Re: [PATCH v4] QEMU fw_cfg DMA interface documentation

From	Stefan Hajnoczi <stefanha@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v4] QEMU fw_cfg DMA interface documentation
Date	2015-10-05 12:20 +0200
Message-ID	<qgb2b-4nd-23@gated-at.bofh.it> (permalink)
References	<qeL06-3Kc-3@gated-at.bofh.it> <qeL06-3Kc-1@gated-at.bofh.it> <qg9jI-1RW-15@gated-at.bofh.it> <qgaSv-4bV-33@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Oct 5, 2015 at 11:06 AM, Marc Marí <markmb@redhat.com> wrote:
> On Mon, 5 Oct 2015 09:20:55 +0100
> Stefan Hajnoczi <stefanha@gmail.com> wrote:
>
>> On Thu, Oct 1, 2015 at 1:15 PM, Marc Marí <markmb@redhat.com> wrote:
>> > +Additionaly, if the DMA interface is available then a read to the
>> > DMA Address +will return 0x51454d5520434647 ("QEMU CFG" in
>> > big-endian format).
>>
>> What does this mean?
>>
>
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg325546.html
>
> Proposed by Kevin O'Connor in v3.
>
> (I could not find this thread in gnu.org or gmane archives. It's
> strange).

The following is clearer to me:

If the DMA interface is available, then reading the DMA Address
Register returns 0x51454d5520434647 ("QEMU CFG" in big-endian format).

Stefan
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[PATCH v4] QEMU fw_cfg DMA interface documentation Marc Marí <markmb@redhat.com> - 2015-10-01 14:20 +0200
  Re: [PATCH v4] QEMU fw_cfg DMA interface documentation Stefan Hajnoczi <stefanha@gmail.com> - 2015-10-05 10:30 +0200
    Re: [PATCH v4] QEMU fw_cfg DMA interface documentation Marc Marí <markmb@redhat.com> - 2015-10-05 12:10 +0200
      Re: [PATCH v4] QEMU fw_cfg DMA interface documentation Stefan Hajnoczi <stefanha@gmail.com> - 2015-10-05 12:20 +0200

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