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 <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Matlack 2016-12-16 14:30:36 -08:00 committed by Greg Kroah-Hartman
parent 3d27cd4b25
commit 1fc673d96f
3 changed files with 8 additions and 0 deletions

View File

@ -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);
}

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@ -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)
{

View File

@ -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))