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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 1F503C11D3D for ; Thu, 27 Feb 2020 17:45:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C946524692 for ; Thu, 27 Feb 2020 17:45:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730796AbgB0RpA (ORCPT ); Thu, 27 Feb 2020 12:45:00 -0500 Received: from mga06.intel.com ([134.134.136.31]:18526 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730669AbgB0Rok (ORCPT ); Thu, 27 Feb 2020 12:44:40 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Feb 2020 09:44:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,492,1574150400"; d="scan'208";a="317859094" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga001.jf.intel.com with ESMTP; 27 Feb 2020 09:44:38 -0800 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, Xiaoyao Li Subject: [PATCH] KVM: nVMX: Consult only the "basic" exit reason when routing nested exit Date: Thu, 27 Feb 2020 09:44:30 -0800 Message-Id: <20200227174430.26371-1-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Consult only the basic exit reason, i.e. bits 15:0 of vmcs.EXIT_REASON, when determining whether a nested VM-Exit should be reflected into L1 or handled by KVM in L0. For better or worse, the switch statement in nested_vmx_exit_reflected() currently defaults to "true", i.e. reflects any nested VM-Exit without dedicated logic. Because the case statements only contain the basic exit reason, any VM-Exit with modifier bits set will be reflected to L1, even if KVM intended to handle it in L0. Practically speaking, this only affects EXIT_REASON_MCE_DURING_VMENTRY, i.e. a #MC that occurs on nested VM-Enter would be incorrectly routed to L1, as "failed VM-Entry" is the only modifier that KVM can currently encounter. The SMM modifiers will never be generated as KVM doesn't support/employ a SMI Transfer Monitor. Ditto for "exit from enclave", as KVM doesn't yet support virtualizing SGX, i.e. it's impossible to enter an enclave in a KVM guest (L1 or L2). Fixes: 644d711aa0e1 ("KVM: nVMX: Deciding if L0 or L1 should handle an L2 exit") Cc: Jim Mattson Cc: Xiaoyao Li Cc: stable@vger.kernel.org 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 0946122a8d3b..127065bbde2c 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5554,7 +5554,7 @@ bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason) vmcs_read32(VM_EXIT_INTR_ERROR_CODE), KVM_ISA_VMX); - switch (exit_reason) { + switch ((u16)exit_reason) { case EXIT_REASON_EXCEPTION_NMI: if (is_nmi(intr_info)) return false; -- 2.24.1