Commit ec304b70 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

net: move mp dev config validation to __net_mp_open_rxq() 



devmem code performs a number of safety checks to avoid having
to reimplement all of them in the drivers. Move those to
__net_mp_open_rxq() and reuse that function for binding to make
sure that io_uring ZC also benefits from them.

While at it rename the queue ID variable to rxq_idx in
__net_mp_open_rxq(), we touch most of the relevant lines.

The XArray insertion is reordered after the netdev_rx_queue_restart()
call, otherwise we'd need to duplicate the queue index check
or risk inserting an invalid pointer. The XArray allocation
failures should be extremely rare.

Reviewed-by: default avatarMina Almasry <almasrymina@google.com>
Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Fixes: 6e18ed92 ("net: add helpers for setting a memory provider on an rx queue")
Link: https://patch.msgid.link/20250403013405.2827250-2-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 053f3ff6

include/net/page_pool/memory_provider.h

+6 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <net/page_pool/types.h>



struct netdev_rx_queue;

struct netlink_ext_ack;

struct sk_buff;



struct memory_provider_ops {
@@ -24,8 +25,13 @@ void net_mp_niov_clear_page_pool(struct net_iov *niov); 


int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,

		    struct pp_memory_provider_params *p);

int __net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,

		      const struct pp_memory_provider_params *p,

		      struct netlink_ext_ack *extack);

void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,

		      struct pp_memory_provider_params *old_p);

void __net_mp_close_rxq(struct net_device *dev, unsigned int rxq_idx,

			const struct pp_memory_provider_params *old_p);



/**

  * net_mp_netmem_place_in_cache() - give a netmem to a page pool

net/core/devmem.c

+10 −40
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 
 */



#include <linux/dma-buf.h>

#include <linux/ethtool_netlink.h>

#include <linux/genalloc.h>

#include <linux/mm.h>

#include <linux/netdevice.h>
@@ -143,57 +142,28 @@ int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx, 
				    struct net_devmem_dmabuf_binding *binding,

				    struct netlink_ext_ack *extack)

{

	struct pp_memory_provider_params mp_params = {

		.mp_priv	= binding,

		.mp_ops		= &dmabuf_devmem_ops,

	};

	struct netdev_rx_queue *rxq;

	u32 xa_idx;

	int err;



	if (rxq_idx >= dev->real_num_rx_queues) {

		NL_SET_ERR_MSG(extack, "rx queue index out of range");

		return -ERANGE;

	}



	if (dev->cfg->hds_config != ETHTOOL_TCP_DATA_SPLIT_ENABLED) {

		NL_SET_ERR_MSG(extack, "tcp-data-split is disabled");

		return -EINVAL;

	}



	if (dev->cfg->hds_thresh) {

		NL_SET_ERR_MSG(extack, "hds-thresh is not zero");

		return -EINVAL;

	}

	err = __net_mp_open_rxq(dev, rxq_idx, &mp_params, extack);

	if (err)

		return err;



	rxq = __netif_get_rx_queue(dev, rxq_idx);

	if (rxq->mp_params.mp_ops) {

		NL_SET_ERR_MSG(extack, "designated queue already memory provider bound");

		return -EEXIST;

	}



#ifdef CONFIG_XDP_SOCKETS

	if (rxq->pool) {

		NL_SET_ERR_MSG(extack, "designated queue already in use by AF_XDP");

		return -EBUSY;

	}

#endif



	err = xa_alloc(&binding->bound_rxqs, &xa_idx, rxq, xa_limit_32b,

		       GFP_KERNEL);

	if (err)

		return err;



	rxq->mp_params.mp_priv = binding;

	rxq->mp_params.mp_ops = &dmabuf_devmem_ops;



	err = netdev_rx_queue_restart(dev, rxq_idx);

	if (err)

		goto err_xa_erase;

		goto err_close_rxq;



	return 0;



err_xa_erase:

	rxq->mp_params.mp_priv = NULL;

	rxq->mp_params.mp_ops = NULL;

	xa_erase(&binding->bound_rxqs, xa_idx);



err_close_rxq:

	__net_mp_close_rxq(dev, rxq_idx, &mp_params);

	return err;

}

net/core/netdev-genl.c

+0 −6
Original line number Diff line number Diff line
@@ -874,12 +874,6 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) 
		goto err_unlock;

	}



	if (dev_xdp_prog_count(netdev)) {

		NL_SET_ERR_MSG(info->extack, "unable to bind dmabuf to device with XDP program attached");

		err = -EEXIST;

		goto err_unlock;

	}



	binding = net_devmem_bind_dmabuf(netdev, dmabuf_fd, info->extack);

	if (IS_ERR(binding)) {

		err = PTR_ERR(binding);

net/core/netdev_rx_queue.c

+38 −11
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later



#include <linux/ethtool_netlink.h>

#include <linux/netdevice.h>

#include <net/netdev_lock.h>

#include <net/netdev_queues.h>
@@ -86,8 +87,9 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) 
}

EXPORT_SYMBOL_NS_GPL(netdev_rx_queue_restart, "NETDEV_INTERNAL");



static int __net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,

			     struct pp_memory_provider_params *p)

int __net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,

		      const struct pp_memory_provider_params *p,

		      struct netlink_ext_ack *extack)

{

	struct netdev_rx_queue *rxq;

	int ret;
@@ -95,16 +97,41 @@ static int __net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx, 
	if (!netdev_need_ops_lock(dev))

		return -EOPNOTSUPP;



	if (ifq_idx >= dev->real_num_rx_queues)

	if (rxq_idx >= dev->real_num_rx_queues)

		return -EINVAL;

	ifq_idx = array_index_nospec(ifq_idx, dev->real_num_rx_queues);

	rxq_idx = array_index_nospec(rxq_idx, dev->real_num_rx_queues);



	rxq = __netif_get_rx_queue(dev, ifq_idx);

	if (rxq->mp_params.mp_ops)

	if (rxq_idx >= dev->real_num_rx_queues) {

		NL_SET_ERR_MSG(extack, "rx queue index out of range");

		return -ERANGE;

	}

	if (dev->cfg->hds_config != ETHTOOL_TCP_DATA_SPLIT_ENABLED) {

		NL_SET_ERR_MSG(extack, "tcp-data-split is disabled");

		return -EINVAL;

	}

	if (dev->cfg->hds_thresh) {

		NL_SET_ERR_MSG(extack, "hds-thresh is not zero");

		return -EINVAL;

	}

	if (dev_xdp_prog_count(dev)) {

		NL_SET_ERR_MSG(extack, "unable to custom memory provider to device with XDP program attached");

		return -EEXIST;

	}



	rxq = __netif_get_rx_queue(dev, rxq_idx);

	if (rxq->mp_params.mp_ops) {

		NL_SET_ERR_MSG(extack, "designated queue already memory provider bound");

		return -EEXIST;

	}

#ifdef CONFIG_XDP_SOCKETS

	if (rxq->pool) {

		NL_SET_ERR_MSG(extack, "designated queue already in use by AF_XDP");

		return -EBUSY;

	}

#endif



	rxq->mp_params = *p;

	ret = netdev_rx_queue_restart(dev, ifq_idx);

	ret = netdev_rx_queue_restart(dev, rxq_idx);

	if (ret) {

		rxq->mp_params.mp_ops = NULL;

		rxq->mp_params.mp_priv = NULL;
@@ -112,19 +139,19 @@ static int __net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx, 
	return ret;

}



int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,

int net_mp_open_rxq(struct net_device *dev, unsigned int rxq_idx,

		    struct pp_memory_provider_params *p)

{

	int ret;



	netdev_lock(dev);

	ret = __net_mp_open_rxq(dev, ifq_idx, p);

	ret = __net_mp_open_rxq(dev, rxq_idx, p, NULL);

	netdev_unlock(dev);

	return ret;

}



static void __net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,

			      struct pp_memory_provider_params *old_p)

void __net_mp_close_rxq(struct net_device *dev, unsigned int ifq_idx,

			const struct pp_memory_provider_params *old_p)

{

	struct netdev_rx_queue *rxq;