From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933292AbcE3NEs (ORCPT ); Mon, 30 May 2016 09:04:48 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50772 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933251AbcE3NEp (ORCPT ); Mon, 30 May 2016 09:04:45 -0400 Message-Id: <201605301304.u4UD4GKn004521@mx0a-001b2d01.pphosted.com> X-IBM-Helo: d28dlp02.in.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: linux-doc@vger.kernel.org;linux-kernel@vger.kernel.org;linux-pci@vger.kernel.org From: Yongji Xie To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org Cc: bhelgaas@google.com, alex.williamson@redhat.com, aik@ozlabs.ru, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, corbet@lwn.net, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, gwshan@linux.vnet.ibm.com Subject: [PATCH v2 0/4] PCI: Add support for enforcing all MMIO BARs not to share PAGE_SIZE Date: Mon, 30 May 2016 21:00:14 +0800 X-Mailer: git-send-email 1.7.1 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16053013-0004-0000-0000-0000028DD664 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16053013-0005-0000-0000-00000D27A788 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-05-30_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=8 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1605300159 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series aims to add an option for PCI resource allocator to force BARs not to share PAGE_SIZE. This would make sense to VFIO driver. Because current VFIO implementation disallows to mmap sub-page(size < PAGE_SIZE) MMIO BARs which may share the same page with other BARs for security reasons. Thus, we have to handle mmio access to these BARs in QEMU emulation rather than in guest which will cause some performance loss. To achieve that, we would like to make use of the existing resource_alignment kernel parameter and force a minimum alignment of PAGE_SIZE. It's flexible. And we can default to enable it on some archs which may easily hit the performance issue because of their 64K page. In this series, patch 1 fixed a bug of resource_alignment; patch 2,3 tried to add a new option for resource_alignment to use IORESOURCE_STARTALIGN to specify the alignment of PCI BARs; patch 4 modified resource_alignment to support syntax which can be used to enforce the alignment of all MMIO BARs to be at least PAGE_SIZE. Changelog v2: - Ignore enforced alignment to VF BARs on pci_reassigndev_resource_alignment() Yongji Xie (4): PCI: Ignore resource_alignment if PCI_PROBE_ONLY was set PCI: Do not Use IORESOURCE_STARTALIGN to identify bridge resources PCI: Add a new option for resource_alignment to reassign alignment PCI: Add support for enforcing all MMIO BARs to be page aligned Documentation/kernel-parameters.txt | 7 ++- arch/powerpc/include/asm/pci.h | 2 + drivers/pci/pci.c | 109 ++++++++++++++++++++++++++++------- drivers/pci/setup-bus.c | 9 ++- 4 files changed, 102 insertions(+), 25 deletions(-) -- 1.7.9.5