From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Junjie Chen <junjie.j.chen@intel.com>,
jianfeng.tan@intel.com, yliu@fridaylinux.org, "Mcnamara,
John" <john.mcnamara@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v4] doc: add driver limitation for vhost dequeue zero copy
Date: Wed, 11 Apr 2018 16:34:47 +0200 [thread overview]
Message-ID: <038762e8-ca3d-fd1e-b531-5761059f8cc3@redhat.com> (raw)
In-Reply-To: <20e69848-eedf-9e53-55eb-d5be1366a629@redhat.com>
On 03/29/2018 02:14 PM, Maxime Coquelin wrote:
>
>
> On 03/14/2018 05:24 PM, Junjie Chen wrote:
>> In vhost-switch example, when binding nic to vfio-pci with iommu enabled,
>> dequeue zero copy cannot work in VM2NIC mode due to no iommu dma mapping
>> is setup for guest memory currently.
>>
>> Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>
> John, as this is a doc patch for Vhost, does it go through the doc tree
> or through Virtio one?
Applied to dpdk-next-virtio/master
Thanks,
Maxime
> Thanks,
> Maxime
>> ---
>> Changes in V4:
>> - make words more accurate
>> Changes in V3:
>> - update limitation to iommu
>> Changes in V2:
>> - add doc in vhost lib
>> doc/guides/prog_guide/vhost_lib.rst | 5 +++++
>> doc/guides/sample_app_ug/vhost.rst | 5 ++++-
>> 2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/guides/prog_guide/vhost_lib.rst
>> b/doc/guides/prog_guide/vhost_lib.rst
>> index 18227b6..b49e36e 100644
>> --- a/doc/guides/prog_guide/vhost_lib.rst
>> +++ b/doc/guides/prog_guide/vhost_lib.rst
>> @@ -83,6 +83,11 @@ The following is an overview of some key Vhost API
>> functions:
>> of those segments, thus the fewer the segments, the quicker we
>> will get
>> the mapping. NOTE: we may speed it by using tree searching in
>> future.
>> + * zero copy can not work when using vfio-pci with iommu mode
>> currently, this
>> + is because we don't setup iommu dma mapping for guest memory.
>> If you have
>> + to use vfio-pci driver, please insert vfio-pci kernel module in
>> noiommu
>> + mode.
>> +
>> - ``RTE_VHOST_USER_IOMMU_SUPPORT``
>> IOMMU support will be enabled when this flag is set. It is
>> disabled by
>> diff --git a/doc/guides/sample_app_ug/vhost.rst
>> b/doc/guides/sample_app_ug/vhost.rst
>> index a4bdc6a..f0bb169 100644
>> --- a/doc/guides/sample_app_ug/vhost.rst
>> +++ b/doc/guides/sample_app_ug/vhost.rst
>> @@ -147,7 +147,10 @@ retries on an RX burst, it takes effect only when
>> rx retry is enabled. The
>> default value is 15.
>> **--dequeue-zero-copy**
>> -Dequeue zero copy will be enabled when this option is given.
>> +Dequeue zero copy will be enabled when this option is given. it is
>> worth to
>> +note that if NIC is binded to driver with iommu enabled, dequeue zero
>> copy
>> +cannot work at VM2NIC mode (vm2vm=0) due to currently we don't setup
>> iommu
>> +dma mapping for guest memory.
>> **--vlan-strip 0|1**
>> VLAN strip option is removed, because different NICs have different
>> behaviors
>>
prev parent reply other threads:[~2018-04-11 14:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-24 14:44 [dpdk-dev] [PATCH] " Junjie Chen
2018-02-26 4:44 ` Tan, Jianfeng
2018-03-13 9:12 ` Kovacevic, Marko
2018-03-13 9:18 ` Chen, Junjie J
2018-02-27 9:21 ` [dpdk-dev] [PATCH v2] " Junjie Chen
2018-03-06 8:57 ` Maxime Coquelin
2018-03-09 5:17 ` Chen, Junjie J
2018-03-09 10:07 ` [dpdk-dev] [PATCH v3] " Junjie Chen
2018-03-12 3:15 ` Tan, Jianfeng
2018-03-13 9:19 ` Chen, Junjie J
2018-03-14 16:24 ` [dpdk-dev] [PATCH v4] " Junjie Chen
2018-03-19 6:56 ` Tan, Jianfeng
2018-03-29 12:14 ` Maxime Coquelin
2018-04-11 14:34 ` Maxime Coquelin [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=038762e8-ca3d-fd1e-b531-5761059f8cc3@redhat.com \
--to=maxime.coquelin@redhat.com \
--cc=dev@dpdk.org \
--cc=jianfeng.tan@intel.com \
--cc=john.mcnamara@intel.com \
--cc=junjie.j.chen@intel.com \
--cc=yliu@fridaylinux.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).