From mboxrd@z Thu Jan 1 00:00:00 1970 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 36D8FC4332F for ; Tue, 20 Dec 2022 07:04:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233489AbiLTHD5 (ORCPT ); Tue, 20 Dec 2022 02:03:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233290AbiLTHBo (ORCPT ); Tue, 20 Dec 2022 02:01:44 -0500 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 106A915F04; Mon, 19 Dec 2022 23:01:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1671519700; x=1703055700; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9Ow+AUlF3YAQbms59Th+YlBw4taXZzsqN7sPL++pLxY=; b=lsxv/yEdrsDp/zOeI2dLcYmfjwWoq3PqZ8oSwV2aseNzMKwVPYr8xQbx QlCgLscpeE8LuntB8mxdw0B3Ek9k39J0peruw1wNcI5AmMwBA9ezJtBtj IQQZ50Zb7+VPFQHiVR1fdH5r8mQexbKmD++HZhvxZLCUoC4djv4YROqnU bmr3I/x44LXRtFpnWqT78swRK8+8r5WV3/6wseYb0tksOkOJjxeaDghjW Gb8urLO1sjp2vgZFEO1l/4uaWUmobTkOCuSIp3viPdzVUWnmr9n1YNdyT qjfEUb9cxcbyvcC1FBAtQDMObn9hsv0CqJYc2ulWS+75Oy7mkl/4Sz+Ls Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10566"; a="302972119" X-IronPort-AV: E=Sophos;i="5.96,258,1665471600"; d="scan'208";a="302972119" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Dec 2022 23:01:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10566"; a="644326526" X-IronPort-AV: E=Sophos;i="5.96,258,1665471600"; d="scan'208";a="644326526" Received: from unknown (HELO fred..) ([172.25.112.68]) by orsmga007.jf.intel.com with ESMTP; 19 Dec 2022 23:01:17 -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 24/32] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Date: Mon, 19 Dec 2022 22:36:50 -0800 Message-Id: <20221220063658.19271-25-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221220063658.19271-1-xin3.li@intel.com> References: <20221220063658.19271-1-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)" Let ret_from_fork() jmp to fred_exit_user when FRED is enabled, otherwise the existing IDT code is chosen. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/entry/entry_64.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index e0c48998d2fb..cdb696cbb2a0 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -297,7 +297,12 @@ SYM_CODE_START(ret_from_fork) UNWIND_HINT_REGS movq %rsp, %rdi call syscall_exit_to_user_mode /* returns with IRQs disabled */ +#ifdef CONFIG_X86_FRED + ALTERNATIVE "jmp swapgs_restore_regs_and_return_to_usermode", \ + "jmp fred_exit_user", X86_FEATURE_FRED +#else jmp swapgs_restore_regs_and_return_to_usermode +#endif 1: /* kernel thread */ -- 2.34.1