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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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=unavailable 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 375F0C433DB for ; Thu, 28 Jan 2021 14:48:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDE1B64DE7 for ; Thu, 28 Jan 2021 14:48:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232377AbhA1Orj (ORCPT ); Thu, 28 Jan 2021 09:47:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43356 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231877AbhA1Oog (ORCPT ); Thu, 28 Jan 2021 09:44:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611844988; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+3jmE6N8rPoESTgIJH4wKKCx1Af/7e/Avo5KLtNY0Vk=; b=G3ejKID0e+1pUMJzx1JMne6wUZLr3jssVvokT9/DnvvtpJB873Tv1TacHVDVHfbpDHfwcK ewm0MgIgph6PMVIsu73EFpPBrIWpRo0ij4kd90GGJfCF4Mi6mDGdWWZV1GsSjjtOEJuFWW 77B6OB4eVjmL/OMpBbZUfvSfRFvsFA4= 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-217-5X9q1AeKMCaCTL8PkALksQ-1; Thu, 28 Jan 2021 09:43:07 -0500 X-MC-Unique: 5X9q1AeKMCaCTL8PkALksQ-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id DED5B8030A7; Thu, 28 Jan 2021 14:43:05 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-113-219.ams2.redhat.com [10.36.113.219]) by smtp.corp.redhat.com (Postfix) with ESMTP id AE44E10027A5; Thu, 28 Jan 2021 14:43:03 +0000 (UTC) From: Stefano Garzarella To: virtualization@lists.linux-foundation.org Cc: Xie Yongji , "Michael S. Tsirkin" , Stefano Garzarella , Laurent Vivier , Stefan Hajnoczi , linux-kernel@vger.kernel.org, Max Gurtovoy , Jason Wang , kvm@vger.kernel.org Subject: [PATCH RFC v2 09/10] vdpa_sim_blk: implement ramdisk behaviour Date: Thu, 28 Jan 2021 15:41:26 +0100 Message-Id: <20210128144127.113245-10-sgarzare@redhat.com> In-Reply-To: <20210128144127.113245-1-sgarzare@redhat.com> References: <20210128144127.113245-1-sgarzare@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The previous implementation wrote only the status of each request. This patch implements a more accurate block device simulator, providing a ramdisk-like behavior. Signed-off-by: Stefano Garzarella --- v2: - used %zd %zx to print size_t and ssize_t variables in dev_err() - removed unnecessary new line [Jason] - moved VIRTIO_BLK_T_GET_ID in another patch [Jason] - used push/pull instead of write/read terminology - added vdpasim_blk_check_range() to avoid overflows [Stefan] - use vdpasim*_to_cpu instead of le*_to_cpu - used vringh_kiov_length() helper [Jason] --- drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 164 ++++++++++++++++++++++++--- 1 file changed, 146 insertions(+), 18 deletions(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c index 999f9ca0b628..fc47e8320358 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c @@ -3,6 +3,7 @@ * VDPA simulator for block device. * * Copyright (c) 2020, Mellanox Technologies. All rights reserved. + * Copyright (c) 2021, Red Hat Inc. All rights reserved. * */ @@ -13,6 +14,7 @@ #include #include #include +#include #include #include "vdpa_sim.h" @@ -36,10 +38,151 @@ static struct vdpasim *vdpasim_blk_dev; +static bool vdpasim_blk_check_range(u64 start_sector, size_t range_size) +{ + u64 range_sectors = range_size >> SECTOR_SHIFT; + + if (range_size > VDPASIM_BLK_SIZE_MAX * VDPASIM_BLK_SEG_MAX) + return false; + + if (start_sector > VDPASIM_BLK_CAPACITY) + return false; + + if (range_sectors > VDPASIM_BLK_CAPACITY - start_sector) + return false; + + return true; +} + +/* Returns 'true' if the request is handled (with or without an I/O error) + * and the status is correctly written in the last byte of the 'in iov', + * 'false' otherwise. + */ +static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim, + struct vdpasim_virtqueue *vq) +{ + size_t pushed = 0, to_pull, to_push; + struct virtio_blk_outhdr hdr; + ssize_t bytes; + loff_t offset; + u64 sector; + u8 status; + u32 type; + int ret; + + ret = vringh_getdesc_iotlb(&vq->vring, &vq->out_iov, &vq->in_iov, + &vq->head, GFP_ATOMIC); + if (ret != 1) + return false; + + if (vq->out_iov.used < 1 || vq->in_iov.used < 1) { + dev_err(&vdpasim->vdpa.dev, "missing headers - out_iov: %u in_iov %u\n", + vq->out_iov.used, vq->in_iov.used); + return false; + } + + if (vq->in_iov.iov[vq->in_iov.used - 1].iov_len < 1) { + dev_err(&vdpasim->vdpa.dev, "request in header too short\n"); + return false; + } + + /* The last byte is the status and we checked if the last iov has + * enough room for it. + */ + to_push = vringh_kiov_length(&vq->in_iov) - 1; + + to_pull = vringh_kiov_length(&vq->out_iov); + + bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov, &hdr, + sizeof(hdr)); + if (bytes != sizeof(hdr)) { + dev_err(&vdpasim->vdpa.dev, "request out header too short\n"); + return false; + } + + to_pull -= bytes; + + type = vdpasim32_to_cpu(vdpasim, hdr.type); + sector = vdpasim64_to_cpu(vdpasim, hdr.sector); + offset = sector << SECTOR_SHIFT; + status = VIRTIO_BLK_S_OK; + + switch (type) { + case VIRTIO_BLK_T_IN: + if (!vdpasim_blk_check_range(sector, to_push)) { + dev_err(&vdpasim->vdpa.dev, + "reading over the capacity - offset: 0x%llx len: 0x%zx\n", + offset, to_push); + status = VIRTIO_BLK_S_IOERR; + break; + } + + bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov, + vdpasim->buffer + offset, + to_push); + if (bytes < 0) { + dev_err(&vdpasim->vdpa.dev, + "vringh_iov_push_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n", + bytes, offset, to_push); + status = VIRTIO_BLK_S_IOERR; + break; + } + + pushed += bytes; + break; + + case VIRTIO_BLK_T_OUT: + if (!vdpasim_blk_check_range(sector, to_pull)) { + dev_err(&vdpasim->vdpa.dev, + "writing over the capacity - offset: 0x%llx len: 0x%zx\n", + offset, to_pull); + status = VIRTIO_BLK_S_IOERR; + break; + } + + bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov, + vdpasim->buffer + offset, + to_pull); + if (bytes < 0) { + dev_err(&vdpasim->vdpa.dev, + "vringh_iov_pull_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n", + bytes, offset, to_pull); + status = VIRTIO_BLK_S_IOERR; + break; + } + break; + + default: + dev_warn(&vdpasim->vdpa.dev, + "Unsupported request type %d\n", type); + status = VIRTIO_BLK_S_IOERR; + break; + } + + /* If some operations fail, we need to skip the remaining bytes + * to put the status in the last byte + */ + if (to_push - pushed > 0) + vringh_kiov_advance(&vq->in_iov, to_push - pushed); + + /* Last byte is the status */ + bytes = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov, &status, 1); + if (bytes != 1) + return false; + + pushed += bytes; + + /* Make sure data is wrote before advancing index */ + smp_wmb(); + + vringh_complete_iotlb(&vq->vring, vq->head, pushed); + + return true; +} + 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); @@ -53,22 +196,7 @@ static void vdpasim_blk_work(struct work_struct *work) if (!vq->ready) continue; - while (vringh_getdesc_iotlb(&vq->vring, &vq->out_iov, - &vq->in_iov, &vq->head, - GFP_ATOMIC) > 0) { - int write; - - vq->in_iov.i = vq->in_iov.used - 1; - write = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov, - &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)) { /* Make sure used is visible before rasing the interrupt. */ smp_wmb(); @@ -109,7 +237,7 @@ static int __init vdpasim_blk_init(void) dev_attr.config_size = sizeof(struct virtio_blk_config); dev_attr.get_config = vdpasim_blk_get_config; dev_attr.work_fn = vdpasim_blk_work; - dev_attr.buffer_size = PAGE_SIZE; + dev_attr.buffer_size = VDPASIM_BLK_CAPACITY << SECTOR_SHIFT; vdpasim_blk_dev = vdpasim_create(&dev_attr); if (IS_ERR(vdpasim_blk_dev)) { -- 2.29.2