Messages in this thread Patch in this message | | | Subject | Re: [PATCH 4/4] KVM: x86: Skip KVM_GUESTDBG_BLOCKIRQ APICv update if APICv is disabled | From | Maxim Levitsky <> | Date | Mon, 18 Apr 2022 15:50:00 +0300 |
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On Sat, 2022-04-16 at 03:42 +0000, Sean Christopherson wrote: > Skip the APICv inhibit update for KVM_GUESTDBG_BLOCKIRQ if APICv is > disabled at the module level to avoid having to acquire the mutex and > potentially process all vCPUs. The DISABLE inhibit will (barring bugs) > never be lifted, so piling on more inhibits is unnecessary. > > Fixes: cae72dcc3b21 ("KVM: x86: inhibit APICv when KVM_GUESTDBG_BLOCKIRQ active") > Cc: Maxim Levitsky <mlevitsk@redhat.com> > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/x86.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 09a270cc1c8f..16c5fa7d165d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -11048,6 +11048,9 @@ static void kvm_arch_vcpu_guestdbg_update_apicv_inhibit(struct kvm *kvm) > struct kvm_vcpu *vcpu; > unsigned long i; > > + if (!enable_apicv) > + return; > + > down_write(&kvm->arch.apicv_update_lock); > > kvm_for_each_vcpu(i, vcpu, kvm) {
Makes sense as a precation.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards, Maxim Levitsky
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