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Date: Fri, 1 Apr 2011 14:21:16 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCH RFC] vga: flag vga ram for notifiers
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: Alex Williamson <alex.williamson@redhat.com>, qemu-devel@nongnu.org

On Fri, Apr 01, 2011 at 08:12:48AM +0100, Peter Maydell wrote:
> On 31 March 2011 22:38, Michael S. Tsirkin <mst@redhat.com> wrote:
> > On Thu, Mar 31, 2011 at 10:32:11PM +0100, Peter Maydell wrote:
> >> On 31 March 2011 21:23, Anthony Liguori <anthony@codemonkey.ws> wrote:
> >> > Maybe the right approach here is to just use a virtio specific API and
> >> > register RAM as register_virtio_dma_area().
> >>
> >> That seems like a clearer API, yes. I think it makes it much more
> >> obvious what it's trying to achieve.
> 
> > Maybe register_dma_area - its' not 100% virtio specific.
> 
> Presumably it is specific to virtualisation-aware devices
> though? Guest DMA has to just work to all the locations you
> can DMA to/from on hardware, right?
> 
> -- PMM

I guess so, yes.  But it might not be possible e.g. for a PCI device
to DMA into an ISA device.

-- 
MST