From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Can I specify a physical memory region for a domU
Date: Thu, 8 Sep 2011 08:59:21 -0400
Message-ID: <20110908125920.GC28591@dumpdata.com>
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To: Eric Camachat <eric.camachat@gmail.com>
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On Wed, Sep 07, 2011 at 05:47:46PM -0700, Eric Camachat wrote:
> Hi,
> 
> I am porting our drivers to XEN's PV domU (with PV PCI passthrouth), I

Use the DMA API that Linux provides (I presume that is what you meant
by PV DomU), and use the dma_alloc_coherent to set your regions.

Also pass in 'iommu=soft' on your Linux command line to enable the
Xen SWIOTLB DMA system.

> have to allocate a memory block and tell the hardware to access it.
> But the hardware can address 32-bit only, so I want dedicate a region
> of memory that below 2GB for the domU only.

Uh, don't you mean 4GB? - 32bit is up to 4GB.
> How do that in XEN?
> 
> Thanks,
> /Eric
> 
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