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Date: Wed, 17 Jul 2013 21:56:45 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PULL 3/5] exec: Support 64-bit operations in
	address_space_rw
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To: Richard Henderson <rth@twiddle.net>
Cc: Anthony Liguori <aliguori@us.ibm.com>, Gerd Hoffmann <kraxel@redhat.com>, Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org

Il 17/07/2013 21:28, Richard Henderson ha scritto:
> On 07/17/2013 11:57 AM, Paolo Bonzini wrote:
>> I'm still not sure what the bug is (so what the FIXME comment would
>> be)... except of course that there may be bug in access_with_adjusted_size.
> 
> The code here in exec.c is not using access_with_adjusted_size.

It is:

cpu_outb
-> address_space_write
-> address_space_rw
-> io_mem_write
-> memory_region_dispatch_write
-> access_with_adjusted_size

memory_access_size is just returning a length that makes sense when
passed to io_mem_write and ultimately to access_with_adjusted_size.

Paolo

> Unfortunately, access_with_adjusted_size only handles single copies,
> one direction at a time.  We're attempting a sort of "memcpy", which
> calls for some amount of caching across the loop...
> 
> 
> r~
>