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From: "Derrick, Jonathan" <jonathan.derrick@intel.com>
To: "hch@lst.de" <hch@lst.de>, "x86@kernel.org" <x86@kernel.org>
Cc: "joro@8bytes.org" <joro@8bytes.org>,
	"Busch, Keith" <keith.busch@intel.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"bhelgaas@google.com" <bhelgaas@google.com>,
	"dwmw2@infradead.org" <dwmw2@infradead.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] vmd: Stop overriding dma_map_ops
Date: Tue, 27 Aug 2019 18:24:05 +0000	[thread overview]
Message-ID: <8cad7eb5b5b37aeb041fd0c464383bb5223e4a64.camel@intel.com> (raw)
In-Reply-To: <20190826150652.10316-1-hch@lst.de>

On Mon, 2019-08-26 at 17:06 +0200, Christoph Hellwig wrote:
> With a little tweak to the intel-iommu code we should be able to work
> around the VMD mess for the requester IDs without having to create giant
> amounts of boilerplate DMA ops wrapping code.  The other advantage of
> this scheme is that we can respect the real DMA masks for the actual
> devices, and I bet it will only be a matter of time until we'll see the
> first DMA challeneged NVMe devices.
> 
> The only downside is that we can't offer vmd as a module given that
> intel-iommu calls into it.  But the driver only has about 700 lines
> of code, so this should not be a major issue.
If we're going to remove its ability to be a module, and given its
small size, could we make this default =y?

Otherwise we risk breaking platforms which have it enabled with OSVs
who miss enabling it


> 
> This also removes the leftover bits of the X86_DEV_DMA_OPS dma_map_ops
> registry.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 

lgtm otherwise

Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>

  reply	other threads:[~2019-08-27 18:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-26 15:06 [PATCH] vmd: Stop overriding dma_map_ops Christoph Hellwig
2019-08-27 18:24 ` Derrick, Jonathan [this message]
2019-08-27 21:56   ` Keith Busch

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