From: David Matlack Date: Fri, 16 Dec 2016 22:30:36 +0000 (-0800) Subject: KVM: x86: flush pending lapic jump label updates on module unload X-Git-Tag: firefly_0821_release~176^2~4^2~3^2~38 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=1fc673d96f9dba0e4e1ad102995bef70e4a2e7cb;p=firefly-linux-kernel-4.4.55.git KVM: x86: flush pending lapic jump label updates on module unload 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: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 4d30b865be30..1c96f09367ae 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2187,3 +2187,9 @@ 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 fde8e35d5850..eb418fd670ff 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -95,6 +95,7 @@ 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 b3c2ae7aa213..25a6efcfdf7f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5842,6 +5842,7 @@ 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))