From: "Xie, Huawei" <huawei.xie@intel.com>
To: Venkateswara Rao Dokku <dvrao.584@gmail.com>,
Stephen Hemminger <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] Regarding MMIO
Date: Mon, 5 Oct 2015 13:39:49 +0000 [thread overview]
Message-ID: <C37D651A908B024F974696C65296B57B4B0FD30B@SHSMSX103.ccr.corp.intel.com> (raw)
In-Reply-To: <CACiOAOA=wPuf_3vUN6b5afw1=Q3TZE+q4nyYjKqdC-e6dH7O+g@mail.gmail.com>
On 10/5/2015 12:41 PM, Venkateswara Rao Dokku wrote:
> Thanks for the response Stephen.
>
> Are you referring to Virt-IO 0.9 in specific here in the response or for
> any Virt-IO versions in general?
>
> On Thu, Oct 1, 2015 at 8:12 PM, Stephen Hemminger <
> stephen@networkplumber.org> wrote:
>
>> 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.
Which is used depends on access time. Check the virtio 1.0 improvement
for mmio access.
http://events.linuxfoundation.org/sites/events/files/slides/misha2015-v1.pdf
Is there any special reason you want to use mmio based notification?
>
>
prev parent reply other threads:[~2015-10-05 13:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CACiOAOAJ-aK02yrMC6m8knMdR7gTscRYF7m8Sqh1E4k4=CrwCA@mail.gmail.com>
2015-10-01 14:42 ` Stephen Hemminger
2015-10-05 4:40 ` Venkateswara Rao Dokku
2015-10-05 13:39 ` Xie, Huawei [this message]
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