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GET /api/patches/2194853/?format=api
{ "id": 2194853, "url": "http://patchwork.ozlabs.org/api/patches/2194853/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260210032348.987549-21-zhao1.liu@intel.com/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/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": "<20260210032348.987549-21-zhao1.liu@intel.com>", "list_archive_url": null, "date": "2026-02-10T03:23:47", "name": "[v2,20/21] target/i386: detect user provided lbr-fmt via property flag", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "644fb9c83711dcf9ad169ebaa4bd9c8284342d30", "submitter": { "id": 86545, "url": "http://patchwork.ozlabs.org/api/people/86545/?format=api", "name": "Zhao Liu", "email": "zhao1.liu@intel.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260210032348.987549-21-zhao1.liu@intel.com/mbox/", "series": [ { "id": 491594, "url": "http://patchwork.ozlabs.org/api/series/491594/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=491594", "date": "2026-02-10T03:23:28", "name": "qom: introduce property flags to track external user input", "version": 2, "mbox": "http://patchwork.ozlabs.org/series/491594/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2194853/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2194853/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 (2048-bit key;\n unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256\n header.s=Intel header.b=dJu5EPvy;\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=lists.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists.gnu.org (lists.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 4f95sh4FRqz1xvb\n\tfor <incoming@patchwork.ozlabs.org>; Tue, 10 Feb 2026 14:00:40 +1100 (AEDT)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1vpdz9-0001vU-MB; Mon, 09 Feb 2026 22:00:19 -0500", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <zhao1.liu@intel.com>)\n id 1vpdyl-00019D-GD\n for qemu-devel@nongnu.org; Mon, 09 Feb 2026 21:59:58 -0500", "from mgamail.intel.com ([198.175.65.14])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <zhao1.liu@intel.com>)\n id 1vpdyi-0004IS-Nh\n for qemu-devel@nongnu.org; Mon, 09 Feb 2026 21:59:55 -0500", "from orviesa008.jf.intel.com ([10.64.159.148])\n by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384;\n 09 Feb 2026 18:59:49 -0800", "from liuzhao-optiplex-7080.sh.intel.com ([10.239.160.39])\n by orviesa008.jf.intel.com with ESMTP; 09 Feb 2026 18:59:43 -0800" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple;\n d=intel.com; i=@intel.com; q=dns/txt; s=Intel;\n t=1770692392; x=1802228392;\n h=from:to:cc:subject:date:message-id:in-reply-to:\n references:mime-version:content-transfer-encoding;\n bh=rHQyqSJDlnq8AfY8ZN5U8grBknt55dcxwohK9sGr+K8=;\n b=dJu5EPvych9Y+1rRq3F9zJrkSM50+M/moxNJT9qfh1Dras/gdRI88NfO\n +4A1QJAr6sderusAEDLU1vfWQq1kha0ay16vhaW8Awqf//+oV08K5DbCO\n Sr21HglSGqKkgH0t8QXG+BiMMk2kaoQ+NoqZ/7+ebyY0PSyo/O699JKTZ\n suiXm3LbEj6lUpNy5jZGa0yqJBnTTRJTLtkejZ6WP62iNgKN2ncKisJc0\n Wogq8y9OWXidROm1zDFYb3YqRRVoVMwpoLcDP0KBTWIP1Fe8UjvmfWOuE\n wlKYV04C6pA7riSRz/KxEhv/dE6G++QIws2VMe6PuC8ZSNXb00pdtLcD8 A==;", "X-CSE-ConnectionGUID": [ "fEBrZWgiTYSeQjS3D4rH0w==", "Rj1KXFK3SZip+20rWdxCqQ==" ], "X-CSE-MsgGUID": [ "4AuLckFpSxatkAsXfCcGJA==", "qeKQ7GTIQkiQ7733GXv+RQ==" ], "X-IronPort-AV": [ "E=McAfee;i=\"6800,10657,11696\"; a=\"75660012\"", "E=Sophos;i=\"6.21,283,1763452800\"; d=\"scan'208\";a=\"75660012\"", "E=Sophos;i=\"6.21,283,1763452800\"; d=\"scan'208\";a=\"211800809\"" ], "X-ExtLoop1": "1", "From": "Zhao Liu <zhao1.liu@intel.com>", "To": "Paolo Bonzini <pbonzini@redhat.com>, =?utf-8?q?Daniel_P_=2E_Berrang?=\n\t=?utf-8?q?=C3=A9?= <berrange@redhat.com>,\n Eduardo Habkost <eduardo@habkost.net>, Markus Armbruster <armbru@redhat.com>,\n Thomas Huth <thuth@redhat.com>, Igor Mammedov <imammedo@redhat.com>,\n\t=?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= <philmd@linaro.org>", "Cc": "Richard Henderson <richard.henderson@linaro.org>,\n Peter Maydell <peter.maydell@linaro.org>,\n \"Michael S . Tsirkin\" <mst@redhat.com>,\n BALATON Zoltan <balaton@eik.bme.hu>,\n Mark Cave-Ayland <mark.caveayland@nutanix.com>,\n Pierrick Bouvier <pierrick.bouvier@linaro.org>,\n Zide Chen <zide.chen@intel.com>, Dapeng Mi <dapeng1.mi@linux.intel.com>,\n Zhao Liu <zhao1.liu@intel.com>, qemu-devel@nongnu.org,\n devel@lists.libvirt.org", "Subject": "[PATCH v2 20/21] target/i386: detect user provided lbr-fmt via\n property flag", "Date": "Tue, 10 Feb 2026 11:23:47 +0800", "Message-Id": "<20260210032348.987549-21-zhao1.liu@intel.com>", "X-Mailer": "git-send-email 2.34.1", "In-Reply-To": "<20260210032348.987549-1-zhao1.liu@intel.com>", "References": "<20260210032348.987549-1-zhao1.liu@intel.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "Received-SPF": "pass client-ip=198.175.65.14; envelope-from=zhao1.liu@intel.com;\n helo=mgamail.intel.com", "X-Spam_score_int": "-43", "X-Spam_score": "-4.4", "X-Spam_bar": "----", "X-Spam_report": "(-4.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001,\n RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001,\n 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": "At present, QEMU determines if the user has set the \"lbr-fmt\" property\nby checking if its value differs from a special value,\n`~PERF_CAP_LBR_FMT` (`~0x3f`).\n\nRelying on such a magic number to distinguish user input from the\ndefault state is implicit and fragile. It also prevents the helper macro\n`DEFINE_PROP_UINT64_CHECKMASK` from supporting a *valid* default value,\nas initializing the property with a valid default would make it\nimpossible to distinguish from a user-provided value.\n\nWith the introduction of `OBJ_PROP_FLAG_USER_SET`, it's possible to\ndirectly check this flag to determine whether the user has modified the\nproperty, which can help get rid of invalid \"sentinel\" value.\n\nTherefore, detect user-provided value by checking the USER_SET property\nflag in x86_cpu_realizefn(). The invalid initialization value will be\ndropped in subsequent work.\n\nSigned-off-by: Zhao Liu <zhao1.liu@intel.com>\n---\n target/i386/cpu.c | 7 ++++++-\n 1 file changed, 6 insertions(+), 1 deletion(-)", "diff": "diff --git a/target/i386/cpu.c b/target/i386/cpu.c\nindex a594747f0030..a6d943c53a3f 100644\n--- a/target/i386/cpu.c\n+++ b/target/i386/cpu.c\n@@ -9779,6 +9779,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)\n CPUX86State *env = &cpu->env;\n Error *local_err = NULL;\n unsigned requested_lbr_fmt;\n+ int lbr_fmt_set;\n \n #if defined(CONFIG_TCG) && !defined(CONFIG_USER_ONLY)\n /* Use pc-relative instructions in system-mode */\n@@ -9815,7 +9816,11 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)\n * Override env->features[FEAT_PERF_CAPABILITIES].LBR_FMT\n * with user-provided setting.\n */\n- if (cpu->lbr_fmt != ~PERF_CAP_LBR_FMT) {\n+ lbr_fmt_set = object_property_check_flags(OBJECT(dev), \"lbr-fmt\",\n+ OBJ_PROP_FLAG_USER_SET, errp);\n+ if (lbr_fmt_set < 0) {\n+ return;\n+ } else if (lbr_fmt_set > 0) {\n env->features[FEAT_PERF_CAPABILITIES] &= ~PERF_CAP_LBR_FMT;\n env->features[FEAT_PERF_CAPABILITIES] |= cpu->lbr_fmt;\n }\n", "prefixes": [ "v2", "20/21" ] }