From patchwork Mon Mar 27 07:58:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13188751 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 A4DCEC761AF for ; Mon, 27 Mar 2023 08:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233037AbjC0IZj (ORCPT ); Mon, 27 Mar 2023 04:25:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233146AbjC0IY5 (ORCPT ); Mon, 27 Mar 2023 04:24:57 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBB6B5BAF; Mon, 27 Mar 2023 01:24:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1679905481; x=1711441481; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YTgEgmA3f1uzY8PacyZ6XmpZcGIgDW5/dB0vDrivilc=; b=nMsYT/+D516rMU7OdG+zZpqVDvNBVMJL14MLn9WoRIC9GHtR12TK+89U PclzXEfeE7swfjmZofCNYMMqH8fjrFInzf23LcXwbOKivAsdxZ85FwVh4 R8s++5TtT5YUdY97E/H0EMBIQAcOUyOKY8Ak32NQxS1K0vVcu2TuPbBAI AEps6S7LV09c1Rogdbj3DLyOHvDqpc5duXPnqt3BW2z5IMZnst1jom/wu B8mgwGjRrwnIbGp9JocAast4w6tNlfhIkdhOgANo2c1AvyU9ncd2R6qAv y+rgcEatElrZJVNq/8rkBgaJtGTTPUW+D+4B395T9rDm3esFU63mWe0DF Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10661"; a="338930351" X-IronPort-AV: E=Sophos;i="5.98,294,1673942400"; d="scan'208";a="338930351" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2023 01:24:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10661"; a="713787126" X-IronPort-AV: E=Sophos;i="5.98,294,1673942400"; d="scan'208";a="713787126" Received: from unknown (HELO fred..) ([172.25.112.68]) by orsmga008.jf.intel.com with ESMTP; 27 Mar 2023 01:24:39 -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 v6 25/33] x86/fred: no ESPFIX needed when FRED is enabled Date: Mon, 27 Mar 2023 00:58:30 -0700 Message-Id: <20230327075838.5403-26-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230327075838.5403-1-xin3.li@intel.com> References: <20230327075838.5403-1-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 */