Re: [dpdk-dev] [PATCH 0/7] fix DMA mask check

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/31/2018 5:29 PM, Alejandro Lucero wrote:
> A patchset sent introducing DMA mask checks has several critical
> issues precluding apps to execute. The patchset was reviewed and
> finally accepted after three versions. Obviously it did not go 
> through the proper testing what can be explained, at least from my
> side, due to the big changes to the memory initialization code these
> last months. It turns out the patchset did work with legacy memory
> and I'm afraid that was mainly my testing.
> 
> This patchset should solve the main problems reported:
> 
>  - deadlock duriing initialization
>  - segmentation fault with secondary processes
> 
> For solving the deadlock, a new API is introduced:
> 
>  rte_mem_check_dma_mask_safe/unsafe
> 
> making the previous rte_mem_check_dma_mask the one those new functions
> end calling. A boolean param is used for calling rte_memseg_walk thread
> safe or thread unsafe. This second option is needed for avoiding the 
> deadlock.
> 
> For the secondary processes problem, the call to check the dma mask is
> avoided from code being executed before the memory initialization. 
> Instead, a new API function, rte_mem_set_dma_mask is introduced, which 
> will be used in those cases. The dma mask check is done once the memory
> initialization is completed.
> 
> This last change implies the IOVA mode can not be set depending on IOMMU
> hardware limitations, and it is assumed IOVA VA is possible. If the dma
> mask check reports a problem after memory initilization, the error 
> message includes now advice for trying with --iova-mode option set to 
> pa.
> 
> The patchet also includes the dma mask check for legacy memory and the 
> no hugepage option.
> 
> Finally, all the DMA mask API has been updated for using the same prefix
> than other EAL memory code.
> 
> An initial version of this patchset has been tested by Intel DPDK 
> Validation team and it seems it solves all the problems reported. This 
> final patchset has the same functionality with minor changes. I have
> successfully tested the patchset with my limited testbench.
> 
> Alejandro Lucero (7):
>   mem: fix call to DMA mask check
>   mem: use proper prefix
>   mem: add function for setting DMA mask
>   bus/pci: avoid call to DMA mask check
>   mem: modify error message for DMA mask check
>   mem: add safe and unsafe versions for checking DMA mask
>   eal/mem: use DMA mask check for legacy memory

Tested-by: Ferruh Yigit <ferruh.yigit@intel.com>