From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Yigit, Ferruh" <ferruh.yigit@intel.com>,
"Liang, Cunming" <cunming.liang@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2 2/7] net/virtio_user: postpone DRIVER OK notification
Date: Mon, 26 Dec 2016 06:55:16 +0000 [thread overview]
Message-ID: <ED26CBA2FAD1BF48A8719AEF02201E36510FC7B6@SHSMSX103.ccr.corp.intel.com> (raw)
In-Reply-To: <20161226062719.GA19288@yliu-dev.sh.intel.com>
> -----Original Message-----
> From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com]
> Sent: Monday, December 26, 2016 2:27 PM
> To: Tan, Jianfeng
> Cc: dev@dpdk.org; Yigit, Ferruh; Liang, Cunming
> Subject: Re: [PATCH v2 2/7] net/virtio_user: postpone DRIVER OK notification
>
> On Fri, Dec 23, 2016 at 07:14:21AM +0000, Jianfeng Tan wrote:
> > In driver probe phase, we obtain device information; and then virtio
> > driver will initialize device and stores info, like negotiated
> > features, in vhost_user layer; finally, vhost_user gets DRIVER_OK
> > notification from virtio driver, and then sync with backend device.
> >
> > Previously, DRIVER_OK could be sent twice: 1. when ether layer invokes
> > eth_device_init to initialize device; 2. when user configures it with
> > different configuration from that of previous.
>
> Yes, but that's wrong. Now only 1) will be taken.
>From code in virtio_dev_configure() as below, if hw_ip_checksum or enable_lro is configured, the device will be reset and re-initialized.
if (rxmode->hw_ip_checksum)
req_features |= (1ULL << VIRTIO_NET_F_GUEST_CSUM);
if (rxmode->enable_lro)
req_features |=
(1ULL << VIRTIO_NET_F_GUEST_TSO4) |
(1ULL << VIRTIO_NET_F_GUEST_TSO6);
/* if request features changed, reinit the device */
if (req_features != hw->req_guest_features) {
ret = virtio_init_device(dev, req_features);
if (ret < 0)
return ret;
}
>
> > Since we can only depend on DRIVER_OK notification to sync with backend
> > device, we postpone it to virtio_dev_start when everything is settled.
>
> I don't quite understand what you were going to fix here; you don't
> state it in the commit log after all. Normally, when everything is
> negotiated (when DRIVER_OK is set), we should not set it again, unless
> a reset has been happened.
I agree that DRIVER_OK should be set only if everything is settled. Under the case of hw_ip_checksum or enable_lro, a reset will be sent and the device will be re-initialized.
So my point is that since the configuration might be changed in dev_configure(), why not just send DRIVER_OK after everything is done.
>
> If you look at QEMU, qemu will simply ignore it once vhost has already
> started.
It does not apply here. The configuration is changed, and it cannot be ignored.
Thanks,
Jianfeng
>
> --yliu
next prev parent reply other threads:[~2016-12-26 6:55 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 14:31 [dpdk-dev] [PATCH 0/3] virtio_user as an alternative exception path Jianfeng Tan
2016-12-02 14:31 ` [dpdk-dev] [PATCH 1/3] net/virtio_user: add vhost layer Jianfeng Tan
2016-12-08 7:21 ` Yuanhan Liu
2016-12-02 14:31 ` [dpdk-dev] [PATCH 2/3] net/virtio_user: add vhost kernel support Jianfeng Tan
2016-12-02 14:31 ` [dpdk-dev] [PATCH 3/3] net/virtio_user: fix wrongly set features Jianfeng Tan
2016-12-08 8:32 ` Yuanhan Liu
2016-12-02 14:44 ` [dpdk-dev] [PATCH 0/3] virtio_user as an alternative exception path Thomas Monjalon
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 0/7] " Jianfeng Tan
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 1/7] net/virtio_user: fix wrongly set features Jianfeng Tan
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 2/7] net/virtio_user: postpone DRIVER OK notification Jianfeng Tan
[not found] ` <20161226062719.GA19288@yliu-dev.sh.intel.com>
2016-12-26 6:55 ` Tan, Jianfeng [this message]
2016-12-26 8:02 ` Yuanhan Liu
2016-12-26 8:26 ` Tan, Jianfeng
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 3/7] net/virtio_user: move vhost user specific code Jianfeng Tan
2016-12-26 6:28 ` Yuanhan Liu
2016-12-26 6:58 ` Tan, Jianfeng
2016-12-26 7:57 ` Yuanhan Liu
2016-12-29 9:40 ` Tan, Jianfeng
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 4/7] net/virtio_user: abstract virtio user backend ops Jianfeng Tan
2016-12-26 6:41 ` Yuanhan Liu
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 5/7] net/virtio_user: add vhost kernel support Jianfeng Tan
2016-12-26 7:44 ` Yuanhan Liu
2017-01-04 7:22 ` Tan, Jianfeng
2017-01-04 7:46 ` Yuanhan Liu
2017-01-09 4:51 ` Jason Wang
2017-01-09 4:39 ` Jason Wang
2017-01-10 6:11 ` Tan, Jianfeng
2017-01-10 8:46 ` Thomas Monjalon
2017-01-10 9:11 ` Tan, Jianfeng
2017-01-11 2:42 ` Jason Wang
2017-01-11 3:13 ` Tan, Jianfeng
2017-01-11 3:23 ` Jason Wang
2017-01-12 9:40 ` Tan, Jianfeng
2017-01-13 2:27 ` Jason Wang
2017-01-11 2:30 ` Tan, Jianfeng
2017-01-11 2:45 ` Jason Wang
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 6/7] net/virtio_user: enable offloading Jianfeng Tan
2016-12-26 7:53 ` Yuanhan Liu
2016-12-23 7:14 ` [dpdk-dev] [PATCH v2 7/7] net/virtio_user: enable multiqueue with vhost kernel Jianfeng Tan
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 0/7] virtio_user as an alternative exception path Jianfeng Tan
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 1/7] net/virtio_user: fix wrongly set features Jianfeng Tan
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 2/7] net/virtio_user: fix not properly reset device Jianfeng Tan
2017-01-04 5:46 ` Yuanhan Liu
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 3/7] net/virtio_user: move vhost user specific code Jianfeng Tan
2017-01-04 6:02 ` Yuanhan Liu
2017-01-04 6:46 ` Tan, Jianfeng
2017-01-04 7:08 ` Yuanhan Liu
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 4/7] net/virtio_user: abstract virtio user backend ops Jianfeng Tan
2017-01-04 6:11 ` Yuanhan Liu
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 5/7] net/virtio_user: add vhost kernel support Jianfeng Tan
2017-01-04 6:13 ` Yuanhan Liu
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 6/7] net/virtio_user: enable offloading Jianfeng Tan
2017-01-04 3:59 ` [dpdk-dev] [PATCH v3 7/7] net/virtio_user: enable multiqueue with vhost kernel Jianfeng Tan
2017-01-09 14:06 ` [dpdk-dev] [PATCH v3 0/7] virtio_user as an alternative exception path Bruce Richardson
2017-01-10 8:46 ` Tan, Jianfeng
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 0/8] " Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 1/8] net/virtio_user: fix wrongly get/set features Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 2/8] net/virtio_user: fix not properly reset device Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 3/8] net/virtio_user: move vhost user specific code Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 4/8] net/virtio_user: abstract virtio user backend ops Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 5/8] net/virtio_user: add vhost kernel support Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 6/8] net/virtio_user: enable offloading Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 7/8] net/virtio_user: enable multiqueue with vhost kernel Jianfeng Tan
2017-01-13 12:18 ` [dpdk-dev] [PATCH v4 8/8] doc: add guide to use virtio_user as exceptional path Jianfeng Tan
2017-01-16 6:00 ` Yuanhan Liu
2017-01-16 6:04 ` Yuanhan Liu
2017-01-16 9:44 ` Thomas Monjalon
2017-01-16 9:49 ` Yuanhan Liu
2017-01-16 14:45 ` Thomas Monjalon
2017-01-22 0:46 ` Aws Ismail
2017-01-22 7:16 ` Tan, Jianfeng
2017-01-16 15:05 ` [dpdk-dev] [PATCH v4 0/8] virtio_user as an alternative exception path Yuanhan Liu
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