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| Started by | Jason Wang <jasowang@redhat.com> |
|---|---|
| First post | 2017-06-28 04:00 +0200 |
| Last post | 2017-06-28 14:10 +0200 |
| Articles | 9 — 2 participants |
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[PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP Jason Wang <jasowang@redhat.com> - 2017-06-28 04:00 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP "Michael S. Tsirkin" <mst@redhat.com> - 2017-06-28 04:10 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP Jason Wang <jasowang@redhat.com> - 2017-06-28 04:20 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP "Michael S. Tsirkin" <mst@redhat.com> - 2017-06-28 04:20 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP Jason Wang <jasowang@redhat.com> - 2017-06-28 04:50 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP "Michael S. Tsirkin" <mst@redhat.com> - 2017-06-28 05:40 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP Jason Wang <jasowang@redhat.com> - 2017-06-28 05:50 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP "Michael S. Tsirkin" <mst@redhat.com> - 2017-06-28 06:10 +0200
Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP Jason Wang <jasowang@redhat.com> - 2017-06-28 14:10 +0200
| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Date | 2017-06-28 04:00 +0200 |
| Subject | [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXaqR-ld-5@gated-at.bofh.it> |
We should allow csumed packet for small buffer, otherwise XDP_PASS
won't work correctly.
Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
The patch is needed for -stable.
---
drivers/net/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 143d8a9..499fcc9 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
void *orig_data;
u32 act;
- if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
+ if (unlikely(hdr->hdr.gso_type))
goto err_xdp;
xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
--
2.7.4
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| From | "Michael S. Tsirkin" <mst@redhat.com> |
|---|---|
| Date | 2017-06-28 04:10 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXaAy-Ds-13@gated-at.bofh.it> |
| In reply to | #1676315 |
On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
> We should allow csumed packet for small buffer, otherwise XDP_PASS
> won't work correctly.
>
> Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
> Signed-off-by: Jason Wang <jasowang@redhat.com>
The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
What do you think?
> ---
> The patch is needed for -stable.
> ---
> drivers/net/virtio_net.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 143d8a9..499fcc9 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
> void *orig_data;
> u32 act;
>
> - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
> + if (unlikely(hdr->hdr.gso_type))
> goto err_xdp;
>
> xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
> --
> 2.7.4
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| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Date | 2017-06-28 04:20 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXaKd-MM-1@gated-at.bofh.it> |
| In reply to | #1676321 |
On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
> On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
>> We should allow csumed packet for small buffer, otherwise XDP_PASS
>> won't work correctly.
>>
>> Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
> What do you think?
I think it's safe. For XDP_PASS, it work like in the past. For XDP_TX,
we zero the vnet header. For adjusting header, XDP prog should deal with
csum.
Thanks
>
>> ---
>> The patch is needed for -stable.
>> ---
>> drivers/net/virtio_net.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 143d8a9..499fcc9 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
>> void *orig_data;
>> u32 act;
>>
>> - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
>> + if (unlikely(hdr->hdr.gso_type))
>> goto err_xdp;
>>
>> xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
>> --
>> 2.7.4
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| From | "Michael S. Tsirkin" <mst@redhat.com> |
|---|---|
| Date | 2017-06-28 04:20 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXaKd-MM-5@gated-at.bofh.it> |
| In reply to | #1676322 |
On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
>
>
> On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
> > On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
> > > We should allow csumed packet for small buffer, otherwise XDP_PASS
> > > won't work correctly.
> > >
> > > Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
> > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
> > What do you think?
>
> I think it's safe. For XDP_PASS, it work like in the past.
That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
tools assume it's value.
> For XDP_TX, we
> zero the vnet header.
Again TX offload is disabled, so packets will go out with an invalid
checksum.
> For adjusting header, XDP prog should deal with csum.
>
> Thanks
That part seems right.
> >
> > > ---
> > > The patch is needed for -stable.
> > > ---
> > > drivers/net/virtio_net.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 143d8a9..499fcc9 100644
> > > --- a/drivers/net/virtio_net.c
> > > +++ b/drivers/net/virtio_net.c
> > > @@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
> > > void *orig_data;
> > > u32 act;
> > > - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
> > > + if (unlikely(hdr->hdr.gso_type))
> > > goto err_xdp;
> > > xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
> > > --
> > > 2.7.4
[toc] | [prev] | [next] | [standalone]
| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Date | 2017-06-28 04:50 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXbdg-Yp-13@gated-at.bofh.it> |
| In reply to | #1676323 |
On 2017年06月28日 10:17, Michael S. Tsirkin wrote:
> On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
>>
>> On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
>>> On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
>>>> We should allow csumed packet for small buffer, otherwise XDP_PASS
>>>> won't work correctly.
>>>>
>>>> Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
>>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>> The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
>>> What do you think?
>> I think it's safe. For XDP_PASS, it work like in the past.
> That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
> tools assume it's value.
DATA_VALID is CHECKSUM_UNCESSARY on the host, and according to the
comment in skbuff.h
"
* The hardware you're dealing with doesn't calculate the full checksum
* (as in CHECKSUM_COMPLETE), but it does parse headers and verify
checksums
* for specific protocols. For such packets it will set
CHECKSUM_UNNECESSARY
* if their checksums are okay. skb->csum is still undefined in this case
* though. A driver or device must never modify the checksum field in the
* packet even if checksum is verified.
"
The csum is correct I believe?
Thanks
>
>> For XDP_TX, we
>> zero the vnet header.
> Again TX offload is disabled, so packets will go out with an invalid
> checksum.
>
>> For adjusting header, XDP prog should deal with csum.
>>
>> Thanks
> That part seems right.
>
>>>> ---
>>>> The patch is needed for -stable.
>>>> ---
>>>> drivers/net/virtio_net.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>>>> index 143d8a9..499fcc9 100644
>>>> --- a/drivers/net/virtio_net.c
>>>> +++ b/drivers/net/virtio_net.c
>>>> @@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
>>>> void *orig_data;
>>>> u32 act;
>>>> - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
>>>> + if (unlikely(hdr->hdr.gso_type))
>>>> goto err_xdp;
>>>> xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
>>>> --
>>>> 2.7.4
[toc] | [prev] | [next] | [standalone]
| From | "Michael S. Tsirkin" <mst@redhat.com> |
|---|---|
| Date | 2017-06-28 05:40 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXbZE-1vY-5@gated-at.bofh.it> |
| In reply to | #1676330 |
On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote:
>
>
> On 2017年06月28日 10:17, Michael S. Tsirkin wrote:
> > On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
> > >
> > > On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
> > > > On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
> > > > > We should allow csumed packet for small buffer, otherwise XDP_PASS
> > > > > won't work correctly.
> > > > >
> > > > > Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
> > > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > > The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
> > > > What do you think?
> > > I think it's safe. For XDP_PASS, it work like in the past.
> > That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
> > tools assume it's value.
>
> DATA_VALID is CHECKSUM_UNCESSARY on the host, and according to the comment
> in skbuff.h
>
>
> "
> * The hardware you're dealing with doesn't calculate the full checksum
> * (as in CHECKSUM_COMPLETE), but it does parse headers and verify
> checksums
> * for specific protocols. For such packets it will set
> CHECKSUM_UNNECESSARY
> * if their checksums are okay. skb->csum is still undefined in this case
> * though. A driver or device must never modify the checksum field in the
> * packet even if checksum is verified.
> "
>
> The csum is correct I believe?
>
> Thanks
That's on input. But I think for tun it's output, where that is equivalent
to CHECKSUM_NONE
> >
> > > For XDP_TX, we
> > > zero the vnet header.
> > Again TX offload is disabled, so packets will go out with an invalid
> > checksum.
> >
> > > For adjusting header, XDP prog should deal with csum.
> > >
> > > Thanks
> > That part seems right.
> >
> > > > > ---
> > > > > The patch is needed for -stable.
> > > > > ---
> > > > > drivers/net/virtio_net.c | 2 +-
> > > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > index 143d8a9..499fcc9 100644
> > > > > --- a/drivers/net/virtio_net.c
> > > > > +++ b/drivers/net/virtio_net.c
> > > > > @@ -413,7 +413,7 @@ static struct sk_buff *receive_small(struct net_device *dev,
> > > > > void *orig_data;
> > > > > u32 act;
> > > > > - if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
> > > > > + if (unlikely(hdr->hdr.gso_type))
> > > > > goto err_xdp;
> > > > > xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len;
> > > > > --
> > > > > 2.7.4
[toc] | [prev] | [next] | [standalone]
| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Date | 2017-06-28 05:50 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXc9j-1zf-3@gated-at.bofh.it> |
| In reply to | #1676342 |
On 2017年06月28日 11:31, Michael S. Tsirkin wrote:
> On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote:
>> On 2017年06月28日 10:17, Michael S. Tsirkin wrote:
>>> On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
>>>> On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
>>>>> On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
>>>>>> We should allow csumed packet for small buffer, otherwise XDP_PASS
>>>>>> won't work correctly.
>>>>>>
>>>>>> Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
>>>>>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>>>>> The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
>>>>> What do you think?
>>>> I think it's safe. For XDP_PASS, it work like in the past.
>>> That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
>>> tools assume it's value.
>> DATA_VALID is CHECKSUM_UNCESSARY on the host, and according to the comment
>> in skbuff.h
>>
>>
>> "
>> * The hardware you're dealing with doesn't calculate the full checksum
>> * (as in CHECKSUM_COMPLETE), but it does parse headers and verify
>> checksums
>> * for specific protocols. For such packets it will set
>> CHECKSUM_UNNECESSARY
>> * if their checksums are okay. skb->csum is still undefined in this case
>> * though. A driver or device must never modify the checksum field in the
>> * packet even if checksum is verified.
>> "
>>
>> The csum is correct I believe?
>>
>> Thanks
> That's on input. But I think for tun it's output, where that is equivalent
> to CHECKSUM_NONE
>
>
Yes, but the comment said:
"
CKSUM_NONE:
*
* The skb was already checksummed by the protocol, or a checksum is not
* required.
*
* CHECKSUM_UNNECESSARY:
*
* This has the same meaning on as CHECKSUM_NONE for checksum offload on
* output.
*
"
So still correct I think?
Thanks
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| From | "Michael S. Tsirkin" <mst@redhat.com> |
|---|---|
| Date | 2017-06-28 06:10 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXcsF-1V2-1@gated-at.bofh.it> |
| In reply to | #1676343 |
On Wed, Jun 28, 2017 at 11:40:30AM +0800, Jason Wang wrote:
>
>
> On 2017年06月28日 11:31, Michael S. Tsirkin wrote:
> > On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote:
> > > On 2017年06月28日 10:17, Michael S. Tsirkin wrote:
> > > > On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
> > > > > On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
> > > > > > On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
> > > > > > > We should allow csumed packet for small buffer, otherwise XDP_PASS
> > > > > > > won't work correctly.
> > > > > > >
> > > > > > > Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
> > > > > > > Signed-off-by: Jason Wang<jasowang@redhat.com>
> > > > > > The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
> > > > > > What do you think?
> > > > > I think it's safe. For XDP_PASS, it work like in the past.
> > > > That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
> > > > tools assume it's value.
> > > DATA_VALID is CHECKSUM_UNCESSARY on the host, and according to the comment
> > > in skbuff.h
> > >
> > >
> > > "
> > > * The hardware you're dealing with doesn't calculate the full checksum
> > > * (as in CHECKSUM_COMPLETE), but it does parse headers and verify
> > > checksums
> > > * for specific protocols. For such packets it will set
> > > CHECKSUM_UNNECESSARY
> > > * if their checksums are okay. skb->csum is still undefined in this case
> > > * though. A driver or device must never modify the checksum field in the
> > > * packet even if checksum is verified.
> > > "
> > >
> > > The csum is correct I believe?
> > >
> > > Thanks
> > That's on input. But I think for tun it's output, where that is equivalent
> > to CHECKSUM_NONE
> >
> >
>
> Yes, but the comment said:
>
> "
> CKSUM_NONE:
> *
> * The skb was already checksummed by the protocol, or a checksum is not
> * required.
> *
> * CHECKSUM_UNNECESSARY:
> *
> * This has the same meaning on as CHECKSUM_NONE for checksum offload on
> * output.
> *
> "
>
> So still correct I think?
>
> Thanks
Hmm maybe I mean NEEDS_CHECKSUM actually.
I'll need to re-read the spec.
--
MST
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| From | Jason Wang <jasowang@redhat.com> |
|---|---|
| Date | 2017-06-28 14:10 +0200 |
| Subject | Re: [PATCH net] virtio-net: unbreak cusmed packet for small buffer XDP |
| Message-ID | <tXjXd-6DX-35@gated-at.bofh.it> |
| In reply to | #1676346 |
On 2017年06月28日 12:01, Michael S. Tsirkin wrote:
> On Wed, Jun 28, 2017 at 11:40:30AM +0800, Jason Wang wrote:
>>
>> On 2017年06月28日 11:31, Michael S. Tsirkin wrote:
>>> On Wed, Jun 28, 2017 at 10:45:18AM +0800, Jason Wang wrote:
>>>> On 2017年06月28日 10:17, Michael S. Tsirkin wrote:
>>>>> On Wed, Jun 28, 2017 at 10:14:34AM +0800, Jason Wang wrote:
>>>>>> On 2017年06月28日 10:02, Michael S. Tsirkin wrote:
>>>>>>> On Wed, Jun 28, 2017 at 09:54:03AM +0800, Jason Wang wrote:
>>>>>>>> We should allow csumed packet for small buffer, otherwise XDP_PASS
>>>>>>>> won't work correctly.
>>>>>>>>
>>>>>>>> Fixes commit bb91accf2733 ("virtio-net: XDP support for small buffers")
>>>>>>>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>>>>>>> The issue would be VIRTIO_NET_HDR_F_DATA_VALID might be set.
>>>>>>> What do you think?
>>>>>> I think it's safe. For XDP_PASS, it work like in the past.
>>>>> That's the part I don't get. With DATA_VALID csum in packet is wrong, XDP
>>>>> tools assume it's value.
>>>> DATA_VALID is CHECKSUM_UNCESSARY on the host, and according to the comment
>>>> in skbuff.h
>>>>
>>>>
>>>> "
>>>> * The hardware you're dealing with doesn't calculate the full checksum
>>>> * (as in CHECKSUM_COMPLETE), but it does parse headers and verify
>>>> checksums
>>>> * for specific protocols. For such packets it will set
>>>> CHECKSUM_UNNECESSARY
>>>> * if their checksums are okay. skb->csum is still undefined in this case
>>>> * though. A driver or device must never modify the checksum field in the
>>>> * packet even if checksum is verified.
>>>> "
>>>>
>>>> The csum is correct I believe?
>>>>
>>>> Thanks
>>> That's on input. But I think for tun it's output, where that is equivalent
>>> to CHECKSUM_NONE
>>>
>>>
>> Yes, but the comment said:
>>
>> "
>> CKSUM_NONE:
>> *
>> * The skb was already checksummed by the protocol, or a checksum is not
>> * required.
>> *
>> * CHECKSUM_UNNECESSARY:
>> *
>> * This has the same meaning on as CHECKSUM_NONE for checksum offload on
>> * output.
>> *
>> "
>>
>> So still correct I think?
>>
>> Thanks
> Hmm maybe I mean NEEDS_CHECKSUM actually.
>
> I'll need to re-read the spec.
>
Not sure this is an issue. But if it is, we can probably checksum the
packet before passing it to XDP. But it would be a little slow.
Thanks
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