From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D4151EC005; Tue, 3 Sep 2024 21:19:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725398392; cv=none; b=IT5zv+fHxwNOMA7OG2wh0OI7JZT69GJGsGzh9zm435XMpIXLZSBOq4deXouSghosCRTKQM4mZZJ9+PWkBmx38OpvN1pXoczBq4gaSHNy5HIG2PS7D5lGqKZSTZ1S5eRrtFuWS+dc4Iz9bEXRMo0loQ+mZDAFDKmZXUcvxJ37kt8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725398392; c=relaxed/simple; bh=3xUDvUxu+fBoSxRhosQcCb3KMN9DYF5vVl9RMgG5t/U=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=D8b377BfOl9+rXGLmEUE6jYK3V4Wg9buPkAfl3UjCH0O09LNlUN1WUauJywy+d2EDbMesKLDJJzycIf6Te0jex8n0dYrLsjo3UbSWg2gNZ77Faj2ociNmMtF46hy4r01fPkEgTXB8lrraD7kDQbG/F2xh28t4F2ZKEDg7LaSjYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SLHdWKFK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SLHdWKFK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4E98C4CEC4; Tue, 3 Sep 2024 21:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725398392; bh=3xUDvUxu+fBoSxRhosQcCb3KMN9DYF5vVl9RMgG5t/U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=SLHdWKFKnN33srU90NZWM34zNUiyvQJlC9s0PCH4X0yJNg+V1GzZ8kErkloQvWmMk Rt0nxKIjpzeFg+lQlR+EoJlYpiupKyhq08r1qj0X+VJ7OID+wMpQSebpgEKaOUG+EZ 02ahgJ4iTdQn5gBAl6IDoGCp50K9nOpTIX7SeMxKNOQHAL9XfJW6886BBt08oexX0c dVjdSTw1+ElQNSjSj13jWDXlRXdrTvVENk1A3+SXNUO6xjbdvt6TywYipI1MWMicXt uhvCBhX3kD79ci5RPR7NY9V4+t4qRZLD4wYCKzMhFLuADTklRMBcHeIGf6fa2f7rNk +/Zkg1NOL6DPg== Date: Tue, 3 Sep 2024 14:19:48 -0700 From: Jakub Kicinski To: Mina Almasry Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arch@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, Donald Hunter , "David S. Miller" , Eric Dumazet , Paolo Abeni , Jonathan Corbet , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Andreas Larsson , Jesper Dangaard Brouer , Ilias Apalodimas , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Arnd Bergmann , Steffen Klassert , Herbert Xu , David Ahern , Willem de Bruijn , "=?UTF-8?B?QmrDtnJuIFTDtnBl?= =?UTF-8?B?bA==?=" , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , Shuah Khan , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Sumit Semwal , "Christian =?UTF-8?B?S8O2bmln?=" , Pavel Begunkov , David Wei , Jason Gunthorpe , Yunsheng Lin , Shailend Chand , Harshitha Ramamurthy , Shakeel Butt , Jeroen de Borst , Praveen Kaligineedi , Bagas Sanjaya , Christoph Hellwig , Nikolay Aleksandrov , Taehee Yoo , Willem de Bruijn , Kaiyuan Zhang Subject: Re: [PATCH net-next v24 06/13] memory-provider: dmabuf devmem memory provider Message-ID: <20240903141948.269e22bb@kernel.org> In-Reply-To: <20240831004313.3713467-7-almasrymina@google.com> References: <20240831004313.3713467-1-almasrymina@google.com> <20240831004313.3713467-7-almasrymina@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 31 Aug 2024 00:43:06 +0000 Mina Almasry wrote: > diff --git a/include/net/mp_dmabuf_devmem.h b/include/net/mp_dmabuf_devmem.h > new file mode 100644 > index 000000000000..6d1cf2a77f6b > --- /dev/null > +++ b/include/net/mp_dmabuf_devmem.h this header can live under net/core/ like netmem_priv.h right? devmem internals should be of no interest outside of core networking. In fact the same is true for include/net/devmem.h ? Sorry for pushing back on all the header exports, we have had bad experiences with people treating anything under include/ as public API for any subsystem to use.. > @@ -0,0 +1,44 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Dmabuf device memory provider. > + * > + * Authors: Mina Almasry > + * > + */ > +#ifndef _NET_MP_DMABUF_DEVMEM_H > +#define _NET_MP_DMABUF_DEVMEM_H > + > +#include > + > +#if defined(CONFIG_NET_DEVMEM) > +int mp_dmabuf_devmem_init(struct page_pool *pool); > + > +netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, gfp_t gfp); > + > +void mp_dmabuf_devmem_destroy(struct page_pool *pool); > + > +bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem); > +#else > +static inline int mp_dmabuf_devmem_init(struct page_pool *pool) > +{ > + return -EOPNOTSUPP; > +} > + > +static inline netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, > + gfp_t gfp) Please break the lines after the return type if the line gets long: static inline netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, gfp_t gfp) Please fix where you can (at least where it cases going over 80 chars) > +{ > + return 0; > +} > + > +static inline void mp_dmabuf_devmem_destroy(struct page_pool *pool) > +{ > +} > + > +static inline bool mp_dmabuf_devmem_release_page(struct page_pool *pool, > + netmem_ref netmem) > +{ > + return false; > +} > +#endif > + > +#endif /* _NET_MP_DMABUF_DEVMEM_H */ > diff --git a/include/net/netmem.h b/include/net/netmem.h > index ac6c7945117b..61400d4b0d66 100644 > --- a/include/net/netmem.h > +++ b/include/net/netmem.h > @@ -8,6 +8,7 @@ > #ifndef _NET_NETMEM_H > #define _NET_NETMEM_H > > +#include > #include > #include > > diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h > index 4afd6dd56351..1b4698710f25 100644 > --- a/include/net/page_pool/types.h > +++ b/include/net/page_pool/types.h > @@ -20,8 +20,17 @@ > * device driver responsibility > */ > #define PP_FLAG_SYSTEM_POOL BIT(2) /* Global system page_pool */ > +#define PP_FLAG_ALLOW_UNREADABLE_NETMEM BIT(3) /* Allow unreadable (net_iov > + * backed) netmem in this > + * page_pool. Drivers setting > + * this must be able to support > + * unreadable netmem, where > + * netmem_address() would return > + * NULL. This flag should not be > + * set for header page_pools. > + */ Maybe move the comment before the define: /* Allow unreadable (net_iov backed) netmem in this page_pool. Drivers setting * this must be able to support unreadable netmem, where netmem_address() would * return NULL. This flag should not be set for header page_pools. */ #define PP_FLAG_ALLOW_UNREADABLE_NETMEM BIT(3) ? up to you. > #define PP_FLAG_ALL (PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV | \ > - PP_FLAG_SYSTEM_POOL) > + PP_FLAG_SYSTEM_POOL | PP_FLAG_ALLOW_UNREADABLE_NETMEM) > > /* > * Fast allocation side cache array/stack > @@ -57,7 +66,9 @@ struct pp_alloc_cache { > * @offset: DMA sync address offset for PP_FLAG_DMA_SYNC_DEV > * @slow: params with slowpath access only (initialization and Netlink) > * @netdev: netdev this pool will serve (leave as NULL if none or multiple) > - * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL > + * @queue: struct netdev_rx_queue this page_pool is being created for. > + * @flags: PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL, > + * PP_FLAG_ALLOW_UNREADABLE_NETMEM. > */ > struct page_pool_params { > struct_group_tagged(page_pool_params_fast, fast, > @@ -72,6 +83,7 @@ struct page_pool_params { > ); > struct_group_tagged(page_pool_params_slow, slow, > struct net_device *netdev; > + struct netdev_rx_queue *queue; Why set a pointer? It should work but drivers don't usually deal with netdev_rx_queue struct directly. struct xdp_rxq_info takes an integer queue id, and it serves a somewhat similar function. Keep in mind that there will be more drivers than core code, so convenience for them matters more. > unsigned int flags; > /* private: used by test code only */ > void (*init_callback)(netmem_ref netmem, void *arg); > diff --git a/net/core/devmem.c b/net/core/devmem.c > index 727e5ee39f30..c8c112360caa 100644 > --- a/net/core/devmem.c > +++ b/net/core/devmem.c > @@ -13,6 +13,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -320,3 +321,68 @@ void dev_dmabuf_uninstall(struct net_device *dev) > } > } > } > + > +/*** "Dmabuf devmem memory provider" ***/ > + > +int mp_dmabuf_devmem_init(struct page_pool *pool) > +{ > + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; > + > + if (!binding) > + return -EINVAL; > + > + if (!pool->dma_map) > + return -EOPNOTSUPP; > + > + if (pool->dma_sync) > + return -EOPNOTSUPP; > + > + if (pool->p.order != 0) > + return -E2BIG; > + > + net_devmem_dmabuf_binding_get(binding); > + return 0; > +} > + > +netmem_ref mp_dmabuf_devmem_alloc_netmems(struct page_pool *pool, gfp_t gfp) > +{ > + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; > + netmem_ref netmem; > + struct net_iov *niov; nit: reverse xmas tree > + niov = net_devmem_alloc_dmabuf(binding); > + if (!niov) > + return 0; > + > + netmem = net_iov_to_netmem(niov); > + > + page_pool_set_pp_info(pool, netmem); > + > + pool->pages_state_hold_cnt++; > + trace_page_pool_state_hold(pool, netmem, pool->pages_state_hold_cnt); > + return netmem; > +} > + > +void mp_dmabuf_devmem_destroy(struct page_pool *pool) > +{ > + struct net_devmem_dmabuf_binding *binding = pool->mp_priv; > + > + net_devmem_dmabuf_binding_put(binding); > +} > + > +bool mp_dmabuf_devmem_release_page(struct page_pool *pool, netmem_ref netmem) > +{ > + if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) > + return false; > + > + if (WARN_ON_ONCE(atomic_long_read(netmem_get_pp_ref_count_ref(netmem)) != > + 1)) something needs factoring out here, to make this line shorter, please.. either netmem -> net_iov conversion or at least reading of the ref count? > + return false; > + > + page_pool_clear_pp_info(netmem); > + > + net_devmem_free_dmabuf(netmem_to_net_iov(netmem)); > + > + /* We don't want the page pool put_page()ing our net_iovs. */ > + return false; > +} > diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c > index da11720a5983..e217a5838c87 100644 > --- a/net/core/netdev_rx_queue.c > +++ b/net/core/netdev_rx_queue.c > @@ -4,8 +4,11 @@ > #include > #include > > +#include "page_pool_priv.h" > + > int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) > { > + struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx); > void *new_mem, *old_mem; > int err; > > @@ -31,6 +34,10 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx) > if (err) > goto err_free_old_mem; > > + err = page_pool_check_memory_provider(dev, rxq); > + if (err) > + goto err_free_new_queue_mem; > + > err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx); > if (err) > goto err_free_new_queue_mem; > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > index 52659db2d765..6e24950f2be4 100644 > --- a/net/core/page_pool.c > +++ b/net/core/page_pool.c > @@ -11,6 +11,8 @@ > #include > #include > > +#include > +#include > #include > #include > > @@ -190,6 +192,7 @@ static int page_pool_init(struct page_pool *pool, > int cpuid) > { > unsigned int ring_qsize = 1024; /* Default */ > + int err; > > page_pool_struct_check(); > > @@ -271,7 +274,36 @@ static int page_pool_init(struct page_pool *pool, > if (pool->dma_map) > get_device(pool->p.dev); > > + if (pool->slow.queue && > + pool->slow.flags & PP_FLAG_ALLOW_UNREADABLE_NETMEM) { > + /* We rely on rtnl_lock()ing to make sure netdev_rx_queue > + * configuration doesn't change while we're initializing the nit: 'the' to next line > + * page_pool. > + */ > + ASSERT_RTNL(); > + pool->mp_priv = pool->slow.queue->mp_params.mp_priv; > + }