From patchwork Tue Aug 16 06:25:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Li X-Patchwork-Id: 1666691 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Lmzd/m9a; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4M6M7Z0QMZz1yft for ; Tue, 16 Aug 2022 16:44:08 +1000 (AEST) Received: from localhost ([::1]:33928 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oNqJ3-0002UE-A9 for incoming@patchwork.ozlabs.org; Tue, 16 Aug 2022 02:44:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60588) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oNq1Z-0006Ez-C9; Tue, 16 Aug 2022 02:26:01 -0400 Received: from mail-pj1-x102e.google.com ([2607:f8b0:4864:20::102e]:35661) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1oNq1X-0003dm-Cr; Tue, 16 Aug 2022 02:26:00 -0400 Received: by mail-pj1-x102e.google.com with SMTP id m10-20020a17090a730a00b001fa986fd8eeso568207pjk.0; Mon, 15 Aug 2022 23:25:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=LR986ojhUARUop8jfo7ruxBtsc8WmLIQeeugiixceKA=; b=Lmzd/m9abN23+bEg6o2tXMtbX4nEkWIG/0WVIv+9kvwz5QeWSDPvexT29XV9wDrmru yQSXX7MvLtuWfbCkUlKV8MGs5WRAORL7FpoFB2QFlgRlU/dDkLRvgqzB5GACA45+H/hW AndjRGZr4jJh2p9Olz4d0gS1cr7H+5aRXhjCPBR2tTC7ea/jJFyslnscrobWToQlGh3f ltkFK2ej0M+SC9wqfaZ/YGUbIDTK5iwN6WVOnJji1gOomT9nisuSZ+f7/IygMAe000JP 7NpVGaKT559n6D/emFvPzIKLBWk7W6FHSFPjUXFnSQUJQmrKmb9VLxBZM9vzhBqyUa9b vVrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=LR986ojhUARUop8jfo7ruxBtsc8WmLIQeeugiixceKA=; b=U0AaBFnYIw5Ay7BhBGE81TAx8SGsDCx2eiAa1x0tZVM9f0OZmBJ3O++DIUFwpluPE+ +aUe38+F4rbnCHHXyPiYK2fzYRaYaepZX+6lSdxegcqUMR4ntO7DQ4HrfFR0yZoCodNA hFbbVRzyCxOO4BTQhSOFBvDp3mJAB3TqbuAEFm+Ix3wCibuIKfigeurqRZnYuLSS84h0 Gyl3yCafKn3DS87seQ0fNQBF+1/v4MBRULkvHHz3M1xcBs6CPXAO+kUfial/oZegyZaR R2eHx0/5+Aeo4uWvUPZAqgOjXsDG57i4jaxC2FDf1nbLBbjSL0SmWqv7MpxpLSkN+rkx GRYQ== X-Gm-Message-State: ACgBeo2+I2ro7qz1kewNd4+nzqftdDSfUp5dkfnRbQHvK5oEAGRyOsUa Z4iKWtBa7524Cq+ZB+azGaWk/lJkJix/KA== X-Google-Smtp-Source: AA6agR7gffjW5qF/OZRY42jPBYq6Rhrj/bRgYgncSC7ZVd8H1qeIqH6JhbMC+XZOtArVvPVTP1DQ6A== X-Received: by 2002:a17:90b:33cb:b0:1f4:f635:93f8 with SMTP id lk11-20020a17090b33cb00b001f4f63593f8mr32885998pjb.74.1660631157472; Mon, 15 Aug 2022 23:25:57 -0700 (PDT) Received: from roots.. ([106.84.129.185]) by smtp.gmail.com with ESMTPSA id e15-20020a170902784f00b0016f1c1f50f4sm8082868pln.235.2022.08.15.23.25.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Aug 2022 23:25:57 -0700 (PDT) From: Sam Li To: qemu-devel@nongnu.org Cc: hare@suse.de, Fam Zheng , Kevin Wolf , Eric Blake , Markus Armbruster , stefanha@redhat.com, Hanna Reitz , dmitry.fomichev@wdc.com, qemu-block@nongnu.org, damien.lemoal@opensource.wdc.com, Sam Li Subject: [PATCH v7 8/8] docs/zoned-storage: add zoned device documentation Date: Tue, 16 Aug 2022 14:25:22 +0800 Message-Id: <20220816062522.85714-9-faithilikerun@gmail.com> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220816062522.85714-1-faithilikerun@gmail.com> References: <20220816062522.85714-1-faithilikerun@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::102e; envelope-from=faithilikerun@gmail.com; helo=mail-pj1-x102e.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add the documentation about the zoned device support to virtio-blk emulation. Signed-off-by: Sam Li Reviewed-by: Stefan Hajnoczi --- docs/devel/zoned-storage.rst | 41 ++++++++++++++++++++++++++ docs/system/qemu-block-drivers.rst.inc | 6 ++++ 2 files changed, 47 insertions(+) create mode 100644 docs/devel/zoned-storage.rst diff --git a/docs/devel/zoned-storage.rst b/docs/devel/zoned-storage.rst new file mode 100644 index 0000000000..ead2d149cc --- /dev/null +++ b/docs/devel/zoned-storage.rst @@ -0,0 +1,41 @@ +============= +zoned-storage +============= + +Zoned Block Devices (ZBDs) devide the LBA space into block regions called zones +that are larger than the LBA size. It can only allow sequential writes, which +reduces write amplification in SSDs, leading to higher throughput and increased +capacity. More details about ZBDs can be found at: + +https://zonedstorage.io/docs/introduction/zoned-storage + +1. Block layer APIs for zoned storage +------------------------------------- +QEMU block layer has three zoned storage model: +- BLK_Z_HM: This model only allows sequential writes access. It supports a set +of ZBD-specific I/O request that used by the host to manage device zones. +- BLK_Z_HA: It deals with both sequential writes and random writes access. +- BLK_Z_NONE: Regular block devices and drive-managed ZBDs are treated as +non-zoned devices. + +The block device information resides inside BlockDriverState. QEMU uses +BlockLimits struct(BlockDriverState::bl) that is continuously accessed by the +block layer while processing I/O requests. A BlockBackend has a root pointer to +a BlockDriverState graph(for example, raw format on top of file-posix). The +zoned storage information can be propagated from the leaf BlockDriverState all +the way up to the BlockBackend. If the zoned storage model in file-posix is +set to BLK_Z_HM, then block drivers will declare support for zoned host device. + +The block layer APIs support commands needed for zoned storage devices, +including report zones, four zone operations, and zone append. + +2. Emulating zoned storage controllers +-------------------------------------- +When the BlockBackend's BlockLimits model reports a zoned storage device, users +like the virtio-blk emulation or the qemu-io-cmds.c utility can use block layer +APIs for zoned storage emulation or testing. + +For example, the command line for zone report testing a null_blk device of +qemu-io-cmds.c is: +$ path/to/qemu-io --image-opts driver=zoned_host_device,filename=/dev/nullb0 -c +"zrp offset nr_zones" diff --git a/docs/system/qemu-block-drivers.rst.inc b/docs/system/qemu-block-drivers.rst.inc index dfe5d2293d..0b97227fd9 100644 --- a/docs/system/qemu-block-drivers.rst.inc +++ b/docs/system/qemu-block-drivers.rst.inc @@ -430,6 +430,12 @@ Hard disks you may corrupt your host data (use the ``-snapshot`` command line option or modify the device permissions accordingly). +Zoned block devices + Zoned block devices can be passed through to the guest if the emulated storage + controller supports zoned storage. Use ``--blockdev zoned_host_device, + node-name=drive0,filename=/dev/nullb0`` to pass through ``/dev/nullb0`` + as ``drive0``. + Windows ^^^^^^^