From patchwork Wed Jul 15 04:05:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 11664101 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BA03814E3 for ; Wed, 15 Jul 2020 04:06:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAF12206F5 for ; Wed, 15 Jul 2020 04:06:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726984AbgGOEGK (ORCPT ); Wed, 15 Jul 2020 00:06:10 -0400 Received: from mga17.intel.com ([192.55.52.151]:16670 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbgGOEGF (ORCPT ); Wed, 15 Jul 2020 00:06:05 -0400 IronPort-SDR: C9m4PEjapDzBOeeY73VOPll7FvKsPzobKdxHRvLxGyxm+lu+WrL3lLJx0lwYBliOkuWE1t6juq k2lXhtbm4ciw== X-IronPort-AV: E=McAfee;i="6000,8403,9682"; a="129167487" X-IronPort-AV: E=Sophos;i="5.75,353,1589266800"; d="scan'208";a="129167487" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2020 21:06:03 -0700 IronPort-SDR: MbssNKGmOLgp4+iuIgCJlNq0VZ+9/tKannUVxw9XEwu6VhjIpFgjRdcSJz0g0FAfzNliXDLnS5 xuqrdcl2Zjjw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,353,1589266800"; d="scan'208";a="485587033" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.152]) by fmsmga006.fm.intel.com with ESMTP; 14 Jul 2020 21:06:03 -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 7/7] KVM: nVMX: WARN on attempt to switch the currently loaded VMCS Date: Tue, 14 Jul 2020 21:05:57 -0700 Message-Id: <20200715040557.5889-8-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200715040557.5889-1-sean.j.christopherson@intel.com> References: <20200715040557.5889-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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 66ed449f0d59f..023055e636d61 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();