linux-gen: socket_xdp: adjust queue count capability reporting

Report maximum input and output queue counts based on the supported
combined count of the underlying driver. Additionally, maximally limit
the count to the system core count as this is typically the actual
maximum count supported by drivers even though theoretically supporting
more.

Signed-off-by: Tuomas Taipale <tuomas.taipale@nokia.com>
Reviewed-by: Matias Elo <matias.elo@nokia.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/platform/linux-generic/pktio/socket_xdp.c b/platform/linux-generic/pktio/socket_xdp.c
index be79ca267..47dbdcdd6 100644
--- a/platform/linux-generic/pktio/socket_xdp.c
+++ b/platform/linux-generic/pktio/socket_xdp.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2022, Nokia
+/* Copyright (c) 2022-2023, Nokia
  * All rights reserved.
  *
  * SPDX-License-Identifier:     BSD-3-Clause
@@ -9,32 +9,33 @@
 #ifdef _ODP_PKTIO_XDP
 
 #include <odp_posix_extensions.h>
+#include <odp/api/cpu.h>
 #include <odp/api/debug.h>
 #include <odp/api/hints.h>
+#include <odp/api/packet_io_stats.h>
 #include <odp/api/system_info.h>
 #include <odp/api/ticketlock.h>
-#include <odp/api/packet_io_stats.h>
 
 #include <odp_classification_internal.h>
 #include <odp_debug_internal.h>
 #include <odp_libconfig_internal.h>
 #include <odp_macros_internal.h>
-#include <odp_packet_io_internal.h>
 #include <odp_packet_internal.h>
+#include <odp_packet_io_internal.h>
 #include <odp_parse_internal.h>
 #include <odp_pool_internal.h>
 #include <odp_socket_common.h>
 
-#include <string.h>
 #include <errno.h>
-#include <sys/socket.h>
-#include <unistd.h>
-#include <poll.h>
-#include <sys/ioctl.h>
 #include <linux/ethtool.h>
+#include <linux/if_xdp.h>
 #include <linux/sockios.h>
 #include <net/if.h>
-#include <linux/if_xdp.h>
+#include <poll.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <unistd.h>
 
 #include <xdp/xsk.h>
 
@@ -830,12 +831,13 @@ static int sock_xdp_link_info(pktio_entry_t *pktio_entry, odp_pktio_link_info_t
 				 pktio_entry->name, info);
 }
 
-static int set_queue_capability(int fd, const char *devname, odp_pktio_capability_t *capa)
+static int get_nic_queue_capability(int fd, const char *devname, odp_pktio_capability_t *capa)
 {
-	struct ifreq ifr;
 	struct ethtool_channels channels;
-	uint32_t max_channels;
+	struct ifreq ifr;
 	int ret;
+	const uint32_t cc = odp_cpu_count();
+	uint32_t max_channels;
 
 	memset(&channels, 0, sizeof(struct ethtool_channels));
 	channels.cmd = ETHTOOL_GCHANNELS;
@@ -845,16 +847,16 @@ static int set_queue_capability(int fd, const char *devname, odp_pktio_capabilit
 
 	if (ret == -1 || channels.max_combined == 0U) {
 		if (ret == -1 && errno != EOPNOTSUPP) {
-			_ODP_ERR("Unable to query NIC channel capabilities: %s\n", strerror(errno));
+			_ODP_ERR("Unable to query NIC queue capabilities: %s\n", strerror(errno));
 			return -1;
 		}
 
 		channels.max_combined = 1U;
 	}
 
-	max_channels = _ODP_MIN((uint32_t)ODP_PKTOUT_MAX_QUEUES, channels.max_combined);
+	max_channels = _ODP_MIN(cc, channels.max_combined);
 	capa->max_input_queues = _ODP_MIN((uint32_t)ODP_PKTIN_MAX_QUEUES, max_channels);
-	capa->max_output_queues = max_channels;
+	capa->max_output_queues = _ODP_MIN((uint32_t)ODP_PKTOUT_MAX_QUEUES, max_channels);
 
 	return 0;
 }
@@ -865,7 +867,7 @@ static int sock_xdp_capability(pktio_entry_t *pktio_entry, odp_pktio_capability_
 
 	memset(capa, 0, sizeof(odp_pktio_capability_t));
 
-	if (set_queue_capability(priv->helper_sock, pktio_entry->name, capa))
+	if (get_nic_queue_capability(priv->helper_sock, pktio_entry->name, capa))
 		return -1;
 
 	capa->set_op.op.promisc_mode = 1U;