KVM: x86: flush pending lapic jump label updates on module unload (cef84c30) · Commits · 戴 / test

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 <dmatlack@google.com> Cc: stable@vger.kernel.org Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/lapic.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -2426,3 +2426,9 @@ 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);
		}

arch/x86/kvm/lapic.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -110,6 +110,7 @@ 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);

		#define VEC_POS(v) ((v) & (32 - 1))
		#define REG_POS(v) (((v) >> 5) << 4)

arch/x86/kvm/x86.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -6045,6 +6045,7 @@ 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))

Admin message