On Tue, 2 Aug 2016 09:54:19 -0600 Alex Williamson <alex.william...@redhat.com> wrote:
> On Tue, 2 Aug 2016 10:21:30 +0000 > chris thompson <the_cartograp...@hotmail.com> wrote: > > > Hi Alex, > > > > Thanks for your patience, I noticed the count != 0 issue shortly after, but > > I get the same EINVAL error anyway when it is zero - but this is because > > the IRQ does not have a mapping yet. When I change the code to map it then > > unmap it then I get: > > IRQx - successful map then unmap > > MSI - unsuccessful map (and unsuccessful unmap) > > MSIX - successful map then unmap (despite the device still being in IRQx > > mode?) > > Error - successfully map, kernel driver crash on the unmap! I remembered that there is a trick here specific to MSI, your device probably supports more than one MSI vector. MSI is a little bit special, not all platforms support multiple MSI vectors and they were pretty much outdated by the much more flexible MSI-X capability for that reason. To help with this the SET_IRQS ioctl returns negative on error, 0 on success, and a positive value indicating the available vectors to retry with if the requested count is not supported/available. BTW, this should fix the oops you found: https://lkml.org/lkml/2016/8/2/1912 Thanks, Alex _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
