Re: "iommu/amd: Set exclusion range correctly" causes smartpqi offline

From: Joerg Roedel
Date: Mon May 06 2019 - 08:30:01 EST

On Sun, May 05, 2019 at 10:56:28PM -0400, Qian Cai wrote:
> It turned out another linux-next commit is needed to reproduce this, i.e.,
> 7a5dbf3ab2f0 ("iommu/amd: Remove the leftover of bypass support"). Specifically,
> the chunks for map_sg() and unmap_sg(). This has been reproduced on 3 different
> HPE ProLiant DL385 Gen10 systems so far.
> Either reverted the chunks (map_sg() and unmap_sg()) on the top of the latest
> linux-next fixed the issue or applied them on the top of the mainline v5.1
> reproduced it immediately.
> Lots of time it triggered this BUG_ON(!iova) in iova_magazine_free_pfns()
> instead of the smartpqi offline.

Thanks a lot for tracking this down further. I queued a revert of the
above patch, as it does some questionable things I missed during review.
We should revisit the patch during the next cycle, but for now it is
better to just revert it. Revert attached.