From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: Tetsuya Mukawa <mukawa@igel.co.jp>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "nakajima.yoshihiro@lab.ntt.co.jp"
<nakajima.yoshihiro@lab.ntt.co.jp>,
"mst@redhat.com" <mst@redhat.com>
Subject: Re: [dpdk-dev] [PATCH v1 0/2] Virtio-net PMD Extension to work on host
Date: Wed, 6 Jan 2016 13:42:40 +0800 [thread overview]
Message-ID: <568CA950.9000205@intel.com> (raw)
In-Reply-To: <568C90A7.9040503@igel.co.jp>
On 1/6/2016 11:57 AM, Tetsuya Mukawa wrote:
> On 2015/12/28 20:06, Tetsuya Mukawa wrote:
>> On 2015/12/24 23:05, Tan, Jianfeng wrote:
>>> Hi Tetsuya,
>>>
>>> After several days' studying your patch, I have some questions as follows:
>>>
>>> 1. Is physically-contig memory really necessary?
>>> This is a too strong requirement IMHO. IVSHMEM doesn't require this in its original meaning. So how do you think of
>>> Huawei Xie's idea of using virtual address for address translation? (In addition, virtual address of mem_table could be
>>> different in application and QTest, but this can be addressed because SET_MEM_TABLE msg will be intercepted by
>>> QTest)
>> Hi Jianfeng,
>>
>> Thanks for your suggestion.
>> Huawei's idea may solve contig-mem restriction.
>> Let me have time to check it more.
> Hi Jianfeng,
>
> I made sure we can remove the restriction with Huawei's idea.
> One thing I concern is below.
> If we don't use contiguous memory, this PMD will not work with other
> 'physical' PMDs like e1000 PMD, virtio-net PMD, and etc.
> (This is because allocated memory may not be physically contiguous.)
>
> One of examples is that if we implement like above, in QEMU guest, we
> can handle a host NIC directly, but in container, we will not be able to
> handle the device.
> This will be a restriction for this virtual addressing changing.
>
> Do you know an use case that the user wants to handle 'physical' PMD and
> 'virtual' virtio-net PMD together?
>
> Tetsuya,
Hi Tetsuya,
I have no use case in hand, which handles 'physical' PMDs and 'virtual'
virtio-net PMD together.
(Pavel Fedin once tried to run ovs in container, but that case just uses
virtual virtio devices, I
don't know if he has plan to add 'physical' PMDs as well.)
Actually, it's not completely contradictory to make them work together.
Like this:
a. containers with root privilege
We can initialize memory as legacy way. (TODO: besides
physical-contiguous, we try allocate
virtual-contiguous big area for all memsegs as well.)
a.1 For vhost-net, before sending memory regions into kernel, we can
merge those virtual-contiguous regions into one region.
a.2 For vhost-user, we can merge memory regions in the vhost. The
blocker is that for now, maximum fd num was restricted
by VHOST_MEMORY_MAX_NREGIONS=8 (so in 2M-hugepage's case, 16M shared
memory is not nearly enough).
b. containers without root privilege
No need to worry about this problem, because it lacks of privilege to
construct physical-contiguous memory.
Thanks,
Jianfeng
next prev parent reply other threads:[~2016-01-06 5:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-19 10:57 [dpdk-dev] [RFC PATCH " Tetsuya Mukawa
2015-11-19 10:57 ` [dpdk-dev] [RFC PATCH 1/2] EAL: Add new EAL "--shm" option Tetsuya Mukawa
2015-12-16 8:37 ` [dpdk-dev] [PATCH v1 0/2] Virtio-net PMD Extension to work on host Tetsuya Mukawa
2015-12-16 8:37 ` [dpdk-dev] [PATCH v1 1/2] EAL: Add new EAL "--contig-mem" option Tetsuya Mukawa
2015-12-16 8:37 ` [dpdk-dev] [PATCH v1 2/2] virtio: Extend virtio-net PMD to support container environment Tetsuya Mukawa
2015-12-28 11:57 ` Pavel Fedin
2016-01-06 3:57 ` Tetsuya Mukawa
2016-01-06 5:56 ` Tan, Jianfeng
2016-01-06 7:27 ` Tetsuya Mukawa
2015-12-24 14:05 ` [dpdk-dev] [PATCH v1 0/2] Virtio-net PMD Extension to work on host Tan, Jianfeng
2015-12-28 11:06 ` Tetsuya Mukawa
2016-01-06 3:57 ` Tetsuya Mukawa
2016-01-06 5:42 ` Tan, Jianfeng [this message]
2016-01-06 7:35 ` Tetsuya Mukawa
2016-01-11 5:31 ` Tan, Jianfeng
2015-11-19 10:57 ` [dpdk-dev] [RFC PATCH 2/2] virtio: Extend virtio-net PMD to support container environment Tetsuya Mukawa
2015-11-19 18:16 ` [dpdk-dev] [RFC PATCH 0/2] Virtio-net PMD Extension to work on host Rich Lane
2015-11-20 2:00 ` Xie, Huawei
2015-11-20 2:35 ` Tetsuya Mukawa
2015-11-20 2:53 ` Tetsuya Mukawa
2015-12-28 5:15 ` Qiu, Michael
2015-12-28 11:06 ` Tetsuya Mukawa
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