From patchwork Fri Jan 6 08:56:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13091178 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 5B392C54EF1 for ; Fri, 6 Jan 2023 09:21:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231646AbjAFJVu (ORCPT ); Fri, 6 Jan 2023 04:21:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231514AbjAFJU0 (ORCPT ); Fri, 6 Jan 2023 04:20:26 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD63463188; Fri, 6 Jan 2023 01:20:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1672996824; x=1704532824; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9Ow+AUlF3YAQbms59Th+YlBw4taXZzsqN7sPL++pLxY=; b=GFrwoDoZzAQYsx0gh11Hqxb8h7fLwmSqNWEyZMek6VpRGQHJe8r5KzEe 5azy9OXAUco3j4MRSfK710d9U3u3xWunR3gQum3iB0mp7oTPlctIijmeU I6SLl9HXMMCsroCwYHzJ288fm4ig2QKFUWrL8audRh6MMM3+FJshVF+w8 GfBgJPhq4Azh7q9cI6IXPnWqirZOqfKulFIZTGozSMM03hCRZnaPRapU7 kn0pY2/OyK6+UFZc3nqCL4AQ/gdGuGMEobirTEvFQOjxBI9ksq5t0rRK3 v4tBaiAcRDqQegOIC/cVPsjjmlMugfgLcGfuTEajrGIwQ6PQY+/95acqF g==; X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="322511592" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="322511592" 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 01:20:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="719139434" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="719139434" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga008.fm.intel.com with ESMTP; 06 Jan 2023 01:20:16 -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 24/32] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Date: Fri, 6 Jan 2023 00:56:09 -0800 Message-Id: <20230106085617.17248-25-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)" 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 */