diff mbox series

[net-next,v9,6/6] vhost/net: Support VIRTIO_NET_F_HASH_REPORT

Message ID 20250307-rss-v9-6-df76624025eb@daynix.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series tun: Introduce virtio-net hashing feature | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 2 maintainers not CCed: eperezma@redhat.com virtualization@lists.linux.dev
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 98 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-03-08--06-00 (tests: 894)

Commit Message

Akihiko Odaki March 7, 2025, 11:01 a.m. UTC
VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
hash values (i.e., the hash_report member is always set to
VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
underlying socket will be reported.

VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Tested-by: Lei Yang <leiyang@redhat.com>
---
 drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
 1 file changed, 29 insertions(+), 20 deletions(-)

Comments

Jason Wang March 10, 2025, 4:43 a.m. UTC | #1
On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
> hash values (i.e., the hash_report member is always set to
> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
> underlying socket will be reported.
>
> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> Tested-by: Lei Yang <leiyang@redhat.com>
> ---
>  drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
>  1 file changed, 29 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -73,6 +73,7 @@ enum {
>         VHOST_NET_FEATURES = VHOST_FEATURES |
>                          (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
>                          (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
>                          (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
>                          (1ULL << VIRTIO_F_RING_RESET)
>  };
> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
>                 .msg_controllen = 0,
>                 .msg_flags = MSG_DONTWAIT,
>         };
> -       struct virtio_net_hdr hdr = {
> -               .flags = 0,
> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
> +       struct virtio_net_hdr_v1_hash hdr = {
> +               .hdr = {
> +                       .flags = 0,
> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
> +               }
>         };
>         size_t total_len = 0;
>         int err, mergeable;
> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
>         bool set_num_buffers;
>         struct socket *sock;
>         struct iov_iter fixup;
> -       __virtio16 num_buffers;
>         int recv_pkts = 0;
>
>         mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
>                         vhost_discard_vq_desc(vq, headcount);
>                         continue;
>                 }
> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
>                 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>                 if (unlikely(vhost_hlen)) {
> -                       if (copy_to_iter(&hdr, sizeof(hdr),
> -                                        &fixup) != sizeof(hdr)) {
> +                       if (copy_to_iter(&hdr, vhost_hlen,
> +                                        &fixup) != vhost_hlen) {
>                                 vq_err(vq, "Unable to write vnet_hdr "
>                                        "at addr %p\n", vq->iov->iov_base);
>                                 goto out;

Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.

Honestly, I'm not sure if it's too late to fix this.

Others look fine.

Thanks
Akihiko Odaki March 10, 2025, 7:04 a.m. UTC | #2
On 2025/03/10 13:43, Jason Wang wrote:
> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>
>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
>> hash values (i.e., the hash_report member is always set to
>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
>> underlying socket will be reported.
>>
>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
>>
>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>> Tested-by: Lei Yang <leiyang@redhat.com>
>> ---
>>   drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
>>   1 file changed, 29 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
>> --- a/drivers/vhost/net.c
>> +++ b/drivers/vhost/net.c
>> @@ -73,6 +73,7 @@ enum {
>>          VHOST_NET_FEATURES = VHOST_FEATURES |
>>                           (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
>>                           (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
>>                           (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
>>                           (1ULL << VIRTIO_F_RING_RESET)
>>   };
>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
>>                  .msg_controllen = 0,
>>                  .msg_flags = MSG_DONTWAIT,
>>          };
>> -       struct virtio_net_hdr hdr = {
>> -               .flags = 0,
>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
>> +       struct virtio_net_hdr_v1_hash hdr = {
>> +               .hdr = {
>> +                       .flags = 0,
>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
>> +               }
>>          };
>>          size_t total_len = 0;
>>          int err, mergeable;
>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
>>          bool set_num_buffers;
>>          struct socket *sock;
>>          struct iov_iter fixup;
>> -       __virtio16 num_buffers;
>>          int recv_pkts = 0;
>>
>>          mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
>>                          vhost_discard_vq_desc(vq, headcount);
>>                          continue;
>>                  }
>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
>>                  /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>                  if (unlikely(vhost_hlen)) {
>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
>> -                                        &fixup) != sizeof(hdr)) {
>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>> +                                        &fixup) != vhost_hlen) {
>>                                  vq_err(vq, "Unable to write vnet_hdr "
>>                                         "at addr %p\n", vq->iov->iov_base);
>>                                  goto out;
> 
> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
> 
> Honestly, I'm not sure if it's too late to fix this.

There is nothing wrong with the current implementation. The current 
implementation fills the header with zero except num_buffers, which it 
fills some real value. This functionality is working fine with 
VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.

Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report 
field, which also needs to be initialized with zero, so I'm making sure 
vhost_net will also initialize it.

Regards,
Akihiko Odaki

> 
> Others look fine.
> 
> Thanks
>
Jason Wang March 11, 2025, 12:42 a.m. UTC | #3
On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> On 2025/03/10 13:43, Jason Wang wrote:
> > On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>
> >> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
> >> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
> >> hash values (i.e., the hash_report member is always set to
> >> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
> >> underlying socket will be reported.
> >>
> >> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
> >>
> >> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> >> Tested-by: Lei Yang <leiyang@redhat.com>
> >> ---
> >>   drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
> >>   1 file changed, 29 insertions(+), 20 deletions(-)
> >>
> >> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> >> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
> >> --- a/drivers/vhost/net.c
> >> +++ b/drivers/vhost/net.c
> >> @@ -73,6 +73,7 @@ enum {
> >>          VHOST_NET_FEATURES = VHOST_FEATURES |
> >>                           (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
> >>                           (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> >> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
> >>                           (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
> >>                           (1ULL << VIRTIO_F_RING_RESET)
> >>   };
> >> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
> >>                  .msg_controllen = 0,
> >>                  .msg_flags = MSG_DONTWAIT,
> >>          };
> >> -       struct virtio_net_hdr hdr = {
> >> -               .flags = 0,
> >> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >> +       struct virtio_net_hdr_v1_hash hdr = {
> >> +               .hdr = {
> >> +                       .flags = 0,
> >> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >> +               }
> >>          };
> >>          size_t total_len = 0;
> >>          int err, mergeable;
> >> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
> >>          bool set_num_buffers;
> >>          struct socket *sock;
> >>          struct iov_iter fixup;
> >> -       __virtio16 num_buffers;
> >>          int recv_pkts = 0;
> >>
> >>          mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
> >> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
> >>                          vhost_discard_vq_desc(vq, headcount);
> >>                          continue;
> >>                  }
> >> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
> >>                  /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> >>                  if (unlikely(vhost_hlen)) {
> >> -                       if (copy_to_iter(&hdr, sizeof(hdr),
> >> -                                        &fixup) != sizeof(hdr)) {
> >> +                       if (copy_to_iter(&hdr, vhost_hlen,
> >> +                                        &fixup) != vhost_hlen) {
> >>                                  vq_err(vq, "Unable to write vnet_hdr "
> >>                                         "at addr %p\n", vq->iov->iov_base);
> >>                                  goto out;
> >
> > Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
> >
> > Honestly, I'm not sure if it's too late to fix this.
>
> There is nothing wrong with the current implementation.

Note that I meant the vhost_hlen part, and the current code is tricky.

The comment said:

"""
/* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
"""

So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
to mrg_rxbuf len.

And this patch changes this behaviour.

Thanks

> The current
> implementation fills the header with zero except num_buffers, which it
> fills some real value. This functionality is working fine with
> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
>
> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
> field, which also needs to be initialized with zero, so I'm making sure
> vhost_net will also initialize it.
>
> Regards,
> Akihiko Odaki
>
> >
> > Others look fine.
> >
> > Thanks
> >
>
Akihiko Odaki March 11, 2025, 6:24 a.m. UTC | #4
On 2025/03/11 9:42, Jason Wang wrote:
> On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>
>> On 2025/03/10 13:43, Jason Wang wrote:
>>> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>
>>>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
>>>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
>>>> hash values (i.e., the hash_report member is always set to
>>>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
>>>> underlying socket will be reported.
>>>>
>>>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
>>>>
>>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>>>> Tested-by: Lei Yang <leiyang@redhat.com>
>>>> ---
>>>>    drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
>>>>    1 file changed, 29 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>>>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
>>>> --- a/drivers/vhost/net.c
>>>> +++ b/drivers/vhost/net.c
>>>> @@ -73,6 +73,7 @@ enum {
>>>>           VHOST_NET_FEATURES = VHOST_FEATURES |
>>>>                            (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
>>>>                            (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
>>>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
>>>>                            (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
>>>>                            (1ULL << VIRTIO_F_RING_RESET)
>>>>    };
>>>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
>>>>                   .msg_controllen = 0,
>>>>                   .msg_flags = MSG_DONTWAIT,
>>>>           };
>>>> -       struct virtio_net_hdr hdr = {
>>>> -               .flags = 0,
>>>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>> +       struct virtio_net_hdr_v1_hash hdr = {
>>>> +               .hdr = {
>>>> +                       .flags = 0,
>>>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>> +               }
>>>>           };
>>>>           size_t total_len = 0;
>>>>           int err, mergeable;
>>>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
>>>>           bool set_num_buffers;
>>>>           struct socket *sock;
>>>>           struct iov_iter fixup;
>>>> -       __virtio16 num_buffers;
>>>>           int recv_pkts = 0;
>>>>
>>>>           mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
>>>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
>>>>                           vhost_discard_vq_desc(vq, headcount);
>>>>                           continue;
>>>>                   }
>>>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
>>>>                   /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>>>                   if (unlikely(vhost_hlen)) {
>>>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
>>>> -                                        &fixup) != sizeof(hdr)) {
>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>> +                                        &fixup) != vhost_hlen) {
>>>>                                   vq_err(vq, "Unable to write vnet_hdr "
>>>>                                          "at addr %p\n", vq->iov->iov_base);
>>>>                                   goto out;
>>>
>>> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
>>>
>>> Honestly, I'm not sure if it's too late to fix this.
>>
>> There is nothing wrong with the current implementation.
> 
> Note that I meant the vhost_hlen part, and the current code is tricky.
> 
> The comment said:
> 
> """
> /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> """
> 
> So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
> to mrg_rxbuf len.
> 
> And this patch changes this behaviour.

mrg_rxbuf only adds the num_buffers field, which is always set for 
mrg_rxbuf.

The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this 
was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for 
virtio 1.0")

So there is no behavioral change for existing features with this patch.

Regards,
Akihiko Odaki

> 
> Thanks
> 
>> The current
>> implementation fills the header with zero except num_buffers, which it
>> fills some real value. This functionality is working fine with
>> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
>>
>> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
>> field, which also needs to be initialized with zero, so I'm making sure
>> vhost_net will also initialize it.
>>
>> Regards,
>> Akihiko Odaki
>>
>>>
>>> Others look fine.
>>>
>>> Thanks
>>>
>>
>
Jason Wang March 12, 2025, 3:36 a.m. UTC | #5
On Tue, Mar 11, 2025 at 2:24 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> On 2025/03/11 9:42, Jason Wang wrote:
> > On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>
> >> On 2025/03/10 13:43, Jason Wang wrote:
> >>> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>>>
> >>>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
> >>>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
> >>>> hash values (i.e., the hash_report member is always set to
> >>>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
> >>>> underlying socket will be reported.
> >>>>
> >>>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
> >>>>
> >>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> >>>> Tested-by: Lei Yang <leiyang@redhat.com>
> >>>> ---
> >>>>    drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
> >>>>    1 file changed, 29 insertions(+), 20 deletions(-)
> >>>>
> >>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> >>>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
> >>>> --- a/drivers/vhost/net.c
> >>>> +++ b/drivers/vhost/net.c
> >>>> @@ -73,6 +73,7 @@ enum {
> >>>>           VHOST_NET_FEATURES = VHOST_FEATURES |
> >>>>                            (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
> >>>>                            (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> >>>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
> >>>>                            (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
> >>>>                            (1ULL << VIRTIO_F_RING_RESET)
> >>>>    };
> >>>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
> >>>>                   .msg_controllen = 0,
> >>>>                   .msg_flags = MSG_DONTWAIT,
> >>>>           };
> >>>> -       struct virtio_net_hdr hdr = {
> >>>> -               .flags = 0,
> >>>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >>>> +       struct virtio_net_hdr_v1_hash hdr = {
> >>>> +               .hdr = {
> >>>> +                       .flags = 0,
> >>>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >>>> +               }
> >>>>           };
> >>>>           size_t total_len = 0;
> >>>>           int err, mergeable;
> >>>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
> >>>>           bool set_num_buffers;
> >>>>           struct socket *sock;
> >>>>           struct iov_iter fixup;
> >>>> -       __virtio16 num_buffers;
> >>>>           int recv_pkts = 0;
> >>>>
> >>>>           mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
> >>>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
> >>>>                           vhost_discard_vq_desc(vq, headcount);
> >>>>                           continue;
> >>>>                   }
> >>>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
> >>>>                   /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> >>>>                   if (unlikely(vhost_hlen)) {
> >>>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
> >>>> -                                        &fixup) != sizeof(hdr)) {
> >>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
> >>>> +                                        &fixup) != vhost_hlen) {
> >>>>                                   vq_err(vq, "Unable to write vnet_hdr "
> >>>>                                          "at addr %p\n", vq->iov->iov_base);
> >>>>                                   goto out;
> >>>
> >>> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
> >>>
> >>> Honestly, I'm not sure if it's too late to fix this.
> >>
> >> There is nothing wrong with the current implementation.
> >
> > Note that I meant the vhost_hlen part, and the current code is tricky.
> >
> > The comment said:
> >
> > """
> > /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> > """
> >
> > So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
> > to mrg_rxbuf len.
> >
> > And this patch changes this behaviour.
>
> mrg_rxbuf only adds the num_buffers field, which is always set for
> mrg_rxbuf.
>
> The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this
> was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for
> virtio 1.0")
>
> So there is no behavioral change for existing features with this patch.

I meant this part.

>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>> +                                        &fixup) != vhost_hlen) {

We should copy only sizeof(hdr) instead of vhost_hlen.

Anything I miss?

Thanks

>
> Regards,
> Akihiko Odaki
>
> >
> > Thanks
> >
> >> The current
> >> implementation fills the header with zero except num_buffers, which it
> >> fills some real value. This functionality is working fine with
> >> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
> >>
> >> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
> >> field, which also needs to be initialized with zero, so I'm making sure
> >> vhost_net will also initialize it.
> >>
> >> Regards,
> >> Akihiko Odaki
> >>
> >>>
> >>> Others look fine.
> >>>
> >>> Thanks
> >>>
> >>
> >
>
Akihiko Odaki March 12, 2025, 5:59 a.m. UTC | #6
On 2025/03/12 12:36, Jason Wang wrote:
> On Tue, Mar 11, 2025 at 2:24 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>
>> On 2025/03/11 9:42, Jason Wang wrote:
>>> On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>
>>>> On 2025/03/10 13:43, Jason Wang wrote:
>>>>> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>>>
>>>>>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
>>>>>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
>>>>>> hash values (i.e., the hash_report member is always set to
>>>>>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
>>>>>> underlying socket will be reported.
>>>>>>
>>>>>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
>>>>>>
>>>>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>>>>>> Tested-by: Lei Yang <leiyang@redhat.com>
>>>>>> ---
>>>>>>     drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
>>>>>>     1 file changed, 29 insertions(+), 20 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>>>>>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
>>>>>> --- a/drivers/vhost/net.c
>>>>>> +++ b/drivers/vhost/net.c
>>>>>> @@ -73,6 +73,7 @@ enum {
>>>>>>            VHOST_NET_FEATURES = VHOST_FEATURES |
>>>>>>                             (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
>>>>>>                             (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
>>>>>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
>>>>>>                             (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
>>>>>>                             (1ULL << VIRTIO_F_RING_RESET)
>>>>>>     };
>>>>>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
>>>>>>                    .msg_controllen = 0,
>>>>>>                    .msg_flags = MSG_DONTWAIT,
>>>>>>            };
>>>>>> -       struct virtio_net_hdr hdr = {
>>>>>> -               .flags = 0,
>>>>>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>>>> +       struct virtio_net_hdr_v1_hash hdr = {
>>>>>> +               .hdr = {
>>>>>> +                       .flags = 0,
>>>>>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>>>> +               }
>>>>>>            };
>>>>>>            size_t total_len = 0;
>>>>>>            int err, mergeable;
>>>>>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
>>>>>>            bool set_num_buffers;
>>>>>>            struct socket *sock;
>>>>>>            struct iov_iter fixup;
>>>>>> -       __virtio16 num_buffers;
>>>>>>            int recv_pkts = 0;
>>>>>>
>>>>>>            mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
>>>>>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
>>>>>>                            vhost_discard_vq_desc(vq, headcount);
>>>>>>                            continue;
>>>>>>                    }
>>>>>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
>>>>>>                    /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>>>>>                    if (unlikely(vhost_hlen)) {
>>>>>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
>>>>>> -                                        &fixup) != sizeof(hdr)) {
>>>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>>>> +                                        &fixup) != vhost_hlen) {
>>>>>>                                    vq_err(vq, "Unable to write vnet_hdr "
>>>>>>                                           "at addr %p\n", vq->iov->iov_base);
>>>>>>                                    goto out;
>>>>>
>>>>> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
>>>>>
>>>>> Honestly, I'm not sure if it's too late to fix this.
>>>>
>>>> There is nothing wrong with the current implementation.
>>>
>>> Note that I meant the vhost_hlen part, and the current code is tricky.
>>>
>>> The comment said:
>>>
>>> """
>>> /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>> """
>>>
>>> So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
>>> to mrg_rxbuf len.
>>>
>>> And this patch changes this behaviour.
>>
>> mrg_rxbuf only adds the num_buffers field, which is always set for
>> mrg_rxbuf.
>>
>> The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this
>> was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for
>> virtio 1.0")
>>
>> So there is no behavioral change for existing features with this patch.
> 
> I meant this part.
> 
>>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>>> +                                        &fixup) != vhost_hlen) {
> 
> We should copy only sizeof(hdr) instead of vhost_hlen.> > Anything I miss?

sizeof(hdr) will be greater than vhost_hlen when neither 
VIRTIO_NET_F_MRG_RXBUF or VIRTIO_F_VERSION_1 is negotiated.

Regards,
Akihiko Odaki

> 
> Thanks
> 
>>
>> Regards,
>> Akihiko Odaki
>>
>>>
>>> Thanks
>>>
>>>> The current
>>>> implementation fills the header with zero except num_buffers, which it
>>>> fills some real value. This functionality is working fine with
>>>> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
>>>>
>>>> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
>>>> field, which also needs to be initialized with zero, so I'm making sure
>>>> vhost_net will also initialize it.
>>>>
>>>> Regards,
>>>> Akihiko Odaki
>>>>
>>>>>
>>>>> Others look fine.
>>>>>
>>>>> Thanks
>>>>>
>>>>
>>>
>>
>
Jason Wang March 17, 2025, 1:15 a.m. UTC | #7
On Wed, Mar 12, 2025 at 1:59 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> On 2025/03/12 12:36, Jason Wang wrote:
> > On Tue, Mar 11, 2025 at 2:24 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>
> >> On 2025/03/11 9:42, Jason Wang wrote:
> >>> On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>>>
> >>>> On 2025/03/10 13:43, Jason Wang wrote:
> >>>>> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
> >>>>>>
> >>>>>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
> >>>>>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
> >>>>>> hash values (i.e., the hash_report member is always set to
> >>>>>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
> >>>>>> underlying socket will be reported.
> >>>>>>
> >>>>>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
> >>>>>>
> >>>>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> >>>>>> Tested-by: Lei Yang <leiyang@redhat.com>
> >>>>>> ---
> >>>>>>     drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
> >>>>>>     1 file changed, 29 insertions(+), 20 deletions(-)
> >>>>>>
> >>>>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> >>>>>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
> >>>>>> --- a/drivers/vhost/net.c
> >>>>>> +++ b/drivers/vhost/net.c
> >>>>>> @@ -73,6 +73,7 @@ enum {
> >>>>>>            VHOST_NET_FEATURES = VHOST_FEATURES |
> >>>>>>                             (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
> >>>>>>                             (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
> >>>>>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
> >>>>>>                             (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
> >>>>>>                             (1ULL << VIRTIO_F_RING_RESET)
> >>>>>>     };
> >>>>>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
> >>>>>>                    .msg_controllen = 0,
> >>>>>>                    .msg_flags = MSG_DONTWAIT,
> >>>>>>            };
> >>>>>> -       struct virtio_net_hdr hdr = {
> >>>>>> -               .flags = 0,
> >>>>>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >>>>>> +       struct virtio_net_hdr_v1_hash hdr = {
> >>>>>> +               .hdr = {
> >>>>>> +                       .flags = 0,
> >>>>>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
> >>>>>> +               }
> >>>>>>            };
> >>>>>>            size_t total_len = 0;
> >>>>>>            int err, mergeable;
> >>>>>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
> >>>>>>            bool set_num_buffers;
> >>>>>>            struct socket *sock;
> >>>>>>            struct iov_iter fixup;
> >>>>>> -       __virtio16 num_buffers;
> >>>>>>            int recv_pkts = 0;
> >>>>>>
> >>>>>>            mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
> >>>>>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
> >>>>>>                            vhost_discard_vq_desc(vq, headcount);
> >>>>>>                            continue;
> >>>>>>                    }
> >>>>>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
> >>>>>>                    /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> >>>>>>                    if (unlikely(vhost_hlen)) {
> >>>>>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
> >>>>>> -                                        &fixup) != sizeof(hdr)) {
> >>>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
> >>>>>> +                                        &fixup) != vhost_hlen) {
> >>>>>>                                    vq_err(vq, "Unable to write vnet_hdr "
> >>>>>>                                           "at addr %p\n", vq->iov->iov_base);
> >>>>>>                                    goto out;
> >>>>>
> >>>>> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
> >>>>>
> >>>>> Honestly, I'm not sure if it's too late to fix this.
> >>>>
> >>>> There is nothing wrong with the current implementation.
> >>>
> >>> Note that I meant the vhost_hlen part, and the current code is tricky.
> >>>
> >>> The comment said:
> >>>
> >>> """
> >>> /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
> >>> """
> >>>
> >>> So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
> >>> to mrg_rxbuf len.
> >>>
> >>> And this patch changes this behaviour.
> >>
> >> mrg_rxbuf only adds the num_buffers field, which is always set for
> >> mrg_rxbuf.
> >>
> >> The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this
> >> was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for
> >> virtio 1.0")
> >>
> >> So there is no behavioral change for existing features with this patch.
> >
> > I meant this part.
> >
> >>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
> >>>>> +                                        &fixup) != vhost_hlen) {
> >
> > We should copy only sizeof(hdr) instead of vhost_hlen.> > Anything I miss?
>
> sizeof(hdr) will be greater than vhost_hlen when neither
> VIRTIO_NET_F_MRG_RXBUF or VIRTIO_F_VERSION_1 is negotiated.

Just to make sure we are on the same page I meant we should only
advance sizeof(struct virtio_net_hdr) here to make sure we can set the
num_buffers correctly.

But this is not what the code did here.

Thanks

>
> Regards,
> Akihiko Odaki
>
> >
> > Thanks
> >
> >>
> >> Regards,
> >> Akihiko Odaki
> >>
> >>>
> >>> Thanks
> >>>
> >>>> The current
> >>>> implementation fills the header with zero except num_buffers, which it
> >>>> fills some real value. This functionality is working fine with
> >>>> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
> >>>>
> >>>> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
> >>>> field, which also needs to be initialized with zero, so I'm making sure
> >>>> vhost_net will also initialize it.
> >>>>
> >>>> Regards,
> >>>> Akihiko Odaki
> >>>>
> >>>>>
> >>>>> Others look fine.
> >>>>>
> >>>>> Thanks
> >>>>>
> >>>>
> >>>
> >>
> >
>
Akihiko Odaki March 19, 2025, 4:43 a.m. UTC | #8
On 2025/03/17 10:15, Jason Wang wrote:
> On Wed, Mar 12, 2025 at 1:59 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>
>> On 2025/03/12 12:36, Jason Wang wrote:
>>> On Tue, Mar 11, 2025 at 2:24 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>
>>>> On 2025/03/11 9:42, Jason Wang wrote:
>>>>> On Mon, Mar 10, 2025 at 3:04 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>>>
>>>>>> On 2025/03/10 13:43, Jason Wang wrote:
>>>>>>> On Fri, Mar 7, 2025 at 7:02 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>>>>>>>>
>>>>>>>> VIRTIO_NET_F_HASH_REPORT allows to report hash values calculated on the
>>>>>>>> host. When VHOST_NET_F_VIRTIO_NET_HDR is employed, it will report no
>>>>>>>> hash values (i.e., the hash_report member is always set to
>>>>>>>> VIRTIO_NET_HASH_REPORT_NONE). Otherwise, the values reported by the
>>>>>>>> underlying socket will be reported.
>>>>>>>>
>>>>>>>> VIRTIO_NET_F_HASH_REPORT requires VIRTIO_F_VERSION_1.
>>>>>>>>
>>>>>>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>>>>>>>> Tested-by: Lei Yang <leiyang@redhat.com>
>>>>>>>> ---
>>>>>>>>      drivers/vhost/net.c | 49 +++++++++++++++++++++++++++++--------------------
>>>>>>>>      1 file changed, 29 insertions(+), 20 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>>>>>>>> index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
>>>>>>>> --- a/drivers/vhost/net.c
>>>>>>>> +++ b/drivers/vhost/net.c
>>>>>>>> @@ -73,6 +73,7 @@ enum {
>>>>>>>>             VHOST_NET_FEATURES = VHOST_FEATURES |
>>>>>>>>                              (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
>>>>>>>>                              (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
>>>>>>>> +                        (1ULL << VIRTIO_NET_F_HASH_REPORT) |
>>>>>>>>                              (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
>>>>>>>>                              (1ULL << VIRTIO_F_RING_RESET)
>>>>>>>>      };
>>>>>>>> @@ -1097,9 +1098,11 @@ static void handle_rx(struct vhost_net *net)
>>>>>>>>                     .msg_controllen = 0,
>>>>>>>>                     .msg_flags = MSG_DONTWAIT,
>>>>>>>>             };
>>>>>>>> -       struct virtio_net_hdr hdr = {
>>>>>>>> -               .flags = 0,
>>>>>>>> -               .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>>>>>> +       struct virtio_net_hdr_v1_hash hdr = {
>>>>>>>> +               .hdr = {
>>>>>>>> +                       .flags = 0,
>>>>>>>> +                       .gso_type = VIRTIO_NET_HDR_GSO_NONE
>>>>>>>> +               }
>>>>>>>>             };
>>>>>>>>             size_t total_len = 0;
>>>>>>>>             int err, mergeable;
>>>>>>>> @@ -1110,7 +1113,6 @@ static void handle_rx(struct vhost_net *net)
>>>>>>>>             bool set_num_buffers;
>>>>>>>>             struct socket *sock;
>>>>>>>>             struct iov_iter fixup;
>>>>>>>> -       __virtio16 num_buffers;
>>>>>>>>             int recv_pkts = 0;
>>>>>>>>
>>>>>>>>             mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
>>>>>>>> @@ -1191,30 +1193,30 @@ static void handle_rx(struct vhost_net *net)
>>>>>>>>                             vhost_discard_vq_desc(vq, headcount);
>>>>>>>>                             continue;
>>>>>>>>                     }
>>>>>>>> +               hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
>>>>>>>>                     /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>>>>>>>                     if (unlikely(vhost_hlen)) {
>>>>>>>> -                       if (copy_to_iter(&hdr, sizeof(hdr),
>>>>>>>> -                                        &fixup) != sizeof(hdr)) {
>>>>>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>>>>>> +                                        &fixup) != vhost_hlen) {
>>>>>>>>                                     vq_err(vq, "Unable to write vnet_hdr "
>>>>>>>>                                            "at addr %p\n", vq->iov->iov_base);
>>>>>>>>                                     goto out;
>>>>>>>
>>>>>>> Is this an "issue" specific to RSS/HASH? If it's not, we need a separate patch.
>>>>>>>
>>>>>>> Honestly, I'm not sure if it's too late to fix this.
>>>>>>
>>>>>> There is nothing wrong with the current implementation.
>>>>>
>>>>> Note that I meant the vhost_hlen part, and the current code is tricky.
>>>>>
>>>>> The comment said:
>>>>>
>>>>> """
>>>>> /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
>>>>> """
>>>>>
>>>>> So it tries to only offer virtio_net_hdr even if vhost_hlen is the set
>>>>> to mrg_rxbuf len.
>>>>>
>>>>> And this patch changes this behaviour.
>>>>
>>>> mrg_rxbuf only adds the num_buffers field, which is always set for
>>>> mrg_rxbuf.
>>>>
>>>> The num_buffers was not set for VIRTIO_F_VERSION_1 in the past, but this
>>>> was also fixed with commit a3b9c053d82a ("vhost/net: Set num_buffers for
>>>> virtio 1.0")
>>>>
>>>> So there is no behavioral change for existing features with this patch.
>>>
>>> I meant this part.
>>>
>>>>>>> +                       if (copy_to_iter(&hdr, vhost_hlen,
>>>>>>> +                                        &fixup) != vhost_hlen) {
>>>
>>> We should copy only sizeof(hdr) instead of vhost_hlen.> > Anything I miss?
>>
>> sizeof(hdr) will be greater than vhost_hlen when neither
>> VIRTIO_NET_F_MRG_RXBUF or VIRTIO_F_VERSION_1 is negotiated.
> 
> Just to make sure we are on the same page I meant we should only
> advance sizeof(struct virtio_net_hdr) here to make sure we can set the
> num_buffers correctly.
> 
> But this is not what the code did here.

This code wrote num_buffers in hdr instead of setting it later.

However, with v10, I changed it again to fill the whole header with zero 
and to set num_buffers later. The end result is identical either way; 
num_buffers has the correct value and the other fields are filled with zero.

Regards,
Akihiko Odaki

> 
> Thanks
> 
>>
>> Regards,
>> Akihiko Odaki
>>
>>>
>>> Thanks
>>>
>>>>
>>>> Regards,
>>>> Akihiko Odaki
>>>>
>>>>>
>>>>> Thanks
>>>>>
>>>>>> The current
>>>>>> implementation fills the header with zero except num_buffers, which it
>>>>>> fills some real value. This functionality is working fine with
>>>>>> VIRTIO_NET_F_MRG_RXBUF and VIRTIO_F_VERSION_1, which change the header size.
>>>>>>
>>>>>> Now I'm adding VIRTIO_NET_F_HASH_REPORT and it adds the hash_report
>>>>>> field, which also needs to be initialized with zero, so I'm making sure
>>>>>> vhost_net will also initialize it.
>>>>>>
>>>>>> Regards,
>>>>>> Akihiko Odaki
>>>>>>
>>>>>>>
>>>>>>> Others look fine.
>>>>>>>
>>>>>>> Thanks
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
diff mbox series

Patch

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index b9b9e9d40951856d881d77ac74331d914473cd56..16b241b44f89820a42c302f3586ea6bb5e0d4289 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -73,6 +73,7 @@  enum {
 	VHOST_NET_FEATURES = VHOST_FEATURES |
 			 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
 			 (1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+			 (1ULL << VIRTIO_NET_F_HASH_REPORT) |
 			 (1ULL << VIRTIO_F_ACCESS_PLATFORM) |
 			 (1ULL << VIRTIO_F_RING_RESET)
 };
@@ -1097,9 +1098,11 @@  static void handle_rx(struct vhost_net *net)
 		.msg_controllen = 0,
 		.msg_flags = MSG_DONTWAIT,
 	};
-	struct virtio_net_hdr hdr = {
-		.flags = 0,
-		.gso_type = VIRTIO_NET_HDR_GSO_NONE
+	struct virtio_net_hdr_v1_hash hdr = {
+		.hdr = {
+			.flags = 0,
+			.gso_type = VIRTIO_NET_HDR_GSO_NONE
+		}
 	};
 	size_t total_len = 0;
 	int err, mergeable;
@@ -1110,7 +1113,6 @@  static void handle_rx(struct vhost_net *net)
 	bool set_num_buffers;
 	struct socket *sock;
 	struct iov_iter fixup;
-	__virtio16 num_buffers;
 	int recv_pkts = 0;
 
 	mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
@@ -1191,30 +1193,30 @@  static void handle_rx(struct vhost_net *net)
 			vhost_discard_vq_desc(vq, headcount);
 			continue;
 		}
+		hdr.hdr.num_buffers = cpu_to_vhost16(vq, headcount);
 		/* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */
 		if (unlikely(vhost_hlen)) {
-			if (copy_to_iter(&hdr, sizeof(hdr),
-					 &fixup) != sizeof(hdr)) {
+			if (copy_to_iter(&hdr, vhost_hlen,
+					 &fixup) != vhost_hlen) {
 				vq_err(vq, "Unable to write vnet_hdr "
 				       "at addr %p\n", vq->iov->iov_base);
 				goto out;
 			}
-		} else {
+		} else if (likely(set_num_buffers)) {
 			/* Header came from socket; we'll need to patch
 			 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF
 			 */
-			iov_iter_advance(&fixup, sizeof(hdr));
+			iov_iter_advance(&fixup, offsetof(struct virtio_net_hdr_v1, num_buffers));
+
+			if (copy_to_iter(&hdr.hdr.num_buffers, sizeof(hdr.hdr.num_buffers),
+					 &fixup) != sizeof(hdr.hdr.num_buffers)) {
+				vq_err(vq, "Failed num_buffers write");
+				vhost_discard_vq_desc(vq, headcount);
+				goto out;
+			}
 		}
 		/* TODO: Should check and handle checksum. */
 
-		num_buffers = cpu_to_vhost16(vq, headcount);
-		if (likely(set_num_buffers) &&
-		    copy_to_iter(&num_buffers, sizeof num_buffers,
-				 &fixup) != sizeof num_buffers) {
-			vq_err(vq, "Failed num_buffers write");
-			vhost_discard_vq_desc(vq, headcount);
-			goto out;
-		}
 		nvq->done_idx += headcount;
 		if (nvq->done_idx > VHOST_NET_BATCH)
 			vhost_net_signal_used(nvq);
@@ -1607,10 +1609,13 @@  static int vhost_net_set_features(struct vhost_net *n, u64 features)
 	size_t vhost_hlen, sock_hlen, hdr_len;
 	int i;
 
-	hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
-			       (1ULL << VIRTIO_F_VERSION_1))) ?
-			sizeof(struct virtio_net_hdr_mrg_rxbuf) :
-			sizeof(struct virtio_net_hdr);
+	if (features & (1ULL << VIRTIO_NET_F_HASH_REPORT))
+		hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
+	else if (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) |
+			     (1ULL << VIRTIO_F_VERSION_1)))
+		hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+	else
+		hdr_len = sizeof(struct virtio_net_hdr);
 	if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
 		/* vhost provides vnet_hdr */
 		vhost_hlen = hdr_len;
@@ -1691,6 +1696,10 @@  static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
 			return -EFAULT;
 		if (features & ~VHOST_NET_FEATURES)
 			return -EOPNOTSUPP;
+		if ((features & ((1ULL << VIRTIO_F_VERSION_1) |
+				 (1ULL << VIRTIO_NET_F_HASH_REPORT))) ==
+		    (1ULL << VIRTIO_NET_F_HASH_REPORT))
+			return -EINVAL;
 		return vhost_net_set_features(n, features);
 	case VHOST_GET_BACKEND_FEATURES:
 		features = VHOST_NET_BACKEND_FEATURES;