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Date: Mon, 15 Oct 2012 12:45:21 +0200
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [RFC v1 0/7] IOMMU support
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To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>, liu ping fan <qemulist@gmail.com>, qemu-devel@nongnu.org, Blue Swirl <blauwirbel@gmail.com>, Alex Williamson <alex.williamson@redhat.com>, Anthony Liguori <anthony@codemonkey.ws>, Paolo Bonzini <pbonzini@redhat.com>

On 10/12/2012 04:36 AM, Benjamin Herrenschmidt wrote:
> On Thu, 2012-10-11 at 15:26 +0200, Avi Kivity wrote:
>> These patches add IOMMU support to the memory core. IOMMUs can be added anywhere in
>> the memory hierarchy, and may be arranged in series.
> 
> I haven't had a chance to review in details yet, but one thing I noticed
> is that you basically have a single read/write protection information
> for a translation.
> 
> This is a loss of functionality to some extent (well, maybe not from the
> existing iommu layer but from what could be done by our HW) in that we
> have separate read and write permission bits.
> 
> This is actually worth fixing I think. Catching incorrect reads from
> write-only regions is probably worth it in term of debugging drivers.
> 

I do have an is_write parameter to translate, in fact I added it in
order to implement the spapr iommu.  Or do you mean something else?



-- 
error compiling committee.c: too many arguments to function