From patchwork Wed May 4 07:40:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 12837267 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D35EFC433F5 for ; Wed, 4 May 2022 07:53:09 +0000 (UTC) Received: from localhost ([::1]:40742 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nm9op-0003rL-DJ for qemu-devel@archiver.kernel.org; Wed, 04 May 2022 03:53:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52412) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nm9cy-0002cK-24 for qemu-devel@nongnu.org; Wed, 04 May 2022 03:40:52 -0400 Received: from mail-pl1-x635.google.com ([2607:f8b0:4864:20::635]:34517) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nm9cv-0006x6-F3 for qemu-devel@nongnu.org; Wed, 04 May 2022 03:40:51 -0400 Received: by mail-pl1-x635.google.com with SMTP id n8so731429plh.1 for ; Wed, 04 May 2022 00:40:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=DlwjnB3ppQFMGTkb5V9gcNR44nngB39VoWLTeVe3H48=; b=4uaLcu5Z2LAcv9AEBys8qzjQgMg88QzWotMggkxrOF/Ki9u9/bhVMvRvtt3R2cJ4XN 0s2z74hIRzbAuRoLKhF7Q+t+ZaCjlXmi1ZNAL7JLLTKIChvCZjdF9JchxYDefgWWspKV AY02XHxpFTKrtvAHumzoUnDCi/BSHGSpEGbOjvHPjx035btV7JY+wg+GFDwTBDGYa9je BPeegZipB8sP0v96ydkDn6OfZSqZzDIELnlHv3QyuA3blruabtSJv3RcjsJl6THDhbOm V7hVRhGBglsYeiff0Y5wD7vQbr+26Yrh4owoedckZbp1jy5yKi7g//nwu0qCMxJQCuDH KG4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=DlwjnB3ppQFMGTkb5V9gcNR44nngB39VoWLTeVe3H48=; b=2DVV68OJmXQF8vlBKYBLQ3ap0T8HcvuxxVaiqIVbMaN1e3G3BWxgVyfBP9m7hogY56 SRrFLjwgWsaK/TImQjU8xJXLVWJnoXAGl8afF0bEvyb/Xoz0G0NGBYxK2sD9erQ9gbXa EraND5dnKpLVbTxjmbtcRf4JE9iwezOMzmjHI7FtO4tkewrjcCJrE+kutHNq75gJtn+q 2qBkSDx1iJoo28YOxXyBlW8upkg2T3eTDgGAZgWr3DB/sFyvaybpxQ2MQ6qC65VsQ2Gi bjK3P958LGSurR549cYEnxXFBUTr2AxOPD7aI+6C6w2jdqrzflToSId4vtDQWCaOzRva FWkA== X-Gm-Message-State: AOAM531KCyjkzDtnRiTkS1P63rkLzIcc9i04WICPH1+yu0W9a6/OijYq zP1fM2ZH59lRldQEZmoEXwuP X-Google-Smtp-Source: ABdhPJz8ImvuReRRSxwXyp+3X0vgaIOK6kcIqbVLSOuWGlaUV54aI2yexoy7bYZ6dmx1QTj13z8UKA== X-Received: by 2002:a17:902:ea11:b0:15e:ae19:f36a with SMTP id s17-20020a170902ea1100b0015eae19f36amr10417811plg.52.1651650048663; Wed, 04 May 2022 00:40:48 -0700 (PDT) Received: from localhost ([139.177.225.233]) by smtp.gmail.com with ESMTPSA id 6-20020aa79146000000b0050dc76281aasm1646036pfi.132.2022.05.04.00.40.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 May 2022 00:40:48 -0700 (PDT) From: Xie Yongji To: mst@redhat.com, jasowang@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, kwolf@redhat.com, mreitz@redhat.com, mlureau@redhat.com, jsnow@redhat.com, eblake@redhat.com, Coiby.Xu@gmail.com, hreitz@redhat.com Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org Subject: [PATCH v5 3/8] block/export: Abstract out the logic of virtio-blk I/O process Date: Wed, 4 May 2022 15:40:46 +0800 Message-Id: <20220504074051.90-4-xieyongji@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220504074051.90-1-xieyongji@bytedance.com> References: <20220504074051.90-1-xieyongji@bytedance.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::635; envelope-from=xieyongji@bytedance.com; helo=mail-pl1-x635.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Abstract the common logic of virtio-blk I/O process to a function named virtio_blk_process_req(). It's needed for the following commit. Signed-off-by: Xie Yongji --- MAINTAINERS | 2 + block/export/meson.build | 2 +- block/export/vhost-user-blk-server.c | 249 ++------------------------- block/export/virtio-blk-handler.c | 237 +++++++++++++++++++++++++ block/export/virtio-blk-handler.h | 33 ++++ 5 files changed, 287 insertions(+), 236 deletions(-) create mode 100644 block/export/virtio-blk-handler.c create mode 100644 block/export/virtio-blk-handler.h diff --git a/MAINTAINERS b/MAINTAINERS index 294c88ace9..4113b6fc5c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3536,6 +3536,8 @@ M: Coiby Xu S: Maintained F: block/export/vhost-user-blk-server.c F: block/export/vhost-user-blk-server.h +F: block/export/virtio-blk-handler.c +F: block/export/virtio-blk-handler.h F: include/qemu/vhost-user-server.h F: tests/qtest/libqos/vhost-user-blk.c F: tests/qtest/libqos/vhost-user-blk.h diff --git a/block/export/meson.build b/block/export/meson.build index 0a08e384c7..431e47ca51 100644 --- a/block/export/meson.build +++ b/block/export/meson.build @@ -1,7 +1,7 @@ blockdev_ss.add(files('export.c')) if have_vhost_user_blk_server - blockdev_ss.add(files('vhost-user-blk-server.c')) + blockdev_ss.add(files('vhost-user-blk-server.c', 'virtio-blk-handler.c')) endif blockdev_ss.add(when: fuse, if_true: files('fuse.c')) diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c index a129204c44..8705f7c27c 100644 --- a/block/export/vhost-user-blk-server.c +++ b/block/export/vhost-user-blk-server.c @@ -17,31 +17,15 @@ #include "vhost-user-blk-server.h" #include "qapi/error.h" #include "qom/object_interfaces.h" -#include "sysemu/block-backend.h" #include "util/block-helpers.h" - -/* - * Sector units are 512 bytes regardless of the - * virtio_blk_config->blk_size value. - */ -#define VIRTIO_BLK_SECTOR_BITS 9 -#define VIRTIO_BLK_SECTOR_SIZE (1ull << VIRTIO_BLK_SECTOR_BITS) +#include "virtio-blk-handler.h" enum { VHOST_USER_BLK_NUM_QUEUES_DEFAULT = 1, - VHOST_USER_BLK_MAX_DISCARD_SECTORS = 32768, - VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS = 32768, -}; -struct virtio_blk_inhdr { - unsigned char status; }; typedef struct VuBlkReq { VuVirtqElement elem; - int64_t sector_num; - size_t size; - struct virtio_blk_inhdr *in; - struct virtio_blk_outhdr out; VuServer *server; struct VuVirtq *vq; } VuBlkReq; @@ -50,248 +34,44 @@ typedef struct VuBlkReq { typedef struct { BlockExport export; VuServer vu_server; - uint32_t blk_size; QIOChannelSocket *sioc; struct virtio_blk_config blkcfg; bool writable; } VuBlkExport; -static void vu_blk_req_complete(VuBlkReq *req) +static void vu_blk_req_complete(VuBlkReq *req, size_t in_len) { VuDev *vu_dev = &req->server->vu_dev; - /* IO size with 1 extra status byte */ - vu_queue_push(vu_dev, req->vq, &req->elem, req->size + 1); + vu_queue_push(vu_dev, req->vq, &req->elem, in_len); vu_queue_notify(vu_dev, req->vq); free(req); } -static bool vu_blk_sect_range_ok(VuBlkExport *vexp, uint64_t sector, - size_t size) -{ - uint64_t nb_sectors; - uint64_t total_sectors; - - if (size % VIRTIO_BLK_SECTOR_SIZE) { - return false; - } - - nb_sectors = size >> VIRTIO_BLK_SECTOR_BITS; - - QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != VIRTIO_BLK_SECTOR_SIZE); - if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { - return false; - } - if ((sector << VIRTIO_BLK_SECTOR_BITS) % vexp->blk_size) { - return false; - } - blk_get_geometry(vexp->export.blk, &total_sectors); - if (sector > total_sectors || nb_sectors > total_sectors - sector) { - return false; - } - return true; -} - -static int coroutine_fn -vu_blk_discard_write_zeroes(VuBlkExport *vexp, struct iovec *iov, - uint32_t iovcnt, uint32_t type) -{ - BlockBackend *blk = vexp->export.blk; - struct virtio_blk_discard_write_zeroes desc; - ssize_t size; - uint64_t sector; - uint32_t num_sectors; - uint32_t max_sectors; - uint32_t flags; - int bytes; - - /* Only one desc is currently supported */ - if (unlikely(iov_size(iov, iovcnt) > sizeof(desc))) { - return VIRTIO_BLK_S_UNSUPP; - } - - size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc)); - if (unlikely(size != sizeof(desc))) { - error_report("Invalid size %zd, expected %zu", size, sizeof(desc)); - return VIRTIO_BLK_S_IOERR; - } - - sector = le64_to_cpu(desc.sector); - num_sectors = le32_to_cpu(desc.num_sectors); - flags = le32_to_cpu(desc.flags); - max_sectors = (type == VIRTIO_BLK_T_WRITE_ZEROES) ? - VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS : - VHOST_USER_BLK_MAX_DISCARD_SECTORS; - - /* This check ensures that 'bytes' fits in an int */ - if (unlikely(num_sectors > max_sectors)) { - return VIRTIO_BLK_S_IOERR; - } - - bytes = num_sectors << VIRTIO_BLK_SECTOR_BITS; - - if (unlikely(!vu_blk_sect_range_ok(vexp, sector, bytes))) { - return VIRTIO_BLK_S_IOERR; - } - - /* - * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard - * and write zeroes commands if any unknown flag is set. - */ - if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { - return VIRTIO_BLK_S_UNSUPP; - } - - if (type == VIRTIO_BLK_T_WRITE_ZEROES) { - int blk_flags = 0; - - if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { - blk_flags |= BDRV_REQ_MAY_UNMAP; - } - - if (blk_co_pwrite_zeroes(blk, sector << VIRTIO_BLK_SECTOR_BITS, - bytes, blk_flags) == 0) { - return VIRTIO_BLK_S_OK; - } - } else if (type == VIRTIO_BLK_T_DISCARD) { - /* - * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for - * discard commands if the unmap flag is set. - */ - if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { - return VIRTIO_BLK_S_UNSUPP; - } - - if (blk_co_pdiscard(blk, sector << VIRTIO_BLK_SECTOR_BITS, - bytes) == 0) { - return VIRTIO_BLK_S_OK; - } - } - - return VIRTIO_BLK_S_IOERR; -} - /* Called with server refcount increased, must decrease before returning */ static void coroutine_fn vu_blk_virtio_process_req(void *opaque) { VuBlkReq *req = opaque; VuServer *server = req->server; VuVirtqElement *elem = &req->elem; - uint32_t type; - VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server); BlockBackend *blk = vexp->export.blk; - struct iovec *in_iov = elem->in_sg; struct iovec *out_iov = elem->out_sg; unsigned in_num = elem->in_num; unsigned out_num = elem->out_num; - - /* refer to hw/block/virtio_blk.c */ - if (elem->out_num < 1 || elem->in_num < 1) { - error_report("virtio-blk request missing headers"); - goto err; - } - - if (unlikely(iov_to_buf(out_iov, out_num, 0, &req->out, - sizeof(req->out)) != sizeof(req->out))) { - error_report("virtio-blk request outhdr too short"); - goto err; + int in_len; + + in_len = virtio_blk_process_req(blk, vexp->writable, "vhost_user_blk", + in_iov, out_iov, in_num, out_num); + if (in_len < 0) { + free(req); + vhost_user_server_unref(server); + return; } - iov_discard_front(&out_iov, &out_num, sizeof(req->out)); - - if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { - error_report("virtio-blk request inhdr too short"); - goto err; - } - - /* We always touch the last byte, so just see how big in_iov is. */ - req->in = (void *)in_iov[in_num - 1].iov_base - + in_iov[in_num - 1].iov_len - - sizeof(struct virtio_blk_inhdr); - iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr)); - - type = le32_to_cpu(req->out.type); - switch (type & ~VIRTIO_BLK_T_BARRIER) { - case VIRTIO_BLK_T_IN: - case VIRTIO_BLK_T_OUT: { - QEMUIOVector qiov; - int64_t offset; - ssize_t ret = 0; - bool is_write = type & VIRTIO_BLK_T_OUT; - req->sector_num = le64_to_cpu(req->out.sector); - - if (is_write && !vexp->writable) { - req->in->status = VIRTIO_BLK_S_IOERR; - break; - } - - if (is_write) { - qemu_iovec_init_external(&qiov, out_iov, out_num); - } else { - qemu_iovec_init_external(&qiov, in_iov, in_num); - } - - if (unlikely(!vu_blk_sect_range_ok(vexp, - req->sector_num, - qiov.size))) { - req->in->status = VIRTIO_BLK_S_IOERR; - break; - } - - offset = req->sector_num << VIRTIO_BLK_SECTOR_BITS; - - if (is_write) { - ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0); - } else { - ret = blk_co_preadv(blk, offset, qiov.size, &qiov, 0); - } - if (ret >= 0) { - req->in->status = VIRTIO_BLK_S_OK; - } else { - req->in->status = VIRTIO_BLK_S_IOERR; - } - break; - } - case VIRTIO_BLK_T_FLUSH: - if (blk_co_flush(blk) == 0) { - req->in->status = VIRTIO_BLK_S_OK; - } else { - req->in->status = VIRTIO_BLK_S_IOERR; - } - break; - case VIRTIO_BLK_T_GET_ID: { - size_t size = MIN(iov_size(&elem->in_sg[0], in_num), - VIRTIO_BLK_ID_BYTES); - snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk"); - req->in->status = VIRTIO_BLK_S_OK; - req->size = elem->in_sg[0].iov_len; - break; - } - case VIRTIO_BLK_T_DISCARD: - case VIRTIO_BLK_T_WRITE_ZEROES: { - if (!vexp->writable) { - req->in->status = VIRTIO_BLK_S_IOERR; - break; - } - - req->in->status = vu_blk_discard_write_zeroes(vexp, out_iov, out_num, - type); - break; - } - default: - req->in->status = VIRTIO_BLK_S_UNSUPP; - break; - } - - vu_blk_req_complete(req); - vhost_user_server_unref(server); - return; - -err: - free(req); + vu_blk_req_complete(req, in_len); vhost_user_server_unref(server); } @@ -455,12 +235,12 @@ vu_blk_initialize_config(BlockDriverState *bs, config->opt_io_size = cpu_to_le32(1); config->num_queues = cpu_to_le16(num_queues); config->max_discard_sectors = - cpu_to_le32(VHOST_USER_BLK_MAX_DISCARD_SECTORS); + cpu_to_le32(VIRTIO_BLK_MAX_DISCARD_SECTORS); config->max_discard_seg = cpu_to_le32(1); config->discard_sector_alignment = cpu_to_le32(blk_size >> VIRTIO_BLK_SECTOR_BITS); config->max_write_zeroes_sectors - = cpu_to_le32(VHOST_USER_BLK_MAX_WRITE_ZEROES_SECTORS); + = cpu_to_le32(VIRTIO_BLK_MAX_WRITE_ZEROES_SECTORS); config->max_write_zeroes_seg = cpu_to_le32(1); } @@ -494,7 +274,6 @@ static int vu_blk_exp_create(BlockExport *exp, BlockExportOptions *opts, error_propagate(errp, local_err); return -EINVAL; } - vexp->blk_size = logical_block_size; blk_set_guest_block_size(exp->blk, logical_block_size); if (vu_opts->has_num_queues) { diff --git a/block/export/virtio-blk-handler.c b/block/export/virtio-blk-handler.c new file mode 100644 index 0000000000..3fe83154ef --- /dev/null +++ b/block/export/virtio-blk-handler.c @@ -0,0 +1,237 @@ +/* + * Handler for virtio-blk I/O + * + * Copyright (c) 2020 Red Hat, Inc. + * Copyright (C) 2022 Bytedance Inc. and/or its affiliates. All rights reserved. + * + * Author: + * Coiby Xu + * Xie Yongji + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/error-report.h" +#include "virtio-blk-handler.h" + +#include "standard-headers/linux/virtio_blk.h" + +struct virtio_blk_inhdr { + unsigned char status; +}; + +static bool virtio_blk_sect_range_ok(BlockBackend *blk, + uint64_t sector, size_t size) +{ + uint64_t nb_sectors; + uint64_t total_sectors; + + if (size % VIRTIO_BLK_SECTOR_SIZE) { + return false; + } + + nb_sectors = size >> VIRTIO_BLK_SECTOR_BITS; + + QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != VIRTIO_BLK_SECTOR_SIZE); + if (nb_sectors > BDRV_REQUEST_MAX_SECTORS) { + return false; + } + if ((sector << VIRTIO_BLK_SECTOR_BITS) % blk_get_guest_block_size(blk)) { + return false; + } + blk_get_geometry(blk, &total_sectors); + if (sector > total_sectors || nb_sectors > total_sectors - sector) { + return false; + } + return true; +} + +static int coroutine_fn +virtio_blk_discard_write_zeroes(BlockBackend *blk, struct iovec *iov, + uint32_t iovcnt, uint32_t type) +{ + struct virtio_blk_discard_write_zeroes desc; + ssize_t size; + uint64_t sector; + uint32_t num_sectors; + uint32_t max_sectors; + uint32_t flags; + int bytes; + + /* Only one desc is currently supported */ + if (unlikely(iov_size(iov, iovcnt) > sizeof(desc))) { + return VIRTIO_BLK_S_UNSUPP; + } + + size = iov_to_buf(iov, iovcnt, 0, &desc, sizeof(desc)); + if (unlikely(size != sizeof(desc))) { + error_report("Invalid size %zd, expected %zu", size, sizeof(desc)); + return VIRTIO_BLK_S_IOERR; + } + + sector = le64_to_cpu(desc.sector); + num_sectors = le32_to_cpu(desc.num_sectors); + flags = le32_to_cpu(desc.flags); + max_sectors = (type == VIRTIO_BLK_T_WRITE_ZEROES) ? + VIRTIO_BLK_MAX_WRITE_ZEROES_SECTORS : + VIRTIO_BLK_MAX_DISCARD_SECTORS; + + /* This check ensures that 'bytes' fits in an int */ + if (unlikely(num_sectors > max_sectors)) { + return VIRTIO_BLK_S_IOERR; + } + + bytes = num_sectors << VIRTIO_BLK_SECTOR_BITS; + + if (unlikely(!virtio_blk_sect_range_ok(blk, sector, bytes))) { + return VIRTIO_BLK_S_IOERR; + } + + /* + * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for discard + * and write zeroes commands if any unknown flag is set. + */ + if (unlikely(flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { + return VIRTIO_BLK_S_UNSUPP; + } + + if (type == VIRTIO_BLK_T_WRITE_ZEROES) { + int blk_flags = 0; + + if (flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) { + blk_flags |= BDRV_REQ_MAY_UNMAP; + } + + if (blk_co_pwrite_zeroes(blk, sector << VIRTIO_BLK_SECTOR_BITS, + bytes, blk_flags) == 0) { + return VIRTIO_BLK_S_OK; + } + } else if (type == VIRTIO_BLK_T_DISCARD) { + /* + * The device MUST set the status byte to VIRTIO_BLK_S_UNSUPP for + * discard commands if the unmap flag is set. + */ + if (unlikely(flags & VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP)) { + return VIRTIO_BLK_S_UNSUPP; + } + + if (blk_co_pdiscard(blk, sector << VIRTIO_BLK_SECTOR_BITS, + bytes) == 0) { + return VIRTIO_BLK_S_OK; + } + } + + return VIRTIO_BLK_S_IOERR; +} + +int coroutine_fn virtio_blk_process_req(BlockBackend *blk, bool writable, + const char *serial, + struct iovec *in_iov, + struct iovec *out_iov, + unsigned int in_num, + unsigned int out_num) +{ + struct virtio_blk_inhdr *in; + struct virtio_blk_outhdr out; + uint32_t type; + int in_len; + + if (out_num < 1 || in_num < 1) { + error_report("virtio-blk request missing headers"); + return -EINVAL; + } + + if (unlikely(iov_to_buf(out_iov, out_num, 0, &out, + sizeof(out)) != sizeof(out))) { + error_report("virtio-blk request outhdr too short"); + return -EINVAL; + } + + iov_discard_front(&out_iov, &out_num, sizeof(out)); + + if (in_iov[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) { + error_report("virtio-blk request inhdr too short"); + return -EINVAL; + } + + /* We always touch the last byte, so just see how big in_iov is. */ + in_len = iov_size(in_iov, in_num); + in = (void *)in_iov[in_num - 1].iov_base + + in_iov[in_num - 1].iov_len + - sizeof(struct virtio_blk_inhdr); + iov_discard_back(in_iov, &in_num, sizeof(struct virtio_blk_inhdr)); + + type = le32_to_cpu(out.type); + switch (type & ~VIRTIO_BLK_T_BARRIER) { + case VIRTIO_BLK_T_IN: + case VIRTIO_BLK_T_OUT: { + QEMUIOVector qiov; + int64_t offset; + ssize_t ret = 0; + bool is_write = type & VIRTIO_BLK_T_OUT; + int64_t sector_num = le64_to_cpu(out.sector); + + if (is_write && !writable) { + in->status = VIRTIO_BLK_S_IOERR; + break; + } + + if (is_write) { + qemu_iovec_init_external(&qiov, out_iov, out_num); + } else { + qemu_iovec_init_external(&qiov, in_iov, in_num); + } + + if (unlikely(!virtio_blk_sect_range_ok(blk, sector_num, + qiov.size))) { + in->status = VIRTIO_BLK_S_IOERR; + break; + } + + offset = sector_num << VIRTIO_BLK_SECTOR_BITS; + + if (is_write) { + ret = blk_co_pwritev(blk, offset, qiov.size, &qiov, 0); + } else { + ret = blk_co_preadv(blk, offset, qiov.size, &qiov, 0); + } + if (ret >= 0) { + in->status = VIRTIO_BLK_S_OK; + } else { + in->status = VIRTIO_BLK_S_IOERR; + } + break; + } + case VIRTIO_BLK_T_FLUSH: + if (blk_co_flush(blk) == 0) { + in->status = VIRTIO_BLK_S_OK; + } else { + in->status = VIRTIO_BLK_S_IOERR; + } + break; + case VIRTIO_BLK_T_GET_ID: { + size_t size = MIN(strlen(serial) + 1, + MIN(iov_size(in_iov, in_num), + VIRTIO_BLK_ID_BYTES)); + iov_from_buf(in_iov, in_num, 0, serial, size); + in->status = VIRTIO_BLK_S_OK; + break; + } + case VIRTIO_BLK_T_DISCARD: + case VIRTIO_BLK_T_WRITE_ZEROES: + if (!writable) { + in->status = VIRTIO_BLK_S_IOERR; + break; + } + in->status = virtio_blk_discard_write_zeroes(blk, out_iov, + out_num, type); + break; + default: + in->status = VIRTIO_BLK_S_UNSUPP; + break; + } + + return in_len; +} diff --git a/block/export/virtio-blk-handler.h b/block/export/virtio-blk-handler.h new file mode 100644 index 0000000000..19f907b3f8 --- /dev/null +++ b/block/export/virtio-blk-handler.h @@ -0,0 +1,33 @@ +/* + * Handler for virtio-blk I/O + * + * Copyright (c) 2020 Red Hat, Inc. + * Copyright (C) 2022 Bytedance Inc. and/or its affiliates. All rights reserved. + * + * Author: + * Coiby Xu + * Xie Yongji + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * later. See the COPYING file in the top-level directory. + */ + +#ifndef VIRTIO_BLK_HANDLER_H +#define VIRTIO_BLK_HANDLER_H + +#include "sysemu/block-backend.h" + +#define VIRTIO_BLK_SECTOR_BITS 9 +#define VIRTIO_BLK_SECTOR_SIZE (1ULL << VIRTIO_BLK_SECTOR_BITS) + +#define VIRTIO_BLK_MAX_DISCARD_SECTORS 32768 +#define VIRTIO_BLK_MAX_WRITE_ZEROES_SECTORS 32768 + +int coroutine_fn virtio_blk_process_req(BlockBackend *blk, bool writable, + const char *serial, + struct iovec *in_iov, + struct iovec *out_iov, + unsigned int in_num, + unsigned int out_num); + +#endif /* VHOST_USER_BLK_SERVER_H */