[PATCH 3/7] net/gve: add gve_rss library for handling RSS-related behaviors

[Joshua Washington <joshwash@google.com>]

This change includes a number of helper functions to facilitate RSS
configuration on the GVE DPDK driver. These methods are declared in
gve_rss.h.
---
 drivers/net/gve/base/gve_adminq.h |  10 +-
 drivers/net/gve/gve_ethdev.c      |   2 +-
 drivers/net/gve/gve_ethdev.h      |   4 +-
 drivers/net/gve/gve_rss.c         | 206 ++++++++++++++++++++++++++++++
 drivers/net/gve/gve_rss.h         | 107 ++++++++++++++++
 drivers/net/gve/meson.build       |   1 +
 6 files changed, 319 insertions(+), 11 deletions(-)
 create mode 100644 drivers/net/gve/gve_rss.c
 create mode 100644 drivers/net/gve/gve_rss.h

diff --git a/drivers/net/gve/base/gve_adminq.h b/drivers/net/gve/base/gve_adminq.h
index 95f4960561..24abd945cc 100644
--- a/drivers/net/gve/base/gve_adminq.h
+++ b/drivers/net/gve/base/gve_adminq.h
@@ -378,15 +378,6 @@ struct gve_adminq_get_ptype_map {
 	__be64 ptype_map_addr;
 };
 
-#define GVE_RSS_HASH_IPV4		BIT(0)
-#define GVE_RSS_HASH_TCPV4		BIT(1)
-#define GVE_RSS_HASH_IPV6		BIT(2)
-#define GVE_RSS_HASH_IPV6_EX		BIT(3)
-#define GVE_RSS_HASH_TCPV6		BIT(4)
-#define GVE_RSS_HASH_TCPV6_EX		BIT(5)
-#define GVE_RSS_HASH_UDPV4		BIT(6)
-#define GVE_RSS_HASH_UDPV6		BIT(7)
-#define GVE_RSS_HASH_UDPV6_EX		BIT(8)
 
 /* RSS configuration command */
 struct gve_adminq_configure_rss {
@@ -428,6 +419,7 @@ union gve_adminq_command {
 GVE_CHECK_UNION_LEN(64, gve_adminq_command);
 
 struct gve_priv;
+struct gve_rss_config;
 struct gve_queue_page_list;
 int gve_adminq_alloc(struct gve_priv *priv);
 void gve_adminq_free(struct gve_priv *priv);
diff --git a/drivers/net/gve/gve_ethdev.c b/drivers/net/gve/gve_ethdev.c
index 6acdb4e13b..936ca22cb9 100644
--- a/drivers/net/gve/gve_ethdev.c
+++ b/drivers/net/gve/gve_ethdev.c
@@ -442,7 +442,7 @@ gve_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 		.nb_align = 1,
 	};
 
-	dev_info->flow_type_rss_offloads = GVE_RSS_OFFLOAD_ALL;
+	dev_info->flow_type_rss_offloads = GVE_RTE_RSS_OFFLOAD_ALL;
 
 	return 0;
 }
diff --git a/drivers/net/gve/gve_ethdev.h b/drivers/net/gve/gve_ethdev.h
index aa8291f235..b5118e737a 100644
--- a/drivers/net/gve/gve_ethdev.h
+++ b/drivers/net/gve/gve_ethdev.h
@@ -33,7 +33,7 @@
 		RTE_MBUF_F_TX_L4_MASK  |	\
 		RTE_MBUF_F_TX_TCP_SEG)
 
-#define GVE_RSS_OFFLOAD_ALL (		\
+#define GVE_RTE_RSS_OFFLOAD_ALL (	\
 	RTE_ETH_RSS_IPV4 |		\
 	RTE_ETH_RSS_NONFRAG_IPV4_TCP |	\
 	RTE_ETH_RSS_IPV6 |		\
@@ -290,6 +290,8 @@ struct gve_priv {
 	const struct rte_memzone *stats_report_mem;
 	uint16_t stats_start_idx; /* start index of array of stats written by NIC */
 	uint16_t stats_end_idx; /* end index of array of stats written by NIC */
+
+	struct gve_rss_config rss_config;
 };
 
 static inline bool
diff --git a/drivers/net/gve/gve_rss.c b/drivers/net/gve/gve_rss.c
new file mode 100644
index 0000000000..b1cd0e16f2
--- /dev/null
+++ b/drivers/net/gve/gve_rss.c
@@ -0,0 +1,206 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2023 Google LLC
+ */
+
+#include "gve_rss.h"
+
+int
+gve_generate_rss_reta(struct rte_eth_dev *dev, struct gve_rss_config* config)
+{
+	int i;
+	if (!config || !config->indir) {
+		return -EINVAL;
+	}
+
+	for (i = 0; i < config->indir_size; i++)
+		config->indir[i] = i % dev->data->nb_rx_queues;
+
+	return 0;
+}
+
+
+int
+gve_init_rss_config(struct gve_rss_config *gve_rss_conf,
+		uint16_t key_size, uint16_t indir_size)
+{
+	int err;
+
+	gve_rss_conf->alg = GVE_RSS_HASH_TOEPLITZ;
+
+	gve_rss_conf->key_size = key_size;
+	gve_rss_conf->key = rte_zmalloc("rss key",
+		key_size * sizeof(*gve_rss_conf->key),
+		RTE_CACHE_LINE_SIZE);
+	if (!gve_rss_conf->key) {
+		return -ENOMEM;
+	}
+
+	gve_rss_conf->indir_size = indir_size;
+	gve_rss_conf->indir = rte_zmalloc("rss reta",
+		indir_size * sizeof(*gve_rss_conf->indir),
+		RTE_CACHE_LINE_SIZE);
+	if (!gve_rss_conf->indir) {
+		err = -ENOMEM;
+		goto err_with_key;
+	}
+
+	return 0;
+err_with_key:
+	rte_free(gve_rss_conf->key);
+	return err;
+}
+
+int
+gve_init_rss_config_from_priv(struct gve_priv *priv,
+	struct gve_rss_config *gve_rss_conf)
+{
+	int err = gve_init_rss_config(gve_rss_conf, priv->rss_config.key_size,
+		priv->rss_config.indir_size);
+	if (err)
+		return err;
+
+	gve_rss_conf->hash_types = priv->rss_config.hash_types;
+	gve_rss_conf->alg = priv->rss_config.alg;
+	memcpy(gve_rss_conf->key, priv->rss_config.key,
+		gve_rss_conf->key_size * sizeof(*gve_rss_conf->key));
+	memcpy(gve_rss_conf->indir, priv->rss_config.indir,
+		gve_rss_conf->indir_size * sizeof(*gve_rss_conf->indir));
+
+	return 0;
+}
+
+void
+gve_free_rss_config(struct gve_rss_config *gve_rss_conf)
+{
+	rte_free(gve_rss_conf->indir);
+	gve_rss_conf->indir = NULL;
+	rte_free(gve_rss_conf->key);
+	gve_rss_conf->key = NULL;
+}
+
+int
+gve_update_priv_rss_config(struct gve_priv *priv, struct gve_rss_config *config)
+{
+	struct gve_rss_config *priv_config = &priv->rss_config;
+	int key_bytes, indir_bytes;
+
+	if (!config)
+		return -EINVAL;
+	if (config->key_size == 0 || !config->key)
+		return -EINVAL;
+	if (config->indir_size == 0 || !config->indir)
+		return -EINVAL;
+
+	priv_config->hash_types = config->hash_types;
+	priv_config->alg = config->alg;
+
+	priv_config->key_size = config->key_size;
+	key_bytes = priv_config->key_size * sizeof(*priv_config->key);
+	if (!priv_config->key)
+		priv_config->key = rte_zmalloc("priv rss key", key_bytes,
+			RTE_CACHE_LINE_SIZE);
+	else
+		priv_config->key = rte_realloc(priv_config->key, key_bytes,
+			RTE_CACHE_LINE_SIZE);
+	if (!priv_config->key)
+		return -ENOMEM;
+
+	priv_config->indir_size = config->indir_size;
+	indir_bytes = priv_config->indir_size * sizeof(*priv_config->indir);
+	if (!priv_config->indir)
+		priv_config->indir = rte_zmalloc("priv rss reta", indir_bytes,
+			RTE_CACHE_LINE_SIZE);
+	else
+		priv_config->indir = rte_realloc(priv_config->indir,
+			indir_bytes, RTE_CACHE_LINE_SIZE);
+
+	if (!priv_config->indir)
+		return -ENOMEM;
+
+	memcpy(priv_config->indir, config->indir,
+		config->indir_size * sizeof(*priv_config->indir));
+	memcpy(priv_config->key, config->key,
+		config->key_size * sizeof(*priv_config->key));
+
+	return 0;
+}
+
+int
+gve_update_rss_key(struct gve_priv *priv, struct gve_rss_config *gve_rss_conf,
+	struct rte_eth_rss_conf *rss_conf)
+{
+	if (rss_conf->rss_key_len && rss_conf->rss_key) {
+		gve_rss_conf->key_size = rss_conf->rss_key_len;
+		memcpy(gve_rss_conf->key, rss_conf->rss_key,
+			gve_rss_conf->key_size * sizeof(*gve_rss_conf->key));
+	} else if (priv->rss_config.key_size && priv->rss_config.key) {
+		gve_rss_conf->key_size = priv->rss_config.key_size;
+		memcpy(gve_rss_conf->key, priv->rss_config.key,
+			gve_rss_conf->key_size * sizeof(*gve_rss_conf->key));
+	} else {
+		PMD_DRV_LOG(ERR, "RSS key must be set as part of initial RSS "
+			"configuration.");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int
+gve_update_rss_hash_types(struct gve_priv *priv,
+	struct gve_rss_config *gve_rss_conf, struct rte_eth_rss_conf *rss_conf)
+{
+	// Initialize to 0 before modifying.
+	gve_rss_conf->hash_types = 0;
+	if (rss_conf->rss_hf)
+		rte_to_gve_rss_hf(rss_conf->rss_hf, gve_rss_conf);
+	else if (priv->rss_config.key_size && priv->rss_config.key)
+		gve_rss_conf->hash_types = priv->rss_config.hash_types;
+	else
+		gve_rss_conf->hash_types = GVE_RSS_OFFLOAD_DEFAULT;
+	return 0;
+}
+
+void
+rte_to_gve_rss_hf(uint64_t rte_rss_hf, struct gve_rss_config *gve_rss_conf) {
+	if (rte_rss_hf & RTE_ETH_RSS_IPV4)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_IPV4;
+	if (rte_rss_hf & RTE_ETH_RSS_NONFRAG_IPV4_TCP)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_TCPV4;
+	if (rte_rss_hf & RTE_ETH_RSS_IPV6)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_IPV6;
+	if (rte_rss_hf & RTE_ETH_RSS_IPV6_EX)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_IPV6_EX;
+	if (rte_rss_hf & RTE_ETH_RSS_NONFRAG_IPV6_TCP)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_TCPV6;
+	if (rte_rss_hf & RTE_ETH_RSS_IPV6_TCP_EX)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_TCPV6_EX;
+	if (rte_rss_hf & RTE_ETH_RSS_NONFRAG_IPV4_UDP)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_UDPV4;
+	if (rte_rss_hf & RTE_ETH_RSS_NONFRAG_IPV6_UDP)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_UDPV6;
+	if (rte_rss_hf & RTE_ETH_RSS_IPV6_UDP_EX)
+		gve_rss_conf->hash_types |= GVE_RSS_HASH_UDPV6_EX;
+}
+
+void
+gve_to_rte_rss_hf(uint16_t gve_rss_types, struct rte_eth_rss_conf *rss_conf) {
+	if (gve_rss_types & GVE_RSS_HASH_IPV4)
+		rss_conf->rss_hf |= RTE_ETH_RSS_IPV4;
+	if (gve_rss_types & GVE_RSS_HASH_TCPV4)
+		rss_conf->rss_hf |= RTE_ETH_RSS_NONFRAG_IPV4_TCP;
+	if (gve_rss_types & GVE_RSS_HASH_IPV6)
+		rss_conf->rss_hf |= RTE_ETH_RSS_IPV6;
+	if (gve_rss_types & GVE_RSS_HASH_IPV6_EX)
+		rss_conf->rss_hf |= RTE_ETH_RSS_IPV6_EX;
+	if (gve_rss_types & GVE_RSS_HASH_TCPV6)
+		rss_conf->rss_hf |= RTE_ETH_RSS_NONFRAG_IPV6_TCP;
+	if (gve_rss_types & GVE_RSS_HASH_TCPV6_EX)
+		rss_conf->rss_hf |= RTE_ETH_RSS_IPV6_TCP_EX;
+	if (gve_rss_types & GVE_RSS_HASH_UDPV4)
+		rss_conf->rss_hf |= RTE_ETH_RSS_NONFRAG_IPV4_UDP;
+	if (gve_rss_types & GVE_RSS_HASH_UDPV6)
+		rss_conf->rss_hf |= RTE_ETH_RSS_NONFRAG_IPV6_UDP;
+	if (gve_rss_types & GVE_RSS_HASH_UDPV6_EX)
+		rss_conf->rss_hf |= RTE_ETH_RSS_IPV6_UDP_EX;
+}
+
diff --git a/drivers/net/gve/gve_rss.h b/drivers/net/gve/gve_rss.h
new file mode 100644
index 0000000000..bea16d8508
--- /dev/null
+++ b/drivers/net/gve/gve_rss.h
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) 2023 Google LLC
+ */
+
+#include "gve_adminq.h"
+#include "gve_ethdev.h"
+
+#define GVE_RSS_HASH_IPV4		BIT(0)
+#define GVE_RSS_HASH_TCPV4		BIT(1)
+#define GVE_RSS_HASH_IPV6		BIT(2)
+#define GVE_RSS_HASH_IPV6_EX		BIT(3)
+#define GVE_RSS_HASH_TCPV6		BIT(4)
+#define GVE_RSS_HASH_TCPV6_EX		BIT(5)
+#define GVE_RSS_HASH_UDPV4		BIT(6)
+#define GVE_RSS_HASH_UDPV6		BIT(7)
+#define GVE_RSS_HASH_UDPV6_EX		BIT(8)
+
+#define GVE_RSS_OFFLOAD_DEFAULT (	\
+	GVE_RSS_HASH_IPV4 |		\
+	GVE_RSS_HASH_TCPV4 |		\
+	GVE_RSS_HASH_IPV6 |		\
+	GVE_RSS_HASH_IPV6_EX |		\
+	GVE_RSS_HASH_TCPV6 |		\
+	GVE_RSS_HASH_TCPV6_EX |		\
+	GVE_RSS_HASH_UDPV4 |		\
+	GVE_RSS_HASH_UDPV6 |		\
+	GVE_RSS_HASH_UDPV6_EX)
+
+/**
+ * Generates default RSS redirection table based on the number of queues the
+ * device is configured with. This assigns hash values to queues in a
+ * round-robin manner.
+ */
+int
+gve_generate_rss_reta(struct rte_eth_dev *dev, struct gve_rss_config* config);
+
+/**
+ * Initializes `gve_rss_conf`, setting the fields to default values and
+ * allocating memory for the RSS key and redirection table.
+ */
+int
+gve_init_rss_config(struct gve_rss_config *gve_rss_conf,
+		uint16_t key_size, uint16_t indir_size);
+
+/**
+ * Initializes `gve_rss_conf` based on the RSS configuration stored in `priv`.
+ */
+int
+gve_init_rss_config_from_priv(struct gve_priv *priv,
+	struct gve_rss_config *gve_rss_conf);
+
+/**
+ * Frees RSS key and redriection table pointers stored in `gve_rss_conf`.
+ */
+void
+gve_free_rss_config(struct gve_rss_config *gve_rss_conf);
+
+/**
+ * Updates the rss_config stored in `priv` with the contents of `config`.
+ */
+int
+gve_update_priv_rss_config(struct gve_priv *priv,
+			   struct gve_rss_config *config);
+
+/**
+ * Updates the RSS key stored in `gve_rss_conf`. It is prioritized as follows:
+ *	1) retrieve from `rss_conf`, if non-null
+ *	2) retrieve from `priv`, if non-null
+ * If keys from both sources are unset, return -EINVAL.
+ */
+int
+gve_update_rss_key(struct gve_priv *priv, struct gve_rss_config *gve_rss_conf,
+		   struct rte_eth_rss_conf *rss_conf);
+
+/**
+ * Updates the RSS hash types stored in `gve_rss_conf`. It is prioritized as
+ * follows:
+ *	1) retreive from `rss_conf`, if set
+ *	2) retrieve from priv, if RSS has been configured
+ *	3) set default RSS offload
+ */
+int
+gve_update_rss_hash_types(struct gve_priv *priv,
+	struct gve_rss_config *gve_rss_conf, struct rte_eth_rss_conf *rss_conf);
+
+/**
+ * Ensures that only supported RSS hash fields are set in `rte_rss_hf`.
+ */
+static inline int
+gve_validate_rss_hf(uint64_t rte_rss_hf) {
+	return rte_rss_hf &~ GVE_RTE_RSS_OFFLOAD_ALL;
+}
+
+/**
+ * Converts RSS hash types from RTE values to GVE values, storing them in
+ * `gve_rss_conf`.
+ */
+void
+rte_to_gve_rss_hf(uint64_t rte_rss_hf, struct gve_rss_config *gve_rss_conf);
+
+/**
+ * Converts RSS hash types from GVE values to RTE values, storing them in
+ * `rss_conf`.
+ */
+void
+gve_to_rte_rss_hf(uint16_t gve_rss_types, struct rte_eth_rss_conf *rss_conf);
+
diff --git a/drivers/net/gve/meson.build b/drivers/net/gve/meson.build
index 61d195009c..6da13a8406 100644
--- a/drivers/net/gve/meson.build
+++ b/drivers/net/gve/meson.build
@@ -15,5 +15,6 @@ sources = files(
         'gve_tx_dqo.c',
         'gve_ethdev.c',
         'gve_version.c',
+        'gve_rss.c',
 )
 includes += include_directories('base')
-- 
2.43.0.429.g432eaa2c6b-goog