From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"david.marchand@6wind.com" <david.marchand@6wind.com>
Subject: Re: [dpdk-dev] [PATCH 3/5] net/virtio-user: support to report net status
Date: Thu, 30 Mar 2017 11:14:55 +0800 [thread overview]
Message-ID: <5a59e0ab-617e-2e5e-60a0-6835d74e5c3e@intel.com> (raw)
In-Reply-To: <20170329083659.GK18844@yliu-dev.sh.intel.com>
On 3/29/2017 4:36 PM, Yuanhan Liu wrote:
> On Wed, Mar 29, 2017 at 04:33:20PM +0800, Tan, Jianfeng wrote:
>>
>> On 3/29/2017 4:00 PM, Yuanhan Liu wrote:
>>> On Wed, Mar 29, 2017 at 03:48:04PM +0800, Tan, Jianfeng wrote:
>>>> On 3/29/2017 3:14 PM, Yuanhan Liu wrote:
>>>>> On Wed, Mar 29, 2017 at 03:07:28PM +0800, Tan, Jianfeng wrote:
>>>>>> On 3/29/2017 2:33 PM, Yuanhan Liu wrote:
>>>>>>> On Mon, Mar 27, 2017 at 07:46:32AM +0000, Tan, Jianfeng wrote:
>>>>>>>>>> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>>>>>>> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>>>>>>>> index 9777d6b..cc6f557 100644
>>>>>>>>>> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>>>>>>>> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>>>>>>>>>> @@ -176,6 +176,7 @@ virtio_user_start_device(struct virtio_user_dev
>>>>>>>>> *dev, uint8_t portid)
>>>>>>>>>> features &= ~(1ull << VIRTIO_NET_F_MAC);
>>>>>>>>>> /* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to
>>>>>>>>> know */
>>>>>>>>>> features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
>>>>>>>>>> + features &= ~(1ull << VIRTIO_NET_F_STATUS);
>>>>>>>>>> ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES,
>>>>>>>>> &features);
>>>>>>>>>> if (ret < 0)
>>>>>>>>>> goto error;
>>>>>>>>>> diff --git a/drivers/net/virtio/virtio_user_ethdev.c
>>>>>>>>> b/drivers/net/virtio/virtio_user_ethdev.c
>>>>>>>>>> index fa79419..fbdd0a8 100644
>>>>>>>>>> --- a/drivers/net/virtio/virtio_user_ethdev.c
>>>>>>>>>> +++ b/drivers/net/virtio/virtio_user_ethdev.c
>>>>>>>>>> @@ -121,7 +121,8 @@ virtio_user_get_features(struct virtio_hw *hw)
>>>>>>>>>> struct virtio_user_dev *dev = virtio_user_get_dev(hw);
>>>>>>>>>>
>>>>>>>>>> /* unmask feature bits defined in vhost user protocol */
>>>>>>>>>> - return dev->device_features &
>>>>>>>>> VIRTIO_PMD_SUPPORTED_GUEST_FEATURES;
>>>>>>>>>> + return (dev->device_features | (1 << VIRTIO_NET_F_STATUS))
>>>>>>>>>> + & VIRTIO_PMD_SUPPORTED_GUEST_FEATURES;
>>>>>>>>> Why not handle the features at virtio_user_dev_init()?
>>>>>>>> You mean add VIRTIO_NET_F_STATUS when get_features from device? Yes, we could do that there. But we originally add device_features to only record features supported by device.
>>>>>>>>
>>>>>>> Aren't you adding the F_STATUS features to this device?
>>>>>>>
>>>>>> For virtio driver, yes, we are adding F_STATUS feature so the it sees a
>>>>>> device supporting LSC.
>>>>> That means you are adding a device feature (F_STATUS) and reporting it to
>>>>> the driver that this feature is always on, no matter whether the device
>>>>> actually supports it or not? This looks wrong to me.
>>>> Why?
>>> Because you were doing hack to make virtio-user work, while there is no
>>> such hack in the QEMU virtio-pci implementation.
>>>
>>>> IMO, device is not necessary to know this feature.
>>> F_STATUS is a device feature. If such feature is not claimed to be
>>> supported by the device, the driver should ignore it. But you are
>>> unconditionally letting the driver handle it, even though the
>>> virito-user device does not claim to support it.
>>>
>>> Note that F_STATUS is set in the QEMU virtio-net PCI device.
>> In QEMU virtio-net PCI device, the device includes QEMU device emulation +
>> vhost backend driver. This feature only shows at QEMU device emulation,
>> instead of vhost backend driver. This is why we did not see this feature at
>> any vhost backends.
>> And the embedded virtio-user actually substitutes QEMU device emulation
>> part, so this feature should end at this layer.
>>
>> Let's look this in this way, if we let this feature go through to vhost
>> user, it will be treated as an error in vhost_user_set_features().
> Again, why can't we (virtio-user) follow QEMU?
Through F2F discussion, I got to know that you treat
virtio_user_ethdev.c as front driver part. That makes sense. I'll move
this change into vhost-user directory.
Thanks,
Jianfeng
next prev parent reply other threads:[~2017-03-30 3:14 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-03 17:56 [dpdk-dev] [PATCH 0/5] add LSC and Rxq interrupt for virtio-user Jianfeng Tan
2017-03-03 17:56 ` [dpdk-dev] [PATCH 1/5] eal/linux: add interrupt type for vdev Jianfeng Tan
2017-03-03 17:56 ` [dpdk-dev] [PATCH 2/5] net/virtio-user: add rxq interrupt mode support Jianfeng Tan
2017-03-17 6:47 ` Yuanhan Liu
2017-03-28 1:33 ` Tan, Jianfeng
2017-03-03 17:56 ` [dpdk-dev] [PATCH 3/5] net/virtio-user: support to report net status Jianfeng Tan
2017-03-17 6:54 ` Yuanhan Liu
2017-03-27 7:46 ` Tan, Jianfeng
2017-03-29 6:33 ` Yuanhan Liu
2017-03-29 7:07 ` Tan, Jianfeng
2017-03-29 7:14 ` Yuanhan Liu
2017-03-29 7:48 ` Tan, Jianfeng
2017-03-29 8:00 ` Yuanhan Liu
2017-03-29 8:33 ` Tan, Jianfeng
2017-03-29 8:36 ` Yuanhan Liu
2017-03-30 3:14 ` Tan, Jianfeng [this message]
2017-03-03 17:56 ` [dpdk-dev] [PATCH 4/5] net/virtio-user: add lsc support with vhost-user adapter Jianfeng Tan
2017-03-17 8:29 ` Yuanhan Liu
2017-03-27 1:51 ` Tan, Jianfeng
2017-03-03 17:56 ` [dpdk-dev] [PATCH 5/5] net/virtio-user: add lsc support with vhost-kernel adapter Jianfeng Tan
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 0/5] add LSC and Rxq interrupt for virtio-user Jianfeng Tan
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 1/5] eal/linux: add interrupt type for vdev Jianfeng Tan
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 2/5] net/virtio: add interrupt configure " Jianfeng Tan
2017-03-29 6:27 ` Yuanhan Liu
2017-03-29 7:03 ` Tan, Jianfeng
2017-03-29 7:09 ` Yuanhan Liu
2017-03-29 7:27 ` Tan, Jianfeng
2017-03-29 7:30 ` Yuanhan Liu
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 3/5] net/virtio-user: add rxq interrupt mode support Jianfeng Tan
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 4/5] net/virtio-user: support to report net status Jianfeng Tan
2017-03-28 8:21 ` [dpdk-dev] [PATCH v2 5/5] net/virtio-user: add lsc support Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 0/5] add LSC and Rxq interrupt for virtio-user Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 1/5] eal/linux: add interrupt type for vdev Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 2/5] net/virtio-user: move eventfd open/close into init/uninit Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 3/5] net/virtio-user: add rxq interrupt mode support Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 4/5] net/virtio-user: support to report net status Jianfeng Tan
2017-03-31 19:44 ` [dpdk-dev] [PATCH v3 5/5] net/virtio-user: add lsc support Jianfeng Tan
2017-04-01 5:13 ` Yuanhan Liu
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=5a59e0ab-617e-2e5e-60a0-6835d74e5c3e@intel.com \
--to=jianfeng.tan@intel.com \
--cc=david.marchand@6wind.com \
--cc=dev@dpdk.org \
--cc=yuanhan.liu@linux.intel.com \
/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).