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authorDavid Matlack <dmatlack@google.com>2016-12-16 14:30:36 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2017-01-12 14:33:17 +0100
commitcef84c302fe051744b983a92764d3fcca933415d (patch)
tree86fc792e45f77560815fde5c000184647a5d1476
parentb6416e61012429e0277bd15a229222fd17afc1c1 (diff)
KVM: x86: flush pending lapic jump label updates on module unload
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>
-rw-r--r--arch/x86/kvm/lapic.c6
-rw-r--r--arch/x86/kvm/lapic.h1
-rw-r--r--arch/x86/kvm/x86.c1
3 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 5fe290c1b7d8..2f6ef5121a4c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -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);
+}
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index e0c80233b3e1..ff8039d61672 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -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)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2f22810a7e0c..a0ac6e0060fb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -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))