Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > Even if APICv is disabled at startup, the backing page and ir_list need > to be initialized in case they are needed later. The only case in > which this can be skipped is for userspace irqchip, and that must be > done because avic_init_backing_page dereferences vcpu->arch.apic > (which is NULL for userspace irqchip). > > Tested-by: rmuncrief@xxxxxxxxxxxxxxx > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=206579 > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > arch/x86/kvm/svm.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index ad3f5b178a03..bd02526300ab 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -2194,8 +2194,9 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) > static int avic_init_vcpu(struct vcpu_svm *svm) > { > int ret; > + struct kvm_vcpu *vcpu = &svm->vcpu; > > - if (!kvm_vcpu_apicv_active(&svm->vcpu)) > + if (!avic || !irqchip_in_kernel(vcpu->kvm)) > return 0; > > ret = avic_init_backing_page(&svm->vcpu); Out of pure curiosity, when irqchip_in_kernel() is false, can we still get to .update_pi_irte() (svm_update_pi_irte()) -> get_pi_vcpu_info() -> "vcpu_info->pi_desc_addr = __sme_set(page_to_phys((*svm)->avic_backing_page));" -> crash! or is there anything which make this impossible? The patch is an improvement anyway, so Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> -- Vitaly
