Re: [PATCH v3 1/3] net/virtio_user: convert cq descriptor IOVA address to Virtual address

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 7/3/24 12:19, Jerin Jacob wrote:
> On Wed, Jul 3, 2024 at 3:43 PM Srujana Challa <schalla@marvell.com> wrote:
>>
>> This patch modifies the code to convert descriptor buffer IOVA
>> addresses to virtual addresses during the processing of shadow
>> control queue when IOVA mode is PA. This change enables Virtio-user
>> to operate with IOVA as the descriptor buffer address.
>>
>> Signed-off-by: Srujana Challa <schalla@marvell.com>
>> ---
>>   .../net/virtio/virtio_user/virtio_user_dev.c  | 33 ++++++++++++-------
>>   1 file changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>> index 1365c8a5c8..7f35f4b06b 100644
>> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
>> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
>> @@ -896,6 +896,15 @@ virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
>>
>>   #define CVQ_MAX_DATA_DESCS 32
>>
>> +static inline void *
>> +virtio_user_iova2virt(rte_iova_t iova)
>> +{
>> +       if (rte_eal_iova_mode() == RTE_IOVA_PA)
> 
> There is RTE_IOVA_DC as well. So we may put positive logic. i.e
> rte_eal_iova_mode() == RTE_IOVA_VA

Indeed, that would be better.
I can fix it while applying.

Thanks,
Maxime

> 
>> +               return rte_mem_iova2virt(iova);
>> +       else
>> +               return (void *)(uintptr_t)iova;
>> +}
>> +
>>   static uint32_t
>>   virtio_user_handle_ctrl_msg_split(struct virtio_user_dev *dev, struct vring *vring,
>>                              uint16_t idx_hdr)
>> @@ -921,17 +930,18 @@ virtio_user_handle_ctrl_msg_split(struct virtio_user_dev *dev, struct vring *vri
>>          idx_status = i;
>>          n_descs++;
>>
>> -       hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
>> +       hdr = virtio_user_iova2virt(vring->desc[idx_hdr].addr);
>>          if (hdr->class == VIRTIO_NET_CTRL_MQ &&
>>              hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
>> -               uint16_t queues;
>> +               uint16_t queues, *addr;
>>
>> -               queues = *(uint16_t *)(uintptr_t)vring->desc[idx_data].addr;
>> +               addr = virtio_user_iova2virt(vring->desc[idx_data].addr);
>> +               queues = *addr;
>>                  status = virtio_user_handle_mq(dev, queues);
>>          } else if (hdr->class == VIRTIO_NET_CTRL_MQ && hdr->cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
>>                  struct virtio_net_ctrl_rss *rss;
>>
>> -               rss = (struct virtio_net_ctrl_rss *)(uintptr_t)vring->desc[idx_data].addr;
>> +               rss = virtio_user_iova2virt(vring->desc[idx_data].addr);
>>                  status = virtio_user_handle_mq(dev, rss->max_tx_vq);
>>          } else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
>>                     hdr->class == VIRTIO_NET_CTRL_MAC ||
>> @@ -944,7 +954,7 @@ virtio_user_handle_ctrl_msg_split(struct virtio_user_dev *dev, struct vring *vri
>>                                  (struct virtio_pmd_ctrl *)hdr, dlen, nb_dlen);
>>
>>          /* Update status */
>> -       *(virtio_net_ctrl_ack *)(uintptr_t)vring->desc[idx_status].addr = status;
>> +       *(virtio_net_ctrl_ack *)virtio_user_iova2virt(vring->desc[idx_status].addr) = status;
>>
>>          return n_descs;
>>   }
>> @@ -986,18 +996,18 @@ virtio_user_handle_ctrl_msg_packed(struct virtio_user_dev *dev,
>>                  n_descs++;
>>          }
>>
>> -       hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
>> +       hdr = virtio_user_iova2virt(vring->desc[idx_hdr].addr);
>>          if (hdr->class == VIRTIO_NET_CTRL_MQ &&
>>              hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
>> -               uint16_t queues;
>> +               uint16_t queues, *addr;
>>
>> -               queues = *(uint16_t *)(uintptr_t)
>> -                               vring->desc[idx_data].addr;
>> +               addr = virtio_user_iova2virt(vring->desc[idx_data].addr);
>> +               queues = *addr;
>>                  status = virtio_user_handle_mq(dev, queues);
>>          } else if (hdr->class == VIRTIO_NET_CTRL_MQ && hdr->cmd == VIRTIO_NET_CTRL_MQ_RSS_CONFIG) {
>>                  struct virtio_net_ctrl_rss *rss;
>>
>> -               rss = (struct virtio_net_ctrl_rss *)(uintptr_t)vring->desc[idx_data].addr;
>> +               rss = virtio_user_iova2virt(vring->desc[idx_data].addr);
>>                  status = virtio_user_handle_mq(dev, rss->max_tx_vq);
>>          } else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
>>                     hdr->class == VIRTIO_NET_CTRL_MAC ||
>> @@ -1010,8 +1020,7 @@ virtio_user_handle_ctrl_msg_packed(struct virtio_user_dev *dev,
>>                                  (struct virtio_pmd_ctrl *)hdr, dlen, nb_dlen);
>>
>>          /* Update status */
>> -       *(virtio_net_ctrl_ack *)(uintptr_t)
>> -               vring->desc[idx_status].addr = status;
>> +       *(virtio_net_ctrl_ack *)virtio_user_iova2virt(vring->desc[idx_status].addr) = status;
>>
>>          /* Update used descriptor */
>>          vring->desc[idx_hdr].id = vring->desc[idx_status].id;
>> --
>> 2.25.1
>>
>