On 9/13/21 10:52 PM, Maxime Coquelin wrote:
>
>
> On 8/20/21 2:48 PM, Andrew Rybchenko wrote:
>> From: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
>>
>> Report max/min/align descriptors limits in device info get callback.
>> Before calling the callback, rte_eth_dev_info_get() provides
>> default values of nb_min as zero and nb_max as UINT16_MAX that are
>> not correct for the driver, so one can't rely on them.
>>
>> Signed-off-by: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
>> Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
>> ---
>> drivers/net/virtio/virtio_ethdev.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/drivers/net/virtio/virtio_ethdev.c
>> b/drivers/net/virtio/virtio_ethdev.c
>> index e58085a2c9..601c03e079 100644
>> --- a/drivers/net/virtio/virtio_ethdev.c
>> +++ b/drivers/net/virtio/virtio_ethdev.c
>> @@ -33,6 +33,7 @@
>> #include "virtio_logs.h"
>> #include "virtqueue.h"
>> #include "virtio_rxtx.h"
>> +#include "virtio_rxtx_simple.h"
>> #include "virtio_user/virtio_user_dev.h"
>>
>> static int virtio_dev_configure(struct rte_eth_dev *dev);
>> @@ -2536,6 +2537,30 @@ virtio_dev_info_get(struct rte_eth_dev *dev, struct
>> rte_eth_dev_info *dev_info)
>> if ((host_features & tso_mask) == tso_mask)
>> dev_info->tx_offload_capa |= DEV_TX_OFFLOAD_TCP_TSO;
>>
>> + if (host_features & (1ULL << VIRTIO_F_RING_PACKED)) {
>> + /*
>> + * According to 2.7 Packed Virtqueues,
>> + * 2.7.10.1 Structure Size and Alignment:
>> + * The Queue Size value does not have to be a power of 2.
>> + */
>> + dev_info->rx_desc_lim.nb_max = UINT16_MAX;
>> + } else {
>> + /*
>> + * According to 2.6 Split Virtqueues:
>> + * Queue Size value is always a power of 2. The maximum Queue
>> + * Size value is 32768.
>> + */
>> + dev_info->rx_desc_lim.nb_max = 32768;
>> + }
>> + /*
>> + * Actual minimum is not the same for virtqueues of different kinds,
>> + * but to avoid tangling the code with separate branches, rely on
>> + * default thresholds since desc number must be at least of their size.
>> + */
>> + dev_info->rx_desc_lim.nb_min = RTE_MAX(DEFAULT_RX_FREE_THRESH,
>> + RTE_VIRTIO_VPMD_RX_REARM_THRESH);
>> + dev_info->rx_desc_lim.nb_align = 1;
>> +
>
> It makes sense, but shouldn't we do the same for dev_info->tx_desc_lim?
Yes, you're right. We'll care about it.
I suggest to add "Rx" in the summary and care about Tx in a
subsequent patch.
net/virtio: report max/min/align Rx desc limits in dev info
OK?
