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Subject: Re: [PATCH] iommu: Update "iommu.strict" documentation
To:     Robin Murphy <robin.murphy@arm.com>, <joro@8bytes.org>
CC:     <will@kernel.org>, <iommu@lists.linux-foundation.org>,
        <linux-kernel@vger.kernel.org>, <baolu.lu@linux.intel.com>
References: <2c8c06e1b449d6b060c5bf9ad3b403cd142f405d.1623682646.git.robin.murphy@arm.com>
From:   John Garry <john.garry@huawei.com>
Message-ID: <1e95deac-b0c3-e122-f1e5-7748424a2c9f@huawei.com>
Date:   Mon, 14 Jun 2021 17:29:31 +0100
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On 14/06/2021 15:57, Robin Murphy wrote:
> Consolidating the flush queue logic also meant that the "iommu.strict"
> option started taking effect on x86 as well. Make sure we document that.
> 
> Fixes: a250c23f15c2 ("iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE")
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

I assumed that all bets were off when we use a cmdline param which is 
not "officially" supported.

Anyway, FWIW:
Reviewed-by: John Garry <john.garry@huawei.com>

> ---
>   Documentation/admin-guide/kernel-parameters.txt | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index cb89dbdedc46..20a32de990ed 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1987,7 +1987,7 @@
>   			  forcing Dual Address Cycle for PCI cards supporting
>   			  greater than 32-bit addressing.
>   
> -	iommu.strict=	[ARM64] Configure TLB invalidation behaviour
> +	iommu.strict=	[ARM64, X86] Configure TLB invalidation behaviour
>   			Format: { "0" | "1" }
>   			0 - Lazy mode.
>   			  Request that DMA unmap operations use deferred