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GET /api/1.2/patches/2224335/?format=api
{ "id": 2224335, "url": "http://patchwork.ozlabs.org/api/1.2/patches/2224335/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260417-sdcard-performance-b4-v4-6-119e66be10c2@avm.de/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/1.2/projects/14/?format=api", "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-v4-6-119e66be10c2@avm.de>", "list_archive_url": null, "date": "2026-04-17T09:51:39", "name": "[v4,6/7] hw/sd/sdcard: Optimize erase blocks as zero.", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "2f3f319bc43b50a0230b9f6aa51d90043831497a", "submitter": { "id": 91343, "url": "http://patchwork.ozlabs.org/api/1.2/people/91343/?format=api", "name": "Christian Speich", "email": "c.speich@avm.de" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260417-sdcard-performance-b4-v4-6-119e66be10c2@avm.de/mbox/", "series": [ { "id": 500297, "url": "http://patchwork.ozlabs.org/api/1.2/series/500297/?format=api", "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/patches/2224335/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2224335/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "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=ZK9i54fo;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fxr184Xvfz1yDF\n\tfor <incoming@patchwork.ozlabs.org>; Fri, 17 Apr 2026 19:58:20 +1000 (AEST)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1wDfxf-0003Ku-Fg; Fri, 17 Apr 2026 05:58:09 -0400", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <c.speich@avm.de>)\n id 1wDfxB-0002pp-OO; Fri, 17 Apr 2026 05:57:37 -0400", "from mail.avm.de ([2001:bf0:244:244::119])\n by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <c.speich@avm.de>)\n id 1wDfx9-000389-GR; Fri, 17 Apr 2026 05:57:36 -0400", "from [172.16.0.1] (helo=mail.avm.de)\n by mail.avm.de with ESMTP (eXpurgate 4.55.2)\n (envelope-from <c.speich@avm.de>)\n id 69e20406-1e6c-7f0000032729-7f000001b2c4-1\n for <multiple-recipients>; Fri, 17 Apr 2026 11:57:26 +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 11:57:26 +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 2026041711572445-2979 ;\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=1776419846; bh=5SYH+A8NyAGbb6vSKm8RhEoSuVLKy93+R7omElZI8D4=;\n h=From:Date:Subject:References:In-Reply-To:To:Cc:From;\n b=ZK9i54fox3XJjwgzlj4oZZGMT+xviuIjKa+l5O2HvQKizvFaHch20mI7QrWVrhR7G\n XkISUDdCmBiW5aQYukofDLW5d5bDLo6CdBz0ziQDpBt5zdHrQrhKqSLoPkHIIqdZfQ\n ooHJafZY5mXIDPjh+dBlIRsOKJRQ6aNcYzQ+yBrk=", "From": "Christian Speich <c.speich@avm.de>", "Date": "Fri, 17 Apr 2026 11:51:39 +0200", "Subject": "[PATCH v4 6/7] hw/sd/sdcard: Optimize erase blocks as zero.", "MIME-Version": "1.0", "Message-Id": "<20260417-sdcard-performance-b4-v4-6-119e66be10c2@avm.de>", "References": "<20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de>", "In-Reply-To": "<20260417-sdcard-performance-b4-v4-0-119e66be10c2@avm.de>", "To": "qemu-devel@nongnu.org", "Cc": "=?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= <philmd@linaro.org>,\n Bin Meng <bmeng.cn@gmail.com>, qemu-block@nongnu.org,\n Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,\n Yanan Wang <wangyanan55@huawei.com>, Zhao Liu <zhao1.liu@intel.com>,\n Christian Speich <c.speich@avm.de>", "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 11:57:26, Serialize complete at 17.04.2026 11:57:26", "X-TNEFEvaluated": "1", "Content-Transfer-Encoding": "7bit", "Content-Type": "text/plain; charset=\"utf-8\"", "X-purgate-ID": "149429::1776419846-50F26373-590759AA/0/0", "X-purgate-type": "clean", "X-purgate-size": "3267", "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 <qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<https://lists.nongnu.org/archive/html/qemu-devel>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org" }, "content": "When erasing blocks as zero, we can use optimized block functions to\nachieve this.\n\nThese allow us to request a large rage to be zeroed, possible optimizing\nthis operation and freeing disk space for sparsesly stored images.\n\nThis only is possible when erase-blocks-as-zero=true is used and can\nprovide a significant performance boost. The case where 0xFF is used\nduring erase is as slow as before.\n\nSigned-off-by: Christian Speich <c.speich@avm.de>\n---\n hw/sd/sd.c | 43 +++++++++++++++++++++++++++++++++----------\n 1 file changed, 33 insertions(+), 10 deletions(-)", "diff": "diff --git a/hw/sd/sd.c b/hw/sd/sd.c\nindex 0f997ed8cc80e38645101cb8f47c86f1c30d5a25..d1ff9badb39b699ce734a533ccebfab894958d2d 100644\n--- a/hw/sd/sd.c\n+++ b/hw/sd/sd.c\n@@ -1331,6 +1331,26 @@ exit:\n trace_sdcard_rpmb_write_block(req, lduw_be_p(&sd->rpmb.result.result));\n }\n \n+/* Requires sd->buf to be filled with 0xFF */\n+static void sd_erase_ff(SDState *sd, uint64_t addr, size_t len)\n+{\n+ int erase_len = 1 << HWBLOCK_SHIFT;\n+ uint64_t erase_addr;\n+\n+ for (erase_addr = addr; erase_addr < addr + len; erase_addr += erase_len) {\n+ sd_blk_write_bounce_buffer(sd, erase_addr, erase_len);\n+ }\n+}\n+\n+static void sd_blk_erase(SDState *sd, uint64_t addr, size_t len)\n+{\n+ if (sd->erase_blocks_as_zero) {\n+ blk_pwrite_zeroes(sd->blk, addr + sd_part_offset(sd), len, 0);\n+ } else {\n+ sd_erase_ff(sd, addr, len);\n+ }\n+}\n+\n static void sd_erase(SDState *sd)\n {\n uint64_t erase_start = sd->erase_start;\n@@ -1338,7 +1358,6 @@ static void sd_erase(SDState *sd)\n bool sdsc = true;\n uint64_t wpnum;\n uint64_t erase_addr;\n- int erase_len = 1 << HWBLOCK_SHIFT;\n \n trace_sdcard_erase(sd->erase_start, sd->erase_end);\n if (sd->erase_start == INVALID_ADDRESS\n@@ -1367,24 +1386,28 @@ static void sd_erase(SDState *sd)\n sd->erase_end = INVALID_ADDRESS;\n sd->csd[14] |= 0x40;\n \n- if (sd->erase_blocks_as_zero) {\n- memset(sd->data, 0x0, erase_len);\n- } else {\n- memset(sd->data, 0xFF, erase_len);\n+ if (!sd->erase_blocks_as_zero) {\n+ memset(sd->data, 0xFF, 1 << HWBLOCK_SHIFT);\n }\n \n- for (erase_addr = erase_start; erase_addr <= erase_end;\n- erase_addr += erase_len) {\n- if (sdsc) {\n- /* Only SDSC cards support write protect groups */\n+ /* Only SDSC cards support write protect groups */\n+ if (sdsc) {\n+ for (erase_addr = erase_start; erase_addr <= erase_end;\n+ erase_addr = ROUND_UP(erase_addr + 1, WPGROUP_SIZE)) {\n+ uint64_t wp_group_end = ROUND_UP(erase_addr + 1, WPGROUP_SIZE) - 1;\n+ size_t erase_len = MIN(erase_end, wp_group_end) - erase_addr;\n+\n wpnum = sd_addr_to_wpnum(erase_addr);\n assert(wpnum < sd->wp_group_bits);\n if (test_bit(wpnum, sd->wp_group_bmap)) {\n sd->card_status |= WP_ERASE_SKIP;\n continue;\n }\n+\n+ sd_blk_erase(sd, erase_addr, erase_len);\n }\n- sd_blk_write_bounce_buffer(sd, erase_addr, erase_len);\n+ } else {\n+ sd_blk_erase(sd, erase_start, erase_end - erase_start);\n }\n }\n \n", "prefixes": [ "v4", "6/7" ] }