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Message-ID: <CAJ8uoz3oZ=63EC8BfenE+-J8AQKPnoZVBF4m_G3ypjYgzME1Fg@mail.gmail.com>
Date: Thu, 9 Jul 2020 08:47:01 +0200
From: Magnus Karlsson <magnus.karlsson@...il.com>
To: Maxim Mikityanskiy <maximmi@...lanox.com>
Cc: Magnus Karlsson <magnus.karlsson@...el.com>,
Björn Töpel <bjorn.topel@...el.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Network Development <netdev@...r.kernel.org>,
Jonathan Lemon <jonathan.lemon@...il.com>,
bpf <bpf@...r.kernel.org>, jeffrey.t.kirsher@...el.com,
"Fijalkowski, Maciej" <maciej.fijalkowski@...el.com>,
Maciej Fijalkowski <maciejromanfijalkowski@...il.com>,
cristian.dumitrescu@...el.com
Subject: Re: [PATCH bpf-next 03/14] xsk: create and free context independently
from umem
On Wed, Jul 8, 2020 at 5:01 PM Maxim Mikityanskiy <maximmi@...lanox.com> wrote:
>
> On 2020-07-02 15:19, Magnus Karlsson wrote:
> > Create and free the buffer pool independently from the umem. Move
> > these operations that are performed on the buffer pool from the
> > umem create and destroy functions to new create and destroy
> > functions just for the buffer pool. This so that in later commits
> > we can instantiate multiple buffer pools per umem when sharing a
> > umem between HW queues and/or devices. We also erradicate the
> > back pointer from the umem to the buffer pool as this will not
> > work when we introduce the possibility to have multiple buffer
> > pools per umem.
> >
> > It might seem a bit odd that we create an empty buffer pool first
> > and then recreate it with its right size when we bind to a device
> > and umem. But the page pool will in later commits be used to
> > carry information before it has been assigned to a umem and its
> > size decided.
>
> What kind of information? I'm looking at the final code: on socket
> creation you just fill the pool with zeros, then we may have setsockopt
> for FQ and CQ, then xsk_bind replaces the pool with the real one. So the
> only information carried from the old pool to the new one is FQ and CQ,
> or did I miss anything?
>
> I don't quite like this design, it's kind of a hack to support the
> initialization order that we have, but it complicates things: when you
> copy the old pool into the new one, it's not clear which fields we care
> about, and which are ignored/overwritten.
>
> Regarding FQ and CQ, for shared UMEM, they won't be filled, so there is
> no point in the temporary pool in this case (unless it also stores
> something that I missed).
>
> I suggest to add a pointer to some kind of a configuration struct to xs.
> All things configured with setsockopt go to that struct. xsk_bind will
> call a function to validate the config struct, and if it's OK, it will
> create the pool (once), fill the fields and free the config struct.
> Config struct can be a union with the pool to save space in xs. Probably
> we will also be able to drop a few fields from xs (such as umem?). How
> do you feel about this idea?
It is used to store FQ and CQ information that is used once we enable
this in patch 10 and 11. But I agree, the current solution is not
good. I will rework this along the lines of your suggestion.
> >
> > Signed-off-by: Magnus Karlsson <magnus.karlsson@...el.com>
> > ---
> > include/net/xdp_sock.h | 3 +-
> > include/net/xsk_buff_pool.h | 14 +++-
> > net/xdp/xdp_umem.c | 164 ++++----------------------------------------
> > net/xdp/xdp_umem.h | 4 +-
> > net/xdp/xsk.c | 83 +++++++++++++++++++---
> > net/xdp/xsk.h | 3 +
> > net/xdp/xsk_buff_pool.c | 154 +++++++++++++++++++++++++++++++++++++----
> > net/xdp/xsk_queue.h | 12 ++--
> > 8 files changed, 250 insertions(+), 187 deletions(-)
> >
> > diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
> > index 6eb9628..b9bb118 100644
> > --- a/include/net/xdp_sock.h
> > +++ b/include/net/xdp_sock.h
> > @@ -20,13 +20,12 @@ struct xdp_buff;
> > struct xdp_umem {
> > struct xsk_queue *fq;
> > struct xsk_queue *cq;
> > - struct xsk_buff_pool *pool;
> > u64 size;
> > u32 headroom;
> > u32 chunk_size;
> > + u32 chunks;
> > struct user_struct *user;
> > refcount_t users;
> > - struct work_struct work;
> > struct page **pgs;
> > u32 npgs;
> > u16 queue_id;
> > diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
> > index a6dec9c..cda8ced 100644
> > --- a/include/net/xsk_buff_pool.h
> > +++ b/include/net/xsk_buff_pool.h
> > @@ -14,6 +14,7 @@ struct xdp_rxq_info;
> > struct xsk_queue;
> > struct xdp_desc;
> > struct xdp_umem;
> > +struct xdp_sock;
> > struct device;
> > struct page;
> >
> > @@ -46,16 +47,23 @@ struct xsk_buff_pool {
> > struct xdp_umem *umem;
> > void *addrs;
> > struct device *dev;
> > + refcount_t users;
> > + struct work_struct work;
> > struct xdp_buff_xsk *free_heads[];
> > };
> >
> > /* AF_XDP core. */
> > -struct xsk_buff_pool *xp_create(struct xdp_umem *umem, u32 chunks,
> > - u32 chunk_size, u32 headroom, u64 size,
> > - bool unaligned);
> > +struct xsk_buff_pool *xp_create(void);
> > +struct xsk_buff_pool *xp_assign_umem(struct xsk_buff_pool *pool,
> > + struct xdp_umem *umem);
> > +int xp_assign_dev(struct xsk_buff_pool *pool, struct xdp_sock *xs,
> > + struct net_device *dev, u16 queue_id, u16 flags);
> > void xp_set_fq(struct xsk_buff_pool *pool, struct xsk_queue *fq);
> > void xp_destroy(struct xsk_buff_pool *pool);
> > void xp_release(struct xdp_buff_xsk *xskb);
> > +void xp_get_pool(struct xsk_buff_pool *pool);
> > +void xp_put_pool(struct xsk_buff_pool *pool);
> > +void xp_clear_dev(struct xsk_buff_pool *pool);
> >
> > /* AF_XDP, and XDP core. */
> > void xp_free(struct xdp_buff_xsk *xskb);
> > diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
> > index adde4d5..f290345 100644
> > --- a/net/xdp/xdp_umem.c
> > +++ b/net/xdp/xdp_umem.c
> > @@ -47,160 +47,41 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
> > spin_unlock_irqrestore(&umem->xsk_tx_list_lock, flags);
> > }
> >
> > -/* The umem is stored both in the _rx struct and the _tx struct as we do
> > - * not know if the device has more tx queues than rx, or the opposite.
> > - * This might also change during run time.
> > - */
> > -static int xsk_reg_pool_at_qid(struct net_device *dev,
> > - struct xsk_buff_pool *pool,
> > - u16 queue_id)
> > -{
> > - if (queue_id >= max_t(unsigned int,
> > - dev->real_num_rx_queues,
> > - dev->real_num_tx_queues))
> > - return -EINVAL;
> > -
> > - if (queue_id < dev->real_num_rx_queues)
> > - dev->_rx[queue_id].pool = pool;
> > - if (queue_id < dev->real_num_tx_queues)
> > - dev->_tx[queue_id].pool = pool;
> > -
> > - return 0;
> > -}
> > -
> > -struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
> > - u16 queue_id)
> > +static void xdp_umem_unpin_pages(struct xdp_umem *umem)
> > {
> > - if (queue_id < dev->real_num_rx_queues)
> > - return dev->_rx[queue_id].pool;
> > - if (queue_id < dev->real_num_tx_queues)
> > - return dev->_tx[queue_id].pool;
> > + unpin_user_pages_dirty_lock(umem->pgs, umem->npgs, true);
> >
> > - return NULL;
> > + kfree(umem->pgs);
> > + umem->pgs = NULL;
> > }
> > -EXPORT_SYMBOL(xsk_get_pool_from_qid);
> >
> > -static void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
> > +static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
> > {
> > - if (queue_id < dev->real_num_rx_queues)
> > - dev->_rx[queue_id].pool = NULL;
> > - if (queue_id < dev->real_num_tx_queues)
> > - dev->_tx[queue_id].pool = NULL;
> > + if (umem->user) {
> > + atomic_long_sub(umem->npgs, &umem->user->locked_vm);
> > + free_uid(umem->user);
> > + }
> > }
> >
> > -int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
> > - u16 queue_id, u16 flags)
> > +void xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
> > + u16 queue_id)
> > {
> > - bool force_zc, force_copy;
> > - struct netdev_bpf bpf;
> > - int err = 0;
> > -
> > - ASSERT_RTNL();
> > -
> > - force_zc = flags & XDP_ZEROCOPY;
> > - force_copy = flags & XDP_COPY;
> > -
> > - if (force_zc && force_copy)
> > - return -EINVAL;
> > -
> > - if (xsk_get_pool_from_qid(dev, queue_id))
> > - return -EBUSY;
> > -
> > - err = xsk_reg_pool_at_qid(dev, umem->pool, queue_id);
> > - if (err)
> > - return err;
> > -
> > umem->dev = dev;
> > umem->queue_id = queue_id;
> >
> > - if (flags & XDP_USE_NEED_WAKEUP) {
> > - umem->flags |= XDP_UMEM_USES_NEED_WAKEUP;
> > - /* Tx needs to be explicitly woken up the first time.
> > - * Also for supporting drivers that do not implement this
> > - * feature. They will always have to call sendto().
> > - */
> > - xsk_set_tx_need_wakeup(umem->pool);
> > - }
> > -
> > dev_hold(dev);
> > -
> > - if (force_copy)
> > - /* For copy-mode, we are done. */
> > - return 0;
> > -
> > - if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_wakeup) {
> > - err = -EOPNOTSUPP;
> > - goto err_unreg_umem;
> > - }
> > -
> > - bpf.command = XDP_SETUP_XSK_POOL;
> > - bpf.xsk.pool = umem->pool;
> > - bpf.xsk.queue_id = queue_id;
> > -
> > - err = dev->netdev_ops->ndo_bpf(dev, &bpf);
> > - if (err)
> > - goto err_unreg_umem;
> > -
> > - umem->zc = true;
> > - return 0;
> > -
> > -err_unreg_umem:
> > - if (!force_zc)
> > - err = 0; /* fallback to copy mode */
> > - if (err)
> > - xsk_clear_pool_at_qid(dev, queue_id);
> > - return err;
> > }
> >
> > void xdp_umem_clear_dev(struct xdp_umem *umem)
> > {
> > - struct netdev_bpf bpf;
> > - int err;
> > -
> > - ASSERT_RTNL();
> > -
> > - if (!umem->dev)
> > - return;
> > -
> > - if (umem->zc) {
> > - bpf.command = XDP_SETUP_XSK_POOL;
> > - bpf.xsk.pool = NULL;
> > - bpf.xsk.queue_id = umem->queue_id;
> > -
> > - err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
> > -
> > - if (err)
> > - WARN(1, "failed to disable umem!\n");
> > - }
> > -
> > - xsk_clear_pool_at_qid(umem->dev, umem->queue_id);
> > -
> > dev_put(umem->dev);
> > umem->dev = NULL;
> > umem->zc = false;
> > }
> >
> > -static void xdp_umem_unpin_pages(struct xdp_umem *umem)
> > -{
> > - unpin_user_pages_dirty_lock(umem->pgs, umem->npgs, true);
> > -
> > - kfree(umem->pgs);
> > - umem->pgs = NULL;
> > -}
> > -
> > -static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
> > -{
> > - if (umem->user) {
> > - atomic_long_sub(umem->npgs, &umem->user->locked_vm);
> > - free_uid(umem->user);
> > - }
> > -}
> > -
> > static void xdp_umem_release(struct xdp_umem *umem)
> > {
> > - rtnl_lock();
> > xdp_umem_clear_dev(umem);
> > - rtnl_unlock();
> >
> > ida_simple_remove(&umem_ida, umem->id);
> >
> > @@ -214,20 +95,12 @@ static void xdp_umem_release(struct xdp_umem *umem)
> > umem->cq = NULL;
> > }
> >
> > - xp_destroy(umem->pool);
> > xdp_umem_unpin_pages(umem);
> >
> > xdp_umem_unaccount_pages(umem);
> > kfree(umem);
> > }
> >
> > -static void xdp_umem_release_deferred(struct work_struct *work)
> > -{
> > - struct xdp_umem *umem = container_of(work, struct xdp_umem, work);
> > -
> > - xdp_umem_release(umem);
> > -}
> > -
> > void xdp_get_umem(struct xdp_umem *umem)
> > {
> > refcount_inc(&umem->users);
> > @@ -238,10 +111,8 @@ void xdp_put_umem(struct xdp_umem *umem)
> > if (!umem)
> > return;
> >
> > - if (refcount_dec_and_test(&umem->users)) {
> > - INIT_WORK(&umem->work, xdp_umem_release_deferred);
> > - schedule_work(&umem->work);
> > - }
> > + if (refcount_dec_and_test(&umem->users))
> > + xdp_umem_release(umem);
> > }
> >
> > static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address)
> > @@ -357,6 +228,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
> > umem->size = size;
> > umem->headroom = headroom;
> > umem->chunk_size = chunk_size;
> > + umem->chunks = chunks;
> > umem->npgs = (u32)npgs;
> > umem->pgs = NULL;
> > umem->user = NULL;
> > @@ -374,16 +246,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
> > if (err)
> > goto out_account;
> >
> > - umem->pool = xp_create(umem, chunks, chunk_size, headroom, size,
> > - unaligned_chunks);
> > - if (!umem->pool) {
> > - err = -ENOMEM;
> > - goto out_pin;
> > - }
> > return 0;
> >
> > -out_pin:
> > - xdp_umem_unpin_pages(umem);
> > out_account:
> > xdp_umem_unaccount_pages(umem);
> > return err;
> > diff --git a/net/xdp/xdp_umem.h b/net/xdp/xdp_umem.h
> > index 32067fe..93e96be 100644
> > --- a/net/xdp/xdp_umem.h
> > +++ b/net/xdp/xdp_umem.h
> > @@ -8,8 +8,8 @@
> >
> > #include <net/xdp_sock_drv.h>
> >
> > -int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
> > - u16 queue_id, u16 flags);
> > +void xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
> > + u16 queue_id);
> > void xdp_umem_clear_dev(struct xdp_umem *umem);
> > bool xdp_umem_validate_queues(struct xdp_umem *umem);
> > void xdp_get_umem(struct xdp_umem *umem);
> > diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> > index 7551f5b..b12a832 100644
> > --- a/net/xdp/xsk.c
> > +++ b/net/xdp/xsk.c
> > @@ -105,6 +105,46 @@ bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
> > }
> > EXPORT_SYMBOL(xsk_uses_need_wakeup);
> >
> > +struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
> > + u16 queue_id)
> > +{
> > + if (queue_id < dev->real_num_rx_queues)
> > + return dev->_rx[queue_id].pool;
> > + if (queue_id < dev->real_num_tx_queues)
> > + return dev->_tx[queue_id].pool;
> > +
> > + return NULL;
> > +}
> > +EXPORT_SYMBOL(xsk_get_pool_from_qid);
> > +
> > +void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id)
> > +{
> > + if (queue_id < dev->real_num_rx_queues)
> > + dev->_rx[queue_id].pool = NULL;
> > + if (queue_id < dev->real_num_tx_queues)
> > + dev->_tx[queue_id].pool = NULL;
> > +}
> > +
> > +/* The buffer pool is stored both in the _rx struct and the _tx struct as we do
> > + * not know if the device has more tx queues than rx, or the opposite.
> > + * This might also change during run time.
> > + */
> > +int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
> > + u16 queue_id)
> > +{
> > + if (queue_id >= max_t(unsigned int,
> > + dev->real_num_rx_queues,
> > + dev->real_num_tx_queues))
> > + return -EINVAL;
> > +
> > + if (queue_id < dev->real_num_rx_queues)
> > + dev->_rx[queue_id].pool = pool;
> > + if (queue_id < dev->real_num_tx_queues)
> > + dev->_tx[queue_id].pool = pool;
> > +
> > + return 0;
> > +}
> > +
> > void xp_release(struct xdp_buff_xsk *xskb)
> > {
> > xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
> > @@ -281,7 +321,7 @@ bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
> >
> > rcu_read_lock();
> > list_for_each_entry_rcu(xs, &umem->xsk_tx_list, list) {
> > - if (!xskq_cons_peek_desc(xs->tx, desc, umem))
> > + if (!xskq_cons_peek_desc(xs->tx, desc, pool))
> > continue;
> >
> > /* This is the backpressure mechanism for the Tx path.
> > @@ -347,7 +387,7 @@ static int xsk_generic_xmit(struct sock *sk)
> > if (xs->queue_id >= xs->dev->real_num_tx_queues)
> > goto out;
> >
> > - while (xskq_cons_peek_desc(xs->tx, &desc, xs->umem)) {
> > + while (xskq_cons_peek_desc(xs->tx, &desc, xs->pool)) {
> > char *buffer;
> > u64 addr;
> > u32 len;
> > @@ -629,6 +669,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > qid = sxdp->sxdp_queue_id;
> >
> > if (flags & XDP_SHARED_UMEM) {
> > + struct xsk_buff_pool *curr_pool;
> > struct xdp_sock *umem_xs;
> > struct socket *sock;
> >
> > @@ -663,6 +704,11 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > goto out_unlock;
> > }
> >
> > + /* Share the buffer pool with the other socket. */
> > + xp_get_pool(umem_xs->pool);
> > + curr_pool = xs->pool;
> > + xs->pool = umem_xs->pool;
> > + xp_destroy(curr_pool);
> > xdp_get_umem(umem_xs->umem);
> > WRITE_ONCE(xs->umem, umem_xs->umem);
> > sockfd_put(sock);
> > @@ -670,10 +716,24 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > err = -EINVAL;
> > goto out_unlock;
> > } else {
> > + struct xsk_buff_pool *new_pool;
> > +
> > /* This xsk has its own umem. */
> > - err = xdp_umem_assign_dev(xs->umem, dev, qid, flags);
> > - if (err)
> > + xdp_umem_assign_dev(xs->umem, dev, qid);
> > + new_pool = xp_assign_umem(xs->pool, xs->umem);
>
> It looks like the old pool (xs->pool) is never freed.
This will go away in the new design.
Thanks: Magnus
> > + if (!new_pool) {
> > + err = -ENOMEM;
> > + xdp_umem_clear_dev(xs->umem);
> > + goto out_unlock;
> > + }
> > +
> > + err = xp_assign_dev(new_pool, xs, dev, qid, flags);
> > + if (err) {
> > + xp_destroy(new_pool);
> > + xdp_umem_clear_dev(xs->umem);
> > goto out_unlock;
> > + }
> > + xs->pool = new_pool;
> > }
> >
> > xs->dev = dev;
> > @@ -765,8 +825,6 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
> > return PTR_ERR(umem);
> > }
> >
> > - xs->pool = umem->pool;
> > -
> > /* Make sure umem is ready before it can be seen by others */
> > smp_wmb();
> > WRITE_ONCE(xs->umem, umem);
> > @@ -796,7 +854,7 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname,
> > &xs->umem->cq;
> > err = xsk_init_queue(entries, q, true);
> > if (optname == XDP_UMEM_FILL_RING)
> > - xp_set_fq(xs->umem->pool, *q);
> > + xp_set_fq(xs->pool, *q);
> > mutex_unlock(&xs->mutex);
> > return err;
> > }
> > @@ -1002,7 +1060,8 @@ static int xsk_notifier(struct notifier_block *this,
> >
> > xsk_unbind_dev(xs);
> >
> > - /* Clear device references in umem. */
> > + /* Clear device references. */
> > + xp_clear_dev(xs->pool);
> > xdp_umem_clear_dev(xs->umem);
> > }
> > mutex_unlock(&xs->mutex);
> > @@ -1047,7 +1106,7 @@ static void xsk_destruct(struct sock *sk)
> > if (!sock_flag(sk, SOCK_DEAD))
> > return;
> >
> > - xdp_put_umem(xs->umem);
> > + xp_put_pool(xs->pool);
> >
> > sk_refcnt_debug_dec(sk);
> > }
> > @@ -1055,8 +1114,8 @@ static void xsk_destruct(struct sock *sk)
> > static int xsk_create(struct net *net, struct socket *sock, int protocol,
> > int kern)
> > {
> > - struct sock *sk;
> > struct xdp_sock *xs;
> > + struct sock *sk;
> >
> > if (!ns_capable(net->user_ns, CAP_NET_RAW))
> > return -EPERM;
> > @@ -1092,6 +1151,10 @@ static int xsk_create(struct net *net, struct socket *sock, int protocol,
> > INIT_LIST_HEAD(&xs->map_list);
> > spin_lock_init(&xs->map_list_lock);
> >
> > + xs->pool = xp_create();
> > + if (!xs->pool)
> > + return -ENOMEM;
> > +
> > mutex_lock(&net->xdp.lock);
> > sk_add_node_rcu(sk, &net->xdp.list);
> > mutex_unlock(&net->xdp.lock);
> > diff --git a/net/xdp/xsk.h b/net/xdp/xsk.h
> > index 455ddd4..a00e3e2 100644
> > --- a/net/xdp/xsk.h
> > +++ b/net/xdp/xsk.h
> > @@ -51,5 +51,8 @@ void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
> > struct xdp_sock **map_entry);
> > int xsk_map_inc(struct xsk_map *map);
> > void xsk_map_put(struct xsk_map *map);
> > +void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id);
> > +int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
> > + u16 queue_id);
> >
> > #endif /* XSK_H_ */
> > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> > index c57f0bb..da93b36 100644
> > --- a/net/xdp/xsk_buff_pool.c
> > +++ b/net/xdp/xsk_buff_pool.c
> > @@ -2,11 +2,14 @@
> >
> > #include <net/xsk_buff_pool.h>
> > #include <net/xdp_sock.h>
> > +#include <net/xdp_sock_drv.h>
> > #include <linux/dma-direct.h>
> > #include <linux/dma-noncoherent.h>
> > #include <linux/swiotlb.h>
> >
> > #include "xsk_queue.h"
> > +#include "xdp_umem.h"
> > +#include "xsk.h"
> >
> > static void xp_addr_unmap(struct xsk_buff_pool *pool)
> > {
> > @@ -32,39 +35,48 @@ void xp_destroy(struct xsk_buff_pool *pool)
> > kvfree(pool);
> > }
> >
> > -struct xsk_buff_pool *xp_create(struct xdp_umem *umem, u32 chunks,
> > - u32 chunk_size, u32 headroom, u64 size,
> > - bool unaligned)
> > +struct xsk_buff_pool *xp_create(void)
> > +{
> > + return kvzalloc(sizeof(struct xsk_buff_pool), GFP_KERNEL);
> > +}
> > +
> > +struct xsk_buff_pool *xp_assign_umem(struct xsk_buff_pool *pool_old,
> > + struct xdp_umem *umem)
> > {
> > struct xsk_buff_pool *pool;
> > struct xdp_buff_xsk *xskb;
> > int err;
> > u32 i;
> >
> > - pool = kvzalloc(struct_size(pool, free_heads, chunks), GFP_KERNEL);
> > + pool = kvzalloc(struct_size(pool, free_heads, umem->chunks),
> > + GFP_KERNEL);
> > if (!pool)
> > goto out;
> >
> > - pool->heads = kvcalloc(chunks, sizeof(*pool->heads), GFP_KERNEL);
> > + memcpy(pool, pool_old, sizeof(*pool_old));
> > +
> > + pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
> > if (!pool->heads)
> > goto out;
> >
> > - pool->chunk_mask = ~((u64)chunk_size - 1);
> > - pool->addrs_cnt = size;
> > - pool->heads_cnt = chunks;
> > - pool->free_heads_cnt = chunks;
> > - pool->headroom = headroom;
> > - pool->chunk_size = chunk_size;
> > + pool->chunk_mask = ~((u64)umem->chunk_size - 1);
> > + pool->addrs_cnt = umem->size;
> > + pool->heads_cnt = umem->chunks;
> > + pool->free_heads_cnt = umem->chunks;
> > + pool->headroom = umem->headroom;
> > + pool->chunk_size = umem->chunk_size;
> > pool->cheap_dma = true;
> > - pool->unaligned = unaligned;
> > - pool->frame_len = chunk_size - headroom - XDP_PACKET_HEADROOM;
> > + pool->unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
> > + pool->frame_len = umem->chunk_size - umem->headroom -
> > + XDP_PACKET_HEADROOM;
> > pool->umem = umem;
> > INIT_LIST_HEAD(&pool->free_list);
> > + refcount_set(&pool->users, 1);
> >
> > for (i = 0; i < pool->free_heads_cnt; i++) {
> > xskb = &pool->heads[i];
> > xskb->pool = pool;
> > - xskb->xdp.frame_sz = chunk_size - headroom;
> > + xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
> > pool->free_heads[i] = xskb;
> > }
> >
> > @@ -91,6 +103,120 @@ void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
> > }
> > EXPORT_SYMBOL(xp_set_rxq_info);
> >
> > +int xp_assign_dev(struct xsk_buff_pool *pool, struct xdp_sock *xs,
> > + struct net_device *dev, u16 queue_id, u16 flags)
> > +{
> > + struct xdp_umem *umem = pool->umem;
> > + bool force_zc, force_copy;
> > + struct netdev_bpf bpf;
> > + int err = 0;
> > +
> > + ASSERT_RTNL();
> > +
> > + force_zc = flags & XDP_ZEROCOPY;
> > + force_copy = flags & XDP_COPY;
> > +
> > + if (force_zc && force_copy)
> > + return -EINVAL;
> > +
> > + if (xsk_get_pool_from_qid(dev, queue_id))
> > + return -EBUSY;
> > +
> > + err = xsk_reg_pool_at_qid(dev, pool, queue_id);
> > + if (err)
> > + return err;
> > +
> > + if ((flags & XDP_USE_NEED_WAKEUP) && xs->tx) {
> > + umem->flags |= XDP_UMEM_USES_NEED_WAKEUP;
> > + /* Tx needs to be explicitly woken up the first time.
> > + * Also for supporting drivers that do not implement this
> > + * feature. They will always have to call sendto().
> > + */
> > + xs->tx->ring->flags |= XDP_RING_NEED_WAKEUP;
> > + }
> > +
> > + if (force_copy)
> > + /* For copy-mode, we are done. */
> > + return 0;
> > +
> > + if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_wakeup) {
> > + err = -EOPNOTSUPP;
> > + goto err_unreg_pool;
> > + }
> > +
> > + bpf.command = XDP_SETUP_XSK_POOL;
> > + bpf.xsk.pool = pool;
> > + bpf.xsk.queue_id = queue_id;
> > +
> > + err = dev->netdev_ops->ndo_bpf(dev, &bpf);
> > + if (err)
> > + goto err_unreg_pool;
> > +
> > + umem->zc = true;
> > + return 0;
> > +
> > +err_unreg_pool:
> > + if (!force_zc)
> > + err = 0; /* fallback to copy mode */
> > + if (err)
> > + xsk_clear_pool_at_qid(dev, queue_id);
> > + return err;
> > +}
> > +
> > +void xp_clear_dev(struct xsk_buff_pool *pool)
> > +{
> > + struct xdp_umem *umem = pool->umem;
> > + struct netdev_bpf bpf;
> > + int err;
> > +
> > + ASSERT_RTNL();
> > +
> > + if (!umem->dev)
> > + return;
> > +
> > + if (umem->zc) {
> > + bpf.command = XDP_SETUP_XSK_POOL;
> > + bpf.xsk.pool = NULL;
> > + bpf.xsk.queue_id = umem->queue_id;
> > +
> > + err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
> > +
> > + if (err)
> > + WARN(1, "failed to disable umem!\n");
> > + }
> > +
> > + xsk_clear_pool_at_qid(umem->dev, umem->queue_id);
> > +}
> > +
> > +static void xp_release_deferred(struct work_struct *work)
> > +{
> > + struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
> > + work);
> > +
> > + rtnl_lock();
> > + xp_clear_dev(pool);
> > + rtnl_unlock();
> > +
> > + xdp_put_umem(pool->umem);
> > + xp_destroy(pool);
> > +}
> > +
> > +void xp_get_pool(struct xsk_buff_pool *pool)
> > +{
> > + refcount_inc(&pool->users);
> > +}
> > +
> > +void xp_put_pool(struct xsk_buff_pool *pool)
> > +{
> > + if (!pool)
> > + return;
> > +
> > + if (refcount_dec_and_test(&pool->users)) {
> > + INIT_WORK(&pool->work, xp_release_deferred);
> > + schedule_work(&pool->work);
> > + }
> > +}
> > +
> > void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
> > {
> > dma_addr_t *dma;
> > diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
> > index 5b5d24d..75f1853 100644
> > --- a/net/xdp/xsk_queue.h
> > +++ b/net/xdp/xsk_queue.h
> > @@ -165,9 +165,9 @@ static inline bool xp_validate_desc(struct xsk_buff_pool *pool,
> >
> > static inline bool xskq_cons_is_valid_desc(struct xsk_queue *q,
> > struct xdp_desc *d,
> > - struct xdp_umem *umem)
> > + struct xsk_buff_pool *pool)
> > {
> > - if (!xp_validate_desc(umem->pool, d)) {
> > + if (!xp_validate_desc(pool, d)) {
> > q->invalid_descs++;
> > return false;
> > }
> > @@ -176,14 +176,14 @@ static inline bool xskq_cons_is_valid_desc(struct xsk_queue *q,
> >
> > static inline bool xskq_cons_read_desc(struct xsk_queue *q,
> > struct xdp_desc *desc,
> > - struct xdp_umem *umem)
> > + struct xsk_buff_pool *pool)
> > {
> > while (q->cached_cons != q->cached_prod) {
> > struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
> > u32 idx = q->cached_cons & q->ring_mask;
> >
> > *desc = ring->desc[idx];
> > - if (xskq_cons_is_valid_desc(q, desc, umem))
> > + if (xskq_cons_is_valid_desc(q, desc, pool))
> > return true;
> >
> > q->cached_cons++;
> > @@ -235,11 +235,11 @@ static inline bool xskq_cons_peek_addr_unchecked(struct xsk_queue *q, u64 *addr)
> >
> > static inline bool xskq_cons_peek_desc(struct xsk_queue *q,
> > struct xdp_desc *desc,
> > - struct xdp_umem *umem)
> > + struct xsk_buff_pool *pool)
> > {
> > if (q->cached_prod == q->cached_cons)
> > xskq_cons_get_entries(q);
> > - return xskq_cons_read_desc(q, desc, umem);
> > + return xskq_cons_read_desc(q, desc, pool);
> > }
> >
> > static inline void xskq_cons_release(struct xsk_queue *q)
> >
>
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