Re: [PATCH v2] powerpc: iommu: Bring back table group release_ownership() call

From: Joerg Roedel
Date: Fri Feb 02 2024 - 03:29:20 EST


On Fri, Jan 26, 2024 at 09:09:18AM -0600, Shivaprasad G Bhat wrote:
> The commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and
> remove set_platform_dma_ops") refactored the code removing the
> set_platform_dma_ops(). It missed out the table group
> release_ownership() call which would have got called otherwise
> during the guest shutdown via vfio_group_detach_container(). On
> PPC64, this particular call actually sets up the 32-bit TCE table,
> and enables the 64-bit DMA bypass etc. Now after guest shutdown,
> the subsequent host driver (e.g megaraid-sas) probe post unbind
> from vfio-pci fails like,
>
> megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0x7fffffffffffffff, table unavailable
> megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0xffffffff, table unavailable
> megaraid_sas 0031:01:00.0: Failed to set DMA mask
> megaraid_sas 0031:01:00.0: Failed from megasas_init_fw 6539
>
> The patch brings back the call to table_group release_ownership()
> call when switching back to PLATFORM domain from BLOCKED, while
> also separates the domain_ops for both.
>
> Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
> Signed-off-by: Shivaprasad G Bhat <sbhat@xxxxxxxxxxxxx>
> ---
> Changelog:
> v1: https://lore.kernel.org/linux-iommu/170618451433.3805.9015493852395837391.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
> - Split the common attach_dev call to platform and blocked attach_dev
> calls as suggested.
>
> arch/powerpc/kernel/iommu.c | 37 ++++++++++++++++++++++++++++---------
> 1 file changed, 28 insertions(+), 9 deletions(-)

Applied, thanks.

--
Jörg Rödel
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