From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 1CF6EA09E0 for ; Fri, 13 Nov 2020 14:00:26 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 5776FC876; Fri, 13 Nov 2020 14:00:24 +0100 (CET) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id BA9D84CA6; Fri, 13 Nov 2020 14:00:19 +0100 (CET) IronPort-SDR: OXAq+ZQdWX64zxtO74tnjcx4N4ZhsIKByasuygDyX5XIdl7mSF5rtDn1lGEjytMyj1zzOHJnoW WOCjaKDfDYVA== X-IronPort-AV: E=McAfee;i="6000,8403,9803"; a="149736848" X-IronPort-AV: E=Sophos;i="5.77,475,1596524400"; d="scan'208";a="149736848" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Nov 2020 05:00:17 -0800 IronPort-SDR: obNoKGUpd9c404uW8NJdMoBX4/HbEXqdkZkJYjisFzFsDt76qdxcF+doc0fm7tyD82hXxGNjmm lPKPaszLzOWA== X-IronPort-AV: E=Sophos;i="5.77,475,1596524400"; d="scan'208";a="474653042" Received: from fyigit-mobl1.ger.corp.intel.com (HELO [10.252.3.208]) ([10.252.3.208]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Nov 2020 05:00:16 -0800 To: Ciara Loftus , dev@dpdk.org Cc: stable@dpdk.org References: <20201112163515.29463-1-ciara.loftus@intel.com> From: Ferruh Yigit Message-ID: <26aa267c-e342-bb5f-4fea-51b3b8d4e9a4@intel.com> Date: Fri, 13 Nov 2020 13:00:12 +0000 MIME-Version: 1.0 In-Reply-To: <20201112163515.29463-1-ciara.loftus@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-stable] [PATCH] net/af_xdp: fix 32-bit build for older kernels X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Sender: "stable" On 11/12/2020 4:35 PM, Ciara Loftus wrote: > 'uint64_t' is used to hold pointers in multiple locations in the > copy-mode code (used for kernels before 5.4). For a 32-bit build > this assumption is wrong and results in build errors. This commit > replaces such instances of 'uint64_t' with 'uintptr_t'. > > While the copy-mode code will now compile for 32-bit, the PMD is > not expected to work and will fail at initialisation due to some > limitations in the kernel that were subsequently removed in v5.4. > Add a note to the docs to flag this limitation. > > Fixes: f1debd77efaf ("net/af_xdp: introduce AF_XDP PMD") > Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks") > Cc: stable@dpdk.org > > Signed-off-by: Ciara Loftus > --- > doc/guides/nics/af_xdp.rst | 1 + > drivers/net/af_xdp/rte_eth_af_xdp.c | 6 +++--- > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst > index 052e59a3ae..5ed24374f8 100644 > --- a/doc/guides/nics/af_xdp.rst > +++ b/doc/guides/nics/af_xdp.rst > @@ -50,6 +50,7 @@ This is a Linux-specific PMD, thus the following prerequisites apply: > * For PMD zero copy, it requires kernel version later than v5.4-rc1; > * For shared_umem, it requires kernel version v5.10 or later and libbpf version > v0.2.0 or later. > +* For 32-bit OS, a kernel with version 5.4 or later is required. > +1 to doc update > Set up an af_xdp interface > ----------------------------- > diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c > index 4076ff797c..75ff1c00b2 100644 > --- a/drivers/net/af_xdp/rte_eth_af_xdp.c > +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c > @@ -349,7 +349,7 @@ af_xdp_rx_cp(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) > > for (i = 0; i < rcvd; i++) { > const struct xdp_desc *desc; > - uint64_t addr; > + uintptr_t addr; > uint32_t len; > void *pkt; > > @@ -402,7 +402,7 @@ pull_umem_cq(struct xsk_umem_info *umem, int size, struct xsk_ring_cons *cq) > n = xsk_ring_cons__peek(cq, size, &idx_cq); > > for (i = 0; i < n; i++) { > - uint64_t addr; > + uintptr_t addr; > addr = *xsk_ring_cons__comp_addr(cq, idx_cq++); Hi Ciara, As far as I can see the API 'xsk_ring_cons__comp_addr()' returns fixed size variable ('__u64'), and when the PMD is compiled for 32bit, won't it be assigning a 64bit variable to the 32bit storage. I guess libbpf also needs to be adjusted for the 32bit support, what about making PMD changes after libbpf changed? > #if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG) > addr = xsk_umem__extract_addr(addr); > @@ -1005,7 +1005,7 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals *internals, > char ring_name[RTE_RING_NAMESIZE]; > char mz_name[RTE_MEMZONE_NAMESIZE]; > int ret; > - uint64_t i; > + uintptr_t i; > Not sure on this one, 'i' seems not to hold a pointer but index, and result of calculation cast to "void *", I assume intention is to prevent calculation result to be 64 bit to cover the case "void *" is 4 bytes, for that what do you think making variable uint32_t?