From patchwork Fri Jun 16 03:23:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tao Su X-Patchwork-Id: 13281985 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 33F6FEB64D9 for ; Fri, 16 Jun 2023 03:24:49 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qA03b-0000EA-6S; Thu, 15 Jun 2023 23:23:27 -0400 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 1qA03Z-0000DK-US for qemu-devel@nongnu.org; Thu, 15 Jun 2023 23:23:25 -0400 Received: from mga04.intel.com ([192.55.52.120]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qA03Y-0002FT-CW for qemu-devel@nongnu.org; Thu, 15 Jun 2023 23:23:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1686885804; x=1718421804; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=g5659xiMVup3wt5LX08hxZGyXfUKj970C0M06dtCxOA=; b=nSeXQtlgQysytmMKWFqpA2aRMJXxIYoAqr/KhsooA50X3kC5sSXRMNiG 4R8J/jZ7gP3bcN8HoH4hxm/gSXSMlpWbnyoRqCIxex25R3bnvasoilbNP V3vJdmJZZ6cNLBFWLnDUNIBk+xa7wYuWyFN3JHI1RDeI6do31tfePxbkq RzTq+mBdr+FCke+RIrMYy8wsGBcZotI5BQPCu75Vxf1UocV8QVRN8427A RBlQ9RZDr/FeLKA3peSNLOdz738Ot5QQpbkiNLkaVKdEUs/yE2cmRxt6v 6H6LoYxf1+OCaCLldQx7jPK+nFV6MgMJVwY82u1ZkgBoizY0xKMV4ZMwf w==; X-IronPort-AV: E=McAfee;i="6600,9927,10742"; a="357979162" X-IronPort-AV: E=Sophos;i="6.00,246,1681196400"; d="scan'208";a="357979162" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2023 20:23:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10742"; a="715845986" X-IronPort-AV: E=Sophos;i="6.00,246,1681196400"; d="scan'208";a="715845986" Received: from st-server.bj.intel.com ([10.240.193.102]) by fmsmga007.fm.intel.com with ESMTP; 15 Jun 2023 20:23:21 -0700 From: Tao Su To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, xiaoyao.li@intel.com, lei4.wang@intel.com, qian.wen@intel.com, imammedo@redhat.com, tao1.su@linux.intel.com Subject: [PATCH 3/7] target/i386: Allow MCDT_NO if host supports Date: Fri, 16 Jun 2023 11:23:07 +0800 Message-Id: <20230616032311.19137-4-tao1.su@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230616032311.19137-1-tao1.su@linux.intel.com> References: <20230616032311.19137-1-tao1.su@linux.intel.com> MIME-Version: 1.0 Received-SPF: none client-ip=192.55.52.120; envelope-from=tao1.su@linux.intel.com; helo=mga04.intel.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 MCDT_NO bit indicates HW contains the security fix and doesn't need to be mitigated to avoid data-dependent behaviour for certain instructions. It needs no hypervisor support. Treat it as supported regardless of what KVM reports. Signed-off-by: Tao Su Reviewed-by: Xiaoyao Li --- target/i386/kvm/kvm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index de531842f6..4defd8b479 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -432,6 +432,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, uint32_t eax; host_cpuid(7, 1, &eax, &unused, &unused, &unused); ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); + } else if (function == 7 && index == 2 && reg == R_EDX) { + /* Not new instructions, just an optimization. */ + uint32_t edx; + host_cpuid(7, 2, &unused, &unused, &unused, &edx); + ret |= edx & CPUID_7_2_EDX_MCDT_NO; } else if (function == 0xd && index == 0 && (reg == R_EAX || reg == R_EDX)) { /*