From patchwork Mon Mar 7 07:48:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 592792 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EABFD1402A1 for ; Mon, 7 Mar 2016 18:50:13 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752398AbcCGHtr (ORCPT ); Mon, 7 Mar 2016 02:49:47 -0500 Received: from e28smtp08.in.ibm.com ([125.16.236.8]:43425 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752377AbcCGHto (ORCPT ); Mon, 7 Mar 2016 02:49:44 -0500 Received: from localhost by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 7 Mar 2016 13:19:36 +0530 Received: from d28relay04.in.ibm.com (9.184.220.61) by e28smtp08.in.ibm.com (192.168.1.138) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Mon, 7 Mar 2016 13:19:34 +0530 X-IBM-Helo: d28relay04.in.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: linux-doc@vger.kernel.org; linux-pci@vger.kernel.org; linux-kernel@vger.kernel.org; kvm@vger.kernel.org Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay04.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u277nL4b27197644; Mon, 7 Mar 2016 13:19:21 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u277nT0g011304; Mon, 7 Mar 2016 13:19:32 +0530 Received: from localhost (commit.cn.ibm.com [9.123.229.145]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u277nStj011256; Mon, 7 Mar 2016 13:19:28 +0530 From: Yongji Xie To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org Cc: bhelgaas@google.com, corbet@lwn.net, aik@ozlabs.ru, alex.williamson@redhat.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, Yongji Xie Subject: [RFC PATCH v4 5/7] vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive Date: Mon, 7 Mar 2016 15:48:36 +0800 Message-Id: <1457336918-3893-6-git-send-email-xyjxie@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1457336918-3893-1-git-send-email-xyjxie@linux.vnet.ibm.com> References: <1457336918-3893-1-git-send-email-xyjxie@linux.vnet.ibm.com> X-TM-AS-MML: disable x-cbid: 16030707-0029-0000-0000-00000B5867E8 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Current vfio-pci implementation disallows to mmap sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio page may be shared with other BARs. But we should allow to mmap these sub-page MMIO BARs if PCI resource allocator can make sure these BARs' mmio page will not be shared with other BARs. Signed-off-by: Yongji Xie --- drivers/vfio/pci/vfio_pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 1ce1d36..49d7a69 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -589,7 +589,8 @@ static long vfio_pci_ioctl(void *device_data, VFIO_REGION_INFO_FLAG_WRITE; if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && pci_resource_flags(pdev, info.index) & - IORESOURCE_MEM && info.size >= PAGE_SIZE) { + IORESOURCE_MEM && !pci_resources_share_page(pdev, + info.index)) { info.flags |= VFIO_REGION_INFO_FLAG_MMAP; if (info.index == vdev->msix_bar) { ret = msix_sparse_mmap_cap(vdev, &caps); @@ -1016,6 +1017,10 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) return -EINVAL; phys_len = pci_resource_len(pdev, index); + + if (!pci_resources_share_page(pdev, index)) + phys_len = PAGE_ALIGN(phys_len); + req_len = vma->vm_end - vma->vm_start; pgoff = vma->vm_pgoff & ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);