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 4E56CC61DA3 for ; Fri, 24 Feb 2023 07:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230009AbjBXH2s (ORCPT ); Fri, 24 Feb 2023 02:28:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbjBXH2Q (ORCPT ); Fri, 24 Feb 2023 02:28:16 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D82813B871; Thu, 23 Feb 2023 23:28:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223683; x=1708759683; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DOSNEZFexx6rcKjeivP+6dofAP4lFXi0PU4el7mRCPw=; b=cfayCtg/qSSK8qR2tmbmLSZdnapv4PghcHymXEGt2ERLGQZbVfY6nRwF uQxz3S3s5jJZ+ATZyUCY0Pzw7oGa6FUUowmRcz3m6Tg0xk5i5ZQ0DXIRm vf9is//wXFbDAX7wF7wqVI8Az9z8RapbnA174u0pvYtea79w9JVpw/79A 9TzWPajLTykCmN9Prxc8q7zqC+U1IkhWT3DodbVqbFeTx/0Ay8JFOa7NM Dv8Y99ygPCKX0lddpGsMTujx85GdQH/G/KP6cPN1lJMXjhlw/ku8dI0TE lGrr56uYRktdoyEG4SgvDy7p59fvhOE4NbSifyBCDTXmVTF26Wi/G5/Hd A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836049" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836049" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639237" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639237" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:22 -0800 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 Subject: [RFC PATCH v3 16/32] x86/fred: reserve space for the FRED stack frame Date: Thu, 23 Feb 2023 23:01:29 -0800 Message-Id: <20230224070145.3572-17-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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) 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 /* -- 2.34.1