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 Received: from lists1p.gnu.org (lists1p.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 9CCA2C61DBD for ; Fri, 28 Aug 2026 06:04:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wzph0-0003u3-Dh; Fri, 28 Aug 2026 02:03:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wzpgx-0003tG-La; Fri, 28 Aug 2026 02:03:55 -0400 Received: from tor.source.kernel.org ([172.105.4.254]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wzpgv-0008HS-Hp; Fri, 28 Aug 2026 02:03:54 -0400 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id C1179602D4; Fri, 28 Aug 2026 06:03:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D1531F000E9; Fri, 28 Aug 2026 06:03:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787897031; bh=/9DcE0oBOTpnnyvav5O79wroy6qgCRGo0tw2dpjsMEs=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=UPurG5PV4nHO6ITGEIsPJPUGeHHvZaFzTHfOBsvyV/XpJPcrB5OlOWXQ+6LOcNvP5 izffe/zhmpFNh5tc/fzDfsJVj0Q4QNUpOmfbZvR/0jIJxfhnxq+Vf8En7qIHDC1sN3 U7EdH9PaJzXDXi5YFVaCU4SGWNh5KfceG339sBzy0BRX4I9JvaqS8FY+TpYYB8fuA6 MTZ1kuHnmqLhBp6VqqFQUVd+x3eWyfnu7gZuB6CSySLnJsWXdvovW0nIjMrMAnaW4F 0DCyG4/NRSR1Gs9zu/60/zDmNb5+d3Th15ko7fXZRg8ewCZ17ykzl1vOrexMszfBoH qee/NsFgD44RA== Message-ID: <71d8cb90-8114-4c53-b786-2e3f0fdf81b6@kernel.org> Date: Fri, 28 Aug 2026 15:03:48 +0900 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 04/12] virtio-blk: report the effective zone write granularity To: Niklas Cassel , Stefan Hajnoczi , John Snow , "Denis V. Lunev" , Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" Cc: Sam Li , qemu-block@nongnu.org, qemu-devel@nongnu.org References: <20260825205748.679968-1-cassel@kernel.org> <20260825205748.679968-5-cassel@kernel.org> Content-Language: en-US From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20260825205748.679968-5-cassel@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=172.105.4.254; envelope-from=dlemoal@kernel.org; helo=tor.source.kernel.org 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, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: qemu development 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 8/26/26 05:57, Niklas Cassel wrote: > For ZBC/ZAC devices the write granularity is the physical block size, so > a 512e SMR disk exposed through a host_device backend has a logical block > size of 512 and a zone write granularity of 4096. We told the guest driver 512 > while raw_co_zone_append() rejects anything that is not 4096 byte > aligned, so the driver saw a plain I/O error for a request it had been > told was valid. > > Report the larger of the backend granularity and the logical block size > instead. The guest driver cannot issue writes finer than the logical > size, so the larger of the two is the constraint that applies. This > matches what a Linux guest derives for itself: blk_validate_zoned_limits() > raises zone_write_granularity to the logical block size, and > blk_stack_limits() stacks it with max(). > > Add it as a helper next to blkconf_blocksizes(), since it is derived from > a BlockConf and the limits of the backend below it, and use it for the > zone append offset check in check_zoned_request(), which validated > against bs->bl.write_granularity. The value reported to the driver and > the value that requests are validated against then cannot drift apart. > The helper cannot return zero because blkconf_blocksizes() always leaves > a logical block size behind, so the check no longer needs to guard > against an unset granularity. > > Fixes: 4f7366506a96 ("virtio-blk: add zoned storage emulation for zoned devices") > Signed-off-by: Niklas Cassel Reviewed-by: Damien Le Moal -- Damien Le Moal Western Digital Research