This is a note to let you know that I've just added the patch titled
KVM: x86: flush pending lapic jump label updates on module unload
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-flush-pending-lapic-jump-label-updates-on-module-unload.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cef84c302fe051744b983a92764d3fcca933415d Mon Sep 17 00:00:00 2001
From: David Matlack <dmatlack@xxxxxxxxxx>
Date: Fri, 16 Dec 2016 14:30:36 -0800
Subject: KVM: x86: flush pending lapic jump label updates on module unload
From: David Matlack <dmatlack@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 6 ++++++
arch/x86/kvm/lapic.h | 1 +
arch/x86/kvm/x86.c | 1 +
3 files changed, 8 insertions(+)
--- 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);
+}
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -95,6 +95,7 @@ static inline bool kvm_hv_vapic_assist_p
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)
{
--- 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))
Patches currently in stable-queue which might be from dmatlack@xxxxxxxxxx are
queue-4.4/kvm-x86-flush-pending-lapic-jump-label-updates-on-module-unload.patch
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