On Wed, Sep 27, 2023 at 05:24:20PM +0200, Niklas Schnelle wrote: > Ok, another update. On trying it out again this problem actually also > occurs when applying this v12 on top of v6.6-rc3 too. Also I guess > unlike my prior thinking it probably doesn't occur with > iommu.forcedac=1 since that still allows IOVAs below 4 GiB and we might > be the only ones who don't support those. From my point of view this > sounds like a mlx5_core issue they really should call > dma_set_mask_and_coherent() before their first call to > dma_alloc_coherent() not after. So I guess I'll send a v13 of this > series rebased on iommu/core and with an additional mlx5 patch and then > let's hope we can get that merged in a way that doesn't leave us with > broken ConnectX VFs for too long. Yes, OK. It definitely sounds wrong that mlx5 is doing dma allocations before setting it's dma_set_mask_and_coherent(). Please link to this thread and we can get Leon or Saeed to ack it for Joerg. (though wondering why s390 is the only case that ever hit this?) Jason