From patchwork Tue Dec 5 10:49:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13479990 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="UwkvqmyD" Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B889112C; Tue, 5 Dec 2023 03:21:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1701775283; x=1733311283; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=at3P90/0BHfZm4A3RDkp4mmTPKN/FQQ6JC7gRORtMwU=; b=UwkvqmyDNKYpEWiRyVAg/oyEluqxzF+5xd8tdrj5rz3cLRdkzTQUeD8D fV614pYbCBAzknlX/Y7GiwXYgekDrc6CmLevy9c+0pAFcp8hDHzJFNiz6 rDV7nS08BQMz89XkDsbTulXB3brd2tPQZpF+ILafzY0NRNB9fTBr824SP BDK+kIIrdL/7FEzS9tWHFl5ccRtfbgOteBago4Q2DyEsxymOa9OCfU7tb rL4yVXqn5UCD1W9TdoIZOFv75lOGP1Gnr1Sit2AiV2Z3t4lObifuhFJO2 nuPHVcw9zrKio9+U4Ajma+np4C1r4V19ECv1iYdvBwx7UUVcaO6Bmb4SW A==; X-IronPort-AV: E=McAfee;i="6600,9927,10914"; a="942404" X-IronPort-AV: E=Sophos;i="6.04,252,1695711600"; d="scan'208";a="942404" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Dec 2023 03:21:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10914"; a="1018192924" X-IronPort-AV: E=Sophos;i="6.04,252,1695711600"; d="scan'208";a="1018192924" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga006.fm.intel.com with ESMTP; 05 Dec 2023 03:21:18 -0800 From: Xin Li To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, pbonzini@redhat.com, seanjc@google.com, peterz@infradead.org, jgross@suse.com, ravi.v.shankar@intel.com, mhiramat@kernel.org, andrew.cooper3@citrix.com, jiangshanlai@gmail.com, nik.borisov@suse.com, shan.kang@intel.com Subject: [PATCH v13 08/35] x86/fred: Disable FRED by default in its early stage Date: Tue, 5 Dec 2023 02:49:57 -0800 Message-ID: <20231205105030.8698-9-xin3.li@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231205105030.8698-1-xin3.li@intel.com> References: <20231205105030.8698-1-xin3.li@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 To enable FRED, a new kernel command line option "fred" needs to be added. Tested-by: Shan Kang Signed-off-by: Xin Li --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/x86/kernel/cpu/common.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 65731b060e3f..6992b392e8d3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1526,6 +1526,9 @@ Warning: use of this parameter will taint the kernel and may cause unknown problems. + fred [X86-64] + Enable flexible return and event delivery + ftrace=[tracer] [FTRACE] will set and start the specified tracer as early as possible in order to facilitate early diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4d4b87c6885d..68102acd63b0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1491,6 +1491,9 @@ static void __init cpu_parse_early_param(void) char *argptr = arg, *opt; int arglen, taint = 0; + if (!cmdline_find_option_bool(boot_command_line, "fred")) + setup_clear_cpu_cap(X86_FEATURE_FRED); + #ifdef CONFIG_X86_32 if (cmdline_find_option_bool(boot_command_line, "no387")) #ifdef CONFIG_MATH_EMULATION