{"id":2224338,"url":"http://patchwork.ozlabs.org/api/1.2/covers/2224338/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/cover/20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.2/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de>","list_archive_url":null,"date":"2026-04-17T09:51:33","name":"[v4,0/7] hw/sd: Improve performance of read/write/erase","submitter":{"id":91343,"url":"http://patchwork.ozlabs.org/api/1.2/people/91343/?format=json","name":"Christian Speich","email":"c.speich@avm.de"},"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/cover/20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de/mbox/","series":[{"id":500297,"url":"http://patchwork.ozlabs.org/api/1.2/series/500297/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=500297","date":"2026-04-17T09:51:34","name":"hw/sd: Improve performance of read/write/erase","version":4,"mbox":"http://patchwork.ozlabs.org/series/500297/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/covers/2224338/comments/","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=avm.de header.i=@avm.de header.a=rsa-sha256\n header.s=mail header.b=aXmWWnx4;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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Fri, 17 Apr 2026 11:57:25 +0200","from mail-notes.avm.de (mail-notes.avm.de [172.16.0.1])\n by mail.avm.de (Postfix) with ESMTP;\n Fri, 17 Apr 2026 11:57:25 +0200 (CEST)","from [127.0.1.1] ([172.17.89.139])\n by mail-notes.avm.de (HCL Domino Release 14.0FP4)\n with ESMTP id 2026041711572441-2973 ;\n Fri, 17 Apr 2026 11:57:24 +0200"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=avm.de; s=mail;\n t=1776419845; bh=hMZI9Of630JExhvUar0FTq2FjOJ5OfP7PFDSsZ5OJ8A=;\n h=From:Subject:Date:To:Cc:From;\n b=aXmWWnx4XW4wW5naiW2n26WFxN8IrFiZ2QMNjVeuSQzSxMqGuN7FL5LTS4Z7tth2V\n cLgk5eR68hl0fK6/LwuxlVhGtFlPlvxKvbb5dUme80MVIrik5RLk5YOXqUqkDfzM8S\n MeiFGlJB61IjdB47lipUx9jy+Ux1iuYKtun4C9qE=","From":"Christian Speich ","Subject":"[PATCH v4 0/7] hw/sd: Improve performance of read/write/erase","Date":"Fri, 17 Apr 2026 11:51:33 +0200","Message-Id":"<20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de>","MIME-Version":"1.0","X-B4-Tracking":"v=1; b=H4sIAKUC4mkC/3XNzQrCMAzA8VeRnq0kWeesJ99DPPQjcz3sg1aKM\n vbudoKCh10C/0B+mUXiGDiJ824WkXNIYRxKqP1OuM4Md5bBlxYEVINGksk7E72cOLZj7M3gWFo\n lvYaTtbY2AEqU2ylyG54f93or3YX0GOPr8ybjuv2KekPMKEEyQtWwOqFBfTG5P3gWK5fpR2AZW\n wQVwitSGixiRfRHVF/iCARqi6hWwqFrsSHmuvkRy7K8Afyn7Ek9AQAA","X-Change-ID":"20250912-sdcard-performance-b4-d908bbb5a004","To":"qemu-devel@nongnu.org","Cc":"=?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= ,\n Bin Meng , qemu-block@nongnu.org,\n Marcel Apfelbaum ,\n Yanan Wang , Zhao Liu ,\n Christian Speich ","X-Mailer":"b4 0.14.2","X-MIMETrack":"Itemize by SMTP Server on ANIS1/AVM(Release 14.0FP4|March 10,\n 2025) at 17.04.2026 11:57:24,\n Serialize by Router on ANIS1/AVM(Release 14.0FP4|March 10, 2025) at\n 17.04.2026 11:57:24, Serialize complete at 17.04.2026 11:57:24","X-TNEFEvaluated":"1","Content-Transfer-Encoding":"7bit","Content-Type":"text/plain; charset=\"utf-8\"","X-purgate-ID":"149429::1776419845-8E72B373-383F0CAF/0/0","X-purgate-type":"clean","X-purgate-size":"3153","X-purgate-Ad":"Categorized by eleven eXpurgate (R) https://www.eleven.de","X-purgate":["This mail is considered clean (visit https://www.eleven.de for\n further information)","clean"],"Received-SPF":"pass client-ip=2001:bf0:244:244::119;\n envelope-from=c.speich@avm.de; helo=mail.avm.de","X-Spam_score_int":"-25","X-Spam_score":"-2.6","X-Spam_bar":"--","X-Spam_report":"(-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.54,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n 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":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"This patch series improves the performance of read/write/erase operations\non sdcards.\n\nThis is done by increasing the maximum buffer size that is worked on.\nFrom 1 byte (master) to 512 bytes (commit 1-3) to larger than 512\n(adma commit).\n\nTesting on my system with fio I see the following rough performance\nvalues in MiB/s.\n\n read write readwrite\n master: 6 6 3/ 3\n first commit: 51 43 23/ 23\nsecond commit: 392 180 144/143\n\nTested on a 2GiB raw image with:\n fio --filename=/dev/mmcblk0 --direct=1 --runtime=60 --time_based --bs=128k --rw={mode}\n\nThe adma values are somewhat unstable but always >100MiB/s, I'm not sure\nwhy but I guess it has something to do with the host side caching.\n\nThe fifth commit fixes the DATA_STAT_AFTER_ERASE bit in SCR and\nintroduces an option to allow to erase blocks to 0x00.\n\nThe sixth commit optimizes block erase when erase-blocks-as-zero=true\nis used, by passing the zeroing request down the to the block device.\nErasing 2GiB now takes 0.1s instead of 26s.\n\nSigned-off-by: Christian Speich \n---\nChanges in v4:\n- Rebase onto master, no changes needed.\n- Renames:\n - sd_blk_{read,write} -> sd_blk_{read,write}_bounce_buffer\n - sd_blk_{read,write}_direct -> sd_blk_{read,write}\n - to_erase -> erase_len\n- Extract erase logic into sd_blk_erase helper\n- Enable erase-blocks-as-zero by default. Add compat for 11.0 and below\n to keep it disabled.\n- Add cleanup commit to update trace events.\n- Link to v3: https://lore.kernel.org/qemu-devel/20260204-sdcard-performance-b4-v3-0-dc1cf172ee57@avm.de\n\nChanges in v3:\n- Rebase onto master, updating read/write path for newly added RBMP\n- Split up commit 1 into multiple commits\n - change interface to allow \"short\" read/writes that are continued\n by the core later by calling again\n- Link to v2: https://lore.kernel.org/qemu-devel/20251202-sdcard-performance-b4-v2-0-d42490b11322@avm.de\n\nChanges in v2:\n- Properly set DATA_STAT_AFTER_ERASE in SCR\n- Add erase-blocks-as-zero option to allow the user to switch between\n 0x00 and 0xFF for erased blocks.\n- Link to v1: https://lore.kernel.org/qemu-devel/20250919-sdcard-performance-b4-v1-0-e1037e481a19@avm.de\n\n---\nChristian Speich (7):\n hw/sd: Switch read/write primitive to buf+len\n hw/sd/sd: Allow multi-byte read/write for generic paths\n hw/sd/sd: Use multi-byte/block writes for block path\n hw/sd/sdhci: Don't use bounce buffer for ADMA\n hw/sd/sdcard: Add erase-blocks-as-zero option.\n hw/sd/sdcard: Optimize erase blocks as zero.\n hw/sd: Update trace events for buf+len data\n\n hw/core/machine.c | 5 +\n hw/sd/core.c | 53 ++++++--\n hw/sd/sd.c | 353 ++++++++++++++++++++++++++++++++++++++++-------------\n hw/sd/sdhci.c | 102 +++++++++-------\n hw/sd/trace-events | 6 +-\n include/hw/sd/sd.h | 22 ++--\n 6 files changed, 389 insertions(+), 152 deletions(-)\n---\nbase-commit: da6c4fe60fee30dd77267764d55b38af9cb89d4b\nchange-id: 20250912-sdcard-performance-b4-d908bbb5a004\n\nBest regards,"}