diff mbox series

[RFC,v2,1/4] vdpa: Use iovec for vhost_vdpa_net_load_cmd()

Message ID 6d3dc0fc076564a03501e222ef1102a6a7a643af.1688051252.git.yin31149@gmail.com
State New
Headers show
Series Vhost-vdpa Shadow Virtqueue _F_CTRL_RX commands support | expand

Commit Message

Hawkins Jiawei June 29, 2023, 3:25 p.m. UTC 
According to VirtIO standard, "The driver MUST follow
the VIRTIO_NET_CTRL_MAC_TABLE_SET command by a le32 number,
followed by that number of non-multicast MAC addresses,
followed by another le32 number, followed by that number
of multicast addresses."

Considering that these data is not stored in contiguous memory,
this patch refactors vhost_vdpa_net_load_cmd() to accept
scattered data, eliminating the need for an addtional data copy or
packing the data into s->cvq_cmd_out_buffer outside of
vhost_vdpa_net_load_cmd().

Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
---
v2:
  - refactor vhost_vdpa_load_cmd() to accept iovec suggested by
Eugenio

 net/vhost-vdpa.c | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

Comments

Eugenio Pérez July 4, 2023, 2:17 p.m. UTC | #1 
On Thu, Jun 29, 2023 at 5:25 PM Hawkins Jiawei <yin31149@gmail.com> wrote:
>
> According to VirtIO standard, "The driver MUST follow
> the VIRTIO_NET_CTRL_MAC_TABLE_SET command by a le32 number,
> followed by that number of non-multicast MAC addresses,
> followed by another le32 number, followed by that number
> of multicast addresses."
>
> Considering that these data is not stored in contiguous memory,
> this patch refactors vhost_vdpa_net_load_cmd() to accept
> scattered data, eliminating the need for an addtional data copy or
> packing the data into s->cvq_cmd_out_buffer outside of
> vhost_vdpa_net_load_cmd().
>
> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
> ---
> v2:
>   - refactor vhost_vdpa_load_cmd() to accept iovec suggested by
> Eugenio
>
>  net/vhost-vdpa.c | 42 ++++++++++++++++++++++++++++++++----------
>  1 file changed, 32 insertions(+), 10 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 6f6a5c6df6..0bd1c7817c 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -620,29 +620,43 @@ static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s, size_t out_len,
>  }
>
>  static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class,
> -                                       uint8_t cmd, const void *data,
> -                                       size_t data_size)
> +                                       uint8_t cmd, const struct iovec *data,
> +                                       size_t data_len)
>  {
>      const struct virtio_net_ctrl_hdr ctrl = {
>          .class = class,
>          .cmd = cmd,
>      };
> +    void *cursor = s->cvq_cmd_out_buffer;
>
> -    assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
> +    /* pack the CVQ command header */
> +    assert(sizeof(ctrl) < vhost_vdpa_net_cvq_cmd_page_len() -
> +                          (cursor - s->cvq_cmd_out_buffer));
> +    memcpy(cursor, &ctrl, sizeof(ctrl));
> +    cursor += sizeof(ctrl);
>
> -    memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl));
> -    memcpy(s->cvq_cmd_out_buffer + sizeof(ctrl), data, data_size);
> +    /* pack the CVQ command command-specific-data */
> +    for (int i = 0; i < data_len; ++i) {
> +        assert(data[i].iov_len < vhost_vdpa_net_cvq_cmd_page_len() -
> +                                 (cursor - s->cvq_cmd_out_buffer));
> +        memcpy(cursor, data[i].iov_base, data[i].iov_len);
> +        cursor += data[i].iov_len;
> +    }

Can we replace all of the above by iov_to_buf?

>
> -    return vhost_vdpa_net_cvq_add(s, sizeof(ctrl) + data_size,
> +    return vhost_vdpa_net_cvq_add(s, cursor - s->cvq_cmd_out_buffer,
>                                    sizeof(virtio_net_ctrl_ack));
>  }
>
>  static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>  {
>      if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> +        const struct iovec data = {
> +            .iov_base = (void *)n->mac,
> +            .iov_len = sizeof(n->mac),
> +        };
>          ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC,
>                                                    VIRTIO_NET_CTRL_MAC_ADDR_SET,
> -                                                  n->mac, sizeof(n->mac));
> +                                                  &data, 1);
>          if (unlikely(dev_written < 0)) {
>              return dev_written;
>          }
> @@ -665,9 +679,13 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>      }
>
>      mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs);
> +    const struct iovec data = {
> +        .iov_base = &mq,
> +        .iov_len = sizeof(mq),
> +    };
>      dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MQ,
> -                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &mq,
> -                                          sizeof(mq));
> +                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET,
> +                                          &data, 1);
>      if (unlikely(dev_written < 0)) {
>          return dev_written;
>      }
> @@ -706,9 +724,13 @@ static int vhost_vdpa_net_load_offloads(VhostVDPAState *s,
>      }
>
>      offloads = cpu_to_le64(n->curr_guest_offloads);
> +    const struct iovec data = {
> +        .iov_base = &offloads,
> +        .iov_len = sizeof(offloads),
> +    };
>      dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
>                                            VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
> -                                          &offloads, sizeof(offloads));
> +                                          &data, 1);
>      if (unlikely(dev_written < 0)) {
>          return dev_written;
>      }
> --
> 2.25.1
>
Hawkins Jiawei July 5, 2023, 1:12 a.m. UTC | #2 
On 2023/7/4 22:17, Eugenio Perez Martin wrote:
> On Thu, Jun 29, 2023 at 5:25 PM Hawkins Jiawei <yin31149@gmail.com> wrote:
>>
>> According to VirtIO standard, "The driver MUST follow
>> the VIRTIO_NET_CTRL_MAC_TABLE_SET command by a le32 number,
>> followed by that number of non-multicast MAC addresses,
>> followed by another le32 number, followed by that number
>> of multicast addresses."
>>
>> Considering that these data is not stored in contiguous memory,
>> this patch refactors vhost_vdpa_net_load_cmd() to accept
>> scattered data, eliminating the need for an addtional data copy or
>> packing the data into s->cvq_cmd_out_buffer outside of
>> vhost_vdpa_net_load_cmd().
>>
>> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
>> ---
>> v2:
>>    - refactor vhost_vdpa_load_cmd() to accept iovec suggested by
>> Eugenio
>>
>>   net/vhost-vdpa.c | 42 ++++++++++++++++++++++++++++++++----------
>>   1 file changed, 32 insertions(+), 10 deletions(-)
>>
>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>> index 6f6a5c6df6..0bd1c7817c 100644
>> --- a/net/vhost-vdpa.c
>> +++ b/net/vhost-vdpa.c
>> @@ -620,29 +620,43 @@ static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s, size_t out_len,
>>   }
>>
>>   static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class,
>> -                                       uint8_t cmd, const void *data,
>> -                                       size_t data_size)
>> +                                       uint8_t cmd, const struct iovec *data,
>> +                                       size_t data_len)
>>   {
>>       const struct virtio_net_ctrl_hdr ctrl = {
>>           .class = class,
>>           .cmd = cmd,
>>       };
>> +    void *cursor = s->cvq_cmd_out_buffer;
>>
>> -    assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
>> +    /* pack the CVQ command header */
>> +    assert(sizeof(ctrl) < vhost_vdpa_net_cvq_cmd_page_len() -
>> +                          (cursor - s->cvq_cmd_out_buffer));
>> +    memcpy(cursor, &ctrl, sizeof(ctrl));
>> +    cursor += sizeof(ctrl);
>>
>> -    memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl));
>> -    memcpy(s->cvq_cmd_out_buffer + sizeof(ctrl), data, data_size);
>> +    /* pack the CVQ command command-specific-data */
>> +    for (int i = 0; i < data_len; ++i) {
>> +        assert(data[i].iov_len < vhost_vdpa_net_cvq_cmd_page_len() -
>> +                                 (cursor - s->cvq_cmd_out_buffer));
>> +        memcpy(cursor, data[i].iov_base, data[i].iov_len);
>> +        cursor += data[i].iov_len;
>> +    }
>
> Can we replace all of the above by iov_to_buf?

Yes, you are right.

We should use iov_to_buf() here. I will refactor this patch according to
your suggestion.

Thanks!


>
>>
>> -    return vhost_vdpa_net_cvq_add(s, sizeof(ctrl) + data_size,
>> +    return vhost_vdpa_net_cvq_add(s, cursor - s->cvq_cmd_out_buffer,
>>                                     sizeof(virtio_net_ctrl_ack));
>>   }
>>
>>   static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>>   {
>>       if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
>> +        const struct iovec data = {
>> +            .iov_base = (void *)n->mac,
>> +            .iov_len = sizeof(n->mac),
>> +        };
>>           ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC,
>>                                                     VIRTIO_NET_CTRL_MAC_ADDR_SET,
>> -                                                  n->mac, sizeof(n->mac));
>> +                                                  &data, 1);
>>           if (unlikely(dev_written < 0)) {
>>               return dev_written;
>>           }
>> @@ -665,9 +679,13 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>>       }
>>
>>       mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs);
>> +    const struct iovec data = {
>> +        .iov_base = &mq,
>> +        .iov_len = sizeof(mq),
>> +    };
>>       dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MQ,
>> -                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &mq,
>> -                                          sizeof(mq));
>> +                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET,
>> +                                          &data, 1);
>>       if (unlikely(dev_written < 0)) {
>>           return dev_written;
>>       }
>> @@ -706,9 +724,13 @@ static int vhost_vdpa_net_load_offloads(VhostVDPAState *s,
>>       }
>>
>>       offloads = cpu_to_le64(n->curr_guest_offloads);
>> +    const struct iovec data = {
>> +        .iov_base = &offloads,
>> +        .iov_len = sizeof(offloads),
>> +    };
>>       dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
>>                                             VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
>> -                                          &offloads, sizeof(offloads));
>> +                                          &data, 1);
>>       if (unlikely(dev_written < 0)) {
>>           return dev_written;
>>       }
>> --
>> 2.25.1
>>
>
diff mbox series

Patch

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 6f6a5c6df6..0bd1c7817c 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -620,29 +620,43 @@  static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s, size_t out_len,
 }
 
 static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class,
-                                       uint8_t cmd, const void *data,
-                                       size_t data_size)
+                                       uint8_t cmd, const struct iovec *data,
+                                       size_t data_len)
 {
     const struct virtio_net_ctrl_hdr ctrl = {
         .class = class,
         .cmd = cmd,
     };
+    void *cursor = s->cvq_cmd_out_buffer;
 
-    assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
+    /* pack the CVQ command header */
+    assert(sizeof(ctrl) < vhost_vdpa_net_cvq_cmd_page_len() -
+                          (cursor - s->cvq_cmd_out_buffer));
+    memcpy(cursor, &ctrl, sizeof(ctrl));
+    cursor += sizeof(ctrl);
 
-    memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl));
-    memcpy(s->cvq_cmd_out_buffer + sizeof(ctrl), data, data_size);
+    /* pack the CVQ command command-specific-data */
+    for (int i = 0; i < data_len; ++i) {
+        assert(data[i].iov_len < vhost_vdpa_net_cvq_cmd_page_len() -
+                                 (cursor - s->cvq_cmd_out_buffer));
+        memcpy(cursor, data[i].iov_base, data[i].iov_len);
+        cursor += data[i].iov_len;
+    }
 
-    return vhost_vdpa_net_cvq_add(s, sizeof(ctrl) + data_size,
+    return vhost_vdpa_net_cvq_add(s, cursor - s->cvq_cmd_out_buffer,
                                   sizeof(virtio_net_ctrl_ack));
 }
 
 static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
 {
     if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
+        const struct iovec data = {
+            .iov_base = (void *)n->mac,
+            .iov_len = sizeof(n->mac),
+        };
         ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC,
                                                   VIRTIO_NET_CTRL_MAC_ADDR_SET,
-                                                  n->mac, sizeof(n->mac));
+                                                  &data, 1);
         if (unlikely(dev_written < 0)) {
             return dev_written;
         }
@@ -665,9 +679,13 @@  static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
     }
 
     mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs);
+    const struct iovec data = {
+        .iov_base = &mq,
+        .iov_len = sizeof(mq),
+    };
     dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MQ,
-                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, &mq,
-                                          sizeof(mq));
+                                          VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET,
+                                          &data, 1);
     if (unlikely(dev_written < 0)) {
         return dev_written;
     }
@@ -706,9 +724,13 @@  static int vhost_vdpa_net_load_offloads(VhostVDPAState *s,
     }
 
     offloads = cpu_to_le64(n->curr_guest_offloads);
+    const struct iovec data = {
+        .iov_base = &offloads,
+        .iov_len = sizeof(offloads),
+    };
     dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_GUEST_OFFLOADS,
                                           VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET,
-                                          &offloads, sizeof(offloads));
+                                          &data, 1);
     if (unlikely(dev_written < 0)) {
         return dev_written;
     }