From patchwork Fri Jan 6 08:56:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13091169 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 06EA1C63707 for ; Fri, 6 Jan 2023 09:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232981AbjAFJVP (ORCPT ); Fri, 6 Jan 2023 04:21:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233043AbjAFJUW (ORCPT ); Fri, 6 Jan 2023 04:20:22 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E92266B5DC; Fri, 6 Jan 2023 01:20:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1672996820; x=1704532820; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=itDwNcmuOavaLbxBus/tcxgByCKbUIXcxoUL6CHXDYI=; b=cRN+9w5C3lUQxwhFQmbF5vCz8744iBJNOK5sjAXapEfidjMVM0tfZOyD O6POVkqB2hPK8cESWNLHdPE7ao6mzXa/jg0TNP3Zx32kkUjrWcpxBjeVF pWo4qmhd7OG8dIEbf5slUm52VY/xRblwG97V+9qm3MuBYrF8Fjc9e4ev6 AYMpUxGH6uA0fYyNDEQLYDc8Oq4/rTwYiNEBr4aF29a5OfA8+8RHByKhv +J9SxUqJnnzV0X5P/FJVfWSFdc3Bed5Z53mKNBXzCx0Ms6iOZX5zC0BAe Pt/5JqQsBaO1v9yusszaHh7ahjzH1rIMnTnXXGHCwZlU8RZ3Gd4gXzp24 g==; X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="322511514" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="322511514" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jan 2023 01:20:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="719139397" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="719139397" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga008.fm.intel.com with ESMTP; 06 Jan 2023 01:20:14 -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 v2 16/32] x86/fred: reserve space for the FRED stack frame Date: Fri, 6 Jan 2023 00:56:01 -0800 Message-Id: <20230106085617.17248-17-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230106085617.17248-1-xin3.li@intel.com> References: <20230106085617.17248-1-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) 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 f0cb881c1d69..fea0e69fc3d4 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 /*