Re: "dma-mapping: remove CONFIG_DMA_REMAP" causes AMD SME boot fail

Alex Xu (Hello71)
2022-03-30T19:18:23Z

Excerpts from Christoph Hellwig's message of March 30, 2022 2:01 pm:
> Can you try this patch, which is a bit of a hack?
>
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 50d209939c66c..61997c2ee0a17 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -28,7 +28,8 @@ bool force_dma_unencrypted(struct device *dev)
> * device does not support DMA to addresses that include the
> * encryption mask.
> */
> - if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
> + if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT) &&
> + !get_dma_ops(dev)) {
> u64 dma_enc_mask = DMA_BIT_MASK(__ffs64(sme_me_mask));
> u64 dma_dev_mask = min_not_zero(dev->coherent_dma_mask,
> dev->bus_dma_limit);
>

This seems to work for me.

Cheers,
Alex.