From patchwork Tue Apr 4 10:27:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13199605 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 8D62EC6FD1D for ; Tue, 4 Apr 2023 10:56:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234947AbjDDK4G (ORCPT ); Tue, 4 Apr 2023 06:56:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234766AbjDDKzI (ORCPT ); Tue, 4 Apr 2023 06:55:08 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3F8246B2; Tue, 4 Apr 2023 03:54:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680605641; x=1712141641; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YTgEgmA3f1uzY8PacyZ6XmpZcGIgDW5/dB0vDrivilc=; b=miyLgQnlGrkEY/0oTJtRQvmM7XytIcTHHI/7dzD1hDgfWOiDf2CjSUxw wEohR4MhMVjAqI3VU5C4f9jfb3wxCZ8j+A7fF207mX570Pu0e0/FO1oe2 E9po4mPedSyhnx+MudBSaqXhSJcFZ7cbBtVfGGBe9MS10ugOte0L6kwd2 rCh6ui2V/S7oKnmXfmTBUsDLTlLaT+M88UxgNV+CNAlNieR4egiVFVDWc xEb1184b38fyfXbD6nCVBX8aDsKKoYozLRdsJDmgReQQLCaGRICTqq6kZ 53MCb1x5EF1Sa2BAeIgZeR+C6wD8yQQ+CTLmncLvmvGUChuUp6zOttF8W A==; X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="330734176" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="330734176" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2023 03:53:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10669"; a="775597853" X-IronPort-AV: E=Sophos;i="5.98,317,1673942400"; d="scan'208";a="775597853" Received: from unknown (HELO fred..) ([172.25.112.68]) by FMSMGA003.fm.intel.com with ESMTP; 04 Apr 2023 03:53:05 -0700 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, jiangshanlai@gmail.com, shan.kang@intel.com Subject: [PATCH v7 25/33] x86/fred: no ESPFIX needed when FRED is enabled Date: Tue, 4 Apr 2023 03:27:08 -0700 Message-Id: <20230404102716.1795-26-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230404102716.1795-1-xin3.li@intel.com> References: <20230404102716.1795-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" 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 */