Re: [PATCH v2 0/4] Reenable VFIO support on POWER systems

[Alex Williamson <alex.williamson@redhat.com>]

On Mon, 6 Mar 2023 18:35:22 -0600 (CST)
Timothy Pearson <tpearson@raptorengineering.com> wrote:

> ----- Original Message -----
> > From: "Alex Williamson" <alex.williamson@redhat.com>
> > To: "Timothy Pearson" <tpearson@raptorengineering.com>
> > Cc: "kvm" <kvm@vger.kernel.org>, "linuxppc-dev" <linuxppc-dev@lists.ozlabs.org>
> > Sent: Monday, March 6, 2023 5:46:07 PM
> > Subject: Re: [PATCH v2 0/4] Reenable VFIO support on POWER systems  
> 
> > On Mon, 6 Mar 2023 11:29:53 -0600 (CST)
> > Timothy Pearson <tpearson@raptorengineering.com> wrote:
> >   
> >> This patch series reenables VFIO support on POWER systems.  It
> >> is based on Alexey Kardashevskiys's patch series, rebased and
> >> successfully tested under QEMU with a Marvell PCIe SATA controller
> >> on a POWER9 Blackbird host.
> >> 
> >> Alexey Kardashevskiy (3):
> >>   powerpc/iommu: Add "borrowing" iommu_table_group_ops
> >>   powerpc/pci_64: Init pcibios subsys a bit later
> >>   powerpc/iommu: Add iommu_ops to report capabilities and allow blocking
> >>     domains
> >> 
> >> Timothy Pearson (1):
> >>   Add myself to MAINTAINERS for Power VFIO support
> >> 
> >>  MAINTAINERS                               |   5 +
> >>  arch/powerpc/include/asm/iommu.h          |   6 +-
> >>  arch/powerpc/include/asm/pci-bridge.h     |   7 +
> >>  arch/powerpc/kernel/iommu.c               | 246 +++++++++++++++++++++-
> >>  arch/powerpc/kernel/pci_64.c              |   2 +-
> >>  arch/powerpc/platforms/powernv/pci-ioda.c |  36 +++-
> >>  arch/powerpc/platforms/pseries/iommu.c    |  27 +++
> >>  arch/powerpc/platforms/pseries/pseries.h  |   4 +
> >>  arch/powerpc/platforms/pseries/setup.c    |   3 +
> >>  drivers/vfio/vfio_iommu_spapr_tce.c       |  96 ++-------
> >>  10 files changed, 338 insertions(+), 94 deletions(-)
> >>   
> > 
> > For vfio and MAINTAINERS portions,
> > 
> > Acked-by: Alex Williamson <alex.williamson@redhat.com>
> > 
> > I'll note though that spapr_tce_take_ownership() looks like it copied a
> > bug from the old tce_iommu_take_ownership() where tbl and tbl->it_map
> > are tested before calling iommu_take_ownership() but not in the unwind
> > loop, ie. tables we might have skipped on setup are unconditionally
> > released on unwind.  Thanks,
> > 
> > Alex  
> 
> Thanks for that.  I'll put together a patch to get rid of that
> potential bug that can be applied after this series is merged, unless
> you'd rather I resubmit a v3 with the issue fixed?

Follow-up fix is fine by me.  Thanks,

Alex