From patchwork Sun Apr 28 08:50:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 2498001 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id D7939DF2E5 for ; Sun, 28 Apr 2013 08:51:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752006Ab3D1IvD (ORCPT ); Sun, 28 Apr 2013 04:51:03 -0400 Received: from mout.web.de ([212.227.15.4]:53601 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751888Ab3D1IvA (ORCPT ); Sun, 28 Apr 2013 04:51:00 -0400 Received: from mchn199C.mchp.siemens.de ([95.157.56.37]) by smtp.web.de (mrweb103) with ESMTPSA (Nemesis) id 0LiUKG-1V29EP1LkS-00d2Jq; Sun, 28 Apr 2013 10:50:53 +0200 Message-ID: <517CE2EC.5010901@web.de> Date: Sun, 28 Apr 2013 10:50:52 +0200 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Gleb Natapov , Marcelo Tosatti CC: kvm , "Nakajima, Jun" , "Ren, Yongjie" Subject: [PATCH] KVM: x86: Rework request for immediate exit References: <517CCE8E.6010805@web.de> <20130428082951.GD30504@redhat.com> In-Reply-To: <20130428082951.GD30504@redhat.com> X-Enigmail-Version: 1.5.1 X-Provags-ID: V02:K0:U6bnR0oAr4hLfb/X9VzT5WGdFVYwyWcekHg51nq2UGM rznZMpCQnhNwjqpvegwgfVzzForiYzsN6bGpknru5zkc52JbKT bzSjPSqYgBvDIwgDcgcLxZsQJGPFblRXJruYYM46WI3muq6cHy 2oDpbaJWtNhI+l7HZP88R9iNsx978sZxZYxKN3Cmvkg4SC4Kb4 LfF5j2rG+BKhTd5Mmxyrw== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Jan Kiszka The VMX implementation of enable_irq_window raised KVM_REQ_IMMEDIATE_EXIT after we checked it in vcpu_enter_guest. This caused infinite loops on vmentry. Fix it by letting enable_irq_window signal the need for an immediate exit via its return value and drop KVM_REQ_IMMEDIATE_EXIT. This issue only affects nested VMX scenarios. Signed-off-by: Jan Kiszka --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/svm.c | 3 ++- arch/x86/kvm/vmx.c | 15 ++++++++------- arch/x86/kvm/x86.c | 7 +++---- include/linux/kvm_host.h | 15 +++++++-------- 5 files changed, 21 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 18635ae..111b4a0 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -694,7 +694,7 @@ struct kvm_x86_ops { bool (*get_nmi_mask)(struct kvm_vcpu *vcpu); void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked); void (*enable_nmi_window)(struct kvm_vcpu *vcpu); - void (*enable_irq_window)(struct kvm_vcpu *vcpu); + int (*enable_irq_window)(struct kvm_vcpu *vcpu); void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr); int (*vm_has_apicv)(struct kvm *kvm); void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index d6713e1..91a7431 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3632,7 +3632,7 @@ static int svm_interrupt_allowed(struct kvm_vcpu *vcpu) return ret; } -static void enable_irq_window(struct kvm_vcpu *vcpu) +static int enable_irq_window(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -3646,6 +3646,7 @@ static void enable_irq_window(struct kvm_vcpu *vcpu) svm_set_vintr(svm); svm_inject_irq(svm, 0x0); } + return 0; } static void enable_nmi_window(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d663a59..1795512 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4398,22 +4398,23 @@ static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu) PIN_BASED_NMI_EXITING; } -static void enable_irq_window(struct kvm_vcpu *vcpu) +static int enable_irq_window(struct kvm_vcpu *vcpu) { u32 cpu_based_vm_exec_control; - if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) { + + if (is_guest_mode(vcpu) && nested_exit_on_intr(vcpu)) /* * We get here if vmx_interrupt_allowed() said we can't - * inject to L1 now because L2 must run. Ask L2 to exit - * right after entry, so we can inject to L1 more promptly. + * inject to L1 now because L2 must run. The caller will have + * to make L2 exit right after entry, so we can inject to L1 + * more promptly. */ - kvm_make_request(KVM_REQ_IMMEDIATE_EXIT, vcpu); - return; - } + return -EBUSY; cpu_based_vm_exec_control = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); cpu_based_vm_exec_control |= CPU_BASED_VIRTUAL_INTR_PENDING; vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control); + return 0; } static void enable_nmi_window(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2a434bf..c522260 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5692,7 +5692,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) int r; bool req_int_win = !irqchip_in_kernel(vcpu->kvm) && vcpu->run->request_interrupt_window; - bool req_immediate_exit = 0; + bool req_immediate_exit = false; if (vcpu->requests) { if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) @@ -5734,8 +5734,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) record_steal_time(vcpu); if (kvm_check_request(KVM_REQ_NMI, vcpu)) process_nmi(vcpu); - req_immediate_exit = - kvm_check_request(KVM_REQ_IMMEDIATE_EXIT, vcpu); if (kvm_check_request(KVM_REQ_PMU, vcpu)) kvm_handle_pmu_event(vcpu); if (kvm_check_request(KVM_REQ_PMI, vcpu)) @@ -5757,7 +5755,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (vcpu->arch.nmi_pending) kvm_x86_ops->enable_nmi_window(vcpu); else if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win) - kvm_x86_ops->enable_irq_window(vcpu); + req_immediate_exit = + kvm_x86_ops->enable_irq_window(vcpu) != 0; if (kvm_lapic_enabled(vcpu)) { /* diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 93a5005..7bde424 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -119,14 +119,13 @@ static inline bool is_error_page(struct page *page) #define KVM_REQ_APF_HALT 12 #define KVM_REQ_STEAL_UPDATE 13 #define KVM_REQ_NMI 14 -#define KVM_REQ_IMMEDIATE_EXIT 15 -#define KVM_REQ_PMU 16 -#define KVM_REQ_PMI 17 -#define KVM_REQ_WATCHDOG 18 -#define KVM_REQ_MASTERCLOCK_UPDATE 19 -#define KVM_REQ_MCLOCK_INPROGRESS 20 -#define KVM_REQ_EPR_EXIT 21 -#define KVM_REQ_SCAN_IOAPIC 22 +#define KVM_REQ_PMU 15 +#define KVM_REQ_PMI 16 +#define KVM_REQ_WATCHDOG 17 +#define KVM_REQ_MASTERCLOCK_UPDATE 18 +#define KVM_REQ_MCLOCK_INPROGRESS 19 +#define KVM_REQ_EPR_EXIT 20 +#define KVM_REQ_SCAN_IOAPIC 21 #define KVM_USERSPACE_IRQ_SOURCE_ID 0 #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1