From 9139a7a64581c80d157027ae20e86f2f24d4292c Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 12 Oct 2021 17:35:54 -0700
Subject: [PATCH] KVM: x86: WARN if APIC HW/SW disable static keys are non-zero
on unload
WARN if the static keys used to track if any vCPU has disabled its APIC
are left elevated at module exit. Unlike the underflow case, nothing in
the static key infrastructure will complain if a key is left elevated,
and because an elevated key only affects performance, nothing in KVM will
fail if either key is improperly incremented.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211013003554.47705-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 7af25304bda9a..d6ac32f3f650c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2946,5 +2946,7 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu)
void kvm_lapic_exit(void)
{
static_key_deferred_flush(&apic_hw_disabled);
+ WARN_ON(static_branch_unlikely(&apic_hw_disabled.key));
static_key_deferred_flush(&apic_sw_disabled);
+ WARN_ON(static_branch_unlikely(&apic_sw_disabled.key));
}
--
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