[PATCH v2 11/46] KVM: x86: WARN if the APIC map is dirty without an in-kernel local APIC

From: Sean Christopherson
Date: Tue Jul 13 2021 - 12:34:13 EST


WARN if KVM ends up in a state where it thinks its APIC map needs to be
recalculated, but KVM is not emulating the local APIC. This is mostly
to document KVM's "rules" in order to provide clarity in future cleanups.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ba5a27879f1d..add4dd1e3528 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -192,6 +192,9 @@ void kvm_recalculate_apic_map(struct kvm *kvm)
if (atomic_read_acquire(&kvm->arch.apic_map_dirty) == CLEAN)
return;

+ WARN_ONCE(!irqchip_in_kernel(kvm),
+ "Dirty APIC map without an in-kernel local APIC");
+
mutex_lock(&kvm->arch.apic_map_lock);
/*
* Read kvm->arch.apic_map_dirty before kvm->arch.apic_map
--
2.32.0.93.g670b81a890-goog