* [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 1:58 ` xiangxia.m.yue
0 siblings, 0 replies; 22+ messages in thread
From: xiangxia.m.yue @ 2020-09-29 1:58 UTC (permalink / raw)
To: jasowang, mst, willemb; +Cc: netdev, virtualization
From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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))
+
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
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Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply related [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 1:58 ` xiangxia.m.yue
@ 2020-09-29 6:23 ` Michael S. Tsirkin
-1 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2020-09-29 6:23 UTC (permalink / raw)
To: xiangxia.m.yue; +Cc: jasowang, willemb, virtualization, netdev
On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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 ...
> 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
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 6:23 ` Michael S. Tsirkin
0 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2020-09-29 6:23 UTC (permalink / raw)
To: xiangxia.m.yue; +Cc: netdev, willemb, virtualization
On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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 ...
> 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
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 6:23 ` Michael S. Tsirkin
@ 2020-09-29 6:59 ` Tonghao Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 6:59 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Jason Wang, Willem de Bruijn, virtualization,
Linux Kernel Network Developers
On Tue, Sep 29, 2020 at 2:23 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > Cc: Jason Wang <jasowang@redhat.com>
> > Cc: Willem de Bruijn <willemb@google.com>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 6:59 ` Tonghao Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 6:59 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Linux Kernel Network Developers, Willem de Bruijn, virtualization
On Tue, Sep 29, 2020 at 2:23 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > Cc: Jason Wang <jasowang@redhat.com>
> > Cc: Willem de Bruijn <willemb@google.com>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 6:59 ` Tonghao Zhang
@ 2020-09-29 7:21 ` Michael S. Tsirkin
-1 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2020-09-29 7:21 UTC (permalink / raw)
To: Tonghao Zhang
Cc: Jason Wang, Willem de Bruijn, virtualization,
Linux Kernel Network Developers
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@redhat.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > Cc: Jason Wang <jasowang@redhat.com>
> > > Cc: Willem de Bruijn <willemb@google.com>
> > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 7:21 ` Michael S. Tsirkin
0 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2020-09-29 7:21 UTC (permalink / raw)
To: Tonghao Zhang
Cc: Linux Kernel Network Developers, Willem de Bruijn, virtualization
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@redhat.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > Cc: Jason Wang <jasowang@redhat.com>
> > > Cc: Willem de Bruijn <willemb@google.com>
> > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 7:21 ` Michael S. Tsirkin
@ 2020-09-29 7:29 ` Willem de Bruijn
-1 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 7:29 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Tonghao Zhang, Jason Wang, virtualization,
Linux Kernel Network Developers
On Tue, Sep 29, 2020 at 9:23 AM Michael S. Tsirkin <mst@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@redhat.com> wrote:
> > >
> > > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > > Cc: Jason Wang <jasowang@redhat.com>
> > > > Cc: Willem de Bruijn <willemb@google.com>
> > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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.
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 7:29 ` Willem de Bruijn
0 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 7:29 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: Linux Kernel Network Developers, virtualization
On Tue, Sep 29, 2020 at 9:23 AM Michael S. Tsirkin <mst@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@redhat.com> wrote:
> > >
> > > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > > Cc: Jason Wang <jasowang@redhat.com>
> > > > Cc: Willem de Bruijn <willemb@google.com>
> > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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.
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 7:29 ` Willem de Bruijn
@ 2020-09-29 8:04 ` Tonghao Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 8:04 UTC (permalink / raw)
To: Willem de Bruijn, Michael S. Tsirkin
Cc: Jason Wang, virtualization, Linux Kernel Network Developers
On Tue, Sep 29, 2020 at 3:29 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 9:23 AM Michael S. Tsirkin <mst@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@redhat.com> wrote:
> > > >
> > > > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > > > Cc: Jason Wang <jasowang@redhat.com>
> > > > > Cc: Willem de Bruijn <willemb@google.com>
> > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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.
Hi Willem, Michael
The first patch v2 is for -net, can we apply it?
and second patch will be sent for -net-next after discussion ? That is ok?
--
Best regards, Tonghao
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 8:04 ` Tonghao Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 8:04 UTC (permalink / raw)
To: Willem de Bruijn, Michael S. Tsirkin
Cc: Linux Kernel Network Developers, virtualization
On Tue, Sep 29, 2020 at 3:29 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 9:23 AM Michael S. Tsirkin <mst@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@redhat.com> wrote:
> > > >
> > > > On Tue, Sep 29, 2020 at 09:58:06AM +0800, xiangxia.m.yue@gmail.com wrote:
> > > > > From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> > > > > Cc: Jason Wang <jasowang@redhat.com>
> > > > > Cc: Willem de Bruijn <willemb@google.com>
> > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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@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.
Hi Willem, Michael
The first patch v2 is for -net, can we apply it?
and second patch will be sent for -net-next after discussion ? That is ok?
--
Best regards, Tonghao
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 1:58 ` xiangxia.m.yue
@ 2020-09-29 7:31 ` Willem de Bruijn
-1 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 7:31 UTC (permalink / raw)
To: Tonghao Zhang
Cc: Jason Wang, Michael S. Tsirkin, virtualization, Network Development
On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@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.
I had focused on the code previously.
The s/w checksum verification cost is significant in a VM with traffic
to local destinations. A bridge does not verify transport layer
checksums OTOH?
> Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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))
> +
> 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
>
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 7:31 ` Willem de Bruijn
0 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 7:31 UTC (permalink / raw)
To: Tonghao Zhang; +Cc: Network Development, virtualization, Michael S. Tsirkin
On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@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.
I had focused on the code previously.
The s/w checksum verification cost is significant in a VM with traffic
to local destinations. A bridge does not verify transport layer
checksums OTOH?
> Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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))
> +
> 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
>
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 7:31 ` Willem de Bruijn
@ 2020-09-29 7:52 ` Tonghao Zhang
-1 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 7:52 UTC (permalink / raw)
To: Willem de Bruijn
Cc: Jason Wang, Michael S. Tsirkin, virtualization, Network Development
On Tue, Sep 29, 2020 at 3:32 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
> >
> > From: Tonghao Zhang <xiangxia.m.yue@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.
>
> I had focused on the code previously.
>
> The s/w checksum verification cost is significant in a VM with traffic
> to local destinations. A bridge does not verify transport layer
> checksums OTOH?
Hi Willem.
No, think about GRO(In the GRO we don't know packets will be forwarded
to other ports or to local). The call tree as below:
+ 5.41% secondary_startup_64
- 1.22% ret_from_fork
....
net_rx_action
napi_poll
virtnet_poll
virtnet_receive
napi_gro_receive
dev_gro_receive
inet_gro_receive
tcp4_gro_receive
__skb_gro_checksum_complete
skb_checksum
__skb_checksum
csum_partial
do_csum
- 1.13% do_csum
$ brctl show
bridge name bridge id STP enabled interfaces
br0 8000.001122330001 no eth1
eth2
> > Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Cc: Jason Wang <jasowang@redhat.com>
> > Cc: Willem de Bruijn <willemb@google.com>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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))
> > +
> > 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
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 7:52 ` Tonghao Zhang
0 siblings, 0 replies; 22+ messages in thread
From: Tonghao Zhang @ 2020-09-29 7:52 UTC (permalink / raw)
To: Willem de Bruijn; +Cc: Network Development, virtualization, Michael S. Tsirkin
On Tue, Sep 29, 2020 at 3:32 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
> >
> > From: Tonghao Zhang <xiangxia.m.yue@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.
>
> I had focused on the code previously.
>
> The s/w checksum verification cost is significant in a VM with traffic
> to local destinations. A bridge does not verify transport layer
> checksums OTOH?
Hi Willem.
No, think about GRO(In the GRO we don't know packets will be forwarded
to other ports or to local). The call tree as below:
+ 5.41% secondary_startup_64
- 1.22% ret_from_fork
....
net_rx_action
napi_poll
virtnet_poll
virtnet_receive
napi_gro_receive
dev_gro_receive
inet_gro_receive
tcp4_gro_receive
__skb_gro_checksum_complete
skb_checksum
__skb_checksum
csum_partial
do_csum
- 1.13% do_csum
$ brctl show
bridge name bridge id STP enabled interfaces
br0 8000.001122330001 no eth1
eth2
> > Fixes: a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> > Cc: Michael S. Tsirkin <mst@redhat.com>
> > Cc: Jason Wang <jasowang@redhat.com>
> > Cc: Willem de Bruijn <willemb@google.com>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@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))
> > +
> > 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
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^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 7:52 ` Tonghao Zhang
@ 2020-09-29 8:38 ` Willem de Bruijn
-1 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 8:38 UTC (permalink / raw)
To: Tonghao Zhang
Cc: Jason Wang, Michael S. Tsirkin, virtualization, Network Development
On Tue, Sep 29, 2020 at 9:56 AM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 3:32 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
> > >
> > > From: Tonghao Zhang <xiangxia.m.yue@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.
> >
> > I had focused on the code previously.
> >
> > The s/w checksum verification cost is significant in a VM with traffic
> > to local destinations. A bridge does not verify transport layer
> > checksums OTOH?
> Hi Willem.
> No, think about GRO(In the GRO we don't know packets will be forwarded
> to other ports or to local).
I had expected a pure bridging setup that disables LRO to disable GRO as well.
But if not, then, indeed, the checksum needs to be verified before
coalescing. Makes sense.
> The call tree as below:
> + 5.41% secondary_startup_64
> - 1.22% ret_from_fork
> ....
> net_rx_action
> napi_poll
> virtnet_poll
> virtnet_receive
> napi_gro_receive
> dev_gro_receive
> inet_gro_receive
> tcp4_gro_receive
> __skb_gro_checksum_complete
> skb_checksum
> __skb_checksum
> csum_partial
> do_csum
> - 1.13% do_csum
>
> $ brctl show
> bridge name bridge id STP enabled interfaces
> br0 8000.001122330001 no eth1
> eth2
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 8:38 ` Willem de Bruijn
0 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 8:38 UTC (permalink / raw)
To: Tonghao Zhang; +Cc: Network Development, virtualization, Michael S. Tsirkin
On Tue, Sep 29, 2020 at 9:56 AM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Tue, Sep 29, 2020 at 3:32 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
> > >
> > > From: Tonghao Zhang <xiangxia.m.yue@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.
> >
> > I had focused on the code previously.
> >
> > The s/w checksum verification cost is significant in a VM with traffic
> > to local destinations. A bridge does not verify transport layer
> > checksums OTOH?
> Hi Willem.
> No, think about GRO(In the GRO we don't know packets will be forwarded
> to other ports or to local).
I had expected a pure bridging setup that disables LRO to disable GRO as well.
But if not, then, indeed, the checksum needs to be verified before
coalescing. Makes sense.
> The call tree as below:
> + 5.41% secondary_startup_64
> - 1.22% ret_from_fork
> ....
> net_rx_action
> napi_poll
> virtnet_poll
> virtnet_receive
> napi_gro_receive
> dev_gro_receive
> inet_gro_receive
> tcp4_gro_receive
> __skb_gro_checksum_complete
> skb_checksum
> __skb_checksum
> csum_partial
> do_csum
> - 1.13% do_csum
>
> $ brctl show
> bridge name bridge id STP enabled interfaces
> br0 8000.001122330001 no eth1
> eth2
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^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 1:58 ` xiangxia.m.yue
@ 2020-09-29 8:39 ` Willem de Bruijn
-1 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 8:39 UTC (permalink / raw)
To: Tonghao Zhang
Cc: Jason Wang, Michael S. Tsirkin, virtualization, Network Development
On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 8:39 ` Willem de Bruijn
0 siblings, 0 replies; 22+ messages in thread
From: Willem de Bruijn @ 2020-09-29 8:39 UTC (permalink / raw)
To: Tonghao Zhang; +Cc: Network Development, virtualization, Michael S. Tsirkin
On Tue, Sep 29, 2020 at 4:00 AM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
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^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
2020-09-29 1:58 ` xiangxia.m.yue
@ 2020-09-29 19:54 ` David Miller
-1 siblings, 0 replies; 22+ messages in thread
From: David Miller @ 2020-09-29 19:54 UTC (permalink / raw)
To: xiangxia.m.yue; +Cc: jasowang, mst, willemb, virtualization, netdev
From: xiangxia.m.yue@gmail.com
Date: Tue, 29 Sep 2020 09:58:06 +0800
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Applied and queued up for -stable, thank you.
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH net v2] virtio-net: don't disable guest csum when disable LRO
@ 2020-09-29 19:54 ` David Miller
0 siblings, 0 replies; 22+ messages in thread
From: David Miller @ 2020-09-29 19:54 UTC (permalink / raw)
To: xiangxia.m.yue; +Cc: netdev, virtualization, willemb, mst
From: xiangxia.m.yue@gmail.com
Date: Tue, 29 Sep 2020 09:58:06 +0800
> From: Tonghao Zhang <xiangxia.m.yue@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@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Applied and queued up for -stable, thank you.
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^ permalink raw reply [flat|nested] 22+ messages in thread