From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753701AbdGNJjX (ORCPT ); Fri, 14 Jul 2017 05:39:23 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:35894 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751380AbdGNJjV (ORCPT ); Fri, 14 Jul 2017 05:39:21 -0400 From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Wanpeng Li Subject: [PATCH] KVM: VMX: Fix losing blocking by NMI in the guest interruptibility-state field Date: Fri, 14 Jul 2017 02:39:05 -0700 Message-Id: <1500025145-96878-1-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wanpeng Li Run kvm-unit-tests/eventinj.flat in L1 w/ ept=0 on both L0 and L1: Before NMI IRET test Sending NMI to self NMI isr running stack 0x461000 Sending nested NMI to self After nested NMI to self Nested NMI isr running rip=40038e After iret After NMI to self FAIL: NMI Reference SDM 31.7.1.2: If the “virtual NMIs” VM-execution control is 1, bit 12 of the VM-exit interruption-information field indicates that the VM exit was due to a fault encountered during an execution of the IRET instruction that removed virtual-NMI blocking. In particular, it provides this indication if the following are both true: - Bit 31 (valid) in the IDT-vectoring information field is 0. - The value of bits 7:0 (vector) of the VM-exit interruption-information field is not 8 (the VM exit is not due to a double-fault exception). If both are true and bit 12 of the VM-exit interruption-information field is 1, there was virtual-NMI blocking before guest software executed the IRET instruction that caused the fault that caused the VM exit. The VMM should set bit 3 (blocking by NMI) in the interruptibility-state field (using VMREAD and VMWRITE) before resuming guest software. However, commit 0be9c7a89f750 (KVM: VMX: set "blocked by NMI" flag if EPT violation happens during IRET from NMI) just fixes the fault due to EPT violation. This patch tries to fix the fault due to the page fault of shadow page table. Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li --- arch/x86/kvm/vmx.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 84e62ac..32ca063 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -5709,6 +5709,11 @@ static int handle_exception(struct kvm_vcpu *vcpu) } if (is_page_fault(intr_info)) { + + if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) && + (intr_info & INTR_INFO_UNBLOCK_NMI)) + vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); + cr2 = vmcs_readl(EXIT_QUALIFICATION); /* EPT won't cause page fault directly */ WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && enable_ept); -- 2.7.4