From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 8FA73DE0; Fri, 14 Apr 2017 08:56:06 +0200 (CEST) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP; 13 Apr 2017 23:56:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,197,1488873600"; d="scan'208";a="88907357" Received: from fmsmsx104.amr.corp.intel.com ([10.18.124.202]) by fmsmga005.fm.intel.com with ESMTP; 13 Apr 2017 23:56:04 -0700 Received: from fmsmsx115.amr.corp.intel.com (10.18.116.19) by fmsmsx104.amr.corp.intel.com (10.18.124.202) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 13 Apr 2017 23:56:04 -0700 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by fmsmsx115.amr.corp.intel.com (10.18.116.19) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 13 Apr 2017 23:56:04 -0700 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.117]) by SHSMSX104.ccr.corp.intel.com ([10.239.4.70]) with mapi id 14.03.0319.002; Fri, 14 Apr 2017 14:56:02 +0800 From: "Tan, Jianfeng" To: Yuanhan Liu CC: "dev@dpdk.org" , "olivier.matz@6wind.com" , "stable@dpdk.org" Thread-Topic: [PATCH] net/virtio-user: fix not working on 32-bit system Thread-Index: AQHStF/xk5zTxFQGQEK1/vlMcRjm3qHD0h8AgACJeXD//4PqgIAAjp3A Date: Fri, 14 Apr 2017 06:56:01 +0000 Message-ID: References: <1492092776-57008-1-git-send-email-jianfeng.tan@intel.com> <20170414053222.GK7333@yliu-dev.sh.intel.com> <20170414062017.GM7333@yliu-dev.sh.intel.com> In-Reply-To: <20170414062017.GM7333@yliu-dev.sh.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-stable] [PATCH] net/virtio-user: fix not working on 32-bit system 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: , X-List-Received-Date: Fri, 14 Apr 2017 06:56:07 -0000 > -----Original Message----- > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com] > Sent: Friday, April 14, 2017 2:20 PM > To: Tan, Jianfeng > Cc: dev@dpdk.org; olivier.matz@6wind.com; stable@dpdk.org > Subject: Re: [PATCH] net/virtio-user: fix not working on 32-bit system >=20 > On Fri, Apr 14, 2017 at 05:53:55AM +0000, Tan, Jianfeng wrote: > > > > diff --git a/drivers/net/virtio/virtqueue.h > b/drivers/net/virtio/virtqueue.h > > > > index f9e3736..f43ea70 100644 > > > > --- a/drivers/net/virtio/virtqueue.h > > > > +++ b/drivers/net/virtio/virtqueue.h > > > > @@ -72,7 +72,8 @@ struct rte_mbuf; > > > > * Return the physical address (or virtual address in case of > > > > * virtio-user) of mbuf data buffer. > > > > */ > > > > -#define VIRTIO_MBUF_ADDR(mb, vq) (*(uint64_t *)((uintptr_t)(mb) > + > > > (vq)->offset)) > > > > +#define VIRTIO_MBUF_ADDR(mb, vq) \ > > > > + ((uint64_t)((uintptr_t)(*(void **)((uintptr_t)(mb) + (vq)->offset= )))) > > > > > > The "void **" cast makes it a bit complex (thus hard to read). I thin= k > > > following should work? > > > > Yes, uintptr_t can work. I thought void ** is easier to understand, mea= ning > a convert to a pointer which pointing to a pointer. >=20 > It's twisted, isn't it? :) >=20 > > I usually use uintptr_t only for converter from pointer to integer, not= the > opposite way. >=20 > Yes, that's a typical usage. But the fact of the matter is uintptr_t > represents the word size, which is exactly what needed in this case. Another fold, if you refer to the definition of struct rte_mbuf, the first = field is defined as void * instead of uintptr_t. I think that why I prefer = to use ((void *)*) in the beginning. Thanks, Jianfeng >=20 > --yliu > > > > > > > > (uint64_t(*(uintptr_t *)((uintptr_t)(mb) + (vq)->offset))) > > > > > > Besides, it deserves a comment. > > > > Will add comment in next version. > > > > Thanks, > > Jianfeng > > > > > > > > --yliu > > > > > > > #else > > > > #define VIRTIO_MBUF_ADDR(mb, vq) ((mb)->buf_physaddr) > > > > #endif > > > > -- > > > > 2.7.4