-----Original Message-----
From: Andrew Rybchenko <redacted>
Sent: Tuesday, March 9, 2021 4:20 PM
To: Xueming(Steven) Li <redacted>
Cc: dev@dpdk.org; Slava Ovsiienko <redacted>; Asaf Penso <redacted>; NBU-Contact-Thomas Monjalon
[off-list ref]; Ferruh Yigit [off-list ref]; Ray Kinsella [off-list ref]; Neil Horman
[off-list ref]
Subject: Re: [PATCH v8 8/9] ethdev: representor iterator compare complete info

On 3/4/21 5:30 PM, Xueming Li wrote:

quoted

The NIC can have multiple PCIe links and can be attached to multiple
hosts, for example the same single NIC can be shared for multiple
server units in the rack. On each PCIe link NIC can provide multiple
PFs and VFs/SFs based on these ones. The full representor identifier
consists of three indices - controller index, PF index, and VF or SF index (if any).

SR-IOV and SubFunction are created on top of PF. PF index is
introduced because there might be multiple PFs in the bonding
configuration and only bonding device is probed.

In eth representor comparator callback, ethdev representor ID was
compared with devarg. Since controller index and PF index not
compared, callback returned representor from other PF or controller.

This patch adds new API to get representor ID from controller, pf and
vf/sf index. Representor comparer callback get representor ID then
compare with device representor ID.

Signed-off-by: Xueming Li <redacted>

Reviewed-by: Andrew Rybchenko <redacted>

One minor suggestions below to make it a bit more robust against errors in PMDs.

Make thanks for careful review notes processing.

Many thanks to your generous and careful review all the time, with patience :)
This is my first long public api patchset, can't do it without your help :)

[snip]

quoted

diff --git a/lib/librte_ethdev/rte_ethdev.c

b/lib/librte_ethdev/rte_ethdev.c index 3d4ec8ad5c..2dc464a7ad 100644

--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c

@@ -5609,6 +5609,94 @@ rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_da)
 	return result;
 }

+int
+rte_eth_representor_id_get(const struct rte_eth_dev *ethdev,
+			   enum rte_eth_representor_type type,
+			   int controller, int pf, int representor_port,
+			   uint16_t *repr_id)
+{
+	int ret, n, i, count;
+	struct rte_eth_representor_info *info = NULL;
+	size_t size;
+
+	if (type == RTE_ETH_REPRESENTOR_NONE)
+		return 0;
+	if (repr_id == NULL)
+		return -EINVAL;
+
+	/* Get PMD representor range info. */
+	ret = rte_eth_representor_info_get(ethdev->data->port_id, NULL);
+	if (ret < 0) {
+		if (type == RTE_ETH_REPRESENTOR_VF && controller == -1 &&
+		    pf == -1) {
+			/* Direct mapping for legacy VF representor. */
+			*repr_id = representor_port;
+			return 0;
+		} else {
+			return ret;
+		}
+	}
+	n = ret;
+	size = sizeof(*info) + n * sizeof(info->ranges[0]);
+	info = calloc(1, size);
+	if (info == NULL)
+		return -ENOMEM;
+	ret = rte_eth_representor_info_get(ethdev->data->port_id, info);
+	if (ret < 0)
+		goto out;
+
+	/* Default controller and pf to caller. */
+	if (controller == -1)
+		controller = info->controller;
+	if (pf == -1)
+		pf = info->pf;
+
+	/* Locate representor ID. */
+	ret = -ENOENT;
+	for (i = 0; i < n; ++i) {
+		if (info->ranges[i].type != type)
+			continue;
+		if (info->ranges[i].controller != controller)
+			continue;
+		count = info->ranges[i].id_end - info->ranges[i].id_base + 1;

I think it would be useful to sanity test these values to ensure that we have no overflow here.
Let's check above, log error and skip the range if id_end is smaller than id_base.

quoted

+		switch (info->ranges[i].type) {
+		case RTE_ETH_REPRESENTOR_PF:
+			if (pf < info->ranges[i].pf ||
+			    pf >= info->ranges[i].pf + count)
+				continue;
+			*repr_id = info->ranges[i].id_base +
+				   (pf - info->ranges[i].pf);
+			ret = 0;
+			goto out;
+		case RTE_ETH_REPRESENTOR_VF:
+			if (info->ranges[i].pf != pf)
+				continue;
+			if (representor_port < info->ranges[i].vf ||
+			    representor_port >= info->ranges[i].vf + count)
+				continue;
+			*repr_id = info->ranges[i].id_base +
+				   (representor_port - info->ranges[i].vf);
+			ret = 0;
+			goto out;
+		case RTE_ETH_REPRESENTOR_SF:
+			if (info->ranges[i].pf != pf)
+				continue;
+			if (representor_port < info->ranges[i].sf ||
+			    representor_port >= info->ranges[i].sf + count)
+				continue;
+			*repr_id = info->ranges[i].id_base +
+			      (representor_port - info->ranges[i].sf);
+			ret = 0;
+			goto out;
+		default:
+			break;
+		}
+	}
+out:
+	free(info);
+	return ret;
+}
+
 static int
 eth_dev_handle_port_list(const char *cmd __rte_unused,
 		const char *params __rte_unused,

[snip]