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

[Timothy Pearson <tpearson@raptorengineering.com>]

----- 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?