On 10/01/2017 06:26, Peter Xu wrote: > On Fri, Dec 16, 2016 at 04:10:05PM +0100, Radim Krčmář wrote: >> The check in kvm_set_pic_irq() and kvm_set_ioapic_irq() was just a >> temporary measure until the code improved enough for us to do this. >> >> This changes APIC in a case when KVM_SET_GSI_ROUTING is called to set up pic >> and ioapic routes before KVM_CREATE_IRQCHIP. Those rules would get >> overwritten >> by KVM_CREATE_IRQCHIP at best, so it is pointless to allow it. Userspaces >> hopefully noticed that things don't work if they do that and don't do that. >> >> Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> >> Signed-off-by: Radim Krčmář <rkrc...@redhat.com> > > Since we are at here, do we need to protect KVM_SET_GSI_ROUTING in > general as well to make sure kernel APIC is there?
Skipping the check is harmless. I agree that it should have been always done like you suggest, but right now it may break something. Paolo > > ---------8<--------- > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 482612b..31141a7 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -3057,6 +3057,10 @@ static long kvm_vm_ioctl(struct file *filp, > struct kvm_irq_routing_entry *entries = NULL; > > r = -EFAULT; > + > + if (!irqchip_in_kernel(kvm)) > + goto out; > + > if (copy_from_user(&routing, argp, sizeof(routing))) > goto out; > r = -EINVAL; > > --------->8--------- > > Thanks, > > -- peterx >
