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 C77BAC61DA3 for ; Fri, 24 Feb 2023 07:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230006AbjBXH3o (ORCPT ); Fri, 24 Feb 2023 02:29:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230048AbjBXH3N (ORCPT ); Fri, 24 Feb 2023 02:29:13 -0500 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D578363542; Thu, 23 Feb 2023 23:28:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677223702; x=1708759702; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dKcGYBnXHQiTsBcKqxrhALysREBc36cYC8m/4NUk9CA=; b=Ug298TNcLjq/0dhk0ArWPlm/WgutFcIs9CJ3s0zTSKcEzYUC6tXrS6HE 9foXwpe3vCdFzKHDvsuU5qDETfe+Dsd7wmlQgu7/eSbURy7livKMGE0dr upyShuMRWSIXohF9H3LdcIVmstYTyW6D1DX5xMs2tH79Z3NE6+tLvYrHL k1RxVUB+jOAa/gGK49EEYSVE19pljvRs7bw+9tNrIPbAeXM0EQxlcam0T eLL0bvIJ9oQhLfit72ll3CtTJW+sbyIkHVVuMS9XdyXpldPB1vaWZzldg 0v6iAh+Z0y0bXqwh5EEqtjP1e0fBqt4XI4BfHUa53CXC0A0XLiEh/AIMv A==; X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="334836143" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="334836143" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2023 23:27:25 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10630"; a="815639271" X-IronPort-AV: E=Sophos;i="5.97,324,1669104000"; d="scan'208";a="815639271" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga001.fm.intel.com with ESMTP; 23 Feb 2023 23:27:25 -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 v3 26/32] x86/fred: no ESPFIX needed when FRED is enabled Date: Thu, 23 Feb 2023 23:01:39 -0800 Message-Id: <20230224070145.3572-27-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230224070145.3572-1-xin3.li@intel.com> References: <20230224070145.3572-1-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)" 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) 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