From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [RFC PATCH] KVM: Specify byte order for KVM_EXIT_MMIO
Date: Fri, 24 Jan 2014 16:32:45 +0100
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To: Victor Kamensky <victor.kamensky@linaro.org>,
	Alexander Graf <agraf@suse.de>,
	Christoffer Dall <christoffer.dall@linaro.org>
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Il 24/01/2014 16:23, Victor Kamensky ha scritto:
> Also if you use ints on real bus as description, you may want to clarify
> restrictions on mmio.len. Basically on 32 bit platform (i.e like V7
> ARM) one cannot have mmio.len=8, because one cannot have 64bit
> value on 32bit data bus. Without such clarification introduction of
> text like "the value as it would go on the bus in real hardware" is
> confusing for len=8 for emulated CPUs where real busses are
> 32bit.

This is not necessarily true.  On a 32-bit CPU you can have a 64-bit 
memory bus.  Even x86 32-bit CPUs can do 64-bit MMIO via MMX or SSE or 
double-word compare-and-swap (CMPXCHG8B).

Paolo