From patchwork Wed Feb 14 22:34:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mina Almasry X-Patchwork-Id: 13557149 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 2811F145347 for ; Wed, 14 Feb 2024 22:34:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707950055; cv=none; b=AO3LM7967PRJcgS/InMzyZ73sWhyfpyjmjZr606zMQZislTn6kCEBnu81eI4xkW6l1+PjDvJKRjzzXUFPNEIiL27Qa03fz1NLwTJS0Ez5Ur7cbWJpHwuajXV72UT2TmiivLwpXnKkn2ENuy+jmdF+7ETtSA66EM7yIWuJtiwu+c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707950055; c=relaxed/simple; bh=nGUqc8rUDRH/MoSUz/6/S1Tk0Dw79H+kXKweg5WpjUo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=mnTdnT31+0V4D/+AkEwEH0FjFN+KLdCHri04nd+4v+BoWGSWWTtrr1Du6BpTxMxpPz1imP/BtPDepppwVQgkwo5qUF0GffsqsclJaqazBpnt0cmqKwCm083bVNkX94bNywSiyXSjsfU31HLCIHcDAQRopS64KrBggACf5w5Ar1k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=YDUUY4m2; arc=none smtp.client-ip=209.85.219.201 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="YDUUY4m2" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dc3645a6790so402237276.0 for ; Wed, 14 Feb 2024 14:34:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1707950052; x=1708554852; 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=yy4qSuFhfwV20o2GLV3Aj99gAN1q07zX9grReXDXi4s=; b=YDUUY4m27iBFDChAQn+IgNUK8KUuWvxUOqfK8uWBxkSeLVG34UGajWc0VKaZMu/wNL 9j9HSbMfVhiAi6b8VMSZCHp9QJzO1RlF4aTmQe5S9D0Zl0VsM6nCPVw+3VRLdmuWAzQK 6SMX3l2+MGEZnSaonHf12v2o4hNynhH/K1hOPitdHXOIpJ8o2Y0B/70PuiZfMzd/2Tso /kRswQotJiCKJsk3Jn2P9dTjwnk9xf10j6nkyCENlGagPUWPiHIDARag7kyCHzU4Ygln UNoElRVGNmxNph4pghdrdDp4VOSAY9m0/9swuk/6SgjT2ilrJ26Xw0K5WhuhaJJgq+xd UxEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707950052; x=1708554852; 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=yy4qSuFhfwV20o2GLV3Aj99gAN1q07zX9grReXDXi4s=; b=dPZrgAeeBj60ceIzmvyRCqwCO0DjHoygKgzVfJsJByB7Ki93TiKpG5nukYm9XUyCWV 33G0iFpRHCHM4HArdU+0caxfbBnR6nzuRDy8xDkJyCeQXkG7yf4nHKmKhE5xQsaO1x94 Ek/tNPdoqCwjsttcvIvmhSUiJ7hPsfLgPQkNUfL7xujaNDdZbDLwJ2be9Sy/z2dBhCpO TTAkub04yFYmvEhCRJ5elFHzN48eayxzbtULV6L1tKaWEH4mVZ3Mxu2XW+dEA/zCOi55 bsjO0XVWyY6RY7DWUPBifjH1mqViSXpgyBrwv4MMrlHjgSuPK9wyZPzYqxrLIhmdvJj6 P8Zg== X-Forwarded-Encrypted: i=1; AJvYcCWyjMAniCG0PzeNrUUiaKscjVtcfQyhxQ76xSJyuOOtTpIi8Z/FD71hLGgpl7BXnwoV545kc1+Mxf3Y7+ecZ3aZZcG99xfv X-Gm-Message-State: AOJu0Yxo8xx1n115HwNDQqSJS9z86cUiVK6lxfzYTH536iHNkRiJqSHK zIpouVYTgmvQ+TulPmwTPFdKgiJwqTRygxXp5iISfUFDBcnI+w/HjDS9IygNmFWa7cOVME71Iw+ AI+SyFbtlFenZm5R15BFB3A== X-Google-Smtp-Source: AGHT+IHQxkmsecmDK9qPlW1gUC9GIqjAYdP2lBSh+mp1x74Pn67JMQiWOXNn/53a7fjjapx4xb6RrH/RpVjBTgQEaQ== X-Received: from almasrymina.svl.corp.google.com ([2620:15c:2c4:200:e4bb:b13c:bc16:afe5]) (user=almasrymina job=sendgmr) by 2002:a05:6902:1021:b0:dc6:fa35:b42 with SMTP id x1-20020a056902102100b00dc6fa350b42mr871543ybt.2.1707950052197; Wed, 14 Feb 2024 14:34:12 -0800 (PST) Date: Wed, 14 Feb 2024 14:34:03 -0800 In-Reply-To: <20240214223405.1972973-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240214223405.1972973-1-almasrymina@google.com> X-Mailer: git-send-email 2.43.0.687.g38aa6559b0-goog Message-ID: <20240214223405.1972973-3-almasrymina@google.com> Subject: [PATCH net-next v8 2/2] net: add netmem to skb_frag_t From: Mina Almasry To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jason Gunthorpe , " =?utf-8?q?Christian_K=C3=B6nig?= " , Shakeel Butt , Yunsheng Lin , Willem de Bruijn X-Patchwork-Delegate: kuba@kernel.org Use struct netmem* instead of page in skb_frag_t. Currently struct netmem* 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 exactly a bio_vec in kcm. For this case, WARN_ON_ONCE and return error before doing 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 Acked-by: Paolo Abeni --- v8: - Move skb_rx_add_frag_netmem back to .c file, only have skb_rx_add_frag() in header file (Paolo). v7: - Move skb_rx_add_frag to header file (Paolo). - Move combine kcm skb_frag_page() check with nr_frags check. v6: - Add static_asserts to validate skb_frag_t to bio_vec cast in kcm_write_msg (Yunsheng) v4: - Handle error in kcm_write_msgs() instead of only warning (Willem) v3: - Renamed the fields in skb_frag_t. v2: - Add skb frag filling helpers. --- include/linux/skbuff.h | 100 +++++++++++++++++++++++++++++------------ net/core/skbuff.c | 34 +++++++++++--- net/kcm/kcmsock.c | 7 +-- 3 files changed, 102 insertions(+), 39 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 696e7680656f..e3a2ed5d09ad 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 { + netmem_ref netmem; + unsigned int len; + unsigned int offset; +} skb_frag_t; /** * skb_frag_size() - Returns the size of a skb fragment @@ -367,7 +372,7 @@ typedef struct bio_vec skb_frag_t; */ static inline unsigned int skb_frag_size(const skb_frag_t *frag) { - return frag->bv_len; + return frag->len; } /** @@ -377,7 +382,7 @@ static inline unsigned int skb_frag_size(const skb_frag_t *frag) */ static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) { - frag->bv_len = size; + frag->len = size; } /** @@ -387,7 +392,7 @@ static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size) */ static inline void skb_frag_size_add(skb_frag_t *frag, int delta) { - frag->bv_len += delta; + frag->len += delta; } /** @@ -397,7 +402,7 @@ static inline void skb_frag_size_add(skb_frag_t *frag, int delta) */ static inline void skb_frag_size_sub(skb_frag_t *frag, int delta) { - frag->bv_len -= delta; + frag->len -= delta; } /** @@ -417,7 +422,7 @@ static inline bool skb_frag_must_loop(struct page *p) * skb_frag_foreach_page - loop over pages in a fragment * * @f: skb frag to operate on - * @f_off: offset from start of f->bv_page + * @f_off: offset from start of f->netmem * @f_len: length from f_off to loop over * @p: (temp var) current page * @p_off: (temp var) offset from start of current page, @@ -2429,22 +2434,37 @@ 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, + netmem_ref netmem, int off, + int size) +{ + frag->netmem = netmem; + frag->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, netmem_ref 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); } /** @@ -2460,10 +2480,10 @@ 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 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 + * @i: fragment index to initialise + * @netmem: the netmem to use for this fragment * @off: the offset to the data with @page * @size: the length of the data * @@ -2472,10 +2492,12 @@ 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, + netmem_ref 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 @@ -2483,7 +2505,20 @@ 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, + netmem_ref netmem, int off, int size) +{ + __skb_fill_netmem_desc(skb, i, netmem, off, size); + skb_shinfo(skb)->nr_frags = i + 1; } /** @@ -2503,8 +2538,7 @@ 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); } /** @@ -2528,8 +2562,16 @@ static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i, shinfo->nr_frags = i + 1; } -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, netmem_ref netmem, + int off, int size, unsigned int truesize); + +static inline 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); +} void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, unsigned int truesize); @@ -3378,7 +3420,7 @@ static inline void skb_propagate_pfmemalloc(const struct page *page, */ static inline unsigned int skb_frag_off(const skb_frag_t *frag) { - return frag->bv_offset; + return frag->offset; } /** @@ -3388,7 +3430,7 @@ static inline unsigned int skb_frag_off(const skb_frag_t *frag) */ static inline void skb_frag_off_add(skb_frag_t *frag, int delta) { - frag->bv_offset += delta; + frag->offset += delta; } /** @@ -3398,7 +3440,7 @@ static inline void skb_frag_off_add(skb_frag_t *frag, int delta) */ static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset) { - frag->bv_offset = offset; + frag->offset = offset; } /** @@ -3409,7 +3451,7 @@ static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset) static inline void skb_frag_off_copy(skb_frag_t *fragto, const skb_frag_t *fragfrom) { - fragto->bv_offset = fragfrom->bv_offset; + fragto->offset = fragfrom->offset; } /** @@ -3420,7 +3462,7 @@ 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->netmem); } /** @@ -3528,7 +3570,7 @@ static inline void *skb_frag_address_safe(const skb_frag_t *frag) static inline void skb_frag_page_copy(skb_frag_t *fragto, const skb_frag_t *fragfrom) { - fragto->bv_page = fragfrom->bv_page; + fragto->netmem = fragfrom->netmem; } bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0d9a489e6ae1..a2bd4734a910 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -115,6 +115,24 @@ static struct kmem_cache *skb_small_head_cache __ro_after_init; int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; EXPORT_SYMBOL(sysctl_max_skb_frags); +/* kcm_write_msgs() relies on casting paged frags to bio_vec to use + * iov_iter_bvec(). These static asserts ensure the cast is valid is long as the + * netmem is a page. + */ +static_assert(offsetof(struct bio_vec, bv_page) == + offsetof(skb_frag_t, netmem)); +static_assert(sizeof_field(struct bio_vec, bv_page) == + sizeof_field(skb_frag_t, netmem)); + +static_assert(offsetof(struct bio_vec, bv_len) == offsetof(skb_frag_t, len)); +static_assert(sizeof_field(struct bio_vec, bv_len) == + sizeof_field(skb_frag_t, len)); + +static_assert(offsetof(struct bio_vec, bv_offset) == + offsetof(skb_frag_t, offset)); +static_assert(sizeof_field(struct bio_vec, bv_offset) == + sizeof_field(skb_frag_t, offset)); + #undef FN #define FN(reason) [SKB_DROP_REASON_##reason] = #reason, static const char * const drop_reasons[] = { @@ -845,17 +863,17 @@ 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, netmem_ref 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); +EXPORT_SYMBOL(skb_add_rx_frag_netmem); void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, unsigned int truesize) @@ -1999,10 +2017,11 @@ 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: @@ -3740,7 +3759,8 @@ 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 1184d40167b8..73c200c5c8e4 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -627,7 +627,8 @@ static int kcm_write_msgs(struct kcm_sock *kcm) skb = txm->frag_skb; } - if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { + if (WARN_ON(!skb_shinfo(skb)->nr_frags) || + WARN_ON_ONCE(!skb_frag_page(&skb_shinfo(skb)->frags[0]))) { ret = -EINVAL; goto out; } @@ -637,8 +638,8 @@ static int kcm_write_msgs(struct kcm_sock *kcm) msize += skb_frag_size(&skb_shinfo(skb)->frags[i]); 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 {