On 2023/8/17 17:23, Eugenio Perez Martin wrote:
> On Fri, Jul 7, 2023 at 5:27 PM Hawkins Jiawei <yin31...@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 <yin31...@gmail.com>
>> ---
>> v3:
>> - rename argument name to `data_sg` and `data_num`
>> - use iov_to_buf() suggested by Eugenio
>>
>> v2:
>> https://lore.kernel.org/all/6d3dc0fc076564a03501e222ef1102a6a7a643af.1688051252.git.yin31...@gmail.com/
>> - refactor vhost_vdpa_load_cmd() to accept iovec suggested by
>> Eugenio
>>
>> net/vhost-vdpa.c | 33 +++++++++++++++++++++++++--------
>> 1 file changed, 25 insertions(+), 8 deletions(-)
>>
>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>> index 373609216f..31ef6ad6ec 100644
>> --- a/net/vhost-vdpa.c
>> +++ b/net/vhost-vdpa.c
>> @@ -620,29 +620,38 @@ 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_sg,
>> + size_t data_num)
>> {
>> const struct virtio_net_ctrl_hdr ctrl = {
>> .class = class,
>> .cmd = cmd,
>> };
>> + size_t data_size = iov_size(data_sg, data_num);
>>
>> assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl));
>>
>> + /* pack the CVQ command header */
>> memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl));
>> - memcpy(s->cvq_cmd_out_buffer + sizeof(ctrl), data, data_size);
>>
>> - return vhost_vdpa_net_cvq_add(s, sizeof(ctrl) + data_size,
>> + /* pack the CVQ command command-specific-data */
>> + iov_to_buf(data_sg, data_num, 0,
>> + s->cvq_cmd_out_buffer + sizeof(ctrl), data_size);
>> +
>> + return vhost_vdpa_net_cvq_add(s, data_size + sizeof(ctrl),
>
> Nit, any reason for changing the order of the addends? sizeof(ctrl) +
> data_size ?
Hi Eugenio,
Here the code should be changed to `sizeof(ctrl) + data_size` as you
point out.
Since this patch series has already been merged into master, I will
submit a separate patch to correct this problem.
>
>> 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,
>
> Assign to void should always be valid, no need for casting here.
Yes, assign to void should be valid for normal pointers.
However, `n->mac` is an array and is treated as a const pointer. It will
trigger the warning "error: initialization discards ‘const’ qualifier
from pointer target type" if we don't add this cast.
Thanks!
>
>> + .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 +674,13 @@ 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 +719,13 @@ 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;
>> }
>
> Apart from that:
>
> Acked-by: Eugenio Pérez <epere...@redhat.com>
>
> Thanks!
>
