From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934530AbdA0LpP (ORCPT ); Fri, 27 Jan 2017 06:45:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:44800 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933576AbdA0LpH (ORCPT ); Fri, 27 Jan 2017 06:45:07 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, David Matlack , Paolo Bonzini , Jiri Slaby Subject: [PATCH 3.12 152/235] KVM: x86: flush pending lapic jump label updates on module unload Date: Fri, 27 Jan 2017 11:54:45 +0100 Message-Id: X-Mailer: git-send-email 2.11.0 In-Reply-To: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> References: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Matlack 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit cef84c302fe051744b983a92764d3fcca933415d upstream. KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled). These are implemented with delayed_work structs which can still be pending when the KVM module is unloaded. We've seen this cause kernel panics when the kvm_intel module is quickly reloaded. Use the new static_key_deferred_flush() API to flush pending updates on module unload. Signed-off-by: David Matlack Signed-off-by: Paolo Bonzini Signed-off-by: Jiri Slaby --- arch/x86/kvm/lapic.c | 6 ++++++ arch/x86/kvm/lapic.h | 1 + arch/x86/kvm/x86.c | 1 + 3 files changed, 8 insertions(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index a4ce2b2f1418..33d479540373 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1908,3 +1908,9 @@ void kvm_lapic_init(void) jump_label_rate_limit(&apic_hw_disabled, HZ); jump_label_rate_limit(&apic_sw_disabled, HZ); } + +void kvm_lapic_exit(void) +{ + static_key_deferred_flush(&apic_hw_disabled); + static_key_deferred_flush(&apic_sw_disabled); +} diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index fc87568fc409..f1fd0753b6ba 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -93,6 +93,7 @@ static inline bool kvm_hv_vapic_assist_page_enabled(struct kvm_vcpu *vcpu) int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data); void kvm_lapic_init(void); +void kvm_lapic_exit(void); static inline u32 kvm_apic_get_reg(struct kvm_lapic *apic, int reg_off) { diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8562aff68884..69e7b0b9a6bb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5573,6 +5573,7 @@ out: void kvm_arch_exit(void) { + kvm_lapic_exit(); perf_unregister_guest_info_callbacks(&kvm_guest_cbs); if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) -- 2.11.0