Message-ID: <c966018b-95f0-7b92-0a5a-9023236b0dfb@infradead.org>
Date:   Sat, 28 Jan 2023 08:41:38 -0800
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Subject: Re: [PATCH 2/4] swiotlb: Add a new cc-swiotlb implementation for
 Confidential VMs
Content-Language: en-US
To:     "GuoRui.Yu" <GuoRui.Yu@linux.alibaba.com>,
        linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
        konrad.wilk@oracle.com, linux-coco@lists.linux.dev
Cc:     robin.murphy@arm.com
References: <20230128083254.86012-1-GuoRui.Yu@linux.alibaba.com>
 <20230128083254.86012-3-GuoRui.Yu@linux.alibaba.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <20230128083254.86012-3-GuoRui.Yu@linux.alibaba.com>
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Hi--

On 1/28/23 00:32, GuoRui.Yu wrote:
> diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
> index 56866aaa2ae1..7e6b20d2091f 100644
> --- a/kernel/dma/Kconfig
> +++ b/kernel/dma/Kconfig
> @@ -78,8 +78,18 @@ config ARCH_HAS_FORCE_DMA_UNENCRYPTED
>  
>  config SWIOTLB
>  	bool
> +	depends on !CC_SWIOTLB
>  	select NEED_DMA_MAP_STATE
>  
> +config CC_SWIOTLB
> +	bool "Enable cc-swiotlb for Confidential VMs"
> +	default n
> +	select NEED_DMA_MAP_STATE
> +	help
> +	  This enables a cc-swiotlb implementation for Confidential VMs,
> +	  which allows allocating the SWIOTLB buffer allocation on runtime.

Two "allocat..." words seems to be redundant. Probably the second one
can be dropped.
Also, instead of "on runtime", how about "at runtime"?

> +	  If unsure, say "n".

Thanks.
-- 
~Randy