From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: stephen@networkplumber.org
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] virtio: fix the vq size issue
Date: Fri, 17 Jul 2015 12:42:02 +0200 [thread overview]
Message-ID: <2270958.zeR53oyNJH@xps13> (raw)
In-Reply-To: <F52918179C57134FAEC9EA62FA2F962511BE833B@shsmsx102.ccr.corp.intel.com>
Stephen,
This patch is partially reverting yours:
http://dpdk.org/browse/dpdk/commit/?id=d78deadae4dca240
A comment or a ack?
2015-07-07 02:32, Ouyang, Changchun:
>
> > -----Original Message-----
> > From: Ouyang, Changchun
> > Sent: Wednesday, July 1, 2015 3:49 PM
> > To: dev@dpdk.org
> > Cc: Cao, Waterman; Xu, Qian Q; Ouyang, Changchun
> > Subject: [PATCH] virtio: fix the vq size issue
> >
> > This commit breaks virtio basic packets rx functionality:
> > d78deadae4dca240e85054bf2d604a801676becc
> >
> > The QEMU use 256 as default vring size, also use this default value to
> > calculate the virtio avail ring base address and used ring base address, and
> > vhost in the backend use the ring base address to do packet IO.
> >
> > Virtio spec also says the queue size in PCI configuration is read-only, so virtio
> > front end can't change it. just need use the read-only value to allocate space
> > for vring and calculate the avail and used ring base address. Otherwise, the
> > avail and used ring base address will be different between host and guest,
> > accordingly, packet IO can't work normally.
> >
> > Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> > ---
> > drivers/net/virtio/virtio_ethdev.c | 14 +++-----------
> > 1 file changed, 3 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/net/virtio/virtio_ethdev.c
> > b/drivers/net/virtio/virtio_ethdev.c
> > index fe5f9a1..d84de13 100644
> > --- a/drivers/net/virtio/virtio_ethdev.c
> > +++ b/drivers/net/virtio/virtio_ethdev.c
> > @@ -263,8 +263,6 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
> > */
> > vq_size = VIRTIO_READ_REG_2(hw, VIRTIO_PCI_QUEUE_NUM);
> > PMD_INIT_LOG(DEBUG, "vq_size: %d nb_desc:%d", vq_size,
> > nb_desc);
> > - if (nb_desc == 0)
> > - nb_desc = vq_size;
> > if (vq_size == 0) {
> > PMD_INIT_LOG(ERR, "%s: virtqueue does not exist",
> > __func__);
> > return -EINVAL;
> > @@ -275,15 +273,9 @@ int virtio_dev_queue_setup(struct rte_eth_dev
> > *dev,
> > return -EINVAL;
> > }
> >
> > - if (nb_desc < vq_size) {
> > - if (!rte_is_power_of_2(nb_desc)) {
> > - PMD_INIT_LOG(ERR,
> > - "nb_desc(%u) size is not powerof 2",
> > - nb_desc);
> > - return -EINVAL;
> > - }
> > - vq_size = nb_desc;
> > - }
> > + if (nb_desc != vq_size)
> > + PMD_INIT_LOG(ERR, "Warning: nb_desc(%d) is not equal to
> > vq size (%d), fall to vq size",
> > + nb_desc, vq_size);
> >
> > if (queue_type == VTNET_RQ) {
> > snprintf(vq_name, sizeof(vq_name), "port%d_rvq%d",
> > --
> > 1.8.4.2
>
> Any more comments for this patch?
>
> Thanks
> Changchun
>
next prev parent reply other threads:[~2015-07-17 10:43 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-01 7:48 Ouyang Changchun
2015-07-01 8:55 ` Xu, Qian Q
2015-07-01 15:53 ` Xie, Huawei
2015-07-02 0:29 ` Ouyang, Changchun
2015-07-02 2:01 ` Xie, Huawei
2015-07-02 2:16 ` Ouyang, Changchun
2015-07-02 9:15 ` Xie, Huawei
2015-07-03 1:53 ` Ouyang, Changchun
2015-07-10 14:05 ` Xie, Huawei
2015-07-10 14:11 ` Thomas Monjalon
2015-07-13 1:40 ` Ouyang, Changchun
2015-07-07 2:32 ` Ouyang, Changchun
2015-07-17 10:42 ` Thomas Monjalon [this message]
2015-07-17 16:27 ` Stephen Hemminger
2015-07-18 12:11 ` Ouyang, Changchun
2015-07-20 15:47 ` Stephen Hemminger
2015-07-20 3:40 ` Xu, Qian Q
2015-07-20 6:18 ` Ouyang, Changchun
2015-07-20 10:42 ` Thomas Monjalon
2015-07-21 5:23 ` Ouyang, Changchun
2015-07-20 15:30 ` Stephen Hemminger
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