringh_kiov_cleanup(&vq->wiov); It looks to me we should do those after vringh_get_desc_iotlb()? See comment above vringh_getdesc_kern(). > + > + ret = vringh_getdesc_iotlb(&vq->vring, &vq->riov, &vq->wiov, > + &vq->head, GFP_ATOMIC); > + if (ret != 1) > + return ret; > + > + for (i = 0; i < vq->wiov.used; i++) > + to_write += vq->wiov.iov[i].iov_len; It's better to introduce a helper for this (or consider to use iov iterator). > + to_write -= 1; /* last byte is the status */ > + > + for (i = 0; i < vq->riov.used; i++) > + to_read += vq->riov.iov[i].iov_len; > + > + bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->riov, &hdr, sizeof(hdr)); > + if (bytes != sizeof(hdr)) > + return 0; > + > + to_read -= bytes; > + > + type = le32_to_cpu(hdr.type); > + offset = le64_to_cpu(hdr.sector) << SECTOR_SHIFT; > + status = VIRTIO_BLK_S_OK; > + > + switch (type) { > + case VIRTIO_BLK_T_IN: > + if (offset + to_write > VDPASIM_BLK_CAPACITY << SECTOR_SHIFT) { > + dev_err(&vdpasim->vdpa.dev, > + "reading over the capacity - offset: 0x%llx len: 0x%lx\n", > + offset, to_write); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + > + bytes = vringh_iov_push_iotlb(&vq->vring, &vq->wiov, > + vdpasim->buffer + offset, > + to_write); > + if (bytes < 0) { > + dev_err(&vdpasim->vdpa.dev, > + "vringh_iov_push_iotlb() error: %ld offset: 0x%llx len: 0x%lx\n", > + bytes, offset, to_write); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + > + wrote += bytes; > + break; > + > + case VIRTIO_BLK_T_OUT: > + if (offset + to_read > VDPASIM_BLK_CAPACITY << SECTOR_SHIFT) { > + dev_err(&vdpasim->vdpa.dev, > + "writing over the capacity - offset: 0x%llx len: 0x%lx\n", > + offset, to_read); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + > + bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->riov, > + vdpasim->buffer + offset, > + to_read); > + if (bytes < 0) { > + dev_err(&vdpasim->vdpa.dev, > + "vringh_iov_pull_iotlb() error: %ld offset: 0x%llx len: 0x%lx\n", > + bytes, offset, to_read); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + break; > + > + case VIRTIO_BLK_T_GET_ID: { > + char id[VIRTIO_BLK_ID_BYTES] = "vdpa_blk_sim"; Let's use a global static one? > + > + bytes = vringh_iov_push_iotlb(&vq->vring, > + &vq->wiov, id, > + VIRTIO_BLK_ID_BYTES); > + if (bytes < 0) { > + dev_err(&vdpasim->vdpa.dev, > + "vringh_iov_push_iotlb() error: %ld\n", bytes); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + > + wrote += bytes; > + break; > + } > + > + default: > + dev_warn(&vdpasim->vdpa.dev, > + "Unsupported request type %d\n", type); > + status = VIRTIO_BLK_S_IOERR; > + break; > + } > + > + /* if VIRTIO_BLK_T_IN or VIRTIO_BLK_T_GET_ID fail, we need to skip > + * the remaining bytes to put the status in the last byte > + */ > + if (to_write - wrote > 0) { > + vringh_iov_push_iotlb(&vq->vring, &vq->wiov, NULL, > + to_write - wrote); > + } > + > + /* last byte is the status */ > + bytes = vringh_iov_push_iotlb(&vq->vring, &vq->wiov, &status, 1); > + if (bytes != 1) > + return 0; > + > + wrote += bytes; > + > + /* Make sure data is wrote before advancing index */ > + smp_wmb(); > + > + vringh_complete_iotlb(&vq->vring, vq->head, wrote); > + > + return ret; > +} > + > static void vdpasim_blk_work(struct work_struct *work) > { > struct vdpasim *vdpasim = container_of(work, struct vdpasim, work); > - u8 status = VIRTIO_BLK_S_OK; > int i; > > spin_lock(&vdpasim->lock); > @@ -41,21 +169,7 @@ static void vdpasim_blk_work(struct work_struct *work) > if (!vq->ready) > continue; > > - while (vringh_getdesc_iotlb(&vq->vring, &vq->riov, &vq->wiov, > - &vq->head, GFP_ATOMIC) > 0) { > - > - int write; > - > - vq->wiov.i = vq->wiov.used - 1; > - write = vringh_iov_push_iotlb(&vq->vring, &vq->wiov, &status, 1); > - if (write <= 0) > - break; > - > - /* Make sure data is wrote before advancing index */ > - smp_wmb(); > - > - vringh_complete_iotlb(&vq->vring, vq->head, write); > - > + while (vdpasim_blk_handle_req(vdpasim, vq) > 0) { > /* Make sure used is visible before rasing the interrupt. */ > smp_wmb(); > > @@ -67,6 +181,7 @@ static void vdpasim_blk_work(struct work_struct *work) > vq->cb(vq->private); > local_bh_enable(); > } > + Unnecessary change. Thanks