From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46113) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c67Kj-0007ro-6O for qemu-devel@nongnu.org; Sun, 13 Nov 2016 21:49:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c67Kg-0006Di-3N for qemu-devel@nongnu.org; Sun, 13 Nov 2016 21:49:21 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50897 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c67Kf-0006De-UJ for qemu-devel@nongnu.org; Sun, 13 Nov 2016 21:49:18 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uAE2nEDk003598 for ; Sun, 13 Nov 2016 21:49:17 -0500 Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) by mx0a-001b2d01.pphosted.com with ESMTP id 26pqqub59x-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 13 Nov 2016 21:49:16 -0500 Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 13 Nov 2016 19:49:16 -0700 Date: Mon, 14 Nov 2016 10:49:10 +0800 From: Dong Jia Shi References: <1478293856-8191-1-git-send-email-kwankhede@nvidia.com> <1478293856-8191-11-git-send-email-kwankhede@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1478293856-8191-11-git-send-email-kwankhede@nvidia.com> Message-Id: <20161114024910.GA13350@bjsdjshi@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH v11 10/22] vfio iommu type1: Add support for mediated devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kirti Wankhede Cc: alex.williamson@redhat.com, pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, kevin.tian@intel.com, jike.song@intel.com, bjsdjshi@linux.vnet.ibm.com, linux-kernel@vger.kernel.org * Kirti Wankhede [2016-11-05 02:40:44 +0530]: Hi Kirti, [...] > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index 8d64528dcc22..e511073446a0 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c [...] > +static int vfio_pfn_account(struct vfio_addr_space *addr_space, > + unsigned long pfn) > +{ > + struct vfio_pfn *p; > + int ret = 1; > + > + mutex_lock(&addr_space->pfn_list_lock); > + p = vfio_find_pfn(addr_space, pfn); > + if (p) > + ret = 0; > + mutex_unlock(&addr_space->pfn_list_lock); > + return ret; > +} We could save a local variables(@ret) here by: return (p ? 0 : 1); > + > struct vwork { > struct mm_struct *mm; > long npage; [...] -- Dong Jia