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Tonghao Zhang

2020-Sep-29 06:59 UTC

[PATCH net v2] virtio-net: don't disable guest csum when disable LRO

On Tue, Sep 29, 2020 at 2:23 PM Michael S. Tsirkin <mst at redhat.com>
wrote:>
> On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue at gmail.com
wrote:
> > From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> >
> > Open vSwitch and Linux bridge will disable LRO of the interface
> > when this interface added to them. Now when disable the LRO, the
> > virtio-net csum is disable too. That drops the forwarding performance.
> >
> > Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> > Cc: Michael S. Tsirkin <mst at redhat.com>
> > Cc: Jason Wang <jasowang at redhat.com>
> > Cc: Willem de Bruijn <willemb at google.com>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> > ---
> > v2:
> > * change the fix-tag
> > ---
> >  drivers/net/virtio_net.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 7145c83c6c8c..21b71148c532 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -63,6 +63,11 @@ static const unsigned long guest_offloads[] = {
> >       VIRTIO_NET_F_GUEST_CSUM
> >  };
> >
> > +#define GUEST_OFFLOAD_LRO_MASK ((1ULL <<
VIRTIO_NET_F_GUEST_TSO4) | \
> > +                             (1ULL << VIRTIO_NET_F_GUEST_TSO6)
| \
> > +                             (1ULL << VIRTIO_NET_F_GUEST_ECN) 
| \
> > +                             (1ULL << VIRTIO_NET_F_GUEST_UFO))
> > +
>
> I think I'd rather we open-coded this, the macro is only
> used in one place ...Yes, in this patch, it is used only in one place. But in next patch
[1], we use it twice and that make the code look a bit nicer.
Would we open-coded this in this patch ?

[1] -
http://patchwork.ozlabs.org/project/netdev/patch/20200928033915.82810-2-xiangxia.m.yue
at gmail.com/
> >  struct virtnet_stat_desc {
> >       char desc[ETH_GSTRING_LEN];
> >       size_t offset;
> > @@ -2531,7 +2536,8 @@ static int virtnet_set_features(struct
net_device *dev,
> >               if (features & NETIF_F_LRO)
> >                       offloads = vi->guest_offloads_capable;
> >               else
> > -                     offloads = 0;
> > +                     offloads = vi->guest_offloads_capable &
> > +                                ~GUEST_OFFLOAD_LRO_MASK;
> >
> >               err = virtnet_set_guest_offloads(vi, offloads);
> >               if (err)
>
> > --
> > 2.23.0
>

-- 
Best regards, Tonghao

Michael S. Tsirkin

2020-Sep-29 07:21 UTC

head link

[PATCH net v2] virtio-net: don't disable guest csum when disable LRO

On Tue, Sep 29, 2020 at 02:59:03PM +0800, Tonghao Zhang
wrote:> On Tue, Sep 29, 2020 at 2:23 PM Michael S. Tsirkin <mst at
redhat.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue at gmail.com
wrote:
> > > From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> > >
> > > Open vSwitch and Linux bridge will disable LRO of the interface
> > > when this interface added to them. Now when disable the LRO, the
> > > virtio-net csum is disable too. That drops the forwarding
performance.
> > >
> > > Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable
LRO")
> > > Cc: Michael S. Tsirkin <mst at redhat.com>
> > > Cc: Jason Wang <jasowang at redhat.com>
> > > Cc: Willem de Bruijn <willemb at google.com>
> > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> > > ---
> > > v2:
> > > * change the fix-tag
> > > ---
> > >  drivers/net/virtio_net.c | 8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 7145c83c6c8c..21b71148c532 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -63,6 +63,11 @@ static const unsigned long guest_offloads[] =
{
> > >       VIRTIO_NET_F_GUEST_CSUM
> > >  };
> > >
> > > +#define GUEST_OFFLOAD_LRO_MASK ((1ULL <<
VIRTIO_NET_F_GUEST_TSO4) | \
> > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_TSO6) | \
> > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_ECN)  | \
> > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_UFO))
> > > +
> >
> > I think I'd rather we open-coded this, the macro is only
> > used in one place ...
> Yes, in this patch, it is used only in one place. But in next patch
> [1], we use it twice and that make the code look a bit nicer.
> Would we open-coded this in this patch ?
> 
> [1] -
http://patchwork.ozlabs.org/project/netdev/patch/20200928033915.82810-2-xiangxia.m.yue
at gmail.com/
OK then maybe keep this in a series like you did with v1.


> > >  struct virtnet_stat_desc {
> > >       char desc[ETH_GSTRING_LEN];
> > >       size_t offset;
> > > @@ -2531,7 +2536,8 @@ static int virtnet_set_features(struct
net_device *dev,
> > >               if (features & NETIF_F_LRO)
> > >                       offloads = vi->guest_offloads_capable;
> > >               else
> > > -                     offloads = 0;
> > > +                     offloads = vi->guest_offloads_capable
&
> > > +                                ~GUEST_OFFLOAD_LRO_MASK;
> > >
> > >               err = virtnet_set_guest_offloads(vi, offloads);
> > >               if (err)
> >
> > > --
> > > 2.23.0
> >
> 
> 
> -- 
> Best regards, Tonghao

Willem de Bruijn

2020-Sep-29 07:29 UTC

head link

[PATCH net v2] virtio-net: don't disable guest csum when disable LRO

On Tue, Sep 29, 2020 at 9:23 AM Michael S. Tsirkin <mst at redhat.com>
wrote:>
> On Tue, Sep 29, 2020 at 02:59:03PM +0800, Tonghao Zhang wrote:
> > On Tue, Sep 29, 2020 at 2:23 PM Michael S. Tsirkin <mst at
redhat.com> wrote:
> > >
> > > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue at
gmail.com wrote:
> > > > From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
> > > >
> > > > Open vSwitch and Linux bridge will disable LRO of the
interface
> > > > when this interface added to them. Now when disable the LRO,
the
> > > > virtio-net csum is disable too. That drops the forwarding
performance.
> > > >
> > > > Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable
LRO")
> > > > Cc: Michael S. Tsirkin <mst at redhat.com>
> > > > Cc: Jason Wang <jasowang at redhat.com>
> > > > Cc: Willem de Bruijn <willemb at google.com>
> > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue at
gmail.com>
> > > > ---
> > > > v2:
> > > > * change the fix-tag
> > > > ---
> > > >  drivers/net/virtio_net.c | 8 +++++++-
> > > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/net/virtio_net.c
b/drivers/net/virtio_net.c
> > > > index 7145c83c6c8c..21b71148c532 100644
> > > > --- a/drivers/net/virtio_net.c
> > > > +++ b/drivers/net/virtio_net.c
> > > > @@ -63,6 +63,11 @@ static const unsigned long
guest_offloads[] = {
> > > >       VIRTIO_NET_F_GUEST_CSUM
> > > >  };
> > > >
> > > > +#define GUEST_OFFLOAD_LRO_MASK ((1ULL <<
VIRTIO_NET_F_GUEST_TSO4) | \
> > > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_TSO6) | \
> > > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_ECN)  | \
> > > > +                             (1ULL <<
VIRTIO_NET_F_GUEST_UFO))
> > > > +
> > >
> > > I think I'd rather we open-coded this, the macro is only
> > > used in one place ...
> > Yes, in this patch, it is used only in one place. But in next patch
> > [1], we use it twice and that make the code look a bit nicer.
> > Would we open-coded this in this patch ?
> >
> > [1] -
http://patchwork.ozlabs.org/project/netdev/patch/20200928033915.82810-2-xiangxia.m.yue
at gmail.com/
>
> OK then maybe keep this in a series like you did with v1.
If this is a fix it has to target net, unlike the other patch.

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