Re: [PATCH 0/3] handle init errors more gracefully in amd_iommu

Kevin Mitchell via iommu
2019-05-07T18:05:40Z

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Sorry to nag, but did anyone have any comments about these patches? Is no
news good news?

Thanks,
Kevin

On Thu, Apr 18, 2019 at 11:14 AM Kevin Mitchell <kevmitch@arista.com> wrote:

> This series makes error handling more robust in the amd_iommu init
> code. It was initially motivated by problematic firmware that does not
> set up the physical address of the iommu. This led to a NULL dereference
> panic when iommu_disable was called during cleanup.
>
> While the first patch is sufficient to avoid the panic, the subsequent
> two move the cleanup closer to the actual error and avoid calling the
> cleanup code twice when amd_iommu=off is specified on the command line.
>
> I have tested this series on a variety of AMD CPUs with firmware
> exhibiting the issue. I have additionally tested on platforms where the
> firmware has been fixed. I tried both with and without amd_iommu=off. I
> have also tested on older CPUs where no IOMMU is detected and even one
> where the GART driver ends up running.
>
> Thanks,
>
> Kevin
>
> Kevin Mitchell (3):
> iommu/amd: make iommu_disable safer
> iommu/amd: move gart fallback to amd_iommu_init
> iommu/amd: only free resources once on init error
>
> drivers/iommu/amd_iommu_init.c | 45 ++++++++++++++++++----------------
> 1 file changed, 24 insertions(+), 21 deletions(-)
>
> --
> 2.20.1
>
>

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