From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: Regarding MMIO
Date: Thu, 1 Oct 2015 07:42:28 -0700
Message-ID: <20151001074228.6c980c96@urahara>
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To: Venkateswara Rao Dokku <dvrao.584@gmail.com>
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On Thu, 1 Oct 2015 09:51:42 +0530
Venkateswara Rao Dokku <dvrao.584@gmail.com> wrote:

> Hi,
> 
> If we go through the DPDK code it is observed that we are using MMIO for
> Virt-IO devices. But in the Virt-IO specification, it is written that from
> Virt-IO 1.0 onwards only they are supporting MMIO, all previous versions
> uses Port IO for RX/TX notifications.
> 
> So, If I use VirtIO 0.9, Can I get the MMIO based notifications for RX/TX
> or is it supported only for Virt-IO 1.0 onwards?
> 

Although the virtio device will bind to the mmio address in some cases,
it does not use that. It uses i/o port access (see iopl) to activate
host.