On 2023/7/4 22:17, Eugenio Perez Martin wrote:
> On Thu, Jun 29, 2023 at 5:25 PM Hawkins Jiawei <[email protected]> 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 <[email protected]>
>> ---
>> 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
>>
>
