Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751283AbdHXEWR (ORCPT ); Thu, 24 Aug 2017 00:22:17 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:37904 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbdHXEWA (ORCPT ); Thu, 24 Aug 2017 00:22:00 -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 v3 4/4] KVM: nVMX: Fix trying to cancel vmlauch/vmresume Date: Wed, 23 Aug 2017 21:21:46 -0700 Message-Id: <1503548506-4457-4-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503548506-4457-1-git-send-email-wanpeng.li@hotmail.com> References: <1503548506-4457-1-git-send-email-wanpeng.li@hotmail.com> 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 Content-Length: 3382 Lines: 86 From: Wanpeng Li ------------[ cut here ]------------ WARNING: CPU: 7 PID: 3861 at /home/kernel/ssd/kvm/arch/x86/kvm//vmx.c:11299 nested_vmx_vmexit+0x176e/0x1980 [kvm_intel] CPU: 7 PID: 3861 Comm: qemu-system-x86 Tainted: G W OE 4.13.0-rc4+ #11 RIP: 0010:nested_vmx_vmexit+0x176e/0x1980 [kvm_intel] Call Trace: ? kvm_multiple_exception+0x149/0x170 [kvm] ? handle_emulation_failure+0x79/0x230 [kvm] ? load_vmcs12_host_state+0xa80/0xa80 [kvm_intel] ? check_chain_key+0x137/0x1e0 ? reexecute_instruction.part.168+0x130/0x130 [kvm] nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel] ? nested_vmx_inject_exception_vmexit+0xb7/0x100 [kvm_intel] vmx_queue_exception+0x197/0x300 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x1b0c/0x2c90 [kvm] ? kvm_arch_vcpu_runnable+0x220/0x220 [kvm] ? preempt_count_sub+0x18/0xc0 ? restart_apic_timer+0x17d/0x300 [kvm] ? kvm_lapic_restart_hv_timer+0x37/0x50 [kvm] ? kvm_arch_vcpu_load+0x1d8/0x350 [kvm] kvm_vcpu_ioctl+0x4e4/0x910 [kvm] ? kvm_vcpu_ioctl+0x4e4/0x910 [kvm] ? kvm_dev_ioctl+0xbe0/0xbe0 [kvm] The flag "nested_run_pending", which can override the decision of which should run next, L1 or L2. nested_run_pending=1 means that we *must* run L2 next, not L1. This is necessary in particular when L1 did a VMLAUNCH of L2 and therefore expects L2 to be run (and perhaps be injected with an event it specified, etc.). Nested_run_pending is especially intended to avoid switching to L1 in the injection decision-point. I catch this in the queue exception path, this patch fixes it by requesting an immediate VM exit from L2 and keeping the exception for L1 pending for a subsequent nested VM exit. Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li --- arch/x86/kvm/vmx.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 21760b8..6f88a79 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2501,16 +2501,8 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned nr = vcpu->arch.exception.nr; bool has_error_code = vcpu->arch.exception.has_error_code; - bool reinject = vcpu->arch.exception.injected; u32 error_code = vcpu->arch.exception.error_code; u32 intr_info = nr | INTR_INFO_VALID_MASK; - unsigned long exit_qual; - - if (!reinject && is_guest_mode(vcpu) && - nested_vmx_check_exception(vcpu, &exit_qual)) { - nested_vmx_inject_exception_vmexit(vcpu, exit_qual); - return; - } if (has_error_code) { vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code); @@ -10988,10 +10980,20 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu, static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr) { struct vcpu_vmx *vmx = to_vmx(vcpu); + unsigned long exit_qual; if (kvm_event_needs_reinjection(vcpu)) return -EBUSY; + if (vcpu->arch.exception.pending && + nested_vmx_check_exception(vcpu, &exit_qual)) { + if (vmx->nested.nested_run_pending) + return -EBUSY; + + nested_vmx_inject_exception_vmexit(vcpu, exit_qual); + return 0; + } + if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) && vmx->nested.preemption_timer_expired) { if (vmx->nested.nested_run_pending) -- 2.7.4