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 5DF4BC64EC4 for ; Tue, 7 Mar 2023 03:07:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230526AbjCGDHe (ORCPT ); Mon, 6 Mar 2023 22:07:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230362AbjCGDGx (ORCPT ); Mon, 6 Mar 2023 22:06:53 -0500 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6C628616F; Mon, 6 Mar 2023 19:05:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678158341; x=1709694341; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YTgEgmA3f1uzY8PacyZ6XmpZcGIgDW5/dB0vDrivilc=; b=FUGBY9IZt28gdICl5x8OojDwdF57jiWR/pySC19f6d999ZYSNrvlY7R8 CFbmLP9eIKC2ORzU9DhpwYEvOoS+eXph+R+QE61lXMbNXZrqXKcbpbwXU 1g4JVIzAK3nn3Q9ynoEcjZSMlbmDq8afojZYjvJEdjRU/6kh69HfHZcpQ GknSOepi3unuo3dGsfcRBL9mSdk4D3WJj144sg4gE0w8eUHKuslrcjVml yu3XcUiyi5tmUB3qA37plTvGENXR4zflVH18A8i1pGLhosxK8NKj4LTiV jCgK0OeWAWifz5BHzMdp7fhnsYYXKUgcr1/p/Lyc4MoZVPWsaC+pMzui3 Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10641"; a="338072558" X-IronPort-AV: E=Sophos;i="5.98,238,1673942400"; d="scan'208";a="338072558" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Mar 2023 19:05:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10641"; a="676409904" X-IronPort-AV: E=Sophos;i="5.98,238,1673942400"; d="scan'208";a="676409904" Received: from unknown (HELO fred..) ([172.25.112.68]) by orsmga002.jf.intel.com with ESMTP; 06 Mar 2023 19:05:20 -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: [PATCH v5 26/34] x86/fred: no ESPFIX needed when FRED is enabled Date: Mon, 6 Mar 2023 18:39:38 -0800 Message-Id: <20230307023946.14516-27-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230307023946.14516-1-xin3.li@intel.com> References: <20230307023946.14516-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" Because FRED always restores the full value of %rsp, ESPFIX is no longer needed when it's enabled. Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/kernel/espfix_64.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c index 16f9814c9be0..48d133a54f45 100644 --- a/arch/x86/kernel/espfix_64.c +++ b/arch/x86/kernel/espfix_64.c @@ -106,6 +106,10 @@ void __init init_espfix_bsp(void) pgd_t *pgd; p4d_t *p4d; + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* Install the espfix pud into the kernel page directory */ pgd = &init_top_pgt[pgd_index(ESPFIX_BASE_ADDR)]; p4d = p4d_alloc(&init_mm, pgd, ESPFIX_BASE_ADDR); @@ -129,6 +133,10 @@ void init_espfix_ap(int cpu) void *stack_page; pteval_t ptemask; + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* We only have to do this once... */ if (likely(per_cpu(espfix_stack, cpu))) return; /* Already initialized */ -- 2.34.1