From patchwork Sun Dec 17 08:09:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 13495809 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 906EF6D19 for ; Sun, 17 Dec 2023 08:09:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="18StM74x" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-5d064f9e2a1so19780447b3.1 for ; Sun, 17 Dec 2023 00:09:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1702800564; x=1703405364; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=QMKZfo7MQTdL4MON6ILyvITz6v7ECb8JCcQoDm+y1oY=; b=18StM74xDhwud0tInlqDNyUZWnx4NYG6hfMYbYEBqjguAvrdoX4aDCVjiBHq1K0wde VtZAiLUJGw2eg5Q77ipohAPJ22T7Dk5LZsHdhB0K7rlIti1/yHOYtcGqIGjV7+2bXvn3 kdK5bIUdpdWGcdlgdMOwkUBu24aLoZl6e8YTPcD4E6P7O699b493lp8H0HC8Ybt5OvjX 4QDvBezVhjDKw7lHNE6luDlFUx/GoqfCCk4f0A+lX7aPV8ERCDQUwsJpbUsJ42t8QXqg ZDL14opL+JIPzIsGQrre/Tr6J4e0w2VoVA3pIRUnbLpqphhgwNDUss97TgC8+gAYgYQF ZNrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702800564; x=1703405364; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=QMKZfo7MQTdL4MON6ILyvITz6v7ECb8JCcQoDm+y1oY=; b=aA86s4vG4HXpGanIRC3eo2JBOKSzeUuLCjlkWhtqAxSpBzljFSC9CG12r6CWDyIF98 0gAgee6R3jYrcgWP7DnZWUhFhB1dq6LmXjfSQiT1Os5kqHp0n+UQ0jMrm20Mw0GMEHrQ 28HON/0TZ2pYZipfcYQmgI1/wcyUz6IYyQFE0jkBsu9oklUXZOnlS+eNO0CVrJsHq449 JI5jryxjQS6N0idn+MKdLr5LQtMriJT/04xe9BVMdAv51XDwfs1KfsxKJuohT+DIH/I5 0DoiB+aKhEiQ5WJoD63cPwVg/50C85aBKSgUxXg49LdC/C6q6pRLfcB28+f5ZQGOUmd2 zWGg== X-Gm-Message-State: AOJu0Yx8gO738KboFDPVJBo7DcVr/SZfEumRxS+oHTd7lJSfOWb8+gvQ vBJzkxxyoOYMIIvPXtZaM2fDApjcaef9ONJ/4g== X-Google-Smtp-Source: AGHT+IFJCnycDJwsU67lKu1qB4q73cruRdEMF2MdI6NqbIK/eO/tqFob5FbZApzAiGPawGrZ+fw8MgSBnnOaG1MLLw== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2c4:200:3eb4:e132:f78a:5ba9]) (user=almasrymina job=sendgmr) by 2002:a05:690c:c02:b0:5e6:2989:a661 with SMTP id cl2-20020a05690c0c0200b005e62989a661mr94697ywb.10.1702800564661; Sun, 17 Dec 2023 00:09:24 -0800 (PST) Date: Sun, 17 Dec 2023 00:09:11 -0800 In-Reply-To: <20231217080913.2025973-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231217080913.2025973-1-almasrymina@google.com> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog Message-ID: <20231217080913.2025973-4-almasrymina@google.com> Subject: [PATCH net-next v2 3/3] net: add netmem_t to skb_frag_t From: Mina Almasry To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux.dev Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Stefan Hajnoczi , Stefano Garzarella , Jason Gunthorpe , " =?utf-8?q?Christian_K=C3=B6nig?= " , Shakeel Butt , Yunsheng Lin , Willem de Bruijn Use netmem_t instead of page directly in skb_frag_t. Currently netmem_t is always a struct page underneath, but the abstraction allows efforts to add support for skb frags not backed by pages. There is unfortunately 1 instance where the skb_frag_t is assumed to be a bio_vec in kcm. For this case, add a debug assert that the skb frag is indeed backed by a page, and do a cast. Add skb[_frag]_fill_netmem_*() and skb_add_rx_frag_netmem() helpers so that the API can be used to create netmem skbs. Signed-off-by: Mina Almasry --- v2: - Add skb frag filling helpers. --- include/linux/skbuff.h | 70 ++++++++++++++++++++++++++++++++---------- net/core/skbuff.c | 22 +++++++++---- net/kcm/kcmsock.c | 10 ++++-- 3 files changed, 78 insertions(+), 24 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 7ce38874dbd1..03ab13072962 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -37,6 +37,7 @@ #endif #include #include +#include /** * DOC: skb checksums @@ -359,7 +360,11 @@ extern int sysctl_max_skb_frags; */ #define GSO_BY_FRAGS 0xFFFF -typedef struct bio_vec skb_frag_t; +typedef struct skb_frag { + struct netmem *bv_page; + unsigned int bv_len; + unsigned int bv_offset; +} skb_frag_t; /** * skb_frag_size() - Returns the size of a skb fragment @@ -2431,22 +2436,37 @@ static inline unsigned int skb_pagelen(const struct sk_buff *skb) return skb_headlen(skb) + __skb_pagelen(skb); } +static inline void skb_frag_fill_netmem_desc(skb_frag_t *frag, + struct netmem *netmem, int off, + int size) +{ + frag->bv_page = netmem; + frag->bv_offset = off; + skb_frag_size_set(frag, size); +} + static inline void skb_frag_fill_page_desc(skb_frag_t *frag, struct page *page, int off, int size) { - frag->bv_page = page; - frag->bv_offset = off; - skb_frag_size_set(frag, size); + skb_frag_fill_netmem_desc(frag, page_to_netmem(page), off, size); +} + +static inline void __skb_fill_netmem_desc_noacc(struct skb_shared_info *shinfo, + int i, struct netmem *netmem, + int off, int size) +{ + skb_frag_t *frag = &shinfo->frags[i]; + + skb_frag_fill_netmem_desc(frag, netmem, off, size); } static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo, int i, struct page *page, int off, int size) { - skb_frag_t *frag = &shinfo->frags[i]; - - skb_frag_fill_page_desc(frag, page, off, size); + __skb_fill_netmem_desc_noacc(shinfo, i, page_to_netmem(page), off, + size); } /** @@ -2462,10 +2482,10 @@ static inline void skb_len_add(struct sk_buff *skb, int delta) } /** - * __skb_fill_page_desc - initialise a paged fragment in an skb + * __skb_fill_netmem_desc - initialise a paged fragment in an skb * @skb: buffer containing fragment to be initialised * @i: paged fragment index to initialise - * @page: the page to use for this fragment + * @netmem: the netmem to use for this fragment * @off: the offset to the data with @page * @size: the length of the data * @@ -2474,10 +2494,13 @@ static inline void skb_len_add(struct sk_buff *skb, int delta) * * Does not take any additional reference on the fragment. */ -static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, - struct page *page, int off, int size) +static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i, + struct netmem *netmem, int off, + int size) { - __skb_fill_page_desc_noacc(skb_shinfo(skb), i, page, off, size); + struct page *page = netmem_to_page(netmem); + + __skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size); /* Propagate page pfmemalloc to the skb if we can. The problem is * that not all callers have unique ownership of the page but rely @@ -2485,7 +2508,21 @@ static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, */ page = compound_head(page); if (page_is_pfmemalloc(page)) - skb->pfmemalloc = true; + skb->pfmemalloc = true; +} + +static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, + struct page *page, int off, int size) +{ + __skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); +} + +static inline void skb_fill_netmem_desc(struct sk_buff *skb, int i, + struct netmem *netmem, int off, + int size) +{ + __skb_fill_netmem_desc(skb, i, netmem, off, size); + skb_shinfo(skb)->nr_frags = i + 1; } /** @@ -2505,8 +2542,7 @@ static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, static inline void skb_fill_page_desc(struct sk_buff *skb, int i, struct page *page, int off, int size) { - __skb_fill_page_desc(skb, i, page, off, size); - skb_shinfo(skb)->nr_frags = i + 1; + skb_fill_netmem_desc(skb, i, page_to_netmem(page), off, size); } /** @@ -2532,6 +2568,8 @@ static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i, void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, int size, unsigned int truesize); +void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, struct netmem *netmem, + int off, int size, unsigned int truesize); void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, unsigned int truesize); @@ -3422,7 +3460,7 @@ static inline void skb_frag_off_copy(skb_frag_t *fragto, */ static inline struct page *skb_frag_page(const skb_frag_t *frag) { - return frag->bv_page; + return netmem_to_page(frag->bv_page); } /** diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 83af8aaeb893..053d220aa2f2 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -845,16 +845,24 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, } EXPORT_SYMBOL(__napi_alloc_skb); -void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, - int size, unsigned int truesize) +void skb_add_rx_frag_netmem(struct sk_buff *skb, int i, struct netmem *netmem, + int off, int size, unsigned int truesize) { DEBUG_NET_WARN_ON_ONCE(size > truesize); - skb_fill_page_desc(skb, i, page, off, size); + skb_fill_netmem_desc(skb, i, netmem, off, size); skb->len += size; skb->data_len += size; skb->truesize += truesize; } +EXPORT_SYMBOL(skb_add_rx_frag_netmem); + +void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, + int size, unsigned int truesize) +{ + skb_add_rx_frag_netmem(skb, i, page_to_netmem(page), off, size, + truesize); +} EXPORT_SYMBOL(skb_add_rx_frag); void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, @@ -1868,10 +1876,11 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) /* skb frags point to kernel buffers */ for (i = 0; i < new_frags - 1; i++) { - __skb_fill_page_desc(skb, i, head, 0, psize); + __skb_fill_netmem_desc(skb, i, page_to_netmem(head), 0, psize); head = (struct page *)page_private(head); } - __skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off); + __skb_fill_netmem_desc(skb, new_frags - 1, page_to_netmem(head), 0, + d_off); skb_shinfo(skb)->nr_frags = new_frags; release: @@ -3609,7 +3618,8 @@ skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) if (plen) { page = virt_to_head_page(from->head); offset = from->data - (unsigned char *)page_address(page); - __skb_fill_page_desc(to, 0, page, offset, plen); + __skb_fill_netmem_desc(to, 0, page_to_netmem(page), + offset, plen); get_page(page); j = 1; len -= plen; diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index 65d1f6755f98..5c46db045f4c 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -636,9 +636,15 @@ static int kcm_write_msgs(struct kcm_sock *kcm) for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) msize += skb_shinfo(skb)->frags[i].bv_len; + /* The cast to struct bio_vec* here assumes the frags are + * struct page based. + */ + DEBUG_NET_WARN_ON_ONCE( + !skb_frag_page(&skb_shinfo(skb)->frags[0])); + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, - skb_shinfo(skb)->frags, skb_shinfo(skb)->nr_frags, - msize); + (const struct bio_vec *)skb_shinfo(skb)->frags, + skb_shinfo(skb)->nr_frags, msize); iov_iter_advance(&msg.msg_iter, txm->frag_offset); do {