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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Mon, 12 Aug 2013 19:43:26 +1000
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Subject: Re: [Qemu-devel] [PATCH 1/8] virtio_get_byteswap: function for
 endian-ambivalent targets using virtio.
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To: Peter Maydell <peter.maydell@linaro.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>, qemu-devel@nongnu.org

On Mon, 2013-08-12 at 10:39 +0100, Peter Maydell wrote:
> On 12 August 2013 10:28, Benjamin Herrenschmidt
> <benh@kernel.crashing.org> wrote:
> > We have explicit knowledge of when our endianness change (we get the
> > hcall or a write to some SPR), we can call virtio *then* to adjust the
> > endianness rather than having a call-out to the platform on every
> > access.
> 
> ARM doesn't -- I wouldn't expect changing the endianness of
> exceptions via writing to the SCTLR to trap to the hypervisor
> (and in any case it certainly won't result in a return to
> userspace).

But don't you need to reconfigure the bridge (as per our previous
discussion) ? In that case you do need to call out to qemu ...

Cheers,
Ben.