From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qvzXl64FTzDqGn for ; Wed, 27 Apr 2016 22:19:19 +1000 (AEST) Received: from localhost by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 27 Apr 2016 22:19:17 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id D7AAE2BB0059 for ; Wed, 27 Apr 2016 22:19:04 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u3RCIuZY64815332 for ; Wed, 27 Apr 2016 22:19:04 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u3RCIUbP004601 for ; Wed, 27 Apr 2016 22:18:32 +1000 From: Yongji Xie To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org Cc: alex.williamson@redhat.com, bhelgaas@google.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, Yongji Xie Subject: [PATCH 0/4] PCI: Add support for enforcing all MMIO BARs not to share PAGE_SIZE Date: Wed, 27 Apr 2016 20:17:07 +0800 Message-Id: <1461759432-5030-1-git-send-email-xyjxie@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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. 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 | 105 ++++++++++++++++++++++++++++------- drivers/pci/setup-bus.c | 9 ++- 4 files changed, 98 insertions(+), 25 deletions(-) -- 1.7.9.5