From patchwork Tue Jan 21 02:06:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tao Su X-Patchwork-Id: 13945588 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B3E16C02185 for ; Tue, 21 Jan 2025 02:15:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ta3nM-00025H-9Y; Mon, 20 Jan 2025 21:15:12 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ta3nJ-00023k-JW for qemu-devel@nongnu.org; Mon, 20 Jan 2025 21:15:09 -0500 Received: from mgamail.intel.com ([198.175.65.11]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ta3nI-0002bj-25 for qemu-devel@nongnu.org; Mon, 20 Jan 2025 21:15:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1737425708; x=1768961708; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/ExwcxXLZOoaeYnlfshScg6n9yUqomMAZ7vYGCbgh+o=; b=VdnY5FFib5qFAPXab67/lUgJdQyXzHoCWe4+UhH/jxjNs7SkYfivk5fm QdXzCG2z/u50vpaVl6eNE5buC11q6LAMNjg4RmIkFmt9WAsk/jZViajSZ pZdp96oEluWE/C/IMK4LDLsgBwEBYi7WWOLaUGgeMhgk7oHl4f4xKT5bo arXV8AybbTYyUU7nEUWBF87GGgDUTSWyXL+IhkOV7s1gWIQtTRYu87wvg qXHIYkMrewHWXyzzol76kp3Z6mHtEjLct8NKF92xC7IZsV2z0fzVbqHB+ sI6xBC8EQ1CcxM5P2b24rFwMPO+ds+kj/zQmzKF876nfR0ZfQz47inEtL w==; X-CSE-ConnectionGUID: Xayk4CuDTbK+ILqcCtqAyA== X-CSE-MsgGUID: PUcOO3G+TWaGMEqO5Rr89Q== X-IronPort-AV: E=McAfee;i="6700,10204,11321"; a="48320163" X-IronPort-AV: E=Sophos;i="6.13,220,1732608000"; d="scan'208";a="48320163" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jan 2025 18:15:05 -0800 X-CSE-ConnectionGUID: zqm4rBt7TZeQerLchLT24w== X-CSE-MsgGUID: RS2vdoviRQmGB3G11ZgE1Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.13,220,1732608000"; d="scan'208";a="106599370" Received: from st-server.bj.intel.com ([10.240.193.102]) by fmviesa007.fm.intel.com with ESMTP; 20 Jan 2025 18:15:03 -0800 From: Tao Su To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, imammedo@redhat.com, xiaoyao.li@intel.com, zhao1.liu@linux.intel.com, xuelian.guo@intel.com, tao1.su@linux.intel.com Subject: [PATCH 2/4] target/i386: Export BHI_NO bit to guests Date: Tue, 21 Jan 2025 10:06:48 +0800 Message-Id: <20250121020650.1899618-3-tao1.su@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250121020650.1899618-1-tao1.su@linux.intel.com> References: <20250121020650.1899618-1-tao1.su@linux.intel.com> MIME-Version: 1.0 Received-SPF: none client-ip=198.175.65.11; envelope-from=tao1.su@linux.intel.com; helo=mgamail.intel.com X-Spam_score_int: -72 X-Spam_score: -7.3 X-Spam_bar: ------- X-Spam_report: (-7.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-3, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Branch History Injection (BHI) is a CPU side-channel vulnerability, where an attacker may manipulate branch history before transitioning from user to supervisor mode or from VMX non-root/guest to root mode. CPUs that set BHI_NO bit in MSR IA32_ARCH_CAPABILITIES to indicate no additional mitigation is required to prevent BHI. Make BHI_NO bit available to guests. Tested-by: Xuelian Guo Signed-off-by: Tao Su Reviewed-by: Zhao Liu Reviewed-by: Pawan Gupta Reviewed-by: Xiaoyao Li --- target/i386/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 6db8d6c9ba..33fb27a611 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1364,7 +1364,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = { "taa-no", NULL, NULL, NULL, NULL, "sbdr-ssdp-no", "fbsdp-no", "psdp-no", NULL, "fb-clear", NULL, NULL, - NULL, NULL, NULL, NULL, + "bhi-no", NULL, NULL, NULL, "pbrsb-no", NULL, "gds-no", "rfds-no", "rfds-clear", NULL, NULL, NULL, },