From patchwork Mon Sep 25 07:14:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: EwanHai X-Patchwork-Id: 13397306 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 96309CE7A89 for ; Mon, 25 Sep 2023 07:15:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229582AbjIYHPG (ORCPT ); Mon, 25 Sep 2023 03:15:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229459AbjIYHPF (ORCPT ); Mon, 25 Sep 2023 03:15:05 -0400 Received: from mx2.zhaoxin.com (mx2.zhaoxin.com [203.110.167.99]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24DD0B8 for ; Mon, 25 Sep 2023 00:14:58 -0700 (PDT) X-ASG-Debug-ID: 1695626094-1eb14e75133b550001-HEqcsx Received: from ZXSHMBX1.zhaoxin.com (ZXSHMBX1.zhaoxin.com [10.28.252.163]) by mx2.zhaoxin.com with ESMTP id MSxhqgC9b91u0ZgS (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Mon, 25 Sep 2023 15:14:54 +0800 (CST) X-Barracuda-Envelope-From: EwanHai-oc@zhaoxin.com X-Barracuda-RBL-Trusted-Forwarder: 10.28.252.163 Received: from zxbjmbx1.zhaoxin.com (10.29.252.163) by ZXSHMBX1.zhaoxin.com (10.28.252.163) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 25 Sep 2023 15:14:54 +0800 Received: from ewan-server.zhaoxin.com (10.28.66.44) by zxbjmbx1.zhaoxin.com (10.29.252.163) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 25 Sep 2023 15:14:53 +0800 X-Barracuda-RBL-Trusted-Forwarder: 10.28.252.163 From: EwanHai X-Barracuda-RBL-Trusted-Forwarder: 10.29.252.163 To: , , CC: Subject: [PATCH] target/i386/kvm: Refine VMX controls setting for backward compatibility Date: Mon, 25 Sep 2023 03:14:53 -0400 X-ASG-Orig-Subj: [PATCH] target/i386/kvm: Refine VMX controls setting for backward compatibility Message-ID: <20230925071453.14908-1-ewanhai-oc@zhaoxin.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Originating-IP: [10.28.66.44] X-ClientProxiedBy: zxbjmbx1.zhaoxin.com (10.29.252.163) To zxbjmbx1.zhaoxin.com (10.29.252.163) X-Barracuda-Connect: ZXSHMBX1.zhaoxin.com[10.28.252.163] X-Barracuda-Start-Time: 1695626094 X-Barracuda-Encrypted: ECDHE-RSA-AES128-GCM-SHA256 X-Barracuda-URL: https://10.28.252.36:4443/cgi-mod/mark.cgi X-Virus-Scanned: by bsmtpd at zhaoxin.com X-Barracuda-Scan-Msg-Size: 1962 X-Barracuda-BRTS-Status: 0 X-Barracuda-Bayes: INNOCENT GLOBAL 0.0000 1.0000 -2.0210 X-Barracuda-Spam-Score: -2.02 X-Barracuda-Spam-Status: No, SCORE=-2.02 using global scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.114571 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit 4a910e1 ("target/i386: do not set unsupported VMX secondary execution controls") implemented a workaround for hosts that have specific CPUID features but do not support the corresponding VMX controls, e.g., hosts support RDSEED but do not support RDSEED-Exiting. In detail, commit 4a910e1 introduced a flag `has_msr_vmx_procbased_clts2`. If KVM has `MSR_IA32_VMX_PROCBASED_CTLS2` in its msr list, QEMU would use KVM's settings, avoiding any modifications to this MSR. However, this commit (4a910e1) didn’t account for cases in older Linux kernels(e.g., linux-4.19.90) where `MSR_IA32_VMX_PROCBASED_CTLS2` is in `kvm_feature_msrs`—obtained by ioctl(KVM_GET_MSR_FEATURE_INDEX_LIST), but not in `kvm_msr_list`—obtained by ioctl(KVM_GET_MSR_INDEX_LIST). As a result,it did not set the `has_msr_vmx_procbased_clts2` flag based on `kvm_msr_list` alone, even though KVM maintains the value of this MSR. This patch supplements the above logic, ensuring that `has_msr_vmx_procbased_clts2` is correctly set by checking both MSR lists, thus maintaining compatibility with older kernels. Signed-off-by: EwanHai --- target/i386/kvm/kvm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index af101fcdf6..6299284de4 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -2343,6 +2343,7 @@ void kvm_arch_do_init_vcpu(X86CPU *cpu) static int kvm_get_supported_feature_msrs(KVMState *s) { int ret = 0; + int i; if (kvm_feature_msrs != NULL) { return 0; @@ -2377,6 +2378,11 @@ static int kvm_get_supported_feature_msrs(KVMState *s) return ret; } + for (i = 0; i < kvm_feature_msrs->nmsrs; i++) { + if (kvm_feature_msrs->indices[i] == MSR_IA32_VMX_PROCBASED_CTLS2) { + has_msr_vmx_procbased_ctls2 = true; + } + } return 0; }