From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BD11C2D0A8 for ; Wed, 23 Sep 2020 18:45:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EB422371F for ; Wed, 23 Sep 2020 18:45:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726963AbgIWSpJ (ORCPT ); Wed, 23 Sep 2020 14:45:09 -0400 Received: from mga07.intel.com ([134.134.136.100]:14513 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbgIWSpG (ORCPT ); Wed, 23 Sep 2020 14:45:06 -0400 IronPort-SDR: oAnOQPo+fGVnoEnZ1VDWJmPmPGWYGsc6dKeDHgOR2xC2Q9yDG4kpLIXK8gVa3xkAnHroqP66dR zsL2C6aWj96g== X-IronPort-AV: E=McAfee;i="6000,8403,9753"; a="225124487" X-IronPort-AV: E=Sophos;i="5.77,293,1596524400"; d="scan'208";a="225124487" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2020 11:44:56 -0700 IronPort-SDR: ipvuSnANJBxVJaIKiu7lfImqITPAsyeQbfSTm8wv0FKyqCo7QM5RGpGzPBHHrNx2kvb6l8rLFr w5lMmwPllLDA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,293,1596524400"; d="scan'208";a="347457677" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.160]) by FMSMGA003.fm.intel.com with ESMTP; 23 Sep 2020 11:44:56 -0700 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Dan Cross , Peter Shier Subject: [PATCH v2 7/7] KVM: nVMX: WARN on attempt to switch the currently loaded VMCS Date: Wed, 23 Sep 2020 11:44:52 -0700 Message-Id: <20200923184452.980-8-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200923184452.980-1-sean.j.christopherson@intel.com> References: <20200923184452.980-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org WARN if KVM attempts to switch to the currently loaded VMCS. Now that nested_vmx_free_vcpu() doesn't blindly call vmx_switch_vmcs(), all paths that lead to vmx_switch_vmcs() are implicitly guarded by guest vs. host mode, e.g. KVM should never emulate VMX instructions when guest mode is active, and nested_vmx_vmexit() should never be called when host mode is active. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 63550dcf6b9f..4bddda078370 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -258,7 +258,7 @@ static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs) struct loaded_vmcs *prev; int cpu; - if (vmx->loaded_vmcs == vmcs) + if (WARN_ON_ONCE(vmx->loaded_vmcs == vmcs)) return; cpu = get_cpu(); -- 2.28.0