On Wed, 2022-08-31 at 00:35 +0000, Sean Christopherson wrote: > Turns out that some warnings exist for good reasons. Restore the warning > in avic_vcpu_load() that guards against calling avic_vcpu_load() on a > running vCPU now that KVM avoids doing so when switching between x2APIC > and xAPIC. The entire point of the WARN is to highlight that KVM should > not be reloading an AVIC. > > Opportunistically convert the WARN_ON() to WARN_ON_ONCE() to avoid > spamming the kernel if it does fire. > > This reverts commit c0caeee65af3944b7b8abbf566e7cc1fae15c775. > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> > --- > arch/x86/kvm/svm/avic.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c > index b2033a56010c..3c300113d40b 100644 > --- a/arch/x86/kvm/svm/avic.c > +++ b/arch/x86/kvm/svm/avic.c > @@ -1080,6 +1080,7 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) > return; > > entry = READ_ONCE(*(svm->avic_physical_id_cache)); > + WARN_ON_ONCE(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK); > > entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK; > entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK); Note that this warning was removed because it would trigger wheh x2avic code would switch between xapic and x2apic. I do agree 100% that this warning is useful. Best regards, Maxim Levitsky
