Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753271AbdHROLh (ORCPT ); Fri, 18 Aug 2017 10:11:37 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:34122 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446AbdHROLd (ORCPT ); Fri, 18 Aug 2017 10:11:33 -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 v2] KVM: nVMX: Fix trying to cancel vmlauch/vmresume Date: Fri, 18 Aug 2017 07:11:28 -0700 Message-Id: <1503065488-108870-1-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 Content-Length: 5589 Lines: 153 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/include/asm/kvm_host.h | 2 +- arch/x86/kvm/svm.c | 6 ++++-- arch/x86/kvm/vmx.c | 15 ++++++++++----- arch/x86/kvm/x86.c | 4 ++-- 4 files changed, 17 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 6db0ed9..e1e6f00 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -962,7 +962,7 @@ struct kvm_x86_ops { unsigned char *hypercall_addr); void (*set_irq)(struct kvm_vcpu *vcpu); void (*set_nmi)(struct kvm_vcpu *vcpu); - void (*queue_exception)(struct kvm_vcpu *vcpu); + int (*queue_exception)(struct kvm_vcpu *vcpu); void (*cancel_injection)(struct kvm_vcpu *vcpu); int (*interrupt_allowed)(struct kvm_vcpu *vcpu); int (*nmi_allowed)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index c21b49b..bee1937 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -632,7 +632,7 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu) svm_set_interrupt_shadow(vcpu, 0); } -static void svm_queue_exception(struct kvm_vcpu *vcpu) +static int svm_queue_exception(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); unsigned nr = vcpu->arch.exception.nr; @@ -646,7 +646,7 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu) */ if (!reinject && nested_svm_check_exception(svm, nr, has_error_code, error_code)) - return; + return 0; if (nr == BP_VECTOR && !static_cpu_has(X86_FEATURE_NRIPS)) { unsigned long rip, old_rip = kvm_rip_read(&svm->vcpu); @@ -669,6 +669,8 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu) | (has_error_code ? SVM_EVTINJ_VALID_ERR : 0) | SVM_EVTINJ_TYPE_EXEPT; svm->vmcb->control.event_inj_err = error_code; + + return 0; } static void svm_init_erratum_383(void) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e398946..cd0ab5d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2500,7 +2500,7 @@ static int nested_vmx_check_exception(struct kvm_vcpu *vcpu) return 0; } -static void vmx_queue_exception(struct kvm_vcpu *vcpu) +static int vmx_queue_exception(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned nr = vcpu->arch.exception.nr; @@ -2509,9 +2509,12 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) u32 error_code = vcpu->arch.exception.error_code; u32 intr_info = nr | INTR_INFO_VALID_MASK; - if (!reinject && is_guest_mode(vcpu) && - nested_vmx_check_exception(vcpu)) - return; + if (!reinject && is_guest_mode(vcpu)) { + if (vmx->nested.nested_run_pending) + return -EBUSY; + if (nested_vmx_check_exception(vcpu)) + return 0; + } if (has_error_code) { vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, error_code); @@ -2524,7 +2527,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) inc_eip = vcpu->arch.event_exit_inst_len; if (kvm_inject_realmode_interrupt(vcpu, nr, inc_eip) != EMULATE_DONE) kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); - return; + return 0; } if (kvm_exception_is_soft(nr)) { @@ -2535,6 +2538,8 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu) intr_info |= INTR_TYPE_HARD_EXCEPTION; vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr_info); + + return 0; } static bool vmx_rdtscp_supported(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 008a0b1..8e53de2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6356,8 +6356,8 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win) kvm_update_dr7(vcpu); } - kvm_x86_ops->queue_exception(vcpu); - return 0; + r = kvm_x86_ops->queue_exception(vcpu); + return r; } if (vcpu->arch.nmi_injected) { -- 2.7.4