Re: [PATCH 4/5] msix: Don't process table changes while disabled

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Oct 18, 2011 at 01:35:37PM +0200, Jan Kiszka wrote:
> On 2011-10-18 13:18, Michael S. Tsirkin wrote:
> > On Tue, Oct 18, 2011 at 09:50:53AM +0200, Jan Kiszka wrote:
> >> As long as MSI-X is disabled, it's incorrect to invoke
> >> msix_handle_mask_update on per-vector mask changes. That may misguide
> >> the config notifier callback or spuriously trigger an MSI event.
> >>
> >> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > Same question as on the previous patch. At the moment, the only user
> > (virtio) seems to check msix_enabled before registering
> > notifiers. See virtio_pci_query_guest_notifiers.
> > Is there some way you see to trigger incorrect behaviour?
> 
> Then it's not an urgent fix, just a conceptual one (the user should not
> have to worry about enable/disabled, we want the core to do the boring
> jobs).
> 
> Jan

Yes, I agree the callback APIs could use some cleanup.
Need to make sure the patch does not cause
unbalanced mask/unmask calls. I need to look closer
to check that's still the case.

> -- 
> Siemens AG, Corporate Technology, CT T DE IT 1
> Corporate Competence Center Embedded Linux