From patchwork Mon Apr 10 08:14:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13206174 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76377C76196 for ; Mon, 10 Apr 2023 08:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229817AbjDJIlb (ORCPT ); Mon, 10 Apr 2023 04:41:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229721AbjDJIlI (ORCPT ); Mon, 10 Apr 2023 04:41:08 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 916EE49D9; Mon, 10 Apr 2023 01:41:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1681116067; x=1712652067; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=voFQVjFSRNzDP3of726cqSfwzN6e3VmowuyZWcsyuKM=; b=CcxZ40RUpjRQDkaBJVclQUXd5tTACuh+CWWPLtKOIMjvkz3wnH/RNOaL kT3tqm74YFqiP54XPTOjLBaQ1YZR0dO9briIxq1Ag5qpD9dB2VEZMq8yX dnIlEN0vzE8sT9WsYc2kHF8w0xGZrrcnmC5P5Bqzh31ipqsAl9PIaOb/l qSStoJJhxDvVtO2LEIBurH6qM1ApLUjnzrvoDL3EQS1AJ2usTpjljDQv7 A3h6QHjPMHBMcq2ixwGtkHVrt+OpVvF+g04OdMxCJZqJzH3kGylpZsqU7 xjxWaUfYXTLNoTShWqR4AmSgexX/QLKH0sfZ9bQCTO38guqxBQtdi3tXC Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10675"; a="342078020" X-IronPort-AV: E=Sophos;i="5.98,333,1673942400"; d="scan'208";a="342078020" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Apr 2023 01:41:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10675"; a="799436298" X-IronPort-AV: E=Sophos;i="5.98,333,1673942400"; d="scan'208";a="799436298" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga002.fm.intel.com with ESMTP; 10 Apr 2023 01:41:04 -0700 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com, jiangshanlai@gmail.com, shan.kang@intel.com Subject: [PATCH v8 15/33] x86/fred: reserve space for the FRED stack frame Date: Mon, 10 Apr 2023 01:14:20 -0700 Message-Id: <20230410081438.1750-16-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230410081438.1750-1-xin3.li@intel.com> References: <20230410081438.1750-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" When using FRED, reserve space at the top of the stack frame, just like i386 does. A future version of FRED might have dynamic frame sizes, though, in which case it might be necessary to make TOP_OF_KERNEL_STACK_PADDING a variable instead of a constant. Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/include/asm/thread_info.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index f1cccba52eb9..998483078d5f 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -31,7 +31,9 @@ * In vm86 mode, the hardware frame is much longer still, so add 16 * bytes to make room for the real-mode segments. * - * x86_64 has a fixed-length stack frame. + * x86-64 has a fixed-length stack frame, but it depends on whether + * or not FRED is enabled. Future versions of FRED might make this + * dynamic, but for now it is always 2 words longer. */ #ifdef CONFIG_X86_32 # ifdef CONFIG_VM86 @@ -39,8 +41,12 @@ # else # define TOP_OF_KERNEL_STACK_PADDING 8 # endif -#else -# define TOP_OF_KERNEL_STACK_PADDING 0 +#else /* x86-64 */ +# ifdef CONFIG_X86_FRED +# define TOP_OF_KERNEL_STACK_PADDING (2*8) +# else +# define TOP_OF_KERNEL_STACK_PADDING 0 +# endif #endif /*