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Subject: Re: [PATCH v2] QEMU fw_cfg DMA interface documentation
To: Gerd Hoffmann <kraxel@redhat.com>,
        =?UTF-8?Q?Marc_Mar=c3=ad?= <markmb@redhat.com>
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Cc: Stefan Hajnoczi <stefanha@gmail.com>,
        linux-kernel <linux-kernel@vger.kernel.org>, Drew <drjones@redhat.com>,
        "Kevin O'Connor" <kevin@koconnor.net>, Arnd Bergmann <arnd@arndb.de>,
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From: Laszlo Ersek <lersek@redhat.com>
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Date: Mon, 7 Sep 2015 13:25:20 +0200
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On 09/07/15 13:08, Gerd Hoffmann wrote:
>   Hi,
> 
>> It's just simplicity. If you want to read a few times from the same
>> field (like in ACPI tables, read the data size and then the data), you
>> need a way to enable and disable the selector and manage the current
>> offset for that entry. This is already provided with the "old"
>> interface.
> 
> Could be handled with a 'select' control bit.  Only when set select
> entry and reset offset to zero.
> 
> Also: would it make sense to allow an *array* of FWCfgDmaAccess structs?
> With a 'more' bit in control we could indicate that there are more
> entries.  I'm not sure firmware would actually use that though ...

Seems far-fetched.

Thanks
Laszlo

> cheers,
>   Gerd
> 
>