Re: [RFC v2 26/32] x86/mm: Move force_dma_unencrypted() to common code

[Dave Hansen]

> +++ b/arch/x86/mm/mem_encrypt_common.c
...
> +/* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
> +bool force_dma_unencrypted(struct device *dev)
> +{
> +	/*
> +	 * For SEV, all DMA must be to unencrypted/shared addresses.
> +	 */
> +	if (sev_active())
> +		return true;
> +
> +	/*
> +	 * For SME, all DMA must be to unencrypted addresses if the
> +	 * device does not support DMA to addresses that include the
> +	 * encryption mask.
> +	 */
> +	if (sme_active()) {
> +		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);
> +
> +		if (dma_dev_mask <= dma_enc_mask)
> +			return true;
> +	}
> +
> +	return false;
> +}

This doesn't seem much like common code to me.  It seems like 100% SEV
code.  Is this really where we want to move it?