[dpdk-dev] [PATCH] net/virtio: report max/min/align desc limits in dev info get
Andrew Rybchenko
andrew.rybchenko at oktetlabs.ru
Fri Aug 20 14:48:12 CEST 2021
From: Ivan Ilchenko <ivan.ilchenko at 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.ilchenko at oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko at 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;
+
return 0;
}
--
2.30.2
More information about the dev
mailing list